Effect of supplementation of Lactobacillus brevis postbiotics on nutrient digestibility, growth and intestinal health in growing mink

The present study was conducted to evaluate the effects of dietary supplementation with Lactobacillus brevis postbiotics on growth performance and intestinal health in growing male mink. A total of 88 male white mink was selected and randomly allocated into four treatments, each with 11 replicates of 2 mink. The mink in the four treatments received a basal diet supplemented with 0 % (control), 0.05 %, 0.1 %, and 0.15 % Lactobacillus brevis postbiotics, respectively. Compared to the control group, 0.1 % Lactobacillus brevis postbiotics decreased feed to weight ratio during the 0–8 weeks period ( P < 0.05) and increased average daily gain during 0–4 and 0–8 weeks of the experiment ( P < 0.05), resulting in greater body weight ( P < 0.05). Compared to the control, all Lactobacillus brevis postbiotics treatments had greater the ether extract apparent digestibility, secretory immunoglobulin A, and less interleukin 6 (all P < 0.05). The 0.05 % and 0.1 % Lactobacillus brevis postbiotics treatments exhibited higher apparent digestibility of crude protein and glutathione peroxidase capacity ( P < 0.05). The 0.1 % and 0.15 % Lactobacillus brevis postbiotics treatments had greater interleukin 10 levels and trypsin activity ( P < 0.05). The 0.05 % Lactobacillus brevis postbiotics treatment had less interleukin 1 beta levels ( P < 0.05 ) . Compared to the control group, dietary supplementation with 0.1 % Lactobacillus brevis postbiotics significantly enhanced duodenal villus height, the villus height to crypt depth ratio, and jejunum villus height ( P < 0.05), decreased crypt depth. Compared to the control group, the abundance of Lactococcus increased and Paraclostridium declined in all Lactobacillus brevis postbiotics supplementation treatments, and 0.1 % Lactobacillus brevis postbiotics treatment increased the abundance of Sphingomonas ( P < 0.05). Based on these results, dietary supplementation with 0.1 % Lactobacillus brevis postbiotics is recommended for growing male mink. Quadratic regression analysis of growth performance and immune responses in relation to Lactobacillus brevis postbiotics inclusion levels indicate an optimal range of 0.091–0.114 %.