Browsing by Person "Grashorn, Michael"

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    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.
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    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.
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    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.
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    Effect of Omega-3 fatty acids and physical exercise on egg quality, bone characteristics and physiological parameters in laying hens
    (2013) Jahja, Ardita; Grashorn, Michael
    It is well proven that eggs enriched with omega-3 fatty (n-3) acids have additional health benefits in humans. Various feeding stuffs may be used for enriching eggs with n-3 PUFA. Besides nutrition physical exercise may play a role in this context. Physical exercise influences both the metabolism of fatty acids and the mechanisms of bone formation. Bone breakage is a serious welfare problem of laying hens. Broken bones were found in about 30% of hens before slaughter and the proportion reached 90% at the end of the processing line. Beneficial effects of n-3 fatty acids have been reported on bone strength in Japanese quail and growing chickens. Thus, the objectives of the present study were to elucidate the relationships between sources of dietary fatty acids and physical exercise in laying hens on performance, egg quality, bone characteristics and some physiological criteria of lipid metabolism. In total 36 brown laying hens were used and 12 hens each were fed with three experimental diets differing only in the fat source: Palm oil (PO), Soybean oil (SO), Linseed oil (LO), corresponding to a low content of poly unsaturated fatty acids (PUFA) ? PO, high content of omega-6 (n-6) fatty acids ? SO, and high content of n-3 fatty acids ? LO. Half of hens of each dietary group (6 birds) were exposed to exercise by walking on a treadmill (EG), whereas, the remaining 6 hens served as a control (CG). EG birds were exposed to a running treadmill every day for the whole experimental period (4 wk). On the first day the birds walked 5 min with the speed of 0.5 miles/h. Then duration of walking and speed was increased progressively until day eleven. Thereafter, until the end of the experiment hens walked 25 min/day. On the first day the distance walked was 67 m and increased to 469 m/day on day eleven. The experimental design was: 3 diets x 2 activities x 6 birds = 36 hens. At the end of the experiment eggs were collected to determine yolk fatty acids profiles and hens were slaughtered to collect blood indicators for lipid metabolism, tibia bones to determine bone characteristics and hearts and livers to calculate relative weights. Diets significantly influenced egg weight, yolk proportion and fatty acids profiles. The highest egg weight was observed for SO and the highest yolk proportion for LO. Contents of SAT and MUFA were significantly higher in eggs of group PO, whereas, LO and SO showed a higher content of PUFA. Eggs of treatments SO and LO had the highest proportions of linoleic acid and linolenic acid, respectively. N-6 and n-3 contents in PO and in SO eggs were eight times higher than for LO (P<0.05). Exercise of birds did not affect egg weight, yolk proportion or fatty acids profiles indicating a dominating effect of dietary fat source. The interaction exercise x diet was significant for yolk proportion only. There was no significant effect of diet or physical exercise on bone characteristics determined by computer tomography, but, there was a consistent trend of higher level of total area and corticalis area in the LO group as compared to PO and SO groups. Total density and cortical density showed the opposite tendency. Significant diet x exercise interactions were observed for total area, corticalis area and corticalis density. Running on the treadmill resulted in lower total area and corticalis area for diets LO and PO, whereas, higher values were observed for birds with exercise fed on diet SO. In contrast, for corticalis density lower values were observed for birds without exercise fed on diets LO and PO. Further characteristics of tibia were not significantly affected by main factors or their interaction, but tibia of birds fed on diet PO showed the highest ash, Ca and P contents (% dry matter). Diet PO resulted in lower body weight, increased relative liver weight and serum cholesterol level. Hens fed with diet SO showed the highest serum ALAT level indicating an accelerated lipid metabolism. There were no significant effects of exercise on other characteristics. Interactions between dietary fat and exercise revealed that exercise can compensate negative side-effects of an increased metabolic activity for diets SO and LO, whereas, the unfavourable effects of a diet with a low content of linoleic acid (PO) cannot be removed. In summary, fatty acids profile of egg yolk has been modified by diets as expected. Physical exercise, in contrast did not show any influence on yolk fatty acid profiles. Higher levels of n-3 fatty acids in free range eggs reported in earlier studies are obviously not caused by higher physical exercise. The effect of physical exercise and diet on bone stability is not caused by the individual factors but by their interactions. While physical exercise in the LO and PO diet reduced bone area and increased bone density, the opposite effect was observed for SO diet. Since lower bone density was compensated by larger bone area the treatments did not affect bone breaking strength.
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    Feldstudie zur Eignung der Biophotonenmessung für die Differenzierung von ökologisch und konventionell erzeugten Hühnereiern
    (2009) Egerer, Ulrike; Grashorn, Michael
    Consumer demand for organic food is increasing. Conventional quality criteria are based on assay of individual chemical compounds, which depend much more on local conditions, climate and breed than on the production method. So alternatives need to be found to distinguish between organic and conventional food. Complementary approaches look at biological systems as a whole and focus on the inner structure of products. As shown in many studies, holistic criterions reflect differences in food quality, which are caused by the production method. F.A. POPP has rediscovered ultra weak light emissions that are presumed to originate from electromagnetic fields in living organisms. So-called 'biophotons' can be detected by highly sensitive photomultipliers as 'delayed luminescence' after illumination of the sample. Associated with living processes, the radiation reflects the state of the living tissue. In 2001 B. KÖHLER showed that egg yolks emit varying biophoton intensities depending on the husbandry system. Using standardized test conditions KÖHLER found that exposition to sunlight or to lighting that was similar to daylight, as well as feeding of green stuff, enhanced biophoton emission of yolks. The present investigation has been carried out under conditions of commercial egg production to discover whether biophoton emission is a suitable quality criterion for organic eggs. From July 2005 to November 2006, about 900 eggs have been collected in food stores and on farms. The biophoton intensity of each egg was determined and entered into a database according to its way of production (cage, deep litter, free-range, organic or from smallholders). The aim of this examination was to determine the differences in light emission of eggs originating from various production systems without standardized husbandry conditions. As a second project, a long-term observation has been conducted to see whether biophoton values of eggs remain stable over time. During the course of one year (from May 2006), biophoton emission has been measured each month. Samples have been taken from twelve hen houses with different husbandry systems: 2 houses with cage system, 4 with deep litter, 2 houses with free-range system and 4 organic farms ? adding up to more than 2,300 eggs. In addition to the measurement of biophoton emissions, conventional egg quality criteria have also been determined: egg mass, breaking strength of egg shell, albumen height, yolk color, proportion of yolk, fatty acid profile and lipid oxidation. Farmers have been interviewed about the age of their hens, flock size, lighting conditions and feed composition. Climatic conditions have been researched on the internet. It was expected that comparison of all collected data would give information on the origin and meaning of biophoton emission of egg yolks. In the present studies yolks were exposed to white light for 30 seconds. Delayed luminescence was detected for the duration of 60 seconds. The biophoton parameter used has been defined as the sum of light emission during the last 40 seconds of the measurement. Egg yolks from different animal husbandry systems differed in biophoton emissions. However, while conventionally produced egg yolks showed only minor differences, organic eggs as well as eggs from smallholders were characterized by clearly higher intensities. The long-term observation of yolks from 12 selected hen houses revealed great fluctuation of biophoton emissions over the course of the year. Nevertheless, it was remarkable that yolk samples with low contents of saturated fatty acids and high contents of polyunsaturated fatty acids showed the highest biophoton intensities. These samples originated from farms that offer both a green free range and feed including vegetables or dried grass. As KÖHLER had shown, feeding green stuff leads to higher light emissions of yolks and also influences the profile of fatty acids. Further examinations will be necessary to clarify the causality between fatty acid composition of the yolk and its biophoton emission. Another target of the described projects was to test the suitability of biophoton measurement for verifying the organic origin of eggs. In discriminant analyses egg samples of both studies were assigned to the categories 'organic' or 'conventional' according to their emission values. The hit ratio was about 70 %. This result is interesting considering the lack of techniques to distinguish between organically and conventionally produced eggs up to now. Optimization of measuring technique and procedure may improve the capability of the method. In any case, biophoton measurement could be used as a screening method. Detection of extremely low values would suggest a check of management conditions at the relevant farm, followed by comparison with standards for the respective animal husbandry system.
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    Verwendung männlicher Hühnerküken aus Legehybridherkünften zur Erzeugung von Stubenküken
    (2012) Sonder, Mirjam; Grashorn, Michael
    This Project referred to the announcement of a directive about the advancement of innovations to improve livestock breeding (Federal Ministry of Food, Agriculture and Consumer Protection). The aim of the study was the development of ethically justifiable methods within the scope of reproduction of laying hens. The purpose was to find an alternative to the present culling of one day old male layer chickens by using them as coquelets. In three trials, different layer breeds and different feeding regimes had been compared for their effects on performance, carcass characteristics and meat quality parameters. In general, by significantly reducing fattening duration an improvement in feed conversion and by this in profitability can be expected. The present study demonstrated the feasibility of coquelet production by using laying-type cockerels. An attractive product of good quality can be produced. Nevertheless, twice as high production costs than for conventional broiler will oppose a widespread marketing. Although, coquelet production contributes to animal welfare, it seems unlikely to convince consumers to pay these higher prices.