Effects of Lactobacillus plantarum-fermented feed and postbiotics on the growth performance, digestibility, serum biochemistry, and caecal microbiota of chickens

This study explored the effects of Lactobacillus plantarum on the growth performance, digestibility, serum biochemical indicators, and intestinal health in dual-purpose chickens. A total of 192 one-day-old Xiangdong chickens were selected and randomly divided into four groups: the basal diet group (C1), the semi-wet feed group (T1), the fermented feed group (T2), the postbiotics group (T3), with six replicates per group and 8 chickens per replicate. The experiment lasted 42 days. The results show that, compared with the control group, the growth performance of the experimental groups was significantly increased, among which the postbiotics (T3) group had the best growth performance: the final body weight (FW) and average daily gain (ADG) were significantly increased (P < 0.05), and the average daily feed intake (ADFI) and feed conversion ratio (FCR) were significantly decreased (P < 0.05). The apparent digestibility of the experimental groups was significantly increased. The levels of aspartate aminotransferase (AST), creatinine (CRE), and low-density lipoprotein (LDL) in the serum of group T2 increased. The levels of serum albumin (ALB), AST, glucose (GLU), high-density lipoprotein (HDL), LDL, triglycerides (TG), and total protein (TP) in postbiotics group (T3) decreased, and the level of HDL/LDL ratio increased (P < 0.05). Compared to the control group, the intestinal morphology of the experimental groups was all improved. And the relative abundance of Firmicutes in the caecal chyme of chickens in groups T1, T2, and T3 increased (P < 0.05), while the relative abundance of Bacteroidetes decreased (P < 0.05). These results indicate that adding L. plantarum postbiotics to the diet can enhance the growth performance of Xiangdong chickens, promote the absorption of nutrients, improve serum biochemical indicators, improve intestinal morphology, alter the structure of the caecal microbiota, increase the relative abundance of dominant bacteria. The postbiotics have a greater effect than feed fermented by L. plantarum.