Comparison of average daily gain, apparent digestibility, rumen fermentation parameters and bacterial communities, and serum antioxidant indices in Leizhou goats fed with or without rumen-protected fat

Introduction: Rumen-protected fat (RPF) is a vital dietary energy source for dairy cows. However, the influences of RPF on rumen volatile fatty acid (VFA) content and bacterial communities in goats are poorly documented.

Methods: In this study, 12 castrated male goats (body weight [BW]: 13.3 ± 0.02 kg; 6 months of age) were used as the experimental animal and then allocated into two groups (n = 6): a control group, fed a basal diet without RPF supplementation, and the RPF supplementation group, fed a basal diet with 2.4% RPF supplementation.

Results: The final BW and ADG were higher (p < 0.05) and the ratio of dry matter (DM) intake to ADG was lower (p < 0.05) in the 2.4% RPF supplementation group compared with those in the control group. The 2.4% RPF supplementation group showed a higher total tract digestibility of DM, CP, OM, neutral and acid detergent fiber compared with that of the control group (p < 0.05). The proportion of acetate was higher (p < 0.05) and that of propionate was lower (p < 0.05) in the 2.4% RPF supplementation group compared with those in the control group. The relative abundances of Christensenellaceae_R-7_group, unclassified_f__Selenomonadaceae, norank_f__Selenomonadaceae, Quinella, norank_f__Bacteroidales_RF16_group, and unclassified_o__Bacteroidales were higher (p < 0.05) and those of Lachnospiraceae_NK3A20_group, norank_f__F082, Olsenella, Erysipelatoclostridiaceae_UCG-004, and Syntrophococcus were lower (p < 0.05) in the 2.4% RPF supplementation group compared with those in the control group.

Discussion: In conclusion, 2.4% RPF supplementation can improve the ADG and antioxidant capacity by regulating the rumen bacterial communities and enhancing the apparent total tract digestibility in growing Leizhou goats.