Institut für Nutztierwissenschaften

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A case study: Fish production in the integrated farming system of the Black Thai in Yen Chau district (Son La province) in mountainous North-western Vietnam - current state and potential
(2009) Steinbronn, Silke; Becker, Klaus
Son La province is located in mountainous north-western Vietnam and belongs to the poorest regions of the country. In the valleys of this province, fish farming is one of the major activities among farmers who belong to the ethnic Black Thai minority. Up until now, the aquaculture system practiced here has not been scientifically investigated. There is generally very little data available regarding the aquaculture of resource-poor farmers in Southeast Asia. This lack of information can be partly explained by the difficulty in obtaining this data. However, a solid understanding of current aquaculture systems is necessary for any kind of future involvement. Within the course of a special research program (SFB 564), aquaculture practices in three communes of Yen Chau district (Son La province) were surveyed between 2004 and 2006. The research was conducted in a holistic way in order to obtain a detailed description of the typical local aquaculture system with its potentials and limitations. In addition, measures for improvement were developed, which will be tested during the next phase of the special research program. The data was collected and analyzed on three different levels. On the ?macro level?, general data is presented regarding the land use and irrigation system in the studied area. Data on the ?meso level? concerns the aquaculture and agriculture system and was predominantly collected through interviews with 155 farmers, 22 village headmen and other stakeholders. On the ?micro level?, an in-depth investigation based on measurements and close observation of 6 individually selected case study farms is presented. This data includes the limnological pond conditions, fish growth rates, food conversion and the profitability of the aquaculture system. The data gathered during these investigations compensates for the information that could not be satisfactorily gathered through the interviews alone. Currently, around 63% of the households in the study area produce fish in ponds. The aquaculture production is closely linked with other farming activities and is integrated into the overall irrigation system. Farmers stock different carp and tilapia in polyculture with the main species being grass carp. Fish are mainly fed leaves and by-products of crop production, weeds and manure, e.g. from buffalo. The pond system is feed-based and exhibits a more or less continuous water flow; both of these features are rather atypical for small-scale aquaculture. In the case study farms, the average fish stocking density was 1.0 fish m-2. Calculated based on one hectare, the average daily feed application was 37.1 kg dry matter (DM) and the annual net production of aquatic species 1.5 tons ha-1, of which roughly 2/3 were sold. The average conversion of feed (DM) to aquatic species biomass was 7.7:1, and the conversion of added nitrogen (feed and manure) to produced nitrogen (aquatic species) was 14.7%. The yields in the presented system are relatively low compared to other feed-based aquaculture systems. Nevertheless, it has been shown that aquaculture production contributes significantly to food security, generates income and plays a significant role in farmers? lives. At present, the local market in Yen Chau cannot be completely satisfied by the districts? fish production alone. Recently, a road was upgraded that connects the north-western mountains with the country?s capital Hanoi. As a result, fish from the more intensive aquaculture in the lowlands has started to flood the local markets. This development is expected to proceed, which will leave farmers unable to compete in the market in the future. In order to produce fish in a sustainable way, the current system must be improved so that the local fish production increases. There are various reasons that can explain the relatively low productivity in the ponds. These include an unclassifiable grass carp disease that leads to high mortalities, poor water quality, low fish growth rates caused by low quality of fish seed, low quality of feed and manure applied as well as low natural food availability in the ponds. Furthermore, farmers seem to have limited knowledge regarding basic aquaculture techniques, which may be explained by the lack of training or extension services available in this field. In the present study, a ?basket? of modification measures have been proposed. These measures concern the farms themselves (e.g. improved pond management), the institutional and political framework (e.g. support of the local hatcheries) as well as the research. The focus of the next part of the special research program will be the identification of the causative agent of the grass carp disease and the development of prevention and treatment strategies. Additionally, a modified watering and feeding management system will be tested scientifically. It is expected that this locally adapted, improved pond system will lead to significantly higher fish production.
The active core microbiota of two high-yielding laying hen breeds fed with different levels of calcium and phosphorus
(2022) Roth, Christoph; Sims, Tanja; Rodehutscord, Markus; Seifert, Jana; Camarinha-Silva, Amélia
The nutrient availability and supplementation of dietary phosphorus (P) and calcium (Ca) in avian feed, especially in laying hens, plays a vital role in phytase degradation and mineral utilization during the laying phase. The required concentration of P and Ca peaks during the laying phase, and the direct interaction between Ca and P concentration shrinks the availability of both supplements in the feed. Our goal was to characterize the active microbiota of the entire gastrointestinal tract (GIT) (crop, gizzard, duodenum, ileum, caeca), including digesta- and mucosa-associated communities of two contrasting high-yielding breeds of laying hens (Lohmann Brown Classic, LB; Lohmann LSL-Classic, LSL) under different P and Ca supplementation levels. Statistical significances were observed for breed, GIT section, Ca, and the interaction of GIT section x breed, P x Ca, Ca x breed and P x Ca x breed (p < 0.05). A core microbiota of five species was detected in more than 97% of all samples. They were represented by an uncl. Lactobacillus (average relative abundance (av. abu.) 12.1%), Lactobacillus helveticus (av. abu. 10.8%), Megamonas funiformis (av. abu. 6.8%), Ligilactobacillus salivarius (av. abu. 4.5%), and an uncl. Fusicatenibacter (av. abu. 1.1%). Our findings indicated that Ca and P supplementation levels 20% below the recommendation have a minor effect on the microbiota compared to the strong impact of the bird’s genetic background. Moreover, a core active microbiota across the GIT of two high-yielding laying hen breeds was revealed for the first time.
Adaptation of herd simulation models to predict the efficiency of the use of resources in tropical ruminant production systems
(2020) Bateki Adjogo, Christian; Dickhöfer, Uta
Agricultural systems in the (Sub-)Tropics are under increasing pressure to produce more food and satisfy the growing demand of a rapidly growing and more affluent human population for agricultural products. With growing rates of urbanization in these regions and the associated dietary changes, the demand for calories from animal-based foods like milk, meat, and eggs could increase by 74 to 114 % between 2010 and 2050. Ruminant livestock have the potential to contribute to satisfying the demand for animal-based foods in the (Sub-)Tropics, but also raise considerable environmental concerns, amongst others due to their emissions. The use of simulation models is a holistic approach to identify how to sustainably harness the potential of ruminants for animal-based food production in the (Sub-)Tropics. Although several ruminant herd models are relevant for studying tropical ruminant production systems, most of them were developed using data that quantify and characterize biological processes of ruminants in temperate regions. Therefore, the present thesis identified and adapted an existing ruminant livestock herd model to adequately predict resource use and the potential outputs from production systems in the (Sub-)Tropics. The present thesis showed that state-of-the-art ruminant livestock herd models used to simulate tropical production systems need further development to enable them to address the modelling needs identified. Instead of developing new models to address these modelling needs, existing simulation models could be adapted using the increasingly available data that quantify and characterize biological processes in ruminants in these regions. This approach will ensure that not only the direction of change for different management strategies will be identified for tropical ruminant production systems, but also the correct magnitude of resources use and productive and reproductive performance.
Analyse komplexer Merkmale beim Schwein mittels SNP-Chip Genotypen, Darmmikrobiota- und Genexpressionsdaten
(2017) Maushammer, Maria; Bennewitz, Jörn
In the present scientific research, SNP chip genotypes, gut microbiota and gene expression data were used for analysing complex traits in a Piétrain population. These data were collected from around 200 performance tested sows and were used for genetic and microbial analyses of complex trait as well as for structural and functional meat quality traits. The gut microbiome plays a major role in the immune system development, state of health and energy supply of the host. Quantitative-genetic methods were applied to analyse the interrelationship between pig gut microbiota compositions, complex traits (daily gain, feed conversion and feed intake) and pig genomes. The specific aims were to characterize the gut microbiota of the pigs, to analyse the effects of host genetics on gut microbial composition, and to investigate the role of gut microbial composition on the host’s complex traits. The pigs were genotyped with a standard 60K SNP chip. Microbial composition was characterized by 16S rRNA gene amplicon sequencing technology. Ten out of 51 investigated bacterial genera showed a significant host heritability, ranging from 0.32 to 0.57. Conducting genome wide association analysis showed associations of 22 SNPs and six bacterial genera. The potential candidate genes identified are involved in the immune system, mucosa structure and secretion of digestive juice. These results show, that parts of the gut microbiota are heritable and that the gut microbiome can be seen as quantitative trait. Microbial mixed linear models were applied to estimate the microbiota variance for each of the investigated traits. The fraction of phenotypic variance explained by the microbial variance was 0.28, 0.21, and 0.16 for daily gain, feed conversion, and feed intake, respectively. The SNP data and the microbiota data were used to predict the phenotypes of the traits using both, genomic best linear unbiased prediction (G-BLUP) and microbial best linear unbiased prediction (M-BLUP) methods. The prediction accuracies of G-BLUP were 0.35, 0.23, and 0.20 for daily gain, feed conversion, and feed intake, respectively. The corresponding prediction accuracies of M-BLUP were 0.41, 0.33, and 0.33. Thus, the gut microbiota can be seen as an explaining variable for complex traits like daily gain, feed conversion and feed intake. In addition, in combination with meat quality traits, transcript levels of muscle tissue were analysed at time of slaughtering. This study should give an insight into the biological processes involved in meat quality characteristics. The aims were to functionally characterise differentially expressed genes, to link the functional information with structural information obtained from GWAS, and to identify potential candidate genes based on these results. An important meat quality trait is the intramuscular fat content, since it affects the juiciness, the taste and the tenderness of the meat. Another important trait is drip loss which causes not only a loss of weight but also a loss of important proteins. Both traits have an impact on the consumer acceptance of fresh meat products. For each of the two traits, eight discordant sibling pairs were selected out of the Piétrain sample and were used for genome-wide gene expression analyses. Thirty five and 114 genes were identified as differentially expressed and trait correlated genes for intramuscular fat content and drip loss, respectively. On the basis of functional annotation, gene groups belonging to the energy metabolism of the mitochondria, the immune response and the metabolism of fat, were associated with intramuscular fat content. Gene groups associated with protein ubiquitination, mitochondrial metabolism, and muscle structural proteins were associated with drip loss. Furthermore, genome-wide association analyses were carried out for these traits and their results were linked to the genome-wide expression analysis by functional annotation. In this context, intramuscular fat was related to muscle contraction, transmembrane transport and nucleotide binding. Drip loss was characterized by the endomembrane system, the energy generation of cells, and phosphorus metabolic processes. Three and four potential candidate genes were identified for intramuscular fat content and drip loss, respectively.
