The effect of partial replacement of soybean meal with fermented soybean meal on chicken performance and immune status

The aim of the study was to evaluate the effect of partial replacement of soybean meal (SM) with 3 or 6% of fermented soybean meal (FSM) on growth performance, gut microbiota, intestinal histology and immunity of chickens. In the study one-day-old male Ross 308 chickens raised to the age of 40 days were used. The experiment was carried out on 600 animals assigned to three experimental groups of 200 birds each (10 replications of 20 individuals each). In the control group (C), SM was the main source of dietary protein, whereas the chickens from FSM-3% and FSM-6% groups were fed diets in which SM was partially replaced with FSM at a dose of 3 and 6%, respectively. It was shown that partial replacement of SM with FSM (both 3 and 6%) improved the chicken growth performance and dressing percentage, and modulated the immune system. However, the introduction of a 6% dose of FSM was found to better improve the morphology of intestines (reflected by increased villi length and crypts depth) than a 3% FSM dose. It also contributed to a decrease in total number of fungi and coliforms in the jejunum. Based on the obtained results, it can be concluded, that it is better to use a 6% share of FSM in chicken feed, than a 3% share.