Optimization Of Technological Parameters Of Fermented Feed Of Residual Jujube And Its Effect On Lambing Performance Of Ewes

In this experiment,the parameters of jujube fermented feed were explored to determine the suitable proportion of jujube,water and fermentation time.By screening the appropriate proportion and concentration of Lactobacillus plantarum,Bacillus subtilis and Saccharomyces cerevisiae,the compound microbial inoculum was optimized,and the optimum fermentation process parameters were determined.The jujube fermented feed was made to improve its nutritional value,and its effect on the lambing performance of lactating ewes was studied.PartⅠ Selection and Optimization of Technological Parameters of Jujube Fermented FeedThree progressive tests were set with p H,dry matter loss rate（DML）,soluble sugar,ammonia nitrogen（N-NH₃）and crude protein（CP）content as evaluation indexes.Experiment 1:Through single factor experiment design to determine the jujube,other raw materials and water roughly proportion,as well as Lactobacillus plantarum,Saccharomyces cerevisiae,Bacillus subtilis concentration range.The results showed that p H and DML increased（P<0.05）and N-NH₃ decreased（P<0.05）with the increase of yeast concentration.When Lactobacillus plantarum concentration increased,p H value and ammonia nitrogen concentration decreased significantly（P<0.05）.With the increase of water concentration,p H decreased significantly（P<0.05）,DML and N-NH₃content increased significantly（P<0.05）.The results showed that jujube would be caking when the proportion of jujube was 40%,and concentrated ammonia would be produced when the proportion of cottonseed meal was 70%.Water accounted for between 30%-50%,adding Bacillus subtilis activity between 10⁴ CFU/g-10⁶ CFU/g ideal inoculation activity.Experiment 2:According to the results of experiment 1,the fermentation time was3 d,5 d,7 d,10 d,the proportion of jujube was 20%,25%,30%,35%,the proportion of cottonseed meal was 50%,55%,60%,65%,the proportion of water was 30%,35%,40%,45%,and the concentration of 10⁵ CFU/g without adding bacteria,Lactobacillus plantarum,Bacillus subtilis,Saccharomyces cerevisiae to design five factors and four levels orthogonal experiment,to further optimize the effect of different fermentation conditions on the fermentation quality of jujube.The results showed that the fermentation time had the greatest impact on p H and DML time（P<0.05）.p H gradually decreased and DML gradually increased with the extension of fermentation time,followed by the proportion of water（P<0.05）.The proportion of jujube and cottonseed meal had little effect on p H.The addition of strains had the greatest effect on lactic acid（LA）and total volatile fatty acid（TVFA）content during jujube fermentation（P<0.05）.The highest contents of LA and TVFA were obtained by Lactobacillus plantarum fermentation.Water had the greatest impact on the content of acetic acid（AA）（P<0.05）.Under the conditions of this experiment,the optimal fermentation substrate ratio was jujube（25%）:corn（15%）:cottonseed meal（60%）.When water was added to 45%of the total weight,the fermentation effect was the best and the fermentation time was 7days.Experiment 3 studied the effects of different bacterial concentrations and fermentation time on fermentation.According to the results of Experiment 1 and Experiment 2.The effects of different combinations and concentrations of microbial inoculums（10⁵ CFU/g Lactobacillus plantarum+Bacillus subtilis with different inoculums+Saccharomyces cerevisiae with different inoculums）on the fermentation quality of jujube were further studied.The addition concentration of Bacillus subtilis:10⁴ CFU/g,10⁵ CFU/g,10⁶ CFU/g,the addition concentration of Saccharomyces cerevisiae:10³ CFU/g,10⁴ CFU/g,10⁵ CFU/g,the fermentation time:5 d,7 d,10 d,L₉（3³）orthogonal test was designed to explore the optimal proportion of fermentation bacteria and fermentation time.The results showed that the addition amount of Saccharomyces cerevisiae had the greatest impact on p H value during jujube fermentation（P<0.05）.fermentation time followed;the addition of Bacillus subtilis had the least effect.The addition of Saccharomyces cerevisiae had the greatest impact on DML during jujube fermentation（P<0.05）.The addition of Bacillus subtilis was the second（P<0.05）.Time had the least effect on it（P<0.05）.Yeast content during jujube fermentation had the greatest impact on soluble sugar content;fermentation time followed;Bacillus subtilis content had the smallest effect.The addition of Bacillus subtilis had the greatest impact on crude protein（CP）during jujube fermentation（P<0.05）,followed by yeast addition and time.According to the analysis of volatile fatty acid（VFA）content,high concentration of Bacillus subtilis could inhibit the formation of LA and promote the production of AA.With the increase of yeast addition,the production of LA and acetic acid was inhibited,and the yield of LA was the highest at 7 d（P<0.05）,which was consistent with the change of p H.The optimal microbial inoculum was 10⁶ CFU/g Bacillus subtilis+10⁵ CFU/g Lactobacillus plantarum+10³CFU/g Saccharomyces cerevisiae.This microbial