The objective of this trial was to evaluate the effect of different dietary fat sources on intake, digestibility, and plasma urea N in feedlot water buffalo steers. Thirteen castrated Murrah steers averaging 297±9 kg of body weigh were assigned to one of the following three treatments: no added fat (control), soybean oil or whole soybean in a completely randomized design. The experiment lasted 84 days with three experimental periods of 28 days each. Samples of feeds, orts and feces were collected in the last six days of each period for determination of intake. Diets were fed twice a day (8 a.m. and 4 p.m.) as total mixed ration and the amount of feed offered was adjusted daily to yield refusals equal to approximately 10 to 20% of intake. Intakes of DM and CP were greater in the control compared to treatments supplemented with fat while the opposite was observed for ether extract intake. Apparent total tract digestibility of dry mater did not differ across treatments but animals fed the diet containing soybean oil had the lowest fiber digestibility. Feeding whole soybean to feedlot steers had no negative impact on fiber digestibility showing that the polyunsaturated fatty acids of this fat source were less available in the rumen. It can be concluded that the higher energy content of diets supplemented with fat sources increased DM intake but feeding soybean oil reduced fiber digestibility in this study.
water buffaloes; feedlot; whole soybean; soybean oil
