Effect of dietary inclusion of cashew nut shell liquid on metabolic functions of rumen bacteria in West African dwarf goats

Abstract

This study investigated the effect of dietary inclusion of cashew nut shell liquid (CNSL) on rumen microbial metabolic functions in West African dwarf goats. Twenty-four West African dwarf goats were divided into four groups of six animals each. Each group of animals was fed a basal diet of Panicum maximum and supplemented with one of four concentrate pellets containing CNSL at the rate of 0, 2, 4 and 6 ml/kg in a completely randomized design. Rumen fluid samples (n=6/animal) were collected from each animal after 60 days of feeding to assess the rumen metabolic functions in response to CNSL using the 16S rRNA metagenomic approach. Results revealed that the function of ammonia oxidizers was prominent while chitin degradation ranked least. The inclusion of 4 and 6 ml/kg of CNSL in supplemental diets for goats increased (P < 0.05) the function of xylan degraders while ammonia oxidizers, dehalogenation, nitrite reducers, methanogens amongst others were unaltered (P > 0.05). It can be concluded that 4 6 ml/kg of CNSL in supplemental pellets for goats enhanced xylan degraders implying higher hemicellulolytic functions which has implication for increased hemicellulose degradation in the rumen.