r EFFECT OF BYPASS PROTEIN ON YIELD AND COMPOSITION OF MILl'" IN CROSS BRED COWS g, V.H. KALBANDE THESIS csubfl21rledin parlia./ ft#benl 0/ L6e reruire.menl/or l./le degree DOCTOR OF PHILOSOPHY!7acu/iy o/ve/erincj..ry and!7/rd.ma./ csc1ences.jeerala!7lgr1cuhura/ Q/ni'oers 1y..', Department of Animal Nutrition COllEGEOf VETERINJ.\RY J.\NDJ.\~UN\AlSCIENCES. Mannuthy -Trichur 1QQS
CERTIFICATE Certified that this thesis entitled "EFFECT OF BYPASS PROTEIN ON YIELD AND COMPOSITION OF MILK IN CROSSBRED COWS" is a record of research work done independently by Shri. Vijay Hanumantrao Kalbande, under my guidance and supervision and that it has not previously formed the basis for the award of any degree, fellowship or associateship to him. Mannuthy, I 12.6.1995. Dr. C.T. 'Thomas Chairman, Advisory Committee Profesqor and Head Department of Animal Nutrition College of veterinary and Animal Sciences Mannuthy
ABS TRACT 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 yuinea (panicum max irnum), para (Brachiaria mutica) and napier grass (pennisetum ~ureum) 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 bra~, 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 Undegradable Dietary Protein (UDP) of 37:63, 52:48 and 70:30 in isonitrogenous' and isoc~loric 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 hi~her 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, propionate 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 partum. The food consumption-of the animals was found post' increase with increasing UDP levels in concentrate mixtures, to the percentage dry matter intake of animals calculated the entire period of experiment and being 3.70, 3.38 over 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 10,0 days, those fed concentrate mixtures with levels of 847.55 and 29.75 per cent lost respectively UDP 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 to be 10.11, 7.18 and 6.32 kg respectively for groups fed found concentrate mixtures with high, medium and low UDP levels. The on results on milk composition as influenced by varying levels in concentrate mixtures revealed that while milk percentage was not altered with degradability changes UDP fat 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 production was also found to be higher with higher UDP over the entire period of ~he experiment. The income milk levels 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 with UOP that based 25.28 the three concentrate mixtures of high, medium and low levels respectively. The overall results clearly revealed in medium producing Jersey crossbred cows on a grass 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 TON for higher production and better economic efficiency in their early part of lactation.