Effect of fumaric acid supplementation on methanogenesis and rumen fermentation in Barbari goats

Methane production in barbari goats was studied using Open Circuit Respiration chamber. A metabolism trial followed by respiration chamber trial was conducted in adult male Barbari goats (mean body weight of 15 +/- 0.7 kg) which were divided into 3 groups (control, T-1 and T-2) of 2 each as per 2x3 switch over design. Animals were fed concentrate mixture and wheat straw in a ratio of 30: 70 to meet out their nutrient requirements (NRC 2007). Animals of treatment 1 and 2 were fed on a diet supplemented with fumaric acid (FA) @ 2.5 and 5% of DM intake, respectively. The rumen liquor collection for rumen fermentation parameters and a respiration chamber study was carried out after metabolism trial. There was no significant difference in rumen fermentation parameters (ammonia nitrogen, total nitrogen, TCA-precipitable nitrogen, TVFA and protozoal counts) among 3 groups due to FA supplementation. However, linear increase in rumen pH with increasing levels of FA supplementation was highly significant (P<0.01). Production of methane (L/d) did not differ significantly among the groups. But when expressed as L/kg DM intake, methane production was significantly (P<0.05) reduced (18.45 and 14.97%) in FA supplemented group as compared to control group. The results showed that FA supplementation (@ of 2.5 and 5.0% of DMI) reduced substantially methane production (L/kg DMI) without altering rumen fermentation pattern in the Barbari goats.