| In the present study,three bacterial species,yeast,bacillus subtilis and bacillus pumilus,were used in solid-state fermentation cottonseed meal to explore the optimal conditions of degrading FG(Free gossypol).Then,using FCM instead of soybean meal in the replacement ratio of 0%(the Control Group),50%(Group B),75%(Group C),100%(Group D)feeding the Ao Baixing ducks,at the same time,setting Group A with ordinary cotton pulp entirely replace soybean meal.The experiment is designed to explore the rate of nutrients utilization of FCM and the influence of FCM in growth performance,serum biochemical index,slaughter performance,immune organ index and villus height and crypt depth ratio in small intestine of ducks.The purpose of the experiment is to evaluate the feeding effect of FCM in ducks.The results of the study are as follows.Experiment 1: Research of process parameters of Mixed fermentation cottonseed meal in solid-state.The determination of optimal inoculation time: Drawing the growth curve by means of cultivating yeast,bacillus subtilis,and short bacillus independently.According to the growth curve,all three bacterial species achieve the maximum absorbance in 22 hours to 24 hours to show that the activity of bacteria was the strongest.So choose cultivation 22 hours as the optimal time in transfer stage to expand cultivation.The determination of optimal inoculation proportion of three bacterial species:According to the orthogonal table set up three factors,four levels orthogonal experiment.Inoculating the three bacterial species with 10% inoculation quantity into cottonseed meal with 1:0.8 material to water to ferment 72 hours in 32℃ and pH value 6.5.The results show that the FG degradation rate up to 83.9% high when the inoculation proportion of yeast,bacillus subtilis and short bacillus is 3:3:2.The determination of optimal combination of fermentation temperature,pH,the ratio of material and water and fermentation time: According to the orthogonal table set up four factors,five levels of orthogonal test.Inoculating the three bacterial species with 10%inoculation quantity and 3:3:2 inoculation proportion into cottonseed meal,fermenting with different temperature,pH,the ratio of material and water and time.The results show that the FG degradation rate up to 87.6% high When the temperature is 34 ℃,pH 6.5,the ratio of material and water is 1:0.8 and the fermentation time is 5 days.The evaluation of nutritional value of fermented product: Contents of crude protein,calcium,phosphorus respectively increased by 24.55%,15.00% and 15.00% after fermentation while contents of crude fat,crude fiber and crude ash have different reduced degree.All kinds of amino acids have increased animals essential amino acid such as methionine,lysine,phenylalanine respectively increased by 13.95%,16.13% and 16.13%,and tyrosine and arginine respectively increased by 19.69% and 14.25%.In addition to produced amylase,protease,the number of living bacterium up to 16.5×10~8 cfu/g after fermentation.Experiment 2: Research of feeding results of FCM in meat ducks.Effects on the rate of nutrients utilization of FCM in meat ducks: Compared with the control group,the rate of utilization of dry matter,crude protein and organic matter of Group A were fallen while that of Group B,C,D were increased in ducks` earlier(3~21d)and later(22~42d)growth.The rate of several nutrients utilization of Group C were significantly improved(P<0.05),for they were respectively increased by 8.89%,12.28%,8.89% in ducks`earlier growth and by 9.56%,12.82%,8.70% in ducks` later growth.Effects on growth performance of FCM in meat ducks:Compared with the control group,feed conversion rate of Group A were significantly improved(P<0.05)while that of Group B,C,D had a tendency to decline,not significantly(P>0.05),in ducks` earlier,later and whole growth.Feed conversion ratio of Group C had a significant reduction(P<0.05),from 2.61 to2.57,in ducks` whole growth.Effects on serum biochemical index of FCM in meat ducks: Compared with the control group,T-CHO,TG,HDL-C,GLU,TP of Group B,C,D had a tendency to rise,not significantly(P>0.05),while LDL-C,BUN had a tendency to decline,not significantly too(P>0.05).All these show that FCM have no significant effect on serum biochemical index of ducks.Effects on slaughter performance of FCM in meat ducks: Compared with the control group,slaughter rate,breast muscle rate and leg muscle rate of Group B,C,D had a tendency to rise,not significantly of slaughter rate and leg muscle rate(P>0.05),significantly of breast muscle rate of Group C(P<0.05).Compared with the control group,eviscerated yield,half eviscerated rate and abdominal fat rate of Group B,C,D had no significant increase or decrease.All these show that FCM have no bad influence on ducks.Effects on immune organ index of FCM in meat ducks: Compared with the control group,immune organ index of Group B,C,D had a tendency to rise of 21 days and 42 days ducks.The effect of group C is best,the spleen and thymus index of 21 days ducks and the spleen index of 42 days ducks improved significantly(P<0.05).Effects on villus height and crypt depth ratio in small intestine of FCM in meat ducks:Compared with the control group,villus height and crypt depth ratio of Group B,C,D had a tendency to rise of 21 days and 42 days ducks.The effect of group C is best,villus height and crypt depth ratio of duodenum and jejunum improved significantly(P<0.05). |
