Enteric methane emission from ruminant livestock reduces the efficiency of feed energy utilization and contributes to global warming. An experiment was conducted to investigate the effects of sunflower (SFL) oil supplementation on methanogenesis, volatile fatty acids composition and feed fermentation pattern by in vitro gas production (IVGP) test. SFL oil was examined at three concentrations (0, 0.4 and 0.8 ml/ 30 ml buffered rumen fluid). In vitro incubation was carried out with sorghum hay (200 ± 5 mg) as substrate in 100 ml calibrated glass syringes following standard IVGP protocol. Addition of SFL oil resulted in increase (p < 0.05) in total gas production and decrease (p < 0.05) in methane concentration in head space gas, irrespective of level of inclusion. Linear decrease (p < 0.001) in feed degradability was evident with increasing doses of oil. Acetate production decreased (p < 0.05) without affecting propionate, however, butyrate production increased (p < 0.05) with addition of oil, irrespective of doses. The ratio of acetate to propionate was reduced (p < 0.01) with addition of oils. It is concluded that sunflower oil supplementation exerted inhibitory effects on methane production; however, dry matter degradability was also reduced. Further studies need to be carried out with lower dose levels for their practical application in animal feeding practices.
Buffalo, Fatty acids, Methanogenesis, Rumen fermentation, Sunflower oil