LAUSR

The study was to evaluate replacing corn meal (CM) by corn gluten (CG) on intake, digestibility, ruminal fermentation, CH4 emissions and microbial abundance in goats. The experiment was performed using randomized block design with 2 dietary treatments (CM and CG with 400 g/kg DM each). Replacing CM with CG increased NDF and CP intake and decreased starch intake. Goats fed CG diet had lower ruminal dissolved hydrogen (dH2) (-43%, P = 0.009) and dissolved methane (dCH4) (-30%, P = 0.001) concentrations than those fed with CM diet. An interaction between treatment and time (P = 0.03) was observed for dH2S with an increase (P < 0.001) in dH2S concentration (CG versus CM, +63%, P < 0.001) happened at 2.5 h after morning feeding. Goats fed with CG diet had lower (P = 0.004) butyrate molar percentage, and greater (P < 0.01) ammonia concentration and molar percentage of valerate and isobutyrate than those fed with the CM diet. Goats fed with CG diet decreased (P = 0.01) CH4 emission expressed as g/d and g/kg DMI. Goats fed with CG diet decreased 16S rRNA gene copies of R. amylophilus (P = 0.003), and increased 18S rRNA gene copies of fungi (P = 0.05) and 16S rRNA gene copies of F. succinogenes (P = 0.03). In summary, replacing CM with CG decreases starch and increases fiber intake, and growth of fibrolytic fungi and F. succinogenes, and inhibits growth of R. amylophilus. An increase in sulfur content after replacing CM with CG provides additional H2 sink, which causes an increase in ruminal dH2S and reduction in CH4 emissions. Corn gluten could be an alternative feed to decrease the enteric CH4 emission in ruminant production.