Effect of Concentrate Supplementation on Methane Emission from Grazing Goats

An experiment was conducted to study the effect of strategic concentrate supplementation on methane production in grazing goats using sulfur hexafluoride (SF₆) technique. Sixteen male Barbari goats (∼1 year age; BW 18.83±0.65 kg) were divided into two equal groups namely, CONT and SUPL in a completely randomized design. All animals were allowed grazing for 6–7 h on a pasture of known botanical composition. Additionally, goats of SUPL group were supplemented with 250g of concentrate pellet before grazing. After six weeks of experimental feeding, feed intake and digestibility of nutrients were estimated by indicator method. Rumen liquor samples were collected for assessment of fermentation metabolites. The results indicated no significant effect of concentrate supplementation on DM intake. There was significant improvement (P<0.05) in the digestibility of DM, OM and CP in SUPL goats with supplementation of concentrate pellet. There was lower ruminal pH and higher ammonia nitrogen value in SUPL goats as compared to CONT. Total volatile fatty acids were significantly (P<0.05) higher in SUPL group of goats. Lower acetate and higher propionate values were observed in the SUPL group. The mean daily methane emission (g) was similar in CONT (10.46) and SUPL group (10.04) of goats. However, methane production when expressed in relation to unit DM and digestible DM intake was reduced (P>0.05) by 7.57 and 22.12 percent in SUPL group in comparison to the CONT group. It is concluded that concentrate supplementation significantly improved the nutrient digestibility with no apparent effects on the methane production in grazing goats.