Effect of Grape Pomace Powder, Mangosteen Peel Powder and Monensin on Nutrient Digestibility, Rumen Fermentation, Nitrogen Balance and Microbial Protein Synthesis in Dairy Steers

Effect of Grape Pomace Powder, Mangosteen Peel Powder and Monensin on Nutrient Digestibility, Rumen Fermentation, Nitrogen Balance and Microbial Protein Synthesis in Dairy Steers

Animal Bioscience, December 2015

26954113

S. Foiklang, M. Wanapat, T. Norrapoke

This study was designed to investigate the effect of grape pomace powder (GPP), mangosteen peel powder (MPP) and monensin on feed intake, nutrients digestibility, microorganisms, rumen fermentation characteristic, microbial protein synthesis and nitrogen balance in dairy steers. Four, rumen fistulated dairy steers with initial BW of 220±15 kg were randomly assigned according to a 4×4 Latin square design to receive four treatments. The treatments were as follows: T1 = control, T2 = supplementation with monensin at 33 mg/kg diet, T3= supplementation with GPP at 2% of DMI and T4 = supplementation with MPP at 30 g/kg diet. The steers were offered the concentrate diet at 0.2 % BW and 3% urea treated rice straw (UTRS) was fed ad libitum. It was found that GPP supplemented group had higher UTRS intake and nutrient digestibility in terms of NDF and ADF than those in control group (P<0.05). Ammonia nitrogen (NH3-N) and BUN concentration were higher in monensin, GPP and MPP supplemented group (P<0.05). Total VFA and propionate in the GPP group were higher than those in the control group (P<0.05) while acetate concentration, and acetate to propionate ratio were decreased (P<0.01) when steers were supplemented with GPP, monensin and MPP, respectively. Moreover, protozoal population in GPP, MPP and monensin supplementation were significantly lower than those in the control group (P<0.05), while cellulolytic bacterial population was significantly higher in the control group (P<0.05). Nitrogen retention, microbial crude protein and efficiency of microbial nitrogen synthesis were found significantly higher in steers received GPP (P<0.05). Based on this study it could be concluded that the GPP is potential to be used as an alternative feed supplement in the concentrate diets which resulted in improved rumen fermentation efficiency, digestibility and microbial protein synthesis in steers fed on treated rice straw.