Analyses of quantitative traits in varying environments in pigs and Brown Swiss cattle
(2020) Imort-Just, Nina Annik; Bennewitz, Jörn
Complex breeding programmes are used worldwide to achieve genetic progress in quantitative traits. These programmes are basically similarly structured, independent of breed and species, and are characterised by successive steps. The adjustment and revision of breeding programmes is of ongoing interest due to several reasons, e.g. research findings and various political, economic, social and ethical aspects. For the long-term improvement of livestock populations, multiple traits are included in the breeding goals of such programmes. Unfavourable genetic correlations between economically important production traits and functional traits compromise the genetic progress in animal health and welfare. Novel functional and behavioural traits and the adjustment of relative economic weights for the optimisation of total merit indices are investigated in research projects. In addition, genotype by environment interactions (GxE) can influence the genetic improvement of livestock populations and their consideration is crucial due to the globalisation of breeding structures and associated varying production environments. The main objectives of this thesis were 1) to investigate novel behavioural traits in pig breeding, 2) to derive environmental-specific relative economic weights based on consumers preferences for Brown Swiss cattle, 3) to estimate GxE at a trait and an index level by applying bivariate sire models in Brown Swiss cattle and 4) to analyse GxE for different production and functional traits in Brown Swiss cattle using reaction norm models. In Chapter 1 genetic parameters for mothering ability traits were estimated. Heritabilities (h²) were estimated by applying a linear mixed- and a threshold model, ranging between 0.02 to 0.07 and 0.05 to 0.15, respectively. The slightly higher estimates for the repeatability ranged from 0.05 to 0.09 and from 0.08 to 0.17, indicating the influence of the permanent environment. Highest h² were found for the group- and nursing behaviour of the sows. Highest genetic correlations were found between group-/nursing behaviour and litter balance and piglet weaning weight with estimates between 0.71 and 0.86. Accelerating genetic gain for improved mothering ability in sows is possible. In Chapter 2, the importance of breeding traits of Brown Swiss cattle in terms of selection decisions of farm managers was evaluated by using a discrete choice experiment (DCE). Environment-specific relative economic weights (REW) and the marginal willingness to pay were estimated by using a conditional logit model. Several trait complexes, the semen price, interactions between these traits and specific characteristics of the farms were included. Farmers showed highest preferences for the milk value, conformation/udder and fitness. Interactions indicated a great importance of the fitness trait complex for organically managed farms compared to conventional farmers. The latter weighted the milk value and the trait complex conformation/udder high. The method is suitable to judge farmers’ preferences for specific traits, especially those which have not yet been monetarily evaluated. Chapter 3 investigated GxE at a trait and an index level for Brown Swiss sires. Bivariate sire models were used to estimate genetic correlations between organic and conventional production systems and two altitude level of the farms for milk production traits and several functional traits. Furthermore, to determine possible GxE and rerankings at an index level, total merit indices for the sires were calculated. The genetic correlations were high between the analysed environments, ranging from 0.79 (first insemination to conception between different altitude levels) to 0.99 (calving to first insemination, cystic ovaries, maternal stillbirth between production systems). The results indicate no severe GxE at a trait level. No putative GxE effects were found for the production system environments at an index level. In Chapter 4, GxE for various production and functional traits in Brown Swiss cattle were analysed using random regression reaction norm models. The continuous environmental descriptor milk energy yield (MEY) was calculated as a linear combination of average herd effects, obtained from the routine breeding value estimation, of milk-, fat- and protein yield. The applied reaction norm model included a random sire effect and a random sire slope effect (environmental sensitivity), i.e. the random regression coefficient of the regression of a specific sire on the environmental descriptor MEY. To investigate putative GxE effects, breeding values for the sires were estimated. Results showed no severe GxE for the functional traits but for the production trait fat yield. In addition, the slope variances as descriptors of the environmental sensitivity and the Spearman rank correlations between the estimated breeding values of the sires at different environmental levels indicate no severe GxE for the investigated traits.
Analysis of phosphorus utilization using the host genome and microbiota variability in Japanese quail
(2021) Vollmar, Solveig Deniece; Bennewitz, Jörn
Phosphorus (P) is an essential element for growth and performance of avian species. It is predominantly bound as phytic acids and salts (phytate) in plant seeds. Phytases and other phosphatases can harness P by cleaving P groups. Nonruminants have low endogenous phytase activity in the gastrointestinal tract, and thus, the requirement of this element is not met from exclusive plant-based diets. Therefore, mineral P or phytase enzymes are supplemented in poultry feed. Due to the finite quantities of high quality mineral P worldwide, it is of great economic interest. P supplementation is increasingly causing environmental problems. Past studies investigated the P utilization (PU) of different poultry species. They revealed a high phenotypic variation in PU among individuals. Moderate heritabilities indicates that breeding for this trait is in principle possible. The overall aim of this thesis was to gain a deeper understanding of the variability of P utilization in relation to host genetics, ileal microbiota composition and their interaction in the model species Japanese quail. The objective of chapter two was to verify whether variation in PU in quail is a heritable trait conditioned by a few quantitative trait loci (QTL) with detectable effects. For this purpose, individuals were genome-wide genotyped with a 4k SNP chip, and a linkage map was generated. Based on this map, QTL linkage analysis was performed using multimarker regression analysis in a line-crossing model to map QTL for PU. We identified a few QTL regions with significant effects. Among them was a QTL peak at Coturnix japonica chromosome (CJA) 3 for PU. Several genes were found in the region surrounding this peak, which requires further functional gene analysis. Based on these results, we hypothesized that these traits are polygenically determined due to several small QTL effects, which we could not detect significantly. The overlap of the QTL regions indicated linkage of the traits and confirmed their genetic correlations. With the aim of predicting microbiota-related host traits, chapter three examined the composition of the ileum microbiota and differential abundance analysis (DAA). Based on this study, it was shown that a sex-specific influence on microbiota composition exists. The digesta samples of all animals were dominated by five genera, which contributed to more than 70% of the total ileum microbial community. In examining the microbiota composition of each of the 50 animals with the highest and lowest PU, DAA revealed genera significantly associated with PU. In chapter four, we characterized the influence of performance-related gut microbiota to unravel the microbial architecture of the traits evaluated. The aim of this study was to determine whether the variation in PU is partly driven by the microbial community in the ileum. We used microbial mixed linear models to estimate microbiabilities (m^2). This determines the fraction of phenotypic variance that can be explained by the gut microbiota. The estimation of m^2 was 0.15 for PU and was highly significant. It was also highly significant for feed intake, body weight gain and feed per gain. This model was bivariately extended and showed a high microbial correlation of the traits. Based on both results, the ileum microbiota composition plays a substantial role in PU as well as in performance traits, and there is a considerable animal microbiota correlation, showing that the microbiota affects multiple traits. The microbial drivers of this microbial fraction were identified by applying microbiome-wide association studies (MWAS). By back-solving the microbial linear mixed model, we approximated the effect of single OTUs on the phenotypic traits from the microbial model solutions. An MWAS at the genus level uncovered several traits associated with bacterial genera. Subsequently, we assessed whether the microbial community in the ileum is a heritable host trait that can be used for breeding individuals with improved PU. In chapter five we applied QTL analysis using specific genera to examine whether they are linked with genomic SNP markers. These QTL analyses revealed a link between some microbiota species and host genomic regions of chromosomes and SNP markers. By estimating significant heritabilities for some genera, we were able to provide evidence for the hypothesis that the microbial community and microbial features are at least partially related to host genetics. We predicted the animal microbial effects on PU and correlated performance traits by applying microbial best linear unbiased predictions (M-BLUP). In addition, genomic best linear unbiased predictions (G-BLUP) were used to predict the SNP effect for the predicted animal microbial effect. A combination of those two may help to predict genomic breeding values of the microbiota effects for future hologenomic breeding programs.
