Effect of un-degradable protein supplementation on semen quality of buffalo bulls under heat stress conditions

摘要

A study was conducted to investigate the effect of feeding un-degradable protein (UDP) supplement on the semen quality of buffalo bulls during hot and humid part of summer season in Peshawar. Six Nili-Ravi buffalo bulls maintained at a semen production unit, Peshawar were randomly divided into two equal groups (control and treatment). Both groups were fed a basal diet of maize fodder (15 Kg/day/bull) and wheat straw (6 Kg/day/bull). Bulls in the control group received 5 kg/day/head of a commercialconcentrate while the treatment group was fed 3 Kg commercial concentrate and 1 Kg UDP supplement. Both supplements were iso-nitrogenous and provided 150g nitrogen/head/day. The diets were fed in a switch over design over two periods. Each period lastedfor 32 days. One-week adaptation period was allowed at the start of each experimental period. In-sacco protein degradability at 12 hours incubation for commercial concentrate and UDP supplement was 72.87 and 43.46 percent, respectively. Mean ambient temperature, humidity and temperature-humidity-index were 32.01 deg C, 66.66 percent and 84.97, respectively. Semen volume of bulls in the control and treatment groups did not vary and averaged 6.87 +- 0.41 and 7.41 +- 0.56 ml/collection day with a mean sperm concentration of 1004.5 +- 69.06 and 969.14 +- 77.88 X 10~6/ml, respectively. Number of defective sperms (head abnormalities, mid-piece defects, proximal droplet and tail defects) in the control and treatment groups was not different. Feeding of UDP supplement did not influence the blood concentrations of calcium, phosphorus, urea and glucose. The absence of UDP effect on semen volume and quality could be attributed to low thermal stress, feeding small quantity of UDP and less number of replicate bulls used in the present study.