Chitosan as a feed additive: Its modulatory effect on methane emission and biohydrogenation under artificial rumen system

Abstract

This study aimed to determine the effects of chitosan addition on methane emission, fatty acid biohydrogenation and fermentation profile of rumen simulation technique (rusitec). Four studies reported chitosan use as a feed additive in the rusitec system were integrated into a database. Treatments were categorized into control (no chitosan addition) and chitosan addition at different levels. Various studies were treated as random effects whereas treatments were considered as fixed effects. Data were analyzed by using mixed model methodology. Significance was declared when P<0.05 and tendency was stated when P<0.1. Results showed that chitosan addition reduced methane emission in comparison to control by as much as 28% (P<0.05). Total volatile fatty acid concentration was not altered due to chitosan, but acetate proportion was decreased (P<0.05) while propionate proportion tended to elevate in the addition of chitosan (P<0.1). Chitosan did not influence ruminal pH, ammonia concentration and nutrient digestibility (organic matter, crude protein and neutral detergent fiber) of substrate. Proportions of vaccenic acid (P<0.01) and conjugated linoleic acid (P<0.001) were increased by the addition of chitosan. In conclusion, chitosan may provide beneficial effects in the rumen by mitigating methane emission and elevating fatty acids contributing to human health.