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Theses

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19952
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Subject: Animal Nutrition × End date: 1997 × Start date: 1990 × Type: Thesis × Thesis Type: Ph.D ×
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    ThesisItemOpen Access
    Optimum energy and protein requirements of broiler rabbits
    (Department of Nutrition, College of Veterinary and Animal Sciences, Mannuthy, 1995) Ganga Devi, P; KAU; James, C S
    A detailed investigation involving two series of growth studies spread over a period of 24 weeks in Soviet Chinchilla and Cross Bred rabbits was carried out to establish the optimum energy and protein requirements for growth and to ascertain the optimum age for economic slaughter. One hundred and eight weanling Soviet Chinchilla and 108 weanling cross bred (SC X NZW) rabbits formed the experimental subjects. Rabbits of each breed were divided into nine identical groups and maintained factorially on three levels of crude protein (CP) viz., 12, 16 and 20 per cent and digestible energy viz., 2000, 2500 and 3000 kcal/kg for over a period of 168 days involving metabolism and slaughter studies during 8th, 16th and 24th week of experiment and production traits along with associated characters were studied and the salient results are presented. Rabbits maintained on different energy protein combinations showed significant difference in growth rate (P <0.01). Both dietary energy and crude protein were found to influence the average daily gain. The highest rate of gain was achieved in animals maintained on ration containing comparatively higher DE and CP while lowest rate of gain was noticed in animals maintained on low energy, low protein diet. On further scrutiny of the data, an appreciably better and identical growth response was observed in animals maintained on ration containing 3000 kcal DE/kg with 16 per cent CP and ration containing 2500 kcal DE/kg with 20 per cent CP in both pure bred and cross bred rabbits. It is also noticed that for maximum growth rate a ration containing 2500 kcal. DE/kg need be sufficient as further increase in DE have not evinced any better response on ADG, which supports the view that for optimum biological response, a ration containing 2500 kcal DE/kg is sufficient for both pure bred and cross bred rabbits. As between the periods it was observed that the animals attained maximum ADG during the first 56 days of experiment and there after ADG gradually declines irrespective of the level of CP or DE in the ration. Both dietary energy and crude protein significantly influenced (P <0.01) the feed conversion efficiency of animals. Highest efficiency of feed conversion was noticed in rabbits maintained on Ration D containing 2500 kcal DE/kg and 20 per cent CP the values being 9.27 in SC and 8.85 in CB rabbits and further increase in DE from 2500 kcal/kg to the extent of 3000 kcal/kg did not contribute better feed efficiency. Data on feed efficiency further revealed that maximum efficiency was observed during the first eight weeks after weaning and there after there is a linear reduction in feed efficiency as the age advances, in all the nine dietary treatments. With regard to cost of production the maximum biological and economical efficiency could be observed in animals maintained on ration containing 2500 kcal DE/kg with 20 per cent CP and when the cost of production was evaluated in between the periods viz., 0-56 days, 56-112 days and 112-168 days, the cost efficiency is seen maximum during 0-56 days of experiment. Dry matter intake on percentage of body weight was found decreasing on increasing the dietary energy level. Haematological values were with in the normal range and were not significantly influenced by the dietary energy and protein levels. Digestibility of nutrients and percentage retention of nitrogen, calcium and phosphorus were significantly influenced by the dietary treatments with an increasing trend on increasing the dietary energy and protein level. From the metabolism studies carried out during 8th, 16th and 24th week of experiment, the percentage retention of nitrogen, calcium and phosphorus were found reduced on advancing the age of animals. Slaughter studies conducted at 8th, 16th and 24th week of experiment revealed that dressing percentage is directly proportional to the pre-slaughter weight of the animals. Higher dressing percentage is recorded in animals having higher body weight and vice-versa. Carcass yield were higher at 16th and 24th week of experiment than that at eighth week of experiment.
