Response of Fumaric Acid Addition on Methanogenesis, Rumen Fermentation, and Dry Matter Degradability in Diets Containing Wheat Straw and Sorghum or Berseem as Roughage Source

An in vitro incubation system was used to evaluate effect of supplementation of fumaric acid at 0, 5, 10, and 15 mM concentration in high-, medium-, and low-fiber wheat straw containing total mixed diets with sorghum (Sorghum vulgare) and berseem clover (Trifolium alexandrinum L.) on rumen fermentation, methane production, and gas kinetics parameters. Three types of diets were prepared with different roughage and concentrate ratio (80 : 20, 50 : 50, and 20 : 80) by taking the representative samples. The roughage part composed of wheat straw (70 parts) and sorghum (30 parts) or berseem (30 parts) and the concentrate part composed of maize (33%), GNC (21%), mustard cake (12%), wheat bran (20%), deoiled rice bran (11%), mineral mixture (2%), and salt (1%). Fumaric acid was added in incubation medium to achieve final concentration of 0, 5, 10, and 15 mM. All the treatment combinations were arranged in 4 × 3 factorial designs with three replicates. It was concluded from the study that fumaric acid addition (5-15 mM) in diets varying in roughage to concentrate ratio significantly (P ≤ 0.05) reduced the methane production without affecting dry matter digestibility and maximum reduction was noticed at 5 mM concentration.