DIE BEDEUTUNG DER LAUFAKTIVITÄT UND DER GEWICHTSENTWICKLUNG BEI DER ENTSTEHUNG VON BEINSCHÄDEN BEIM MASTGEFLÜGEL
(2006) Djukic, Mirjana; Bessei, Werner
Within the last 50 years, an intensive selection took place in broilers on high growth and therefore there exists a clear reduction of the age at slaughter. Side effects of the selection of faster and higher growth are leg disorders. RUTTEN et al. (2002) tried to reveal the causal relations between weight load, activity and leg disorders by reducing the weight load on legs of fast growing broilers (FB) by a special device. The weight reduced FB showed higher locomotor activity and better bone quality. However, the harness used for the reduction of weight load on the legs impaired the growth rate. In the present study, the experiment of RUTTEN et al (2002) was repeated with an improved device for reduction of weight load of FB. In addition, slow growing broilers (SB) were used, and were brought to the same weight load as weight reduced FB by additional load. In total three experiment were carried out. The first experiment was split in two parts (1a and 1b) so as to incrase the number of replicates. For each experiment, 24 male broilers were used: 12 FG (ROSS 308) and 12 SB (ISA S 257). Load reduced birds weared a harness which was connected to the load reducing device. The load increase of SB weared the same harness with small pieces of led. The chicks of the groups were treated as follows: one with harness and suspension (HS), one with a harness and without suspension ? control bird 1 (C1) and a control bird with no harness and no suspension ? control bird 2 (C2). The load of FB was reduced to the average weight of SB-C2 and FB C2. The load of the SB was increased to the same average value. The following parameters were recorded: body weight, food consumption, weight of breast muscle, thigh, tibiotarsus, femur; length of tibiotarsus and femur; angular deformity of distal femur, distal and proximal tibiotarsus; torsional deformity of femur and tibiotarsus, total area, total density, Corticalis area, Corticalis density, SSI, walking, sitting, standing, eating and ?other behavior?. The weight load reduction in FB led to a significant increase of the locomotor activity. Both the torsional and angular deformities of the Tibiotarsus were clearly reduced, while total area, total density, Corticalis area and SSI were increased. It can be assumed that this was caused by the higher locomotor activity of load reduced FB. The increase of load in the SB diminished the locomotor activity but bone characteristics were not deteriorated. The improvement in the bone conditions of the FB was obviously caused by the increase in activity. In order to determine the influence of decreased load in FB and of increased load in SB the opportunity to move was restricted by reduction of the length of the compartments from 2 to .45 meters. All other experimental conditions remained the same as in experiment 1. Despite the restricted space there was a significant increase in locomotor activity of the load reduced FB. The torsion and angular deformity of the proximal and distal angular deformities of the Tibiotarsus were reduced. There was no significant effect of the increase and decrease of load on the CT-criteria. As in experiment 1, the weight load in the SB diminished the locomotor activity, but the bone characteristics were not influenced significantly. In the third experiment the gait of the load increased SB and load decreased FB was analyzed by a foot print program. For this purpose the length and width of the steps were measured at 4, 5 and 6 weeks of age. The same breeds and the same technique of the modification of the load were used. The load treated birds were kept individually and could use the full length of the test pens. In contrast to the previous experiments the control birds were kept in pens of 1 m² floor space (1 x 1 m). Only the birds without harness (C2) were kept as control. The results of the morphometric and CT- criteria confirmed the results. The FB control birds showed higher step length and greater step width than SB controls. The step length of FB was increased through the load reduction, and decreased through load increase in SB. The treatment had no influence on the step width. SB broilers showed problems to keep their balance under increased weight load. As indicated in the low width of the foot prints the load increased SB broilers tried to place their feet, as usual, under the point of gravity of their body. This seems to impair the stability of gait under increased weight load. FB in contrast, move their centre of gravity above the supporting leg which allows a stable gait under high load. FB did not change the width of their foot prints when the load was decreased, and only the length of the steps increased. The results underline the importance of locomotor activity on the leg conditions of FB. They clearly show that low activity of FB is not caused by lack of motivation but by the high weight load.
Bestimmung des Verknöcherungsverlaufs des Brustbeins von schnell und langsam wachsenden Masthühnern
(2007) Schmid, Britta Ariane; Grashorn, Michael
According to EU marketing regulations for poultry chicken carcasses have to be marketed either as ?young chicken with a flexible breastbone processus? or as ?chickens with a rigid breastbone processus? due to their age at slaughter. Market prices of meat form young chickens are manifold higher than for old ones. Meanwhile, extensive (especially organic) broiler meat production has increased. As in these production systems age at slaughter has to be at least 81 days the question arises whether the breastbone processus is yet not ossified. Up to now the knowledge on the development of the breast bone in chicken is limited. More extended information is only available for bones of extremities. The objective of the present study was, therefore, to investigate the ossification process of breastbones in fast and slow growing broiler strains between first weeks of life and sexual maturity. Visual assessment and assistant characteristics (metric measurements, computerized tomography, chemical composition) of the breastbone and the Os coracoideum, should be applied to analyze the course of ossification. In total, 1000 fast growing broilers of the breed Ross 308 and 1000 slow growing broilers of the breed Isa S 457 were reared for this experiment under standard conditions in a temperature controlled poultry house. Finally, 480 chickens of each breed were used for determination of the breastbone characteristics. Starting with week 4, 12 cocks and 12 hens of each breed were slaughtered weekly until week 23 of life. Life weight and weight of breast meat were recorded besides breastbone characteristics. The breastbone was completely removed and its weight, as well as numerous measures of the breastbone were recorded: Breastbone weight (BBG), Breastbone length (L), Width between the Proc. craniolaterali (BPC), Width between the Trab. intermediae (BTI), Width between the Trab. lateralis (BTL), Length of the Trab. intermedia (LTI), Length of the Trab. lateralis (LTL), Length and width of the Inc. medialis (LIM and BIM), Length and width of the Inc. lateralis (LIL and BIL), Height at Rostrum (HR), Heigth of breastbone keel at 50% of total length (HK), Cartilage length of the Trab. mediana (LC), Relationship between LC and L, Weight of cartilage of the Trab. mediana (GK) and Relationship between GK and BBG. Furthermore, the Os coracoides were removed as bones of reference. Computerized tomography (pQCT) scans were taken at special reference points from 10 randomly sampled breastbones and their Os coracoids of each genotype and gender. The reference points of the breastbone were located at 33% and 66% of total length, whereas, the reference points of the Os coracoides were located at 50% of total length. Total area, Total density, Cortical area, Cortical density as well as SSI were measured by pQCT. Furthermore, photos were taken of characteristic breastbones from each gender and breed and 6 breastbones of each breed and gender were analyzed for contents of dry matter, ash, calcium and phosphorus. Fast growing broilers reached higher life weights and breast muscle weights than slow growing broilers. While weight differences between cocks and hens of the fast growing strain diminished at the end of the experiment, slow growing broilers still showed distinct weight differences between genders in week 23. The breastbone dimensions reached their final values at different times. Determination of breastbone characteristics by metric measurements of dimensions, by computerized tomography and by chemical analyses showed clearly that the ossification process of breastbones of hens is faster than for cocks. This was also reflected by the relations Cartilage length of the Trab. mediana (LC) / breastbone length (L) and Weight of cartilage of the Trab. mediana (GK)/ breastbone weight (BBG). Both indices were higher in males than in females. Breastbones of Ross 308 hens are ossified faster than of Isa S 457 hens. In general, most breastbone parameters differed between breeds. The development of the dry matter content of the breastbone was not finished till the end of week 23. The storage of inorganic material (ash, calcium and phosphorus) showed breed specific differences at the beginning of the experiment, but during the experiment the increase of inorganic material in breastbones was higher for hens than for cocks. The breastbone of a newly hatched chicken consists completely of cartilage and ossification started immediately after hatch from a central ossification centre to caudal and to cranial. Further ossification centres existed at the lateral Trabeculae. The ossification of the lateral Trabeculae progressed independently of the ossification of the breastbone processus. In the present investigation the direction of ossification to the caudal end of the breastbone processus was of special interest. The central ossification centre showed up in the front keel range of the breastbone. With the sprouting of blood vessels and increased metabolic activity the colour of the centre turned to deep red and spread to cranial and caudal. During the proceeding ossification process due to pneumatisation the deeply red coloured areas turned to bright and finally transparent, especially in the front of the breastbone. The results from computerized tomography of breastbones confirmed the visual observations of the ossification of the breastbone processus. Obviously, the ossification process of the breastbone needs a large time frame and ossification seems to be a multilayered process. The increase in breastbone dimensions is paralleled by an increased storage of inorganic material. The weight of the breastbones was decreasing with increasing age due to the reduction of the water content during the process of pneumatisation. The breastbone processus was not completely ossified in fast and slow growing broilers up to the end of the experiment (week 23 of life). The results on the ossification process in fast and slow growing broiler breeds clearly revealed that a prolongation of the fattening process does not affect marketing of broiler meat from extensive production. The breastbone processus is not fully ossified at the normal slaughter age of 81 to 84 days. But, the results also indicated that a more clear definition of the term ?ossified breastbone processus? is necessary as the breastbone is still not fully ossified on start of laying in hens.
