Interactive Effects Of Sodium Butyrate Into Starter Mixture And Whole Milk On Growth Performance,Gastrointestinal Physical Barrier And Microbiota Of Preweaning Calves

This experiment investigated the interactive effects of adding sodium butyrate to starter mixture and whole milk,respectively,on growth performance,gastrointestinal physical barrier and microbiota of Holstein preweaning calves,with the aim of providing a theoretical basis for the optimal use of sodium butyrate in calf breeding process.Four main aspects are divided as follows:Experiment 1: Interactive effects of sodium butyrate addition to starter mixture and whole milk on growth performance and blood biochemical parameters of lactating calvesThe objective of this experiment was to investigate the interactive effects of adding sodium butyrate to the starter mixture and whole milk,respectively,on growth performance and blood parameters of Holstein lactating calves.Eighty healthy 4-day-old calves were randomly divided into four groups of 20 calves each,according to the principle of similar body weight and age,group CON: no sodium butyrate added to both starter and milk,group S: 0.3% DM sodium butyrate added to starter mixture,group M:8.8 g/d sodium butyrate added to whole milk,group SM: sodium butyrate added to both starter mixture and whole milk.The feeding conditions were the same for all groups throughout the trial period.Calves were weighed and blood was collected for body measurements before the start of the trial,then weighed and recorded every 10 days,and blood was collected from the jugular vein every 20 days,and body measurements were taken at the end of the trial.The test results were as follows: 1.The addition of sodium butyrate to starter mixture and whole milk had no effect on calf weight,feed intake and body size(P > 0.05),the addition of sodium butyrate to whole milk decreased daily weight gain at 15-24 days of age(P < 0.05),and the addition of sodium butyrate to starter mixture increased calf daily weight gain throughout lactation(P < 0.05);2.The addition of sodium butyrate to whole milk decreased calf diarrhea rate(P < 0.05),adding sodium butyrate to the starter mixture reduced calf diarrhea score(P < 0.05),and there was no interaction between starter mixture sodium butyrate and whole milk sodium butyrate on fecal score and diarrhea rate(P >0.05);3.Adding sodium butyrate to the starter mixture significantly increasedβ-hydroxybutyrate and diamine oxidase concentrations in 24-day-old calves(P < 0.05)and increased 44-day-old insulin-like growth factor 1,interleukin-6 concentrations(P < 0.05),decreased serum γ-interferon concentrations at 64 days of age(P < 0.05),adding sodium butyrate to whole milk significantly increased insulin-like growth factor 1,interleukin-4,interleukin-10 concentrations at 44 days of age(P < 0.05),increased β-hydroxybutyric acid concentrations at 74 days of age(P < 0.05),and there was a positive interaction between starter mixture sodium butyrate and whole milk sodium butyrate on the concentrations of growth hormone,immunoglobulin M,interleukin-4,interleukin-6,and interleukin-10(P<0.05).These results indicate that the addition of sodium butyrate to stater mixture and whole milk had no effect on calf growth performance,increased calf immunity and reduced inflammatory response in calves.Experiment 2: Interactive effects of sodium butyrate addition to starter mixture and whole milk on structural development and epithelial permeability of the gastrointestinal tract of preweaning calvesThe test method and diet were the same as in experiment 1.At 74 days of age,four calves of similar age and weight were selected from each group,bled to death by carotid artery bleeding,dissected the abdominal cavity,removed the compound stomach,small intestine,large intestine and each organ,weighed and recorded,and the epithelial tissues of rumen,jejunum and colon were taken and preserved for testing.The electrophysiological parameters of the gastrointestinal epithelial tissues were measured by using Ussing Chamber to respond to the permeability of the gastrointestinal epithelium.The test results were as follows: 1.There was a significant negative interaction effect(P<0.05)between sodium butyrate in the starter mixture and sodium butyrate in whole milk on the weight of the whole intestine and small intestine,which decreased the weight of the whole intestine and small intestine,and the addition of sodium butyrate in whole milk decreased the organ index of the duodenum(P < 0.01)and increased the organ index of the ileum(P < 0.05),and there was a negative interaction effect(P<0.05)between sodium butyrate in the starter mixture and sodium butyrate in whole milk on the weight of the whole intestine and organ index of small intestine had a negative interaction(P < 0.05);2.Addition of sodium butyrate to the starter mixture increased the thickness of the mucosal layer of the rumen dorsal sac(P < 0.01),the thickness of the mucosal layer of the rumen ventral sac(P < 0.05),and the thickness of the mucosal layer of the abomasum(P < 