Effects Of Rumen Content Exchange On Absorption Of Lipopolysaccharide In Dairy Goats With Health And Subacute Ruminal Acidosis

With the development of the economy,the people’s living standards have increased significantly,and the demand for dairy products has also increased.In order to improve milk production,farms are usually fed a diet that is fed high-concentration for a long time,but this will cause the rumen pH of ruminants to remain at a lower state and resulting in Subacute ruminal acidosis(SARA).SARA severely reduced the production performance of ruminants,and lipopolysaccharide(LPS)is an important abnormal metabolite in the production of SARA.Some clinical symptoms of SARA may be related to the content of LPS in the body.The exchange of rumen contents can avoid the influence of external factors to a certain extent,thereby comparing the effects of digestive tract barrier on LPS absorption in the body.The purpose of this study was to investigate the effects of the exchange of rumen contents and animal condition to the absorption of LPS into the circulatory system in health and SARA dairy goats,and further validate the factors affecting LPS absorption.In this experiment,six Laoshan dairy goats were selected and divided into two groups on average,and a permanent rumen fistula was installed.Feeding was carried out using two different granule diets with different ratios of coarse to coarser until SARA occurred in the high concentrate group.After the successful induction of SARA,the rumen contents of the two groups of goats were exchanged to observe the effects of LPS,Histamine(HIS),Interleukin-1β(IL-1β),Tumor necrosis factor-α(TNF-α)in rumen fluid and plasma;the lactic acid in rumen fluid and acute phase proteins and immunoglobulins in plasma.The results showed that the levels of LPS in the rumen fluid of the H group were significantly higher than those of the L group(P<0.01).Similarly,the H group was compared with the L group,the content of HIS in the rumen fluid of the goats was significantly increased(P<0.01).There was a significant increase in the plasma LPS content of the H group by feeding different diets(P<0.01).Similarly,the HIS content in the plasma increased significantly(P<0.05).Feeding high-concentration diets significantly increased the levels of IL-1β and IL-6 in rumen fluid(P<0.05).The plasma levels of lipopolysaccharide bindingprotein(LBP)in group H were significantly increased(P<0.01),and serum amyloid A(Serum)was also significantly increased in plasma.The content of Serum amyloid A(SAA)(P<0.05).High-concentration diets had a significant increase in plasma immunoglobulin content(P<0.05).After the rumen contents were exchanged,the content of LPS in the rumen of group H dairy goats increased significantly with time(P<0.01);also increased significantly in the rumen of group L dairy goats(P<0.01).The plasma LPS content in group H dairy goats changed significantly with time(P<0.01).Similarly,the LPS content in the rumen of group L dairy goats also changed significantly with time(P<0.01).).The contents of C-reactive protein(CRP)in the plasma of H group and L group goats increased significantly with time(P<0.01),and the plasma haptoglobin in group H dairy goats.The content of Haptoglobin(Hp)increased significantly(P<0.05),and the content of SAA in plasma of L group goats increased significantly with time(P<0.05).Conclusion: Through experiments,we can find that the exchanges in rumen contents are factors that affect the entry of LPS into the systemic circulatory system,but the animal body itself seems to have no effect on the absorption of LPS.