Effects of Rumen-Protected Methionine and Lysine on the Fecal Microbiota of Leizhou Goats

This study investigates the effects of rumen-protected methionine and lysine (RPML) on the fecal microbiota of Leizhou goats, focusing on growth performance and fecal microbial community composition. A total of 10 three-month female Leizhou goats (9.90 ± 0.08 kg) were randomly assigned to one of two dietary treatments: a CON group fed a basal diet and an RPML group receiving the basal diet supplemented with 1.5 g/d/head of rumen-protected methionine and 4.5 g/d/head of rumen-protected lysine. Results indicated that RPML significantly enhanced average daily gain (ADG) and final body weight (FBW), as well as significantly decreased the ratio of dry matter intake (DMI) to ADG (<i>p</i> < 0.001). Fecal microbiota composition showed a decrease in abundance of <i>UCG-005</i>, <i>Phascolarctobacterium,</i> and <i>norank_f__Bacteroidales_RF16_group</i> and an increase in others like <i>Christensenellaceae R-7</i> and <i>unclassified_c__Clostridia</i> (<i>p</i> < 0.05). Moreover, the correlations between the abundance of certain bacterial genera and the concentrations of short-chain fatty acids (SCFAs) suggest that the modulation of the gut microbiota is associated with improved growth performance and feed efficiency in Leizhou goats, indicating that RPML supplementation can modulate the gut microbiota to improve growth performance and feed efficiency in Leizhou goats.