0.05),and addition of sodium butyrate to whole milk increased the height of the papilla of the rumen dorsal sac(P < 0.01),the thickness of the mucosal layer(P < 0.05),significantly increased the thickness of the mucosal layer of the rumen dorsal sac(P < 0.05),and there was a significant positive interaction between sodium butyrate in the starter mixture and sodium butyrate in whole milk on the papilla height of the rumen dorsal sac(P < 0.05);3.The addition of sodium butyrate to the starter mixture had no effect on the structural development of the jejunum and colon(P > 0.05),and the addition of sodium butyrate in whole milk decreased the jejunum crypt depth,villi length,and villi length/crypt depth(P<0.05),and there was a significant negative interaction between sodium butyrate in the stater mixture and sodium butyrate in whole milk on jejunum villi length(P < 0.05).The results of the above tests showed that both starter mixture and whole milk into sodium butyrate promote the structural development of the gastrointestinal tract,and there is no interaction between them.Experiment 3: Interactive effects of sodium butyrate addition to starter mixture and whole milk on gastrointestinal tract tight junction gene and protein expression in preweaning calvesThe test methods and diets were the same as in test 1,and the slaughter methods and sampling were the same as in test 2.Ruminal,jejunum and colon tissues were taken and the expression levels of tight junctions m RNA were detected by q RT-PCR and the expression levels of tightly linked proteins were detected by Western-blot.The experimental results were as follows: 1.The addition of sodium butyrate to the stater mixture and whole milk had a significant(P < 0.01)effect on the m RNA expression levels of rumen,jejunum and colon Claudin-1,Claudin-4,Claudin-7,Occludin and ZO-1,and the addition of sodium butyrate to the stater mixture and whole milk had a positive(P< 0.01)effect on the m RNA expression of rumen,jejunum and colon Claudin-1,Claudin-4,Claudin-7,Occludin and ZO-1 m RNA expression(P < 0.01);2.The addition of sodium butyrate to the starter mixture significantly increased the expression levels of tight junction proteins in the rumen,jejunum and colon(P < 0.05),and the addition of sodium butyrate to whole milk had no significant effect on the expression levels of tight junction proteins(P>0.05).There was no interaction between sodium butyrate in starter mixture and sodium butyrate in whole milk on the level of tight junction protein expression in rumen,jejunum and colon(P > 0.05).The above experimental results showed that the addition of sodium butyrate to starter mixture and whole milk could up-regulate the level of gastrointestinal tight junction m RNA and protein expression,and there was no interaction between starter mixture sodium butyrate and whole milk sodium butyrate on tight junction expression with additivity.Experiment 4: Interactive effects of sodium butyrate addition to starter mixture and whole milk on the gastrointestinal microbiota of preweaning calvesThe test methods and diets were the same as in test 1,and the slaughter methods were the same as in test 2.Ruminal and cecum food surimi were taken and stored in liquid nitrogen.The microbial composition was examined using macrogenomics.The test results were as follows: 1.Firmicutes and Bacteroidetes were the dominant phylum at the rumen phylum level,and Lachnospiraceae was the dominant phylum and Prevotella was the dominant genus at the family level.Sodium butyrate increased the abundance of ruminal Olsenella and Lactimicorbium spp.(P < 0.05)and decreased the abundance of Megasphaera and Mitsuokella spp.(P < 0.05),and there was no interaction between sodium butyrate of starter mixture and sodium butyrate of whole milk on ruminal microorganisms(P > 0.05).2.At the level of cecum phylum Firmicutes,Bacteroidetes was the dominant phylum and Lachnospiraceae was the dominant family.Addition of sodium butyrate to whole milk decreased Agathobaculum abundance(P < 0.05),and there was a positive interaction between sodium butyrate of starter mixture and sodium butyrate of whole milk on Agathobaculum(P < 0.05).The results of the above tests showed that supplementation of sodium butyrate in starter mixture and whole milk improved the microbial composition of the rumen and cecum,increased the abundance of beneficial bacteria and decreased the abundance of harmful bacteria,and there was no interaction between sodium butyrate in starter mixture and sodium butyrate in whole milk on rumen and cecum microorganisms.In conclusion,the addition of sodium butyrate to starter mixture and whole milk will improve the immunity of lactating calves,reduce the inflammatory response,enhance the physical barrier function of the gastrointestinal tract,and improve the gastrointestinal microbiota of calves.There is no interaction between the effects of sodium butyrate in starter mixture and sodium butyrate in whole milk on the growth performance,gastrointestinal development and microbiota of calves,but there is an additive effect.