Bestimmung präcecaler Verdaulichkeitskoeffizienten für heimische Energie- und Proteinfuttermittel für die Bio-Hühnermast
(2016) Ritteser, Carolin; Grashorn, Michael
To improving the supply of slow growing broiler chicken in organic poultry production with essential amino acids the ileal digestibility (ID) of 15 organically cultivated feedstuffs was determined using a linear regression approach. The ID was determined for three and six week old chickens. The feedstuffs included common cereal species such as wheat, rye, spelt and summer barley, hull-less cereals such as naked barley and naked oats, forgotten cereals or pseudo-cereals such as brown top millet, pearl millet and buckwheat but also corn silage, strip waste of lentils, alfalfa leaves, and clover grass silage (extruded and untreated). The cultivars were added to a basal diet in 3 concentrations in exchange to corn starch. Therefore, the increase for crude protein (CP) and amino acids (AA) resulted from the cultivar only. Titanium dioxide was used as an indigestible marker. Each diet was fed ad libitum between day 15 and 21 d of age to 6 pens of 15 chickens or between day 36 and 42 d of age to 6 pens of 6 chickens, each. On day 21 and/or day 42 birds were killed by carbon dioxide, the chymus was collected and pooled for the 15 or 6 chickens per pen, respectively and analyzed on pen basis. Contents of crude protein, amino acids and titanium dioxide have been determined. The slope of the regression line between the amount of AA intake by feed and the amount of AA digested up to the ileum is considered to be the true ileal digestibility. The crude nutrient contents of the organically grown feedstuffs show different results in comparison to conventionally grown ones. The highest crude protein content was determined for lentils, followed by clover grass silage and dried alfalfa leaves. However, the alfalfa leaves also showed the highest content of crude fiber. Brown top millet, pearl millet, clover grass silage and alfalfa leaves contained the highest amount of methionine. The highest lysine contents were found for lentils, clover grass silage and alfalfa leaves. Values for digestibility of crude protein and amino acids varied strongly among the feedstuffs. Rye, spelt and the clover grass silages were digested only poorly by both, the three and the six week old broilers. This was probably caused by an increased content of antinutritional substances and crude fiber. Extrusion didn´t have any positive effect on the amino acids digestibility of the clover grass silage, it rather impaired digestibility. For buckwheat and clover grass silage the high contents of crude protein and amino acids were compensated by poor digestibility. Brown top millet, pearl millet, strip waste of lentils and especially alfalfa leaves turned out to be appropriate feedstuffs for an adequate protein and amino acids supply in broiler nutrition. Due to the high fiber content alfalfa leaves should be used carefully in the diet. Their high crude fiber content causes an increase in feed volume and this may result in a too low feed intake of broilers to fulfill their nutritional requirements. This again can cause growth disturbances. In general, digestibility values for the organically grown feedstuffs were found to be similar to the values of conventionally grown feedstuffs.
Bewertung praxisüblicher Mastschweinehaltungen in Nordrhein-Westfalen hinsichtlich der Tiergerechtheit
(2002) Zaludik, Katrina; Valle Zárate, Anne
The aim of this study was to assess animal welfare in conventional fattening pig systems. Development of means to improve animal welfare shall put the producer in a position to structure the production more in line with consumer requirements. To carry out this assessment the data of 100 fattening pig farms in North-Rhine Westphalia have been analysed. The study comprises of two parts, firstly the collection of operational data and data of housingsystems, and secondly behaviour investigations. In the analysis of the farm data it was found that, particularly in farms with slatted systems important points of the SVHO (1995) were not followed. Deficits were found in space allowance, dimensions of the slatted floors, drinking systems and objects for occupation. Problems apparent in all housing systems were mainly caused by climatic conditions and lighting. In the observational data the most frequent observation was the lying behaviour. This was significantly lower in deep litter systems. The values for the lying behaviour were in line with the figures quoted in the literature for intensively kept pigs. Animals on farms with straw systems, were significantly more active than animals on farms with fully slatted floors, due to the incentives given by the availability of straw. In slatted floor systems the manipulation of penmate and occupational objects were much higher represented in the total behaviour than in straw systems. Abnormal behaviour was found in all housing systems, however only in small amounts. At the end of this study suggestions for ways of improvement were made specific to the relevant husbandry systems, which included housing as well as management factors.
Bi-objective optimization of nutrient intake and performance of broiler chickens using Gaussian process regression and genetic algorithm
(2023) Ahmadi, Hamed; Rodehutscord, Markus; Siegert, Wolfgang
This study investigated whether quantifying the trade-off between the maxima of two response traits increases the accuracy of diet formulation. To achieve this, average daily weight gain (ADG) and gain:feed ratio (G:F) responses of 7–21-day-old broiler chickens to the dietary supply of three nutrients (intake of digestible glycine equivalents, digestible threonine, and total choline) were modeled using a newly developed hybrid machine learning-based method of Gaussian process regression and genetic algorithm. The dataset comprised 90 data lines. Model-fit-criteria indicated a high model adjustment and no prediction bias of the models. The bi-objective optimization scenarios through Pareto front revealed the trade-off between maximized ADG and maximized G:F and provided information on the needed input of the three nutrients that interact with each other to achieve the trade-off scenarios. The trade-off scenarios followed a nonlinear pattern. This indicated that choosing target values intermediate to maximized ADG and G:F after single-objective optimization is less accurate than feed formulation after quantifying the trade-off. In conclusion, knowledge of the trade-off between maximized ADG and maximized G:F and the needed nutrient inputs will help feed formulators to optimize their feed with a more holistic approach.
Bone ash data in the context of phosphorus and phytase evaluation in poultry
(2021) Künzel, Susanne; Rodehutscord, Markus
Phosphorus (P) is an essential element that is crucial for various metabolic processes in the body of animals and humans. To keep the animals healthy and to obtain food products rich in nutrients, an adequate P supply is indispensable. Plant feedstuffs, the main components of poultry diets, contain P in a form that is only partially available to poultry. For this reason, poultry diets are often supplemented with mineral P. However, global rock phosphate reserves, where mineral P is mined from, are limited. Additionally, excessive P supply should also be avoided because of the environmental impact of P accumulation in the soil. Consequently, P supply not exceeding the requirements of poultry is essential to ensure animal wellbeing and to protect the environment. In order to feed diets with adequate concentrations of P, it is necessary to have suitable approaches for the determination of available P in the animal. The availability of P varies widely between feed components and it is also influenced by feed supplements and other factors. Bone ash analysis is an often-used tool to evaluate the relative bioavailability of P since a high amount of P is stored in the bones. A standard assay for bone ash analyses has never been agreed on. Therefore, many different approaches are described in the literature with an unknown impact on the results of P bioavailability studies. The main objective of the present thesis was to examine the suitability of bone ash data for the evaluation of available P in poultry with emphasis on methodological aspects. Therefore, different studies with broiler chickens and Japanese quail were conducted. The experiments comprised various aspects related to P availability in poultry. The effect of feed supplements in the form of phytase products, myo-inositol and a coccidiostat were evaluated. Furthermore, quantitative genetic analyses were performed. All experiments had in common that tibiotarsus (tibia) or foot ash data or both were used for the examination of the relative bioavailability of P. Based on the data that accrued during the studies described in the four manuscripts of this thesis, comprehensive methodological analyses were performed. The tibia and foot were compared regarding their appropriateness as a trait for the evaluation of the relative bioavailability of P by using bone ash data. The relationship between the two traits was investigated, as well as the relationship between foot or tibia ash and quantitative P measurements. Additionally, P concentration in the ash of both bone fractions was analysed and compared. Results indicated only minor differences between tibia and foot ash data. No clear preference for one of them could be deduced from the data. The left and right feet of broiler chickens were compared in terms of both ash concentration and total ash amount. Significant differences between the two feet of the same animal were detected for both traits. Consequently, not only the choice of the bone fraction but also of the body side should be considered when sampling for bone ash data. Ash data are mostly expressed as a concentration of the dry matter content of the bone. Also possible is the use of the absolute ash amount. The relationship of both ways of expression with traits of quantitative P measurements was analysed by using correlation coefficients and regression analyses. Results showed that the absolute ash amount was at least as suitable as ash concentration but has the advantage that it is easier to determine. Possible selection procedures for animals for bone ash analyses were simulated with data from two of the experiments. Often it is not possible to use all animals involved in an experiment for bone ash analyses. Therefore, the influence of sampling frequency and selection method on the outcome of P availability studies was evaluated. Results indicated that the number and selection method of animals for bone ash data might influence the results. However, it was not possible to recommend a specific selection method based on the obtained results. Estimates of heritability and genetic correlations showed the suitability of bone ash data as a proxy trait for P efficiency breeding of poultry. The absolute amount of bone ash data appeared to be most promising for this purpose. Bone ash data are a very useful and easy to determine trait to estimate the relative bioavailability of P. However, investigations performed in this thesis showed the importance of a careful selection of methods. A standardised assay would be helpful to obtain meaningful and more comparable estimates of relative P bioavailability.
