Study On Solid Fermentation Techniques Of Cottonseed Protein And Effects Of Application Of Its Product In Carassius Auratus

Cottonseed meal is an important protein resources, which contain anti-nutritive factors that limit its use in compound feeds.In this paper, through the research of different strains of solid-state fermentation on gossypol and protein quality of cottonseed meal,we aim to improve the utilization ratio of cottonseed meal, alleviate the shortage of quality protein source, and use fermented cottonseed meal as a protein supplement in feeds for, crucian carp’s growth and the water quality improvements. This paper studies the effects of different strains on the degradation of free gossypol in cottonseed meal, and the process of Bacillus subtilis fermented cottonseed meal were also studied.A feeding experiment was conducted to investigate the effects of dietary soybean meal replacement by cottonseed meal on growth performance of the crucian carp. This study includes the three parts as follows:1 The effects of different strains on free gossypol content in fermented cottonseed meal.Cottonseed meal was fermented by bacillus subtilis, Bacillus licheniformis, Saccharomyces cerevisiae, and Lactobacillus. Compared with control group, the present results of this study showed that free gossypol content in other treatment group decreased 240.35mg/kg,380.24mg/kg,337.26mg/kg and 370.38mg/kg, respectively, which were decreased by 75.56%,61.34%,65.71% and 62.35%. These results dedicated that bacillus subtilis fermentation can obviously decrease free gossypol fermented cottonseed meal. Bacillus subtilis, Bacillus licheniformis, lactic acid bacteria and yeast on cottonseed meal were independently fermented, which can increase the content of crude protein.2 Effects of different strains on free gossypol content of fermented cottonseed mealThe orthogonal experiment was carried out to explore the effects of parameters (temperature, time, pH,inoculum size et al) on free gossypol content of cottonseed meal. The results indicated that the best fermented conditions were 39℃,60h, pH6.5 and inoculation of 5%. In this condition, free gossypol content decreased from 983.62 mg/kg to 150.00 mg/kg, detoxification rate was reached 84.80%.3 Effects of dietary soybean meal replacement by fermented cottonseed meal on growth performance of the crucian carpThis experiment was conducted to invetigate the effects of partial replacement of soybean meal by cottonseed meal in practical diets on growth weight rate, feed coefficient, feed intake, organ body ratio and water quality of crucian carp under the circulating waterindoor and the cage culture outdoor conditions. The results show that no significant differences were observed on growth performance of cucian carp. Regardless of indoor culture and outdoor breeding carp, the water ammonia nitrogen and nitrite content in fermented cottonseed meal groups were better than the control group, and within a certain range, the addition of fermentation products increased nutrient digestion and absorption rate, reduce the pollution to water quality, In order to improve of the quality of water.Under the conditions of this experiment, the optimum adding amount of fermented cottonseed was 11% of fermented cottonseed instead of 10% of soybean and 1% of fishmeal.