Study On The Effect Of Grape Pomace Instead Of Wheat Bran On Finishiing Pigs Immune Performance And Intestinal Health

In order to improve the quality and safety of livestock products and ensure human health,in 2019 the Ministry of Agriculture and Rural Affairs issued the "stop production,import,operation,and use of some drug feed additives",stating that "feed manufacturers are prohibited from adding growth-promoting drug feed additives(excluding traditional Chinese medicine)in the process of producing commercial feed".Therefore,how to use bioactive substances to improve immune performance and thus reduce or replace the application of antibiotics has become an urgent problem to be solved in pig production.In China,the production of grape pomace is about 500,000 tons per year.Studies have shown that grape pomace contains a large number of bioactive components(phenolic compounds and unsaturated fatty acids,etc.),which have good antioxidant and antibacterial functions.We hypothesize that grape pomace can be an ideal substance to reduce antioxidant resistance in pig breeding.In this study,24 growing finishing pigs with similar body weight(initial weight controlled at 55.14 ± 0.59 kg)were selected and randomly divided into 2 groups(6 pens per group,2 pigs per pen randomly assigned)for77 days of feeding,using methods and techniques such as real-time fluorescence quantification and 16 S r RNA amplicon sequencing to investigate the effects of grape pomace on immune performance and intestinal health of growing finishing pigs.The main results of the study were obtained as follows.1.Compared with the control group,the immune performance indexes of serum Ig A,Ig G,Ig M and IFN-γ were significantly higher(P<0.05)and IL-1β was significantly lower(P<0.05)in the growing finishing pigs with grape pomace.It also improved the expression levels of m RNA of immune-related genes in the spleen and ileum.2.Compared with the control group,the antioxidant indexes such as CAT,T-AOC and SOD of growing finishing pigs in the grape pomace addition group were significantly improved(P<0.05).It also improved the expression levels of m RNA of antioxidant-related genes in the spleen and ileum.3.Compared with the control group,the villi height(VH)of ileum was significantly higher(P<0.05),the crypt depth(CD)of ileum,cecum and colon was significantly lower(P<0.05),the villi to crypt ratio(V/H)of ileum and colon was significantly higher(P<0.05),and the expression of ileal tight junction protein(ZO-1,Occludin-1 and Claudin-1)was also significantly higher(P<0.05)in the ileal group with the addition of grape pomace.4.The relative abundance of Treponema and Streptococcus in the intestine of the finishing pigs was significantly lower in the group supplemented with grape pomace compared to the control group(P<0.05).Meanwhile,on day 25,Treponema showed a negative linear correlation with Ig G,IFN-γ,Ig A and IL-6(P<0.05),and Streptococcus showed a negative linear correlation with Ig G,IFN-γ,Ig A and IL-6(P<0.05);on day 50,Treponema showed a negative linear correlation with Ig G,IFN-γ,Ig A and IL-6(P<0.05),and Streptococcus showed a negative linear correlation with Ig A and IL-6(P<0.05);Streptococcus showed a negative linear correlation with Ig A at day 75(P<0.05).In conclusion,grape pomace can significantly improve the antioxidant performance of finishing pigs,protect the integrity of the intestinal barrier,and significantly improve the immune performance of finishing pigs by inhibiting the growth and reproduction of streptococci and dense spirochetes in the intestinal tract.This study is of great significance to reduce antioxidant resistance in pig breeding,improve pork safety and protect human health.