Optimization Of The Conditions Of Solid State Fermentation Of Feather Meal With Two Strains Of Bacteria And The Research On Developing Protein Feed With The Fermented Product

The structure of feather keratin was very stable, it’s water-solubility was very low, it was very hard for pepsin and trypsin to hydrolyze keratin, so non-processed feather meal’s digestibility was very low. High pressure hydrolyzed feather meal was a new kind of protein feed, it was produced by high temperature stewing, stoving, and pulverizing with poultry’s feather. It’s basis was keratin, it’s CP (80%-85%) was the highest of all protein feed. Though high pressure hydrolyzed feather meal’s structure was a little loose, but the difference of digestibility between it and bean pulp, fish meal was really big, the situation restrict it’s adjunction in animal’s manufactured feed. Now, it’s max adjunction was 5%, overuse would cause innutrition and growth retardation.Our laboratory had separated two bacilli NJQ2, NJQ3 in poultry slaughterhouse, NJQ2 and NJQ3 could all secrete keratinase. NJQ2 and NJQ3 could hydrolyze keratin effectively, then the digestibility of high pressure hydrolyzed feather meal would increase obviously. So our plan was fermenting the high pressure hydrolyzed feather meal with NJQ2 and NJQ3, then developing a new type protein feed with the fermented product. Taking into account the nutritive peculiarity of high pressure hydrolyzed feather meal, our purpose and the usability of ferment method, finally, we chose solid state fermentation of feather meal with NJQ2 and NJQ3.In order to optimize the conditions of solid state fermentation, mensurated the productivity of fermentation and the digestibility of fermented product, calculated the productivity of digestible fermented product, optimized the conditions (the feather meal dosage, the buffer solution dosage, the buffer pH, the inoculum, the inoculum dosage of NJQ2, the thickness of culture medium, the fermentation temperature, the fermentation time) based on the productivity of digestible fermented product. First, optimized the conditions by single factor experiments, screened out 3 significant conditions which have the biggest influence on the productivity of digestible fermented product, and confirmed the other 5 conditions’ optimal level, then further optimization of the 3 significant conditions by complete trail. The results showed that the best feather meal dosage was 50%, the best buffer solution dosage was 100%, the best buffer pH was 7.5, the best inoculum was 10%, the best inoculum dosage of NJQ2 and NJQ3 were 60% and 40%, the best thickness of culture medium was 1.5 cm, the best fermentation temperature was 37℃ the best fermentation time was 7 d. The productivity of fermentation was 86.2%, the digestibility of fermented product was 60.3%, the productivity of digestible fermented product was 52.0% with the best fermentation condition. The digestibility of non-fermented feather meal and the mixture of feather and bran were 42.6% and 41.7%, through the optimization of fermentation conditions, the digestibility of feather meal increased by 99%, the digestibility of the mixture of feather meal and bran increased by 45%, the applied range of feather meal expanded in theory, it announced a big potential economic value.In order to develop new pattern protein feed with the product of solid state fermentation of feather meal, first, tested the safety and nutrition ingredient of solid state fermented product, according to the result, confected a series of feed for mice with solid state fermented product which substitute some rate of full cream soybean meal. Feeding experiment based on the feed for mice, found the max adjunction of solid state fermented product in the feed for mice by comparing the weight of mice and F/G of feed for mice. The results showed that solid state fermented product was safe, the nutrition ingredient was:CP: 52.56%, EE:3.13%, CF:4.10%, ASH:5.83%, Ca:0.16%, P:0.86%, Lys:1.55%, Met+Cys: 1.49%, the digestibility of fermented product was 60.3%. When the adjunction of solid state fermented product in the feed for mice was 4.80% and 8.00%, the weight of mice and F/G of feed for mice would not be affected significantly, the max adjunction of solid state fermented product in the feed for mice was 8.00%.