Combinations of nitrate, saponin, and sulfate additively reduce methane production by rumen cultures in vitro while not adversely affecting feed digestion, fermentation or microbial communities.
This study investigated the effects of saponin (0.6g/L), nitrate (5mM) and sulfate (5mM), alone and in combinations, on methanogenesis, rumen fermentation, microbial community, and abundances of select microbial populations using in vitro rumen culture. Combinations of nitrate with saponin and/or sulfate additively suppressed methane production, with the lowest reduction (nearly 46%) observed for the combination of all the three inhibitors. None of the treatments adversely affected feed digestion or rumen fermentation. All the inhibitors, either alone or in combinations, did not alter the abundances of total bacteria, Ruminococcus albus, or archaea. However, saponin, alone and together with nitrate and/or sulfate, increased the abundance of Fibrobacter succinogenes and Ruminococcus flavefaciens, but decreased that of protozoa. DGGE analyses revealed limited changes in both bacterial and archaeal communities by the treatments. The nitrate-saponin-sulfate combination may be an effective and practical strategy to mitigate methane emission from ruminants.
Department of Animal Sciences, The Ohio State University, Columbus, OH 43210, USA; Department of Animal Nutrition, West Bengal University of Animal and Fishery Sciences, 37 K. B. Sarani, Belgachia, Kolkata 700037, India. Electronic address: patra_amlan@yahoo.com.
Amlan Kumar
AK
Patra
Department of Animal Sciences, The Ohio State University, Columbus, OH 43210, USA. Electronic address: yu.226@osu.edu.
Zhongtang
Z
Yu
D000704:Analysis of Variance; D000818:Animals; D001105:Archaea / Q000187:drug effects / Q000378:metabolism*; D001419:Bacteria / Q000187:drug effects / Q000378:metabolism*; D058645:Denaturing Gradient Gel Electrophoresis; D004063:Digestion / Q000187:drug effects / Q000502:physiology; D005285:Fermentation / Q000187:drug effects; D054892:Metagenome / Q000235:genetics; D008697:Methane / Q000096:biosynthesis*; D064307:Microbiota / Q000187:drug effects / Q000502:physiology*; D009566:Nitrates / Q000494:pharmacology; D016133:Polymerase Chain Reaction; D025341:Principal Component Analysis; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012417:Rumen / Q000382:microbiology*; D012503:Saponins / Q000494:pharmacology; D013431:Sulfates / Q000494:pharmacology
D009566:Nitrates; D012336:RNA, Ribosomal, 16S; D012503:Saponins; D013431:Sulfates; D008697:Methane
Additive methane inhibition; Archaea; Cellulolytic bacteria; DGGE; qPCR