Authors : Shengchang Chen, Pramote Paengkoum, Xianlin Xia and Pongchan Na-Lumpang
Abstract: Six male growing Thai-indigenous beef cattle with Body Weight (BW) of 154±13.18 kg were randomly assigned in replicated 3x3 Latin square design and fed with differences levels Crude Protein (CP) Total Mixed Ratio (TMR) diets. Crude Protein (CP) levels in diets were 4, 7% and 10% base on Dry Matter (DM), respectively. Dry Matter Intake (DMI) increased iinearly (p<0.01) with increasing crude protein concentration. There was not significantly different (p>0.05) digestibility of DM, Organic Matter (OM), Acid Detergent Fiber (ADF) and Neutral Detergent Fiber (NDF). Ruminal ammonia nitrogen (NH3-N) concentration increased (p<0.01) with increasing CP level. Rumen pH, total VFA, acetate, propionate and butyrate were not affected by CP levels (p>0.05). Nitrogen (N) intake, urinary N excretion, N digestibility, N retention (g day-1) and N retention (Percentage of N intake) increased linearly with increasing dietary CP levels (p<0.05) and was affected significantly (p<0.01) by diet of CP levels, respectively. However, the fecal N excretion was not affected (p>0.05) by dietary CP levels. The CP for maintenance requirement in growing Thai-indigenous beef cattle was 3.54 g kg-1 BW0.75 which was estimated by using linear regression of N retention and N intake.
Shengchang Chen, Pramote Paengkoum, Xianlin Xia and Pongchan Na-Lumpang, 2010. Effects of Dietary Protein on Ruminal Fermentation, Nitrogen Utilization and Crude Protein Maintenance in Growing Thai-indigenous Beef Cattle Fed Rice Straw as Roughage. Journal of Animal and Veterinary Advances, 9: 2396-2400.