| The purpose of this experiment was to study the effects of OPS-Zn in three different doses on growth performance,blood physiological and biochemical indexes,on tissue zinc deposition and on protective barrier of intestine stimulated by LPS in weaned piglets.30 weaned piglets(Duroc×Landrace×Yorkshire)at the age of 28d±1 were rondomly allocated into five groups,named blank control group(A group),immunological stress control group(B group)and OPS-Zn low dose group(C group),middle dose group(D group)and high dose group(E group)with six replicates per group according to the principle of similar weight.The piglets fed basal diet supplemented with(Control)or 1.2%,0.8%,0.5%OPS-Zn for 32 days.The piglets were injected with a dose of Escherichia coli LPS(100 ?g/kg BW)except the Blank control which were injected with the dose of normal saline.The blood samples were collected from each group after 3 hours of the injection for measuring Route blood test,biochemical parameters.The liver,spleen,kidney and different parts of the intestine were dissected immediately after blood sampling.Each repeated experiment had recorded weight,organ fresh weight and feed intake.Results:(1)The growth performance:compared with A,B groups,the ADG value of D,E groups was not significant(P>0.05),and the mean values of C,D and E were respectively increased by 2.28%,11.77%,and 27.12%higher than A group.In the D group,the daily feed intake(ADFI)value was different significantly(P<0.05),and the mean values of C,D and E groups were respectively increased by 11.31%,12.58%and 13.72%higher than A group.In each group,the mean value of F/G was A>B>C>D=E.The results showed that the palatability of OPS-Zn was better.It was beneficial to improve the feeding of weaned piglets and the growth performance of weaned piglets,which the middle and high doses had the best effect.(2)Organ index:Compared with A group,the absolute weight of liver,spleen and kidney in the weaned piglets organs was not significant difference in C,D and E groups(P>0.05).Compared with B group,the liver of C,D and E groups related to absolute weight was increased,which the increased trend of D group was the most obvious.While the spleen related to absolute weight was decreased,decreased with the addition of OPS-Zn negatively correlated with the level of the trend;the absolute weight changes in the kidney were slightly different but not obvious.Compared with the A group,the effects of different levels of dietary OPS-Zn was no significant difference on the spleen,kidney and liver index of weaned piglets(P>0.05).The mean value of the indexes in spleen was B>E>A>C,the mean value of the indexes in kidney was D>E>C>A.Compared with the B group,the liver index of the A group showed a downward trend,while the spleen and kidney index showed an upward trend.The liver,spleen and kidney index were not significantly different in C,D and E groups(P>0.05).The results showed that the addition of OPS-Zn could improve the liver weight and alleviate the acute stress induced by LPS.(3)Blood routine indexes:Compared with A group,WBC was decreased significantly in B,C,D and E groups(P<0.05);PCT was decreased significantly in B and C groups(P<0.05);MCHC was decreased significantly in D group(P<0.05);PLT and MCHC were significantly decreased in E group(P<0.05),MPV was significantly increased(P<0.05).Compared with B group,WBC was significantly decreased in C and D groups(P<0.05),PCT was increased significantly(P<0.05),PLT and RBC level had a rising trend;WBC,PLT and MPV were significantly decreased in E group(P<0.05),while RBC and PCT were significantly increased(P<0.05).The results showed that OPS-Zn could improve the function of blood coagulation and anti inflammation.It could improve the absorption of nutrients to promote the generation of hematopoietic cells and the formation of hemoglobin in stress.(4)Blood biochemical indicators:Compared with A group,the levels of GLU,ALB and CREA were increased significantly in B group(P<0.05),the levels of AST,ALT,LPH and CK were decreased significantly(P<0.05);the levels of AST,ALT and LPH were decreased significantly in C group(P<0.05),the levels of CREA,ALB and BUN/CR were increased significantly in D group(P<0.05),the levels of AST,ALT,TP,GLB,CK and LDH were decreased significantly(P<0.05);the levels of BUN,BUN/CR,ALB,A/G,AST and CREA were increased significantly in E group(P<0.05),the level of LPH showed an increasing trend.Compared with B group,CREA and ALT were decreased significantly in C group(P<0.05),the level of LPH was decreased;the levels of GLU,ALT,TP and GLB were decreased significantly in D group(P<0.05),the levels of AST,CK and LPH were decreased;elevated the levels of BUN,ALT,CK and LDH were significantly decreased in E group(P<0.05),the levels of AST and TP had an increasing trend.The results showed that OPS-Zn could decrease the function of blood glucose,protect the liver and enhance the anti stress ability.(5)Tissue zinc content:Compared with A group,the liver,kidney and spleen zinc content of weaned piglets had no significant difference in B group(P>0.05),the liver zinc content had significant difference in E and A groups(P<0.05),the liver zinc content were increased by 33.46%,49.92%and 98.84%in C,D and E groups;the kidney and spleen zinc content of weaned piglets had no significant difference in C,D and E groups(P>0.05),the kidney zinc content was increased 11.58%,19.25%and 7.83%in C,D and E groups;the zinc containing of spleen was increased 0.16%in D group,the zinc containing of spleen the amount was decreased by 19.37%and 2.14%in C and E groups.The results showed that:The OPS-Zn suggested that the bioavailability of zinc chelate was higher than inorganic zinc,and promoted the synthesis of liver protein in order to respond to stress and infection.(6)Fecal zinc content:Compared with A group,the fecal zinc content of weaned piglets had no significant difference in B,C,D groups(P>0.05);the feces zinc content of weaned piglets had significant difference in E groups(P<0.05),At the same time,the average value is C>B>D>E in order of magnitude.The results showed that LPS stress had no effect on the excretion of zinc content