Effect Of Saccharomyces Cerevisiae Culture On Muscle Quality And Intestinal Microorganism In Fattening Pigs

In order to study the effects of yeast cultures on the muscle quality and intestinal microflora of Duroc×Landrace×Yorkshire?DLY?fattening pigs,330 healthy and DLY ternary crossbred fattening pigs with a weight of 60 kg were randomly selected.The pigs were divided into three groups of five replicates each with 22 replicates.The control group was fed a corn-soybean-based basal diet,and the 2.5%and 5%groups added 2.5%and 5.0%Saccharomyces cerevisiae cultures to the corn-soybean meal diet.The fattening pigs were fed ad libitum every day during the test,and the test period was 60 days.At the end of the experiment,the animals were weighed and slaughtered.The longest muscles on the left side of the pigs were collected for muscle quality analysis,and each replicate of fresh feces was collected for the detection of fecal microflora.The results were showed as follows:1)There was no significant differences in water and crude protein between the longissimus dorsi of each group of fattening pigs?P>0.05?.Compared with the control group,the 2.5%and 5%groups had significantly higher pH_24h than the control group?P<0.05?,and the drip loss rate and shear force were significantly lower in 2.5%and 5%groups than these in the control group?P<0.05?.There were no significant difference in intramuscular fat,flesh color,marbled vein among control,2.5%and 5%groups?P>0.05??P>0.05?.2)The malondialdehyde?MDA?of the longissimus dorsi muscle of the 2.5%and 5%groups was significantly lower than that of the control group?P<0.01?,and there was no significant difference in the superoxide dismutase among the control,2.5%and 5%groups?P>0.05?.The glutathione peroxidase?GSH-PX?and total antioxidant capacity?T-AOC?in the 2.5%and 5%groups were significantly higher than those in the control group?P<0.01?.3)The diameter and area of the longissimus dorsi muscle fibers in the 2.5%and 5%groups were significantly lower than those in the control group?P<0.05?,and there was no significant difference between the 2.5%and 5%groups in these items?P>0.05?.4)Transmission electron microscopy showed that the muscle fiber structure of 5%yeast culture was the most complete,the sarcomere was the longest,the 2.5%muscle fiber structure was degraded,the muscle fiber structure of the control group was degraded,and the sarcomere was shorter.5)Through high-throughput sequencing,the abundance of Bacteroides in the intestinal microbes of the fattening pigs decreased,and the abundance of the thick-walled bacteria increased,and the change trend of the proteobacteria and the spirochete was not significant.At the genus level,the yeast culture was added after the Anaerofustis,the abundances of Anaerostipes,Anaerovora,Bacteroides and Staphylococcus were significantly up-regulated?P<0.05?.The abundance of Vibrio genus,Prevotella and Rusococcus was the highest in the 2.5%yeast group,which was significantly higher than that in the control and 5%yeast groups?P<0.05?.The 5%yeast group was significantly higher than that in the control group?P<0.05?.The changes of intestinal microbial levels in the fattening pigs after adding yeast culture:Butyrivibrio crossotus,rumen rumen,yellow rumen cocci were significantly up-regulated?P<0.05?,and non-S.lactis was significantly down-regulated?P<0.05?.In the 2.5%addition group,the abundance of Clostridium butyricum and Roseburia faecis was significantly higher than that in the control group?P<0.05?,and the Clostridium was significantly higher than that in the control group?P<0.01?,Coprococcus catus,Lactobacillus reuteri was significantly lower than these in the control group?P<0.05?.In the 5%addition group,Lactobacillus mucins was significantly higher than that in the control group?P<0.05?,and Clostridium butyricum was significantly higher than that in the control group?P<0.05?.6)Functional prediction analysis of intestinal microbes in fattening pigs found that the isogenic functions?lipid metabolism,carbohydrate metabolism,starch and sucrose metabolism and transporters?were significantly upregulated after adding yeast culture?P<0.05?.From above results,it can be seen that the addition of Saccharomyces cerevisiae culture to the diet can significantly improve muscle quality and regulate intestinal microflora of pigs.Compared with the control group,the addition of Saccharomyces cerevisiae cultures in the diet significantly improved the muscle quality of the fattening pigs,possibly because the metabolites in the S.cerevisiae culture resulted in a change in the relative abundance of bacterial gene functions that would improve muscle quality or improve muscle mass by improving the body's antioxidant capacity.Adding 5%of Saccharomyces cerevisiae cultures to the fattening diet significantly improves the suitability of S.cerevisiae cultures in pig diets compared to 2.5%of the Saccharomyces cerevisiae culture group,therefore,a quality of 5%addition is suitable for pigs.