The Effect of Supplementation of Oak Tannin Extract on Digestibility, Metabolisable Energy, Methane Production and Ammonia Production in Lamb Diets

Abstract

The aim of current experiment was to determine the effect of supplementation of oak tannin extract on gas production, methane production, digestibility, metabolisable energy and ammonia production of lamb diets using in vitro gas production technique. Oak tannin extract was included into total mixed ration at the 0, 2, 4 and 6 % on a dry matter basis. Although supplementation of oak tannin had no significant effect on gas, methane whereas supplementation had a significant effect on ammonia production of lamb diets. Gas and methane production of total mixed rations ranged from 50.25 to 53.25 ml and 7.72 to 8.15 ml respectively. Ammonia concentration of mixed rations ranged from 54.97 to 62.67 mg/100 ml. The decrease in ammonia of lamb diets per g oak supplementation was 0.1263 mg /100 ml. Metabolisable energy and organic matter digestibility of lamb diets ranged from 10.42 to 10.80 MJ kg DM and 70.27 to 73.02 % respectively. This study clearly showed that oak tannin had an anti-proteolytic potential for ruminant animals and supplementation of oak tannin significantly reduced ammonia production without compromising digestibility of diets. Therefore, oak tannin can be used to manipulate the rate and extent of degradation of protein in the rumen. However, before large implication, oak tannin should be further investigated using in vivo experiment to determine the toxic level of oak tannin in ruminant animals.