Impact of corn steep liquor on nitrogen fixation in urea treated wheat straw and its influence on feed consumption, digestion kinetics, nitrogen metabolism and milk yield in buffaloes

The 5 kg urea was dissolved in 50 litter water with or without Corn Steep Liquor (CSL) and this solution was uniformly sprayed on 100 kg wheat straw. This treated wheat straw was put into four different cemented pits and ensiled for a period of 5 days with air, temperatures of 35-45 degree C. In the control pit, the wheat straw was treated with 5% urea only. In the second, third and fourth pit, 3, 6 and 9% CSL on dry matter basis was added, respectively, to the 5% urea treated wheat straw. Each pit was covered with 4 niches thick layer of rice straw, followed by the plastic film covering which was plastered with a blend of wheat straw and mud to avoid any cracking on drying. Four buffalo bulls, each were formulated to contain 20 % concentrate and 80% urea treated wheat straw ensiled with or without CSL. The urea was used to make all diets iso- nitrogenous. Four buffalo bulls, each weighing 350 kg, fitted with ruminal cannulae, using 4x4 Latin Square Design, were used. All diets were mixed daily and fed twice daily at 75% of body weight for each feeding in restricted fed trial and animals were fed free of choice in ad libitum fed trial. The first 10 days were given for adaptation to the new feed followed by 7 days of sample collection. Data were analyzed as a 4 x 4 Latin Square Design with factorial arrangement of levels of CSL and duration of ensiling treatments. Dry matter, digestible DM, OM, CP, ADF and NDF intakes were the highest in animals fed diets containing urea treated wheat straw ensiled with 9% CSL and was the lowest in animals fed diets containing urea treated wheat straw ensiled without CSI, in ad libitum trial. A significant increase both in DM disappearance and rate of disappearance and a reduction in lag time of urea treated wheat straw ensiled with CSL was noticed. There were significant differences in ruminal ammonia (NH3) concentrations between diets containing urea treated wheat straw ensiled with or without CSL at 3, 6 and 12 h sampling periods. The concentrations of total ruminal volatile fatty acids (VFA), acetate, total, viable and cellulolytic bacteria were higher in the rumens of animals fed diets containing urea treated wheat straw ensiled with CSL than those fed diets containing urea treated wheat straw ensiled without CSL. The cellulolytic bacteria were isolated at higher dilutions (P less than 05) in animals fed diets containing 3, 6 and 9% CSL than those fed diets without CSL. In lactation trial, sixteen early lactating Nili-Ravi buffaloes, four animals in each group, were used in a Completely Randomized Design. Four experimental diets were formulated and urea treated wheat straw ensiled with or without CSL was the roughage used in the experimental diets. The WS35 diet was balanced to contain 35% urea treated wheat straw ensiled with 0 % CSL and WS45, WS55 and WS65 diets were formulated to have 45, 55 and 65% urea treated wheat straw ensiled with 9% CSL, respectively. All diets were formulated to be iso- nitrogenous and iso-energetic. Diets were mixed daily and fed twice a day at ad libitum intakes. The buffaloes were fed for 40 days. Dry matter intakes by buffaloes remained similar across all treatments. However, DM as a percent of body weight and digestible DM intakes were higher in WS65 diets when compared to WS35, WS45 and WS65 diets. The apparent DM digestibility was statistically significant across all diets. Apparent DM digestibility was the highest in animals WS35 diet and was the lowest in those fed WS45 diet. Milk yield (4% FCM) was the higher in buffaloes fed WS65, WS55 and WS45 diets than those fed WS35 diet. A tendency for a linear increase in milk production by cows fed diets with decreasing NSC concentration may be attributed to increasing fat in the diet to maintain NEL in the experimental diets. In conclusion, feeding of urea treated wheat straw ensiled with 9% CSL had no adverse effect on the milk yield and its composition. However, digestibility and ruminal data from short term trials are considered reliable, but lactation performance should be tested in continuous lactation trial (s) for long enough time to determine actual effects of formulating diets using fairly high (65%) level of urea treated wheat straw ensiled with CSL on milk yield and its composition, body weight loss and feed efficiency. Therefore, more information is needed before these diets should be recommended for use by the dairy farming community.