Construction Of A Rapid Quality Assessment Model For Fermented Corn Processing By-products And Its Evaluation On The Feeding Effect Of Meat Sheep

The aim of this thesis is to establish a rapid evaluation method of fermented maize processing by-products based on near-infrared spectroscopy,and then continue to investigate its effects on growth performance,blood index and rumen fermentation parameters of meat sheeps after screening the optimum addition amount through in vitro fermentation experiments.The experimental results are as follows:Experiment1:Modeling polysaccharides and soluble proteins of fermented maize processing by-products based on NIR spectroscopy.In this experiment,the SPXY algorithm was used to classify the NIR raw spectra of a total of 104 collected fermented maize processing by-product samples;the spectra were pre-processed by the combined FD+SNV method,and the CARS algorithm selected the characteristic bands,and the final R2 of the training set model for polysaccharide content was 0.920,RMSEC was 7.170,MSE was 51.415,and The R2 of the test set model was0.921,RMSEC was 7.116,MSE was 50.634,and RPD was 3.663;after the FD+SG combination method for spectral preprocessing and the SPA algorithm for feature band selection,the R2 of the training set model for soluble protein content was 0.930,RMSEC was 5.646,and MSE was 3.663.5.646,MSE was 31.876,and RPD was 3.914,and the R2of the test set model was 0.920,RMSEC was 7.101,MSE was 50.417,and RPD was 3.415.Experiment2:Effect of fermented maize processing by-products on in vitro fermentation parameters in lamb rumen.The optimum addition was screened by measuring rumen fermentation parameters at different concentrations at different time points.In this experiment,a one-way completely randomized design was used to select four healthy small-tailed cold meat sheeps of similar body condition as rumen fluid donors,and the experiment was divided into one control group and six experimental groups.In the control group,the fermentation substrate was the basal diet,and in the experimental group,0.1%,0.3%and 0.5%doses of maize processing by-products and fermented maize processing by-products were added to the fermentation substrate,and five fermentation time points of3h,6h,9h,12h and 24h were set for each group,and three replicates were set for each time point.The results showed that at a certain fermentation time,the addition of certain concentration of corn processing by-products could improve rumen fluid p H,ammoniacal nitrogen（NH₃-N）concentration,rumen fluid bacteriological protein（BCP）concentration and rumen gas production to a certain extent.And the effect of fermented maize processing by-products was better than unfermented.Finally,when combined with the multiple combination effect index（MFAEI）,the promotion of rumen in vitro fermentation was better when fermented maize processing by-products were added at 0.3%.Experiment 3 was conducted to investigate the feeding effect of fermented maize processing by-products on meat sheep based on the optimum addition level screened in experiment 2.A one-way completely randomized test design was adopted to select 50healthy 4-month-old small-tailed cold lambs of similar weight（21.4±1.51）kg and randomly divided into two groups.The control group was fed the basal diet and the experimental group was fed the basal diet with 0.3%of fermented corn processing by-products.Growth performance,blood biochemical and immune indexes,rumen fermentation were measured and analyzed at the end of the trial period to provide a theoretical and practical basis for the application of fermented maize processing by-products in meat sheep.The results showed that compared with the control group,the average daily weight gain of the experimental group supplemented with fermented corn processing by-products tended to increase（P<0.05）;the concentration of creatinine in its serum tended to decrease（P<0.01）,and the content of urea in its serum also decreased significantly（P<0.05）;the content of immunoproteins and cytokines in its serum also increased significantly,and it also significantly increased its rumen There was a significant increase in the p H of the rumen,and the concentrations of Ig G,Ig A,Ig M,IFN-γand IL-1βwere significantly increased（P<0.01）;the p H of the rumen and the concentration of butyric acid were significantly increased（P<0.05）,and the concentration of acetic acid in the rumen was significantly increased（P<0.01）.