Influence of solid state fermentation with Bacillus subtilis 67 strain on the nutritional value of rapeseed meal and its effects on performance and meat quality of broiler chickens

The study aimed to evaluate the influence of solid-state fermentation on the nutritional value and enzymatic activity of rapeseed meal and its effects on the performance of broiler chickens and meat quality, including physicochemical properties (proximate analysis, pH, water holding capacity), antioxidant capabilities, dipeptide composition of the meat and sensory traits. Three dietary treatments were evaluated using broiler chickens: a control without incorporation of rapeseed meal; a second treatment with the incorporation of 3% unfermented rapeseed meal; and a third with the incorporation of 3% rapeseed meal fermented with Bacillus subtilis 67. The study showed that fermented compared to unfermented rapeseed meal was characterized by a significantly higher content of dry matter, crude ash, crude fat and metabolic energy (P < 0.05), and a significantly lower content of crude fiber and glucosinolates (P < 0.05). The B. subtilis 67 strain shows cellulolytic and xylulolytic activity. Fermented rapeseed meal has a positive effect on body weight of birds, daily gain, and European Production Efficiency Factor (P < 0.05). Both rapeseed meal treatments significantly reduced the pH of leg muscles and the water-holding capacity of breast muscles (P < 0.05). The fermented meal had a negative impact on some sensory parameters of poultry meat. There was no significant influence of fermented rapeseed meal on the composition of dipeptides in poultry meat and its antioxidant status.