Breeding objectives and selection schemes for Boran cattle in Kenya
(2009) Rewe, Thomas; Valle Zárate, Anne
Beef production with Boran cattle of Kenya presents an opportunity for utilising the potential of an indigenous breed. Improving the performance of these cattle through production of quality breeding stock may support the livelihoods of Boran cattle farmers. Organised breeding programmes for Boran cattle in Kenya are lacking. This thesis focussed on the design of optimal genetic improvement programmes for Boran cattle raised in the semi-arid tropics of Kenya. Specifically, the aims were: 1) to review the potential for beef cattle genetic improvement in sub-Saharan Africa, 2) to describe the state of institutional framework supporting Boran breeding in Kenya while considering the different categories of Boran cattle farmers, 3) to investigate the genetic and economic merit of alternative breeding programmes based on improved Boran, the unimproved Boran and the possibilities of expanding an inclusive breeding programme for these two strains of Boran cattle, 4) to discuss the feasibility of alternative breeding strategies within the context of a formal breeding programme in Kenya. The methodological approach entailed a review of the literature on cattle production and genetic improvement strategies for sub-Saharan Africa. This was done by identifying previous and on-going breeding activities among indigenous cattle breeds based on their regional distribution in Africa. An institutional framework analysis to characterise the Boran breeding sector in Kenya was also performed. Open questions were presented to the Boran cattle Breeders? Society of Kenya through an online survey to ascertain the structure of the society in terms of membership, cattle populations and animal breeding activities. The production systems, cattle types and breeding objectives were also sought from previous studies on Boran cattle in the process of developing appropriate breeding programmes. Design and evaluation of nucleus breeding programmes (genetically and economically) was done with the ZPLAN computer programme by defining the breeding objectives and selection criteria traits, describing breeding and commercial populations, describing selection groups as well as their reproduction performance parameters. The costs of the breeding programme included fixed costs and costs of animal recording. To account for genetic gain and the flow of animal genetics, a gene transmission matrix was defined utilising the selection groups alongside genetic and phenotypic parameter matrices. The information sources for the selection criteria were mainly parental selection groups and halfsibs of animal. The number of animals forming the selection groups and information sources was calculated in the NBILD and NUMBER subroutines of the ZPLAN. The interest rates for returns and costs were 8% and 6% respectively while the investment period was set at 25 years. The scope of the study was limited to two classes of farmers keeping Boran, the commercial beef ranchers and the market-oriented low-input beef producers that interact with commercial beef ranchers. Three breeding objectives were evaluated, 1) conventional breeding objectives with market (economic) values derived from bio-economic modelling, namely: direct sale weight, dressing percentage, consumable meat percentage, cow weaning rate, cow survival rate, cow weight, age at first calving, milk yield, feed intake and post weaning survival rate, 2) a combination of selected conventional target traits in addition to traits important to low-input farmers to exploit the ongoing informal interaction between the large scale ranchers and low-input systems, and 3) trait preferences for low-input farmers derived from conjoint analysis studies namely; sale weight, calving interval, temperament, tick resistance, trypanotolerance and lactation milk yield. To evaluate the benefit of perceived trypanotolerance in unimproved low-input herds, strategic recording for trypanotolerance for offspring of nucleus sires born in these herds was assumed. Closed and open-nucleus types were evaluated and variations on the nucleus size (5%, 10% and 25%). proportion of gene transfer to commercial herds (25%, 50%, 70%) and the proportion of gene importation into the nucleus (10%, 20% and 30%) were tested. The results from the institutional framework analysis showed that the Boran sector is structured with a section of the farmers being large scale commercial ranchers keeping approximately 17% of a total population of 580,000 heads of cattle. The rest were Boran farmers operating in low-input production systems keeping over 80% of the total population. The large scale commercial ranchers were found to be divided into two groups, about 52% of these farmers were elite breeders that record with the Kenya Stud Book and the rest were mainly commercial. The large scale commercial ranchers keep the improved Boran while the low-input farmers keep the unimproved Boran. The large scale commercial ranchers were organised into a breed society, namely, the Boran Cattle Breeders Society (BCBS), incorporating both the elite breeders and the commercial group. The BCBS was identified as a key stakeholder in the breeding of Boran cattle because of their informal role as suppliers of breeding stock. The results from the evaluation of alternative open and closed-nucleus breeding programmes utilising the Boran cattle populations were obtained with the ZPLAN computer programme. For the elite breeders?, where a total population of 52,000 cows with a breeding unit of 25% was assumed, the overall monetary genetic gain was KSh86 per cow while the profit per cow was KSh361 under the conventional breeding objective. The breeding programme with the entire BCBS group where a population of 99,972 cows was assumed obtained a higher monetary genetic gain and profit than the elite group per cow of KSh93 and KSh431 respectively under the same breeding objective. The results revealed the effect of a larger effective population size on performance of breeding programmes. The breeding programme based wholly on market oriented low-input producers was evaluated using farmer trait preferences as the breeding objective. This breeding programme posted a negative gain for milk yield of -1.1 kg, which improved when restrictions on growth and adaptation were applied. The introduction of the combined breeding objective that included adaptation and disease tolerance traits resulted in a drop in sale weight gain by almost 2 kg. However, post-weaning survival rate improved from 0.4% to 1% and trypanotolerance gained 20% packed cell volume within this breeding objective. There was reduction in feed intake under the combined breeding objective, which is desirable considering the prevailing limitations on land, feed and climatic conditions. This may induce a change in focus from the continuous improvement in sale weight. The gains in post weaning survival rate would support this objective. The results from the expanded breeding programme may be beneficial to both the low-input farmers and the commercial ranchers because of the advantages conferred from the improvement in adaptation traits. The benefits of extra recording for trypanotolerance in the commercial herds of the expanded programme were not realised. In general, the open-nucleus programmes were superior genetically while the closed-nucleus programmes were superior economically. The larger nucleus sizes (25%), higher gene contributions to commercial herd (70%) and limiting nucleus opening to 10% were most profitable. The limitations of the study were observed from the online interviews with respect to the amount of information that could be retrieved from key persons. Similarly, information on the legal framework of the breeding sector was scarce since Kenya has no active livestock breeding policy. The design and evaluation of the breeding programmes was possible with ZPLAN, however, in this study, genetic variance for traits, which normally diminishes with selection and inbreeding, was not account for. This may have had implications related to overestimation of genetic response and economic returns. Nonetheless, the potential of the Boran for both beef production and fitness traits coupled with the presence of institutional support for animal recording in Kenya were evaluated as strengths of the system. This study has shown the possibilities of combining market and non-market traits useful in breeding programmes for cattle utilised in different production systems. This approach is useful in cases where interactions exist between different categories of farmers. To benefit from advantages offered by open-nucleus breeding, recording may be avoided in the commercial herds and selection be done under criteria that are acceptable by the farmers. Further investigations on farmer organisations and comprehensive livestock breeding policies may aid the process of establishing co-ordinated breeding programmes for Boran cattle in Kenya.
