Partially substituting roughage with traditional Chinese herbal medicine residues in the diet of goats improved feed quality, growth performance, hematology, and rumen microbial profiles

This study aimed to reveal the effect of traditional Chinese herbal medicine residues (TCHMR) on growth performance, hematology, ruminal microbiota, and economic benefits of Guizhou black male goats through the fermented total mixed ration (FTMR) diet technique. A total of 22 Guizhou black male goats with an initial weight of 21.77 ± 0.85 kg were randomly divided into 2 groups (n = 11), with 11 goats in each group. The control group (CON) was fed a traditional total mixed ration (TMR) diet without the TCHMR. The TCHMR group was fed an FTMR diet containing 40%TCHMR. Compared with the CON group, the results showed that the incorporation of TCHMR into goat diets reduced feeding costs and Feed conversion ratio (FCR). On the contrary, it improved (P < 0.01) feed quality, apparent digestibility of Dry matter (DM), Crude Protein (CP), Neutral detergent fiber (NDF), average daily gain (ADG), and dry matter intake. Interestingly, TCHMR also reduced (P < 0.01) acetate levels in the rumen of goats. Supplementally, TCHMR significantly increased (P < 0.01) the levels of GH, IgM, IgA (p < 0.05), and IFN-γ (P < 0.05), while significantly reducing (P < 0.01) the levels of IL-6, ALT, and AST in serum. Notably, at the phylum level, TCHMR significantly reduced (P < 0.01) the abundance of Bacteroidota and increased (P < 0.01) the abundance of Firmicutes. Moreover. at the genus level, TCHMR significantly reduced (P < 0.01) the abundance of Prevotella, F082, and Bacteroidales_RF16_group, while Muribaculaceae, Proteus, Lachnospiraceae_ND3007_group, and Ruminococcus were increased (P < 0.01). In conclusion, our current findings indicated that 40% TCHMR improved feed quality and the apparent digestibility of nutrients. Additionally, 40% TCHMR improved the growth performance and immunity of Guizhou black male goats, while also reorganizing the composition of ruminal microbiota. So far, under the conditions of this experiment, we have not found any negative effects of 40% TCHMR on goats. This study will be a new idea for developing feed resources, which will reduce environmental pollution and the cost of animal husbandry.