Authors : C. Yuangklang, K. Vasupen, S. Wongsuthavas and S. Bureenok
Abstract: Four male purebred Brahman bulls about 2 years olds were used in a 4x4 Latin square design. Their initial body weight was 151+13 kg (mean±SD). Treatments were 8.0, 10.0, 12.0 and 14.0% crude protein in total diets. Rice straw was used as main roughage sources. Animals were offered in form of total mixed ration. Feed intake was linearly decreased (p<0.05) as increased protein level. Digestion of DM, OM, NDF, ADF and EE were not significantly difference (p>0.05) among treatments. Nitrogen intake was 81.95, 103.0, 115.5 and 147.2 g day-1 in 8.0, 10.0, 12.0 and 14.0% CP in diets, respectively (p<0.05). Fecal nitrogen excretion was linearly enhanced (p<0.05) as increased protein level. Urinary nitrogen and total nitrogen excretions were significantly difference (p<0.05) among treatments. Apparent N digestibility was 67.53, 72.97, 80.60 and 78.78 % in 8.0, 10.0, 12.0 and 14.0% CP in diets, respectively (p<0.05; quadratic). Plasma urea nitrogen was linearly elevated (p<0.05) as increased protein level. In conclusion, it can be concluded that CP level 12.0% did increase apparent total tract N digestibility without any adversely effect on feed intake.
C. Yuangklang, K. Vasupen, S. Wongsuthavas and S. Bureenok, 2010. Effect of Protein Level on Nutrient Digestion and Nitrogen Utilization in Beef Cattle. Journal of Animal and Veterinary Advances, 9: 1776-1779.