Fermented Chinese Herbal Medicine Promoted Growth Performance, Intestinal Health, and Regulated Bacterial Microbiota of Weaned Piglets

To investigate the effects of fermented Chinese herbal medicine on growth performance, diarrhea rate, nutrient digestibility, and intestinal health of weaned piglets, and to provide the theoretical basis for applying fermented Chinese herbal medicines to weaned piglet production, a total of 162 weaned and castrated piglets at 25 days of age (Duroc × Landrace × Yorkshire, half male and half female) with an initial body weight of 7.77 ± 0.03 kg were randomly divided into the following three groups according to the principle of similar body weight: basal diet (CON) group, basal diet + 3 kg/t fermented Chinese herbal medicine (LFHM) group, and basal diet + 5 g/kg fermented Chinese herbal medicine (HFHM) group. Each group underwent six replicates and there were nine piglets in each replicate. The experiment lasted 24 days, i.e., 3 days for preliminary feeding, and 21 days for the experiment. From Day 1 of the experiment, the piglets were observed and recorded for diarrhea each day. As compared with the CON group, the results indicated: Following the addition of fermented Chinese herbal medicine, the piglets in the LFHM and HFHM groups increased final weight (FW); average daily feed intake (ADFI); average daily gain (ADG) (p < 0.01); apparent digestibility of crude protein (CP) (p < 0.05); as well as chymotrypsin, α-amylase, and lipase activities (p < 0.01). In addition, α-amylase activity in the LFHM group was higher than that in the HFHM group (p < 0.05); chymotrypsin activity in the LFHM group was lower than that in the HFHM group (p < 0.05); as compared with the CON group, the LFHM and the HFHM increased villus height (VH) and crypt depth (CD) in piglet jejunum; isovaleric acid concentration with the HFHM was higher than those with the CON and the LFHM (p < 0.05), but butyrate concentration with the HFFM was lower than those with the CON and the LFHM (p < 0.05). The high-throughput 16S rRNA sequencing of intestinal microbiota results showed that the LFHM and the HFHM affected the microbial α diversity index in weaned piglet colon (p < 0.01). In conclusion, fermented Chinese herbs can improve the growth performance of weaned piglets by promoting the secretion of intestinal digestive enzymes, changing intestinal microbial diversity, regulating the contents of intestinal short chain fatty acids (SCFAs), promoting intestinal health, and improving nutrients digestibility.