Breeding strategies for Sahiwal cattle genetic resources in Kenya
(2011) Ilatsia, Evans D.; Valle Zárate, Anne
The Sahiwal breed is an important cattle genetic resource in the tropics where it is vital for subsistence and economic development among various communities. In Kenya a breeding and conservation programme has been in existence for over 45 years with the ascertains of its relevance in light of the producers? production aims and breeding goals still left pending. Moreover, there have been no systematic efforts undertaken to evaluate the suitability of the existing breeding programme or to examine how competitive it is compared to other alternative programmes in terms of genetic and economic merit. This thesis focused on understanding the breeding strategies for improvement of Sahiwal cattle genetic resources in Kenya. Specific objectives were; 1) to critically examine the existing breeding and conservation programmes for Sahiwal cattle genetic resources in the tropics focussing mainly on the strengths and weaknesses in Pakistan, India and Kenya as the core regions of development, 2) to understand the production conditions under which Sahiwal cattle genetic resources are raised, determine producers production aims and assess the relative importance of breeding goals and production challenges, 3) to identify and define the roles of various stakeholder institutions that are crucial in the realisation of a promising and sustainable Sahiwal cattle breeding programme, 4) to identify based on genetic and economic merits the optimal breeding programme for Sahiwal cattle genetic resources by evaluating the current and alternative breeding programmes, and 5) to analyse and discuss organisational options for implementation of promising breeding and conversion programmes. The results from the literature review study show that most studies on Sahiwal cattle genetic resources in the tropics have mainly concentrated on evaluating their performance levels with only a few published reports describing other breed characteristics. The Sahiwal breed is utilised for dairy and beef production under smallholder dairy pastoral extensive and ranching production systems both as purebreds or crossbreds. The necessary components to strengthen the breeding programme such as performance recording genetic evaluation and AI facilities exist albeit at different degree. Breeding and conservation efforts benefit from the technical and financial support from government research institutions, which also provide incentives to enhance participation in the programmes. However, breeding goals are rather informal and only defined in terms of high production levels with functional traits largely ignored. Field data analysis revealed that Sahiwal genetic resources were mainly kept for domestic milk production and for revenue generation through sales of milk and live animals. To a limited extent they were kept for breeding and also for multiple objectives that included insurance against risks and social functions. Production aims were influenced to varying extents by various household and farmer characteristics. Sahiwal cattle and their crosses were generally perceived to be better with respect to productive traits and fertility traits when compared to the EAZ. However, the EAZ was rated higher with respect to adaptation traits. The breeding objective traits of primary importance were high milk yield and big body size, good reproductive efficiency and relatively good adaptation to local production conditions. Performance and functional traits are important breeding goals that play a major role in fulfilling the multiple production objectives. This forms the basis for the optimisation of a breeding programme for sustainable utilisation to meet the needs of Sahiwal cattle producers. All the breeding programmes evaluated in this study showed positive genetic and economic gains, however, the difference was only in the margins of these benefits. Given the small population of the Sahiwal breed, an open-nucleus breeding programme is economically and genetically optimal because it will allow for efficient utilisation of the existing genetic base by allowing participation of more diverse pastoral born sires in the nucleus. The CNCROSS will continue to play an important role of facilitating the exploitation of trade-offs that exist between the Sahiwal and the EAZ with regard to production and adaption, as well as an intermediate phase in the up-grading programme. However, the full benefits of the open-nucleus breeding programme can only be realised in the presence of proper logistical organisation to facilitate exchange of breeding bulls between the pastoral herds and the nucleus farms and ensure equitable distribution. Co-operation between producers and relevant stakeholder institutions is necessary to ensure the requisite structures for implementation and sustainable execution of the breeding programme.
Classification and characterization of Ethiopian honey bees (Apis mellifera) based on morphometric, genetic and socio-economic analyses
(2022) Hailu, Teweldemedhn Gebretinsae; Hasselmann, Martin
Ethiopia is a major beekeeping country located in northeast Africa where several evolutionary lineages of Apis mellifera contact. A unique practice of honey bee colony marketing which involves broad agro-ecological zones (AEZs) is a developing trend in the northern part of the country such as Tigray region in association with apicultural development. Several studies based on classical morphometry on the Ethiopian honey bee subspecies classification debated from the unique Apis mellifera simensis to five others. Moreover, the genetic diversity, adaptation, gene flow and inter-relationships of the honey bees between AEZs were not disentangled – a challenge for planning sustainable apicultural development and conservation. Therefore, this study was conducted to elucidate the honey bees of Ethiopia in a context of apicultural transformation using integrated methods: morphometrics, genetics, colony market survey and metadata analyses on beekeeping development. The results of geometric morphometric analyses confirmed that Ethiopian honey bees represented by Apis mellifera simensis references belong to a separate lineage (Y) compared to A, O, M and C, and the present sample belonged to Y. This supported the hypothesis of five major honey bee lineages of the honey bee Apis mellifera. Similarly, a maximum likelihood phylogenetic tree analysis based on the mitochondrial COI-COII showed that most of the Ethiopian honey bees belong to lineage Y. However, a substantial proportion of the samples from the northern part of the country clustered with lineage O, which support the hypothesis that there is close contact between Y and O. Both geometric morphometry and classical morphometry differentiated the Ethiopian honey bees from all references including A. m. monticola, A. m. scutellata, A. m. jementica, A. m. adansonii but grouped with A. m. simensis. Genetically, five DraI haplotypes (COI-COII) were found to be randomly distributed across AEZs, indicating a substantial gene flow. Consequently, the level of genetic differentiation among the Ethiopian honey bee subpopulations defined by local areas and AEZs was generally low based on r7-frag nuclear marker, which is identified to be associated with adaptation to habitat elevation in East African honey bees. Similarly, nucleotide diversity consistently decreased with increasing elevation – indicating a reduced effective population size in the highlands. Results obtained from colony market survey showed that the honey bee swarms are reproduced in a few highlands and re-distributed throughout the region. Colony buyers have preferences of color and AEZ of origin of the honey bees, which led to a one-way flow and eroded the overall level of genetic differentiation. However, a marked differentiation was detected between the highland and lowland honey bees in relic communities where an allelic length polymorphism was observed as a signature of local adaptation. Altogether, Ethiopian honey bees belong to the lineage Y and subspecies A. m. simensis, and are characterized by a high level of gene flow enhanced by colony marketing; but a conserved signature of local adaptation to higher elevations was identified in less disturbed communities. Further studies based on genome-wide analyses and field experiments, focusing on undisturbed communities, can provide more insights into adaptation, admixture and management implications. Sustainable bee breeding and extension services that enable local beekeeping without colony trade and transportation will help to promote apiculture and genetic conservation.
Climate change, cattle herd vulnerability and food insecurity : adaptation through livestock diversification in the Borana pastoral system of Ethiopia
(2013) Megersa Bati, Bekele; Valle Zárate, Anne
Climate change is one of the dominant drivers of changing patterns in precipitation, rise in temperature and increasing frequency of extreme weather events that present a major challenge to livestock production in arid and semi-arid environments. In the Borana region of southern Ethiopia, the resulting reduction in the resilience of rangelands and heavy cattle losses associated with recurrent droughts pose serious challenges to cattle pastoralism. This study aimed at investigating regional manifestations of climate change and variability, and their impacts on cattle production and household food security, as well as the role of livestock species diversification as an adaptation strategy of Borana pastoralists in southern Ethiopia. The study involved the use of questionnaire surveys, participatory discussions and monthly meteorological data from 1970 to 2011. A total of 242 households sampled from Yabelo and Dire districts of the Borana zone were surveyed between August 2011 and December 2011. Data collection also included cattle herd histories, which were reconstructed for a period spanning five major droughts (between 1980 and 2011), and household-level livestock mortalities due to the 2010/2011 drought. With the use of 24-hour food recalls, data on individual dietary diversity were collected from 339 respondents during the beginning (September) and the end of the short rains (December). Besides descriptive analyses, a range of statistical models including general linear models, generalized linear mixed models, generalized additive models, ordered and binary logit models, and a proportional hazard regression model were applied to different data sets using SAS version 9.3. Herders? perceptions showed that rainfall has become more unpredictable with lower amounts and shorter durations, while temperature and the frequency of droughts have increased. The analysis of empirical data revealed a similar declining trend in annual precipitation and cattle holdings, while droughts became more frequent. A spectral analysis of annual rainfall series showed a quasi-periodic cycle of about 8.4 years for annual precipitation with recurring droughts every 4.2 dry years. The Borana herders suffered heavy cattle losses and experienced severe food insecurity in consequence of increased climate variability. Hence, the study showed that climate change and variability have impacts on cattle production, pointing to a critical future for the sustainability of cattle pastoralism in southern Ethiopia. Analysis of the data on food security showed a high prevalence of food insecurity (78%) and low dietary diversity, with the majority of the households (81%) merely consuming one to three food groups. A large number of the respondents consumed no fruits, vegetables (93%) and meat (96%), suggesting a high risk of micronutrient deficiencies given the declining trend in milk intake. Livestock diversification indeed significantly has improved dietary intake and household food security. Households with large herd sizes, farmland sizes and large family sizes, or households having off-farm income sources were also found to be better-off compared to their counterparts. Analysis of the data on livestock species composition showed that all of the respondents were keeping cattle, while 94%, 85% and 40% kept goats, sheep and camels, respectively. Recurrent droughts, bush encroachment and increased cattle herd vulnerability were among the major drivers of livestock diversification. Species diversity fulfilled a broad spectrum of the herders? livelihood priorities, of which milk production and cash revenues from live animal sales were of highest importance. Adaptability assessments based on a set of nine adaptive traits showed that camels had the highest adaptive capacity, followed by goats, while cattle were the least adapted species. Species vulnerability to drought also reflected the adaptability patterns with cattle being the most vulnerable to drought followed by sheep, and camels being the most tolerant species. In general, the present study showed that climate change and its variability posed a challenge to cattle production, with recurrent droughts causing enormous mortalities and worsening household food insecurity. The adaptation measure of herders through diversifying their herd composition was found to alleviate food insecurity and reduce vulnerability to the periodic climatic shocks. To further enhance herders? adaptive capacity, implementing adaptation strategies aimed at proactively reducing vulnerability to climate risks and enhancing ex-post risk management capacity are vitally important.
Clinical, haematological and pathomorphological findings in Mycoplasma suis infected pigs
(2021) Stadler, Julia; Ade, Julia; Hermanns, Walter; Ritzmann, Mathias; Wentzel, Sarah; Hoelzle, Katharina; Hoelzle, Ludwig E.
Background: Mycoplasma suis (M. suis) belongs to the group of haemotrophic mycoplasmas and is known as the causative agent of infectious anaemia in pigs. In the last few years valuable insights into the mechanism of adhesion and invasion, shedding patterns and cell tropism of M. suis were gained by the use of new molecular techniques. However, details on M. suis induced lesions as well as the distribution of M. suis in different organs are still lacking. Therefore, seven splenectomised pigs were experimentally infected and clinical and laboratory investigations as well as a detailed histopathological examination were performed. Detection and quantification of M. suis DNA in blood and various tissue samples was done using a quantitative real-time PCR. Results: During the course of experimental infection, periodically occurring signs of infectious anaemia of pigs including severe icteroanaemia, fever, apathy and anorexia were observed. In addition, dermatological manifestations such as haemorrhagic diathesis presenting as petechiae occurred. The most important haematological alterations were normochromic, normocytic anaemia, hypoglycaemia as well as increased bilirubin and urea concentrations. Necropsy revealed predominant evidence of haemolysis with consecutive anaemia, as well as disseminated intravascular coagulation. M. suis was found in all investigated tissues with the highest copy numbers found in the kidneys. In Giemsa stained sections M. suis was only detected red blood cell (RBC)-associated. Conclusion: In the present study, no RBC independent sequestration of M. suis was detected in organs of experimentally infected pigs. Pathological findings are most likely resulting from haemolysis, consecutive anaemia as well as from disseminated intravascular coagulation and subsequent organ impairments.
Comparison of effects of Echinacea purpurea juices and Nigella sativa seeds on performance, some blood parameters, carcass and meat quality of broilers
(2009) Nasir, Zahid; Grashorn, Michael
Use of phytogenic substances in animal production is increasing due to their beneficial effects on feed digestion, promotion of production performance and improving product quality. They contain a number of pharmacologically active substances which have shown their activities in different body systems and, therefore, they are considered as one viable alternative to in-feed antibiotics. Presence of a variety of active ingredients indicates that phytogenic substances may have affects on different metabolic pathways, activity of different enzyme systems, immunity and performance parameters. Especially, improvement of immunity may help birds to cope in a better way with stress situations during fattening and by this may enhance well-being as well as quality of products of animal origin. Echinacea purpurea (EP) and Nigella sativa (NS) belong to the group of phytogenic substances that have been reported to stimulate immune system in laboratory trials as well as in human studies. Positive effects of EP and NS have been observed in a number of in vitro and in vivo experiments, which show that their application in poultry can be beneficial for maintaining health, improving immunity and performance parameters. However, no study was conducted to evaluate the comparative as well as synergistic effects of EP juices and NS seeds on broiler health, performance and activities of different enzymes related to heart and liver functions. The objectives of this thesis were set to investigate the effects of EP juices and grounded NS seeds on performance, metabolism (serum protein, blood picture and some liver and heart associated enzymes in blood), carcass and meat quality in broilers (Ross 308). For this purpose five preliminary trials were performed to investigate the effects on bird?s metabolism. Fattening trial was carried out to study the comparative and synergistic effects of EP juice and NS seeds on performance, carcass and meat quality. Three preliminary experiments were performed using two different preparations of EP juices; EP-F (EP fermented juice) and EP-A (EP juice on alcohol basis). Initially, effects of EP-F and EP-A were compared along with testing different dose levels. EP juices were orally supplemented intermittently for a 3 days (1-3, 13-15 and 25-27), followed by 9 days without EP application. Comparing the effects of EP-F and EP-A, better performance and improved health was observed by application of EP-F juices. Application of 0.25 ml/kg BW0.75 EP-F juice has shown more positive effects as compared to other treatment levels. EP-F treated birds showed significantly better average daily weight gain and significant improvement of serum globulins, indicating beneficial treatment effect on broiler performance as well as immunity. Levels of serum CK were significantly reduced in EP-F treated birds as compared to control, which shows that EP-F posses the potential to reduce incidence of mortality related to dysfunction of the cardio-vascular system in broilers. Two preliminary experiments were performed using grounded NS seeds. In first experiment different levels (0, 0.5, 1.0, 1.5, 2.0, and 2.5 %) of NS seeds were supplemented in basal broiler diets. 1 % NS was found to be most suitable, which was used in second experiment against a negative control. Numerically better FCR during starter phase was obtained by application of 1 % NS seeds, but these effects were decreased during grower phase. Less number of mortalities was observed in NS treated birds as compared to control. In the fattening trial, four treatment combinations were tested as: control (without any feed or water additive), E (drinking water intermittently supplemented with EP-F), N (feed supplemented with NS seeds) and EN (drinking water intermittently supplemented with EP-F and feed supplemented with NS). The results showed that application of EP-F as well as NS has no negative effect on broiler performance, carcass and meat quality. Birds performed to their maximum potential and supplementation of EP-F and NS helped birds to perform better. Combined application of EP and NS resulted in reduced mortality and numerical improvement in weight gain and feed consumption, significantly (P<0.05) higher meat CP as compared to E and N treatments. In general, a synergistic positive effect of simultaneous application of EP and NS was observed on performance, carcass and meat quality in broilers. Based on these results, it can be concluded that intermittent application of EP-F and continuous application of NS seeds has no negative effect on broiler performance, carcass and meat quality. Beneficial effects of Echinacea supplementation on broiler performance, health and immunity can be obtained by intermittent application of EP-F through drinking water. Combined application of EP-F and NS seeds has shown a trend of improved broiler performance and meat quality, which indicate synergistic effects of active ingredients of both phytogenic compounds.
