Studies On Condition Optimization Of Cotton Seed Mill Solid State Fermentation With Asp.niger

As a kind of protein feed, CSM (cotton seed mill) has a great nutrition value. But because of toxic matter-free gossypol and some antinutrition, the application of CSM is limited as a portion of feed. In this experiment, CSM is fermented by Aspergillus niger, fermentation processing parameters are optimized respectively, and the content of free gossypol is reduced. So the availability of CSM on farming feed is promoted. Asper.niger 2238 was used as initial strain. The optimization indicator included: acid protease activity and the content of free gossypol. The treatment factors included: the constitution of culture medium and fermentation conditions. Fermented CSM was used on feed of broiler replacing part of soybean. The effects on broiler quality, nitrogen coefficient of digestibility, the development of immunity organ and alimentrary canal were studied. The results included: optimized culture medium (CSM 30g, wheat bran 12g, ruben seed mill 4g, (NH₄)₂SO₄ 2.0g, CaCO₃0.2g, K₂HPO₄ 0.08g, MgSO₄ 0.16g, H₂O 73ml.)and the optimized conditions (the temperature 32℃, initial moisture content 60%, initial pH5.0, the period 96h, the inoculum 5ml) The maximal acid protease activity was 8258u/g after optimization, and the absolute content of free gossypol reduced 48.64%. There were no effects on ADG, ADFI, F/G of broiler with 10% fermented CSM in the date feeds. There were no effects on broiler quality, nitrogen coefficient of digestibility, the development of immunity organ and alimentrary canal within 15% fermented CSM in the date feeds.