Effect of different levels of raw and fermented cottonseed meal on performance, gastrointestinal microbial population, and some blood parameters of laying hens

The effects of feeding fermented cottonseed meal on performance, egg quality characteristics, gastrointestinal microbial population, and blood serum parameters were studied in a completely randomized design with nine treatments, six replicates, and 12 birds per replication using 648 Hy-Line W-36 laying hens. Raw cottonseed meal was fermented with a liquid mixed culture containing Lactobacillus plantarum, Bacillus subtilis, and Saccharomyces cerevisiae with a ratio of one to 1.2. The experimental treatments included replacing 7.5, 15, 22.5, and 30 percent of the raw or fermented cottonseed meal with soybean meal in the diet. After seven days of fermentation, free gossypol content of cottonseed meal was reduced from 985 to 107 mg/kg (P<0.05). The use of different levels of fermented cottonseed meal in the diet increased egg production percentage and egg mass and decreased feed conversion ratio compared to raw cottonseed meal (P <0.05). The eggshell strength in hens fed diets containing fermented cottonseed meal was higher than control birds and chickens receiving diets containing raw cottonseed (P <0.05). Feeding the diets containing different levels of fermented cottonseed meal significantly increased lactic acid bacteria population in crop and cecal of laying hens (P <0.05). Blood cholesterol concentration was lower in birds receiving diets containing fermented cottonseed meal than in other birds (P <0.05). The results of this research showed that replacing fermented cotton meal up to 30% with soybean meal in the diet of laying hens improves the parameters of eggshell quality, microbial flora in the gastrointestinal tract, and blood cholesterol of laying hens without negatively affecting performance.