Study On Optimization Of Solid Fermentation Of Protein Feedstuffs By Aspergillus Oryzae And Its Effect Of Pig Production

Now there is severely short of protein resources in the world, especially in China.With the development of animal husbandry and improvement of living standard, the resources of protein feedstuffs are far beyond the requirement of feed industry. The discovery of new unconventional protein feed resources has become an important subject in our country. The production of high- quality protein stuffs from the low-quality unconventional protein resources by microorganism fermentation is the main research direction all over the world. In this study, the low-quality protein stuffs such as cottonseed meal, blood meal and feather meal were fenmented by Aspergillus oryzae so as to relace soybean meal for pig production. The main contents are as follows:Experiment 1, study on the optimum solid-state fermentation of Aspergillus oryzae:The results showed that the best fermentation conditions were:initial pH 6, moisture 40%, 4% fungal incubation,15g/250ml volume, and 60 h fermentation. Under the best conditions of fermentation, the soluble protein content in the fermentation products was 133.72 mg/g and increased by 109.69%; the activities of protease, amylase, and cellulase were 1821.27,2778.35 and 5562.43 U/g; and FAA and AA of the fermented product were increased by 211% and 2.11% respectively, compared with the unfermented product (P<0.05).Experiment 2, effect of fermentation product in diet on growing pig performance. Seventy growing pigs were divided randomly into 7 groups according to their healthy and weight, including the unfermented protein group (control group), fermented cottonseed meal-blood meal-feather meal groups (Treatmentâ… ,â…¡,â…¢containing 7%, 14%,21% fermented protein stuffs, respectively), unfermented cottonseed meal-blood meal-feather meal group (Treatmentâ…£containing 14% unfermented protein stuffs), fermented cottonseed meal-blood meal-feather meal group added with soybean oil to keep the same digestible enegy with the control group (Treatmentâ…£containing 14% fermented protein stuffs), and fermented soybean meal group (Treatmentâ…¥containing 14% fermented soybean meal). The result showed that ADG and ADFI in treatmentâ… was incerased by 8.35%(P<0.05) and 7.83%, compared with the control group. ADG in treatmentâ…¡was significantly higher than that in treatmentâ…£(P<0.05), and F/G was not significant (P>0.05). Compared with the control group, ADG in treatmentâ…¥was incerased by 4.02%, while ADFI and F/G were reduced by 3.61% and 7.36%(P>0.05). Analysis of economic benefits indicated that the net income in treatmentâ… andâ…¥was incerased by 19.52% and 38.19%, compared with the control.Experiment 3, effect of fermentation product on apparent digestibility of nutrients and gut microflora of pigs. Apparent digestibilities of nutrients (CP, EE, Ca, P) in treatmentâ… were not significant different with that in the control (P>0.05). Apparent digestibilities of nutrients in treatmentâ… ,â…¡,â…¢,â…¤were significantly higher than that in treatment IV (P<0.05). Apparent digestibilities of nutrients in treatmentâ…¥were significantly higher than that in the control group (P<0.05), and incerased by 3.32%,4.72%,7.91%,9.36% for CP, EE, Ca and P, respectively. Gut microflora analyses indicated that the number of E.coli in pig faeces were not significant (P>0.05), while the number of lactic acid bacteria in pig faeces were increased (P<0.05) in treatment I, compared with the control group. Compared with treatment V, the number of E.coli in pig faeces were reduced (P<0.05), and the number of lactic acid bacteria in pig faeecs were increased (P<0.05) in treatmentâ…¡. Compared with the control group, the number of E.coli in pig faeces were reduced (P<0.05), and the number of lactic acid bacteria in pig faeces were increased in treatmentâ…¥(P<0.05).