Effect of feeding graded levels of bypass protein on nutrient utilization, nutrient partitioning and on performance of lactating crossbred cows

摘要

Three groups of 5 lactating crossbred cows were fed on three isonitrogenous concentrate mixtures varying in RDP/UDP ratio, viz. 71:29 (T_1), 58:42 (T_2) and 44:56 (T_3), along with green maize and wheat straw given as 2/3 and 1/3 of total roughage respectively, for a period of 120 days. The dry matter intake was significantly (P<0.01) lower for T_1 than for T_2 and T_3. The average fat corrected milk yield (kg/d) was significantly (P<0.05) higher in T_3 (10.47+-1.00) than T_2 (9.81+-0.95) and T_1 (9.68+-0.90). The plasma insulin concentration (uU/ml) and alpha-amino acid N (mg/l) showed a significant (P<0.05) increasing trend from day 1 to day 120 of blood collection in all the treatments, with the highest values being recorded for T_3 and the lowest for T_1. Concentration of plasma growth hormone (GH) as (ng/ml) and non esterified fatty acids showed a significant (P<0.01) decreasing trend in all the treatments. Feeding of bypass protein increased FCM yield in medium producing crossbred cows. However, it failed to increase plasma GH concentration for partitioning of nutrients in favour of milk production.