Effect of Fermented Rapeseed Meal on the Gastrointestinal Microbiota and Immune Status of Rabbit (Oryctolagus cuniculus)

SIMPLE SUMMARY: The unique digestive properties of rabbits consist of highly specialised communities of intestinal microbes that, unfortunately, make them susceptible to metabolic diseases. This is why breeders, to improve the functions of the digestive tract, often use special feed additives, i.e., probiotics, prebiotics or synbiotics. The need to become independent from soybean meal (SBM), which is currently the basic source of protein in animal nutrition, and the need to stimulate the gastrointestinal tract (GIT), has increased interest in fermented components that have a positive effect on the intestinal microbiota and are a source of valuable protein. In this study, the impact of the diversified proportion of fermented rapeseed meal (FRSM) in the diet of rabbits on the immune parameters and the microbiota of the digestive tract was assessed. The reducing effect of the tested feed component against coliform bacteria and Escherichia coli within the small intestine and colon of animals and the anaerobic biota of Clostridium perfringens in the duodenum and cecum of animals was observed while in the duodenum—an increase in the beneficial biota of lactic acid bacteria. The conducted analysis also showed many complex correlations between the number of intestinal microbiota groups and the level of immunoglobulins. The results of the conducted research indicate that FRSM, in addition to valuable nutritional values, may play an important probiotic role in the GIT of rabbits. Research of this type is especially important in terms of reducing the use of antibiotics for therapeutic purposes through nutritional prevention of animals. ABSTRACT: The present study was conducted to determine the effect of the use of varying amounts of fermented rapeseed meal in diets for rabbits on the immune status and microbiota of segments of the GIT. Forty 35 day old rabbits used in the experiment were assigned to four groups: the control group (group C) were fed a standard diet and the experimental received 4%, 8% or 12% fermented rapeseed meal (included in place of standard soybean meal). Class A, G and M immunoglobulins were determined in the blood plasma. In the food content collected after slaughter, microbiological parameters were determined for individual sections of the digestive tract. Rabbits from the groups receiving a diet with an increased proportion of fermented rapeseed meal (8% or 12%) had lower concentrations of anaerobic bacteria and Escherichia coli in the intestinal contents. Research has shown that the increase in intake of fermented rapeseed meal was correlated with an increase in the correlations between the immunoglobulin level and the size of the microbial population in the GIT. In light of the presented results fermented rapeseed meal, by supplying valuable bioactive substances, appears to be a good component in the diet of rabbits, enhancing immune system development and helping to prevent disturbances of the gut microbiota.