标题：Digestibility, Fermentation Characteristic, Protein Microbial Synthesis and Growth Performance of Beef Cattle Fed High Forage Ration with Lerak Extract Supplementation
摘要：This research was aimed to investigate the utilization of whole lerak extract to improve rumen fermentation, nitrogen retention and performance of beef cattle received high forage based ration. Experimental diet composed of forage (70%) and concentrate (30%). The in vivo study was conducted using 12 local beef cattle which were divided into three treatments ie three different levels of lerak extract (0, 100 and 200 mg/kg body weight) were added to the diet. Parameters measured were nutrient digestibility, volatile fatty acid (VFA) profile, NH3 concentration, microbial protein synthesis, feed intake and daily gain of beef cattle during 90 days of feeding trial. The addition of lerak extract up to the level of 200 mg/kg BW did not affect nutrient digestibility. Total VFA and propionate proportion increased (p<0.05) and the ratio of acetate: propionate decreased (p<0.05) with the addition of lerak extract. Concentration of NH3 in the rumen tended to decrease. Nitrogen retention, microbial protein synthesis, feed intake and daily gain of local beef cattle fed high forage ration tended to increase with the addition of lerak extract at the level up to 200 mg/kg BW. The addition of lerak extract at the level of 200 mg/kg BW increased average daily gain up to 12.5% compared to the control treatment.