inoculum was the best for fermentation for 7 days.Experiment 4,according to the optimized fermentation conditions,the effect of larger scale（5 kg/bag）on the fermentation quality of jujube was verified.They were divided into 1 control group（C）and 4 treatment groups:the 0 d and 7 d fermentation of the compound fermentation bacteria group were recorded as T0 and T7 groups,respectively;the 0 d and 7 d of fermentation in the group without compound fermentation bacteria were recorded as groups:N0 and N7.The fermentation effect was evaluated by measuring conventional nutrient determination,VFA determination,soluble sugar content,N-NH₃ content and microbial changes.The results showed that compared with group C,the acid detergent fiber（ADF）and CP of group N7 increased significantly（P<0.05）.The CP of T7 increased significantly（P<0.05）.Compared with group N0 and T0,the contents of CP,ADF and p H in group N7 were significantly decreased（P<0.05）.CP content in group T7 was significantly increased（P<0.05）.Compared with group N7,ADF content and p H in group T7 were significantly decreased（P<0.05）,and other differences were not significant（P>0.05）.Compared with N7 group and T0 group,the total number of observed species,Chao1 index,Shannon index and Simpson index in T7 group decreased.T7 was significantly lower than N7（P<0.05）.The Simpson index of N7 was significantly higher than that of N0（P<0.05）.The proportion of Lactobacillus increased,and the proportion of Alternaria and Mucor decreased.The results showed that the CP of jujube cottonseed meal feed increased and the ADF content decreased after the optimization of fermentation process and the use of compound fermentation bacteria,which improved the nutritional value of feed.At the same time,increasing the content of VFA in fermented feed promoted the production of LA.The abundance,uniformity and diversity of bacteria were reduced,and the proportion of lactic acid bacteria was increased.It inhibited the growth of harmful fungi such as Mucor and Alternaria.PartⅡ Effect of jujube fermentation concentrate supplement on lambing performance of lactation ewesIn order to verify the application effect of jujube concentrate supplement before and after fermentation in lactating ewes,30 experimental sheep were divided into 5treatment groups,including 1 control group and 4 experimental groups,and divided into control group:（C）group（100%basal diet）.Experimental group:A1 group（50%unfermented jujube concentrate replacement group）,A2 group（50%unfermented jujube concentrate replacement+additive group）,B1 group（50%fermented jujube concentrate replacement group）,B2 group（50%fermented jujube concentrate replacement+additive group）.Additives are 0.1%water,sodium silicate calcium and0.1%sodium diacetate.Six ewes and their lambs in each group were raised in one column.The results showed that the weight of ewes decreased during lactation.Under the condition of fixed concentrate feeding amount,the weight loss of ewes in group B2was significantly lower than that in group A2（P<0.05）,and there was no significant difference compared with other groups（P<0.05）,indicating that the feeding group B2was more conducive to alleviating the postpartum weight loss of ewes.At the same time,the dry matter intake（DMI）,protein digestibility（CPD）and crude fat digestibility（EED）of 50%fermented jujube powder and supplementary additive group were significantly higher than those of unfermented feed and control group（P<0.05）.Overall,B1 and B2 groups were conducive to promoting lamb weight gain.There was no significant difference in estradiol（E2）,prolactin（PRL）and growth hormone（GH）among different treatment groups（P>0.05）.The total antioxidant index（T-AOC）of B2group was significantly lower than that of the other four groups（P<0.05）.The blood glucose（GLU）content of group B2 was the highest,which was significantly higher than that of group C and A1（P<0.05）.The results showed that group B2 could effectively alleviate the postpartum weight loss of ewes,increase the DMI of ewes,and improve the effects of GLU,CPD and EED.But it also reduces insulin（INS）and antioxidant capacity in sheep.Group B1 could increase the daily gain of lambs,GLU of ewes,DMI of ewes and CPD.GeneralizeUnder the experimental conditions,the best microbial inoculum was 10⁶ CFU/g Bacillus subtilis+10⁵ CFU/g Lactobacillus plantarum+10³ CFU/g Saccharomyces cerevisiae.The best fermentation substrate ratio was jujube:corn:cottonseed meal ratio of 25:15:60,adding water accounted for 45%of the total weight of fermentation,fermentation time was 7 d.After this treatment,CP increased and ADF content decreased,which improved the nutritional value of feed.At the same time,the content of VFA in fermented feed was increased,the proportion of lactic acid bacteria was increased,and the production of LA was promoted.It inhibited the growth of harmful fungi such as Mucor and Alternaria.Using this fermented feed to replace 50%concentrate feed of ewe can improve the daily gain of lamb,GLU of ewe,DMI of ewe and CPD.Addition of 0.1%water,calcium silicate and 0.1%sodium diacetate can alleviate postpartum weight loss,increase DMI,GLU,CPD and EED of ewes.