Comparison of plant cell wall degrading community in the rumen of N’Dama and N’Dama x Jersey crossbred cattle in relation to in vivo and in vitro cell wall degradation
(2004) Nouala-Fonkou, Simplice; Becker, Klaus
This thesis presents a unique combination of an in vivo feeding trial, the analysis of the microbial community structure in the rumen, and in vitro fermentation studies, in order to assess the impact of breeds and diets on animal performance in a West African production setting. Pure N?Dama and N?Dama x Jersey crossbred cattle were fed two basal diets, baby corn and groundnut hay, supplemented with graded levels of either conventional concentrate or moringa leaf meal, to compare animal responses in productivity. In this context, Moringa oleifera leaf meal constitutes a locally available, potential alternative to commercial concentrate for cattle production. The cell wall digesting community of N?Dama and its crosses was analysed using phylogenetically based hybridisation probes to account for the contribution of rumen microbes to differences in fermentation patterns and animal response. In vitro fermentation studies were carried out using the same diets and supplementation levels as fed in vivo, to test the accuracy of the in vitro gas production technique in predicting the optimum level of supplementation. The in vivo feeding experiment focussed on the comparison of breed performance with diets relevant for local production conditions. Six N?Dama and six N?Dama x Jersey (crossbred) animals were used in a cross over design. They were fed consecutively three combinations of roughage and supplement, baby corn stover and concentrate (BCS:Co), groundnut hay and concentrate (GNH:Co) and groundnut hay and moringa meal (GNH:Mo), each at 5 levels of supplementation (0, 10, 20, 30 and 40%). Results from this study showed that there was a clear difference in animal response to different feeding regimes between the two breeds. When averaged over all diets organic matter intake (OMI) was higher in crossbred compared to N?Dama (94 and 87.6 g/kg 0.75 d-1, respectively). When analyzed for the diets and averaged over the breeds OMI was higher when animals were fed the baby corn based diet compared to groundnut based diets (95 against 88 g/kg 0.75 d-1). Only when the diet consisted of BCS:Co, and at low levels of supplementation, N?Dama ingested more than crossbred, but the difference was not significant. With GNH:Co crossbred ingested significantly more at levels of supplementation less or equal to 20%. With GNH:Mo crossbred ingested more, whatever the level of supplementation. The optimum level of supplementation in vivo, estimated with the single slope broken line model, was 10% and 20% for both breeds when they were fed BCS:Co and GNH:Co respectively, but 30% for N?Dama and 10% for the crossbreds when animals were fed GNH:Mo. Organic matter digestibility (OMD) was higher in N?Dama (64.6% against 60.7% in crossbreds) when animals were fed BCS:Co and supplementation had no effect on OMD of BCS:Co whatever the breed. When animals were fed groundnut hay as basal diet, OMD was also significantly higher in N?Dama at low levels of supplementation, but the differences became insignificant beyond 10% and 20% of concentrate or moringa, respectively. With GNH:Co OMD showed a quadratic response (p<0.001) with increasing level of supplementation when it was fed to crossbreds and was not affected when it was fed to N?Dama. Increasing levels of moringa meal supplementation increased OMD in both breeds up to a peak at 20 and 30% for N?Dama and crossbred, respectively. Average daily weight gain (ADG) was not affected by the breed, however it was higher on BCS:Co compared to other diets. On BCS:Co ADG increased with the level of supplementation, reaching a peak at 30%, whereas supplementation had no effect on ADG when animals were fed groundnut hay based diets. As N?Dama could take in and digest more of the low quality BCS:Co diet, they were less efficient in feed conversion under this feeding regime (FCE: 14 vs. 9 for the crossbreds). On GNH based diets, however, N?Dama surpassed the crossbreds in feed conversion efficiency with ratios of 11 vs. 13 for GNH:Co and 9 vs. 27 on GNH:Mo. Rumen microbes play the key role for the digestibility of a given feed and thus also for feed intake and finally animal performance. Obviously, the community composition and activity is highly dependent on the diet. With the present set-up, however, with identical external conditions and three different, well defined diets fed to both, N?Dama and crossbred cattle, a comparison of the microbial community structure between breeds could be attempted. The in vivo and in vitro data taken in the other parts of the study allow a sensible interpretation of potential changes in microbial composition. Rumen fluid was collected from three fistulated N?Dama and three crossbred animals adapted to the experimental diets at medium supplementation level. The cell wall degrading community was analyzed using the phylogenetically based 16S rRNA hybridisation probes. The results showed that on BCS:Co diet the Fibrobacter and R. flavefaciens RNA concentrations were higher in rumen fluid of N?Dama compared to crossbred. These concentrations were also significantly affected by the diet, such that they were higher on baby corn stover compared to groundnut hay based diets. The results of the microbial community analysis suggested that the differences between breeds observed in digestibility could be partially explained by the composition of the cell wall degrading community. Parallel to the in vivo experiment, in vitro fermentation studies were undertaken to evaluate the predictability of the in vivo response to supplementation by the in vitro data. Rumen fluid from 3 N?Dama and 3 crossbred donor animals was used for 24 hour in vitro fermentations. The donor animals were fed consecutively the same three diets used in vivo (BCS:Co, GNH:Co and GNH:Mo) at 20% level of supplementation. Each of these inocula was incubated with in vitro substrates consisting of all the combinations tested in vivo (i.e. 3 diets, 5 levels of supplementation) plus supplement alone. This design should allow to analyze for both, the impact of donor breed as well as that of the donor diet and to conclude which factors may be varied while maintaining predictability. The breed of the donor animals did not significantly affect 24 hour gas production, but short chain fatty acid concentration was higher with rumen fluid from crossbreds when donors were fed BCS:Co and GNH:Mo. Moringa meal as supplement to donor animals changed the fermentation pattern of all the substrates, such that gas production and SCFA increased substantially in groundnut hay based substrates, whereas gas production of BCS:Co substrates decreased and SCFA did not substantially change. In vitro digestibility was higher with rumen fluid from N?Dama whatever the diet of donor animals and the substrate incubated. GNH:Mo as donor diet also increased IVTD of all the substrates. Even though there was no clear response in vivo, this indicates a general stimulation of microbial activity in the rumen and renders moringa leaf meal a promising supplement. Averaged over all data there was a positive correlation (r2=0.53 p<0.001) between IVTD and in vivo OMD. This correlation was much stronger when calculated for a specific diet (e.g. r2=0.90 p<0.001 for BCS:Co, averaged over the breeds). Analyzing the data for the individual breeds affected correlations only to a minor degree. Thus, when testing a supplementation strategy in vitro, it should be important that donor animals are fed the same components (roughage and supplement) that will be combined at different levels in vitro, whilst the breed of donor animals may be of second importance. This work provides conclusive evidence that in vitro incubations may be used to design supplementation strategies, thus reducing the need for in vivo experiments. Moringa leaf meal is a promising local resource to substitute for conventional concentrate. Differences in productivity between breeds could be correlated to (and may be partially manifested through) a divergent community structure of rumen microbes. That, in turn, indicates that animals of different breeds might have a ?genetic background? that favours the establishment of a certain community, even if the animals are kept under identical conditions. This relationship should be investigated by more advanced molecular techniques.
Comprehensive characterization of microbiota in the gastrointestinal tract of quails and two high yielding laying hen breeds
(2023) Roth, Christoph Florian; Camarinha-Silva, Amélia
The microbiomes composition in the gastrointestinal tract (GIT) is subject to several changes and influences. In addition to breed, sex, or diet, age affects the GIT microbiome dynamics of laying hens and quails. From the first day, the microbiome develops and increases its bacterial load to thousands of species. Then, depending on the diet fed, the animals microbiome and associated active bacteria vary and directly influence the animals nutrient uptake and efficiency. Omics technologies give insights into changes in microbes in the GIT (crop, gizzard, duodenum, ileum, caeca). In addition, they can reveal how feed supplements such as calcium (Ca) or phosphorus (P) can affect host health and performance through alterations in the microbiome. The Japanese quail has been an established animal model for nutritional and biological studies in poultry for the last 60 years. In particular, its short development time makes it a convenient model for microbiome research. However, compared to broiler microbiome research, the quail microbiome is still poorly understood. Animals of the breed Coturnix japonica were housed under the same conditions, fed a diet with P below recommendation, and the ileum microbiota characterized. Microbiota relations with gender and higher or lower predisposition of the birds for PU, CaU, FI, BWG, and FC were described (Chapter II). In addition, these performance parameters influenced the relative average abundance of bacteria like Candidatus Arthromitus, Bacillus, and Leuconostoc. Gender affects specific bacterial groups of the GIT, such as Lactobacillus, Streptococcus, Escherichia, and Clostridium, which differ in average abundance between male and female quails. Despite the comprehensive microbiota analysis, the interplay between animal genetics, diet, sex, and microbiome functionality is not yet understood. The laying hen breeds Lohmann LSL-Classic and Lohmann Brown-Classic are used worldwide. Little is known about the interaction with microbiome composition, performance, dietary effects, and changes during the productive life that might help develop feeding strategies and microbiome responses on a large scale. Because of the importance of P and Ca in poultry diet, the research in Chapter III was conducted to challenge laying hens with reduced dietary P and Ca and describe the effect on GIT active microbiota. The breed was the primary driver of microbial differences. A core microbiome of active bacteria, present along the complete GIT, was revealed for the first time and consisted of five bacteria detected in 97% of all samples, including digesta and mucosa samples (uncl. Lactobacillus, Megamonas funiformis, Ligilactobacillus salivarius, Lactobacillus helveticus, uncl. Fuscatenibacter). Furthermore, significant microbial differences between the GIT sections and between the breeds were described. Minor dietary effects of the P and Ca reduction on the microbiota showed that a further decrease in Ca and P supplementation might be possible without affecting the gut microbial composition and bird performance. Furthermore, the microbiome of laying hens was characterized at five productive stages (weeks 10, 16, 24, 30, and 60) to analyze the age effect on the GIT microbiome (Chapter IV). Although the two breeds of laying hens were offered the same diet and housed under similar conditions, the active microbiota composition changed between the analyzed productive stages, the breed and the GIT sections. The major shift occurred between weeks 16 and 24 and supported the hypothesis of bacterial fluctuations due to the onset of the laying period. Those changes occurred mainly in the abundance of the genera Lactobacillus and Ligilactobacillus. However, it remains unclear whether the dietary changes, due to the development of the birds, influenced the microbiota shifts or if the anatomical and physiological modifications influenced the GIT microbiota. Furthermore, the shotgun metagenomic analysis revealed differences in regulatory functions and pathways between breeds, sections, and the two production stages. Different relative abundance levels of the microbial composition were observed between the RNA-based targeted sequencing and the DNA-based shotgun metagenomics. In conclusion, the comprehensive characterization of the microbiota in the GIT of quails and two high-yielding breeds of laying hens contributes to a broader knowledge of the microbiome dynamics within the fowl GIT. Age and breed play a more important role than diet in influencing the dynamics of microbial composition in laying hens, and individual performance and sex in quails. Research characterizing the microbiome in poultry and its effect on diet and host genetics will help improve feeding and breeding strategies in the future and reduce excretion of nutrients into the environment while ensuring overall animal health.

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