Browsing by Subject "Meal"

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    Jatropha meal and protein isolate as a protein source in aquafeed
    (2011) Kumar, Vikas; Becker, Klaus
    As aquaculture continues to develop, there will be an increasing need to use alternative plant proteins in aquaculture diets so that aqua eco-systems will be sustainable. Jatropha (DJKM, H-JPKM and DJPI) can be used as protein rich sources in the diets of fish and shrimp. There is a high potential for the safe use of DJKM, H-JPKM and DJPI in diets for fish and shrimp without compromising performance, provided that these ingredients are free of toxic factors. The detoxification process developed in Hohenheim is simple and robust and produces products that are safe and of good quality. Their addition to fish and shrimp diets gave excellent performance responses without any ill effects on animal health or safety. Effects on growth and nutrient utilization: ? Detoxified Jatropha kernel meal, H-JPKM and DJPI could replace 50%, 62.5% and 75% fish meal protein respectively without compromising growth performance and nutrient utilization in fish. In addition, DJKM could also replace 50% fish meal protein with no adverse effects on growth and nutrient utilization in shrimp. If the replacement levels are exceeded, the producer must examine the nutrient profile of the feeds carefully to ensure that desired production levels can be achieved and fish and shrimp health maintained. ? High inclusion (>50% fish meal protein replacement) of DJKM decreased the efficiency of conversion of feed to body mass. This could be explained partly by the increased mean feed intake which was possibly a reaction to the reduced protein retention, measured as protein efficiency ratio and protein productive value. No such effects were seen with the use of DJPI in common carp diets. ? Increased DJKM inclusion in diets caused a significant lowering of protein, lipid and energy digestibilities. No such effects were seen when DJPI was used in common carp diets. Effects on energy budget: ? Feeding DJKM and H-JPKM to common carp and Nile tilapia respectively did not change the major components of the energy budget (routine metabolic rate, heat released and metabolisable energy) compared to fish meal and soybean meal fed groups. These results revealed that dietary protein sources DJKM and H-JPKM can be efficiently utilized for growth by common carp and Nile tilapia respectively, as well as soybean meal and fish meal. Effects on expression of growth hormone and insulin-like growth factor-1 encoding genes ? As the level of DJKM inclusion increased in the common carp diet, growth rate decreased. The expression of Insulin-like growth factor-1 (IGF-1) in liver also decreased with increase of DJKM in the diet and that of the growth hormone in liver decreased. Effects on clinical health parameters and gut health: ? No mortality and unaffected haematological values suggested the fish were all in normal health. Alkaline phosphatase and ALT activities; urea nitrogen, bilirubin and creatinine concentration in blood were in the normal ranges which showed that there was no liver or kidney dysfunction. ? The measured plasma nutrient levels gave no indications of stress, but increasing the level of plant protein in the diet decreased plasma cholesterol. This may be related to high NSP content or reduced dietary intake of cholesterol. Decrease in muscle cholesterol level is also expected which could be considered good for human health. ? Histopathological evaluation of organs showed no damage to the stomach, intestine or liver of common carp or rainbow trout. Effects of Jatropha-phytate in Nile tilapia The defatted Jatropha kernel meal obtained after oil extraction is rich in protein (58−66%) and phytate (9 −11%). The phytate rich fraction was isolated from defatted kernel meal using organic solvents (acetone and carbon tetrachloride). It had 66% phytate and 22% crude protein and its inclusion in fish diets showed the following: ? Negative effects on growth performance, nutrient utilization and digestive physiology (nutrient digestibility and digestive enzymes). ? Adverse influences on biochemical entities such as metabolic enzymes (alkaline phosphatase and alanine transaminase) and electrolytes/metabolites. Salient changes include decreased red blood cell count and hematocrit content, decreased cholesterol and triglyceride concentrations in plasma and decreased blood glucose levels. The adverse effects observed may be due to the interaction of phytate with minerals and enzymes in the gastro intestinal tract, resulting in poor bioavailability of minerals and lower nutrient digestibility. The level of phytate used in the present study (1.5 and 3.0%) corresponds to 16.5% and 33.0% of DJKM in the fish diet. The DJKM at levels > 16.5% in the diet would exhibit adverse effects in Nile tilapia. Addition of phytase to the phytate containing diets would mitigate the adverse effects of at least up to 3% Jatropha phytate (or 33% DJKM) in the diet. Addition of phytase (1500 FTU/kg) in diets containing DJKM is recommended to maximize their utilization by Nile tilapia.
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    Untersuchungen zur Variation und Rhythmik der individuellen Futteraufnahme bei Pekingenten in Gruppenhaltung
    (2003) Bley, Tobias Alexander Georg; Bessei, Werner
    Methods to record feed intake in group reared individuals were only available for larger domestic species, such as pigs and cattle. Similar equipment for ducks using an antenna-receiver system had to be developed for the present study. The antenna was fitted nearby the feeder and the transponder was attached to the wing mark. The feeders were connected to an electronic scale and the following characteristics were recorded by a PC continuously: number of the bird, day, time of day, time of visits to the feeder, feed consumption. The system was suitable for duckling from 14 days old onwards. Two experiments were carried out. In experiment 1 a total of 50 male Pekin-type hybrid from 14 to 49 days of age were used. In experiment 2 records were taken from 480 male and female ducks of an experimental line from day 21 to 45. The birds were raised in groups on deep litter (straw). Commercial pelleted feed and water were provided ad libitum. The distance between feeders and drinkers was 1 m in experiment 1 and 5 m in experiment 2. The following traits were extracted from the records: Number of meals per day (defined as visits to the feeder with feed intake) Duration of meals (sec.) Size of meals (grams.) Intensity of feeding (feed intake in grams. per min): feed intake per meal in relation to duration of meal Duration of pauses (sec. or min.) Duration of feed intake per day (min.) Feed intake per day (grams.) Live weight (grams.) Dates of a total of 530 ducks and containing 260000 visits to the feeder were recorded and analysed On the basis of the duration of the frequency of meals per day two distinct groups, birds with large number of short meals (HM), and birds with a small number of big meals (LM), were identified. Comparisons were made between the two meal-type groups for all traits and the circadian rhythms of feed intake. HM ducks were characterised by short duration and small size of meals, and short pauses between meals. There was only a small difference between the meal-types for the total duration of feeding and feeding intensity. HM birds were lighter than LM birds. With increasing age, number of meals per day and duration of feeding per day decreased while daily feed consumption increased. Duration and size of meals, and intensity of feeding increased with age. Changes in feeding activities were most important between 3 and 4 weeks of age. An effect of sex was only noted for the number of meals at seven weeks of age. Differences in the occurrence of pauses were found in response to the experiment, meal-type and age. With regard to the presentation and analysis of pauses the usual procedures using log survivorship functions were discussed. In the present study, however, the differences in the distribution of pauses have been demonstrated using the relative frequency for the pauses of long duration and the cumulative frequency for the pauses of shorter duration. With regard to the high variation of the duration of pauses among individuals and with age the calculation of a single meal criterion, which separates pauses within and between meals, for all individuals and over all ages was not considered useful. On the basis of the distribution of pauses of the different meal-types it seems that the meal criterion is less than one minute in the HM types, and over 35 minutes in the LM types. The circadian rhythm of feed intake was similar in both meal-type groups and shows a biphasic shape with maxima at the beginning and the end of the light period. There was also feed intake during the dark period, the consumption, however, was lower than in the light period. The power spectra of the feed intake showed main components in the 24; 12; 6 and 4.8 hours rhythms and, in addition, various different rhythms in the area of 2-4 hours. The rhythm pattern was more pronounced in the HM types as compared to the LM types. The power of the 24 hours rhythms decreased with age, while a 6 hours rhythm developed at the end of the test period. In general it can be said, that there are distinct types of temporal structures in feeding behaviour in ducks. Age-depending changes appear mainly in the early fattening phase up to 5 weeks of age. There is no general meal criterion in ducks which may be applied to all individuals and at all ages. Feed intake underlies rhythmic processes which are modified with age.