Effects Of Long-distance Transportation On Main Clinical Indexes,blood Related Cytokines And Intestinal Flora Of Simmental Cattle

With the intensification,standardization and modernization of animal husbandry and the accelerated growth of the economy in China,beef consumption has increased year by year,which has greatly stimulated the development of China’s cattle industry.Therefore,transportation has become one of the important links in the cattle industry,but due to transportation stress,it is easy to lead to diseases and even death,which seriously restricts and affects the healthy development of the cattle industry.Therefore,this study aimed to explore the effects of long-distance transportation on the main clinical indicators,serum correlation factors and intestinal flora of Simmental cattle,and provide basic theoretical data for the prevention of long-distance transport stress in domestic beef cattle.Experiment 1 Effect of long-distance transportation on the main clinical indicators of Simmental cattle In this experiment,Seventy 8-month-old Simmental cattle with similar clinical health and similar physical condition were selected and transported from Tongliao City,Inner Mongolia Autonomous Region to Luding County,Sichuan Province using a double-decker canopy transport vehicle with a length of 14.6 m and a width of 2.5 m,with 35 heads in both upper and lower layers,and a transport density was about 1.04 m~2/head,and 12 heads in the upper layer were randomly selected as research objects and marked.The beef cattle were marked as(Tb)on the day of loading,(Ta)on the day of arrival,and(T2d-T7d)on the 2nd to7th days after arrival.The test cattle rectal temperature,heart rate,respiratory rate,single rumination chewing times,etc.were measured and recorded in detail at 6:00 a.m.daily from Tb to T7d,and the degree of dehydration of the test cattle were scored,the weight loss rate were calculated,and the morbidity and mortality were recorded.The test results showed that after long-distance transportation,(1)the degree of dehydration,body temperature,heart rate and respiratory rate of Simmental cattle increased significantly(P<0.01),while their body weight and single rumination chewing times decreased significantly(P<0.01);(2)The incidence rate was significantly increased(P<0.01),mainly including respiratory diseases(13 heads,the incidence rate was 19%)and digestive tract diseases(11 heads,the incidence rate was 16%).Experiment 2 Effect of long-distance transportation on blood related factors of Simmental cattle The ELISA method was used to detect Simmental cattle serum immune factors such as Ig G,Ig A and Ig M before transport(Tb)and on the day of arrival(Ta),serum inflammatory factor levels such as IL-1β,IL-4,IL-6,IL-10 and TNF-α,serum hormones contents such as Cor and ACTH,and oxidation factors contents such as CAT,MDA and SOD.The results showed that after long-distance transport,serum Ig G,Ig M and CAT levels decreased significantly(P<0.01),while TNF-αand SAA levels increased significantly(P<0.01),MDA,CRP,IL-1βand IL-6 levels increased significantly(P<0.05),but there was no significant difference between Ig A,Cor,ACTH and HP levels before and after long-distance transport(P>0.05).Experiment 3 Effects of long-distance transportation on intestinal flora of Simmental cattle 16S r DNA amplicon sequencing was used to detect the changes of intestinal fecal flora in Simmental cattle before transport(Tb)and after transport(Ta),and the community structure and diversity of microbiota were analyzed.The results showed that(1)the diversity and richness of intestinal flora decreased significantly(P<0.05)after long-distance transportation of Simmental cattle;(2)At the phylum level,Firmicutes and Bacteroides were the most abundant phylums in the two groups;At the genus level,the relative abundance of UCG-005(11.74%),Christensenellaceae＿R-7＿group(7.88%),and Rikenellaceae＿RC9＿gut＿group(6.25%)were higher than 5%.Bacteroides(3.18%),Akkermansia(3.12%),Alistipes(2.77%),Monoglobus(2.58%),Prevotellaceae＿UCG-003(1.42%),UCG-002(1.41%),and Prevotellaceae＿UCG-004(1.09%)were the dominant genera(relative abundance>1%).The difference between phylum and genus with a relative abundance of>1%showed that the abundance of Bacteroides decreased significantly at the post-transport door level(P<0.05),and the abundance of Dethiobacillus increased significantly after transport(P<0.05).At the genus level,the relative a-bundance of Rikenellaceae＿RC9＿gut＿group,Alistipes,Monoglobus and Prevotellaceae＿UCG-004 decreased significantly after transport(P<0.05)and NK4A214＿group abundance increased significantly after transport(P<0.05).There was a extremely significant negative correlation between Ig G level and NK4A214＿group abundance(P<0.01),Ig G leve-ls were significantly positively correlated with Monoglobus and Rikenellaceae＿RC9＿gut＿group abundance(P<0.05).Ig M level was significantly negatively correlated with NK4A214＿group abundance(P<0.05).CAT level was significantly negatively correlated wit-h NK4A214＿group abundance(P<0.05).CRP levels were significantly negatively correl-ated with Alistipes abundance(P<0.05)and extremely significantly with Rikenellaceae＿RC9＿gut＿group abundance(P<0.01).IL-βlevels were significantly negatively correlated with Alstipes abundance(P<0.05).SAA levels were significantly negatively correlated with Alstipes and Rikenellaceae＿RC9＿gut＿group abundance(P<0.05),and NK4A214＿group abundance(P<0.05).TNF-αlevels were significantly negatively correlated with Monoglobus abundance(P<0.05)and was significantly positively correlated with NK4A214＿group abundance(P<0.05).Conclusion:Long-distance transportation was easy to cause Simmental cattle:(1)Severe dehydration,weight loss,significantly increased in body temperature,heart rate and respiratory rate,and affected rumination;(2)The incidence is extremely significantly increased,mainly in respiratory and digestive tract diseases.(3)Caused inflammatory response and oxidative damage,but did not show a significant increase in acute reactive protein levels.(4)The diversity and richness of intestinal flora decreased significantly,and the abundance of beneficial bacteria such as Bacteroides decreased significantly,while harmful bacteria increased significantly,mainly affected digestion and absorption functions;There was a potential relationship between gut microbiota and serum-associated cytokines,stress-induced inflammation,immune factors,and acute phase proteins leaded to changes in the intestinal flora,which also affected cytokine secretion.