Effects Of Different Forms Of Zinc Oxide On Growth Performance,blood Index,Intestinal Barrier And Intestinal Flora In Weaned Piglets

Numerous studies have shown that Dietary addition of 3000mg/kg of common zinc oxide can alleviate diarrhea in weaned piglets and improve the growth performance of weaned piglets.However,the absorption and utilization rate of zinc in production and use are low,and high dosage will lead to excessive zinc residue in manure,polluting the environment.Therefore,This experiment through the experimental study on the different forms of zinc oxide antibacterial effect in vitro and stomach digestive retention rate,at the same time by the research on animal feeding different form zinc oxide on weaning piglet growth performance and blood index,the influence of the intestinal barrier,system research of nano zinc oxide,modified zinc oxide,coated zinc oxide and the feasibility of the inclusion zinc oxide instead of ordinary zinc oxide.Experiment 1,different forms of zinc oxide bacteriostatic test in vitro.To study the antibacterial effects of different forms of zinc oxide on staphylococcus aureus,escherichia coli and salmonella.The bacteriostatic effect was compared by measuring the diameter of bacteriostatic circle.Experiment 2.Different forms of zinc oxide were tested for gastric digestion.The residual mass of different forms of zinc oxide digested by gastric juice with different p H values was determined and the retention rate was determined.Meanwhile,the effects of different forms of zinc oxide on gastric juice p H were compared.Experiment 3: effects of different forms of zinc oxide on growth performance,blood indexes and intestinal barrier of weaned piglets.125 "du × long × big" hybrid piglets with an average weight of 7 kg at 28 days old were selected and randomly divided into 5 groups with 5 replicates in each group and 5 pigs in each repeat.Group 1 was the control group(basic diet +3 000 mg/kg common zinc oxide).The second group was nanometer zinc oxide group(basic diet +800 mg/kg nanometer zinc oxide).The third group was the modified zinc oxide group(basic diet +1 000 mg/kg modified zinc oxide).The fourth group was zinc inclusion group(basic diet +1 500 mg/kg zinc inclusion).Group 5 was capsule zinc oxide group(basal diet +2 500 mg/kg capsule zinc oxide group).The trial period was 14 days.The growth performance,blood index,intestinal morphology,function and intestinal flora of piglets were determined.1.Vitro bacteriostatic test: The results of bacteriostasis test in vitro showed that thebacteriostasis effects of coated zinc oxide group,modified zinc oxide group,nano-zinc oxide group and included zinc oxide group on Escherichia coli,Salmonella were significantly lower than those of control group(P<0.01),The bacteriostatic effects of nano-zinc oxide and modified zinc oxide on Staphylococcus aureus were not significantly different from those of the control group(P>0.05),but those of other zinc groups were significantly lower than those of the control group(P<0.01).2.Stomach digestion test: The results of over-gastric digestion test showed that the retention rate of four different forms of zinc oxide after over-gastric digestion was higher than that of the control group,and the retention rate of coated zinc oxide after over-gastric digestion was higher(P<0.01).At the same time,coated zinc oxide and included zinc oxide had little effect on p H value of gastric juice(P<0.01).3.Growth performance: Feeding experiment results showed that there was no significant difference in daily gain between the modified zinc oxide group and the included zinc oxide group(P>0.05)and the control group.The daily intake and Feed/ Gain Ratio of the modified zinc oxide group were not significantly different from those of the control group(P>0.05),while the production performance of other forms of zinc oxide was lower than that of the control group.The diarrhea rates of weaned piglets with modified zinc oxide and included zinc oxide were not significantly different from those of the control group(P>0.05).The diarrhea rates of weaned piglets with coated zinc oxide group and nano zinc oxide group were significantly higher than those of the control group(P<0.01).4.Blood index: A combination of basal ration and different forms of zinc oxide had no significant effect on serum GLU,GLB,UN,GOT,GPT and AKP of weaned piglets(P>0.05).The levels of ALB and TP in serum of weaned piglets in nano-zinc oxide group,coated zinc oxide group and included zinc oxide group were lower than those in control group(P<0.01),except that the levels of ALB and TP in serum of weaned piglets in modified zinc oxide group were not significantly different from those in control group(P>0.05).5.Intestinal morphology: There was no significant difference in duodenal villus height,recess depth and villus recess ratio between the modified zinc oxide group and the control group(P>0.05),but the duodenal villus height and villus recess ratio of the weaned pigletswith nano-zinc oxide,coated zinc oxide and included zinc oxide were significantly lower than those of the control group(P<0.01).The duodenal recess depth of the weaned piglets with modified zinc oxide group,nano-zinc oxide group and included zinc oxide group were not significantly different from those in control group(P>0.05)The depth of duodenal recess of weaned piglets with coated zinc oxide was significantly higher than that of the control group(P<0.01).6.Intestinal barrier: The levels of serum DAO and D-lactic acid in weaned piglets fed with basal ration as well as modified zinc oxide were significantly lower than those in the control group(P<0.01),while the levels of serum DAO in the coated zinc oxide group and the included zinc oxide group were significantly lower than those in the control group(P<0.01),and there was no significant difference in serum D-lactic acid between the coated and included zinc oxide group and the control group(P>0.05).The expressions of Claudin-1,Occludin,ZO-2 and Zo-1 in ileal epithelial cells of weaned piglets fed with basal ration as well as nano-zinc oxide,modified zinc oxide,coated zinc oxide and included zinc oxide were significantly lower than those of the control group(P<0.01).7.Cecal flora: Modified zinc oxide increased the Chao index,Ace index and OTU number of cecum microorganisms(P<0.01),and improved the abundance and diversity of intestinal microflora in weaned piglets.The proportion of cecum E.coli in the coated zinc oxide group was significantly higher than that in the other groups(P<0.01).The proportion of cecum Lactobacillus in the coated zinc oxide group and the included zinc oxide group was significantly lower than that in the control group(P<0.01),while there was no significant difference between the nano zinc oxide group and the modified zinc oxide group and the control group(P>0.05).In summary,1000mg/kg modified zinc oxide has similar effect on improving growth performance,blood index and intestinal barrier of piglets as 3000mg/kg ordinary zinc oxide,which is superior to other forms of zinc oxide.It can not only reduce the use of zinc,but also achieve the goal of environmental protection.