Effects Of Dietary Novel Saccharomyces Cerevisiae Culture Supplementation On Immune Function,Meat Quality And Intestinal Microbiota In White Pekin Ducks

Unconventional protein diets such as cottonseed meal and rapeseed meal can not be well digested,absorbed and utilized by animals due to high content of anti-nutritional factors.Microbial fermentation is one of the effective means to improve the utilization efficiency of unconventional diets.However,little research has been done on the fermentation of miscellaneous meal by Saccharomyces cerevisiae.The novel Saccharomyces cerevisiae culture used in this experiment was based on the fermentation of miscellaneous meal.This study was conducted to investigate the effects of dietary novel Saccharomyces cerevisiae culture supplementation on immune function,meat quality,and intestinal microbiota in White Pekin ducks,which can provide a reference and theoretical basis for the reasonable application of the novel Saccharomyces cerevisiae culture in the diet of White Pekin ducks.A total of 660 one-day-old healthy White Pekin ducks with similar body weight were randomly divided into 5 groups?group?,group?,group?,group?and group??with 6 replicates per group and 22 ducks per replicate.The White Pekin ducks in group?were fed a corn-soybean meal basal diet,whereas the White Pekin ducks in groups?and?were fed the basal diet supplemented with 2.5%and 5.0%novel Saccharomyces cerevisiae culture substrates?media?,the White Pekin ducks in groups?and?were fed the basal diet supplemented with 2.5%and 5.0%novel Saccharomyces cerevisiae culture,respectively.The experiment lasted for 42 days.The results showed as follows:1)diets supplemented with novel Saccharomyces cerevisiae culture substrates and novel Saccharomyces cerevisiae culture had no significant effects on the average daily gain and average daily feed intake of White Pekin ducks?P>0.05?.The feed/gain of White Pekin ducks aged 1 to 21 days in groups?,?and?was significantly higher than that in group??P<0.01?,while there was no significant difference between groups?and??P>0.05?.2)The dressing percentage and percentage of half-eviscerated weight in group?were significantly lower than those in groups?,?,?and??P<0.01?.The percentage of eviscerated weight in group?was significantly lower than that in groups?,?,?and??P<0.05?.However,there was no significant difference in the dressing percentage,percentage of half-eviscerated weight and percentage of eviscerated weight in groups?,?,?and??P>0.05?.3)The levels of serum total antioxidant capacity of White Pekin ducks at 42days of age in groups?,?and?were significantly higher than those in group??P<0.05?.The levels of serum malondialdehyde in groups?,?,?and?were significantly lower than those in group??P<0.05?.4)The thymus index and levels of serum immunoglobulin M?IgM?of White Pekin ducks at 42 days of age in group?were significantly higher than those in groups?,?,?and??P<0.01?,while there was no significant difference in groups?,?and??P>0.05?.The levels of serum immunoglobulin A?IgA?of White Pekin ducks at 42 days of age in group?were significantly higher than those in groups?and??P<0.05?.The expression of spleen interleukin-1?in group?was significantly lower than that in groups?and??P<0.05?.5)The levels of serum triglyceride of White Pekin ducks at 21 days of age in groups?,?,?and?were significantly lower than those in group??P<0.01?.6)The abundances of intramuscular fat of breast muscle in groups?and?were significantly higher than those in groups?,?and??P<0.01?,while there was no significant difference in groups?,?and??P>0.05?;the pH_45min and pH_24h of leg muscle in groups?and?were significantly higher than those in groups?,?and??P<0.01?,while there was no significant difference in groups?,?and??P>0.05?;the muscle fiber diameter and muscle fiber area of leg muscle in groups?and?were significantly lower than those in group??P<0.05?.7)According to the results of high throughput sequencing,there was no significant difference in Alpha diversity?P>0.05?.At phylum level,the relative abundance of Bacteroidetes in groups?and?was significantly higher than that in group??P<0.01?;the relative abundance of Actinobacteria in group?was significantly higher than that in group??P<0.05?,while there was no significant difference in groups?and??P>0.05?;the relative abundance of Proteobacteria of gut bacteria in group?was significantly lower than that in group??P<0.01?,while there was no significant difference between groups?and??P>0.05?.PICRUSt analysis showed the relative abundance of nucleotide metabolism gene function of gut microbiota,which were related to meat quality in group?was significantly higher than that in group??P<0.01?.The relative abundance of metabolism of other amino acid gene function of gut microbiota in group?was significantly higher than that in group??P<0.05?.However,there were no significant differences in the relative abundances of nucleotide metabolism and metabolism of other amino acid gene function of gut microbiota between groups?and??P>0.05?.8)Based on the further metabolomic analysis,the levels of procyanidins in novel Saccharomyces cerevisiae culture were significantly higher than those in novel Saccharomyces cerevisiae culture substrates?Fold change?1.2 and Q<0.05?.In conclusion,the supplementation of 2.5%novel Saccharomyces cerevisiae culture in diet significantly enhances immune function and antioxidant capability,and improves meat quality and gut microbial composition in White Pekin ducks.The results suggest that the recommended supplementation of novel Saccharomyces cerevisiae culture in the diet of White Pekin ducks is 2.5%.Compared with the control group,the supplementation of 2.5%novel Saccharomyces cerevisiae culture in diet can significantly improve meat quality of White Pekin ducks.This may be due to that metabolites in novel Saccharomyces cerevisiae culture alter the relative abundance of gut bacteria,which are beneficial to improve meat quality or enhance antioxidant capacity,thus improve meat quality.Compared with the novel Saccharomyces cerevisiae culture substrate group,the supplementation of 2.5%novel Saccharomyces cerevisiae culture in diet can significantly improve meat quality of White Pekin ducks.This may be due to that metabolites in novel Saccharomyces cerevisiae culture enhance antioxidant capacity,thus improve meat quality.