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    ThesisItemOpen Access
    Effect of bypass protein on yield and composition of milk in cross bred cows
    (Department of Animal Nutrition, College of Veterinary and Animal Sciences, Mannuthy, 1995) Kalbande, V H; KAU; Thomas, C T
    Experiments were carried out to evaluate common feeds and fodders based on their rumen degradability rates and to assess the effect of varying bypass protein levels in concentrate mixtures on rumen fermentation profile and yield and composition of milk in Jersey crossbred cows. The dry matter and nitrogen disappearance rates in respect of nine concentrate feed ingredients and five green roughages commonly used in cattle rations, were determined using nylon bag technique in rumen fistulated crossbred cows. The effective protein degradability rates for groundnut cake, gingelly cake, cotton seed cake, coconut cake, yellow maize, jowar, wheat bran, rice bran, tapioca flour, green maize (Zea mays), green jowar (Sorghum bicolor) and guinea (Panicum maximum), para (Brachiariamutica) and napier grass (Pennisetumpurpureum) were found to be 66.17, 78.89, 27.72, 19.93, 22.64, 47.96,74.16, 60.59, 68.83, 56.93, 58.80, and 35.74, 45.39 and 36.68 per cent respectively at a rumen outflow rate of 0.05 per hour. Among the four oil cakes, gingelly cake and groundnut cake were more degradable in the rumen, whereas, cotton seed cake and coconut cake were comparatively insoluble and more resistant to degradation and thereby better sources of bypass protein for ruminants. The results on degradability measurements with respect to energy feeds revealed that yellow maize contained the least amounts of both soluble and degradable nitrogen as compared to jowar, wheat bran, rice bran and tapioca flour. Wheat bran was found to have higher contents of both rapidly soluble and potentially degradable protein as compared to rice bran. Among the different green fodders tested for protein degradability measurements, cereal fodders like maize and jowar were found more soluble and degradable as compared to different grasses. The effect of three varying ratios (high, medium and low) of Rumen Degradable Protein (RDP) to Undergradable Dietary Protein (UDP) of 37:63, 52:48 and 70:30 in isonitrogenous and isocaloric concentrate mixtures on rumen fermentation profile was studied using rumen fistulated Jersey crossbred cows. Rumen pH and ammonia nitrogen concentrations were found to be lower with concentrate mixture containing a higher UDP level of 63.38 per cent when compared with those having medium and low UDP levels of 47.55 and 29.75 per cent respectively at all post feeding intervals. Total volatile fatty acid concentrations as well as the concentration of individual fatty acids viz., acetate, propoionate and butyrate were also found higher in animals fed on concentrate mixture with the highest UDP level. The effect of the three UDP/bypass protein levels in isonitrogenous and isocaloric concentrate mixtures on milk yield and milk composition was studied using eighteen medium producing Jersey crossbred cows in their early lactation period for 100 days starting from 5th day post partum. The food consumption of the animals was found to increase with increasing UDP levels in concentrate mixtures, the percentage dry matter intake of animals calculated over the entire period of experiment being 3.70, 3.38 and 3.14 respectively for groups fed on concentrate mixtures of high, medium and low bypass protein levels. While animals maintained on the concentrate mixture with the higher UDP level of 63.38 per cent recorded a total gain of 10.83 kg over a period of 100 days, those fed concentrate mixtures with UDP levels of 47.55 and 29.75 per cent respectively lost body weights to the extent of 3.33 and 5.83 kg over the same period of the experiment. The average daily milk yields were found to be 10.11, 7.18 and 6.32 kg respectively for groups fed on concentrate mixtures with high, medium and low UDP levels. The results on milk composition as influenced by varying UDP levels in concentrate mixtures revealed that while milk fat percentage was not altered with degradability changes both milk protein and total solids were found to increase corresponding to increase in UDP levels. The feed conversion efficiency of milk production as well as persistency of milk production was also found to be higher UDP levels over the entire period of the experiment. The income over feed cost per cow per day, calculated over the experimental period of 100 days were found to be Rs. 44.54, 29.91 and 25.28 with the three concentrate mixtures of high, medium and low UDP levels respectively. The overall results clearly revealed that in medium producing Jersey crossbred cows on a grass based diet, a UDP level of 63.38 per cent may be considered optimum in a concentrate mixture with 20 per cent CP and 70 per cent TDN for higher production and better economic efficiency in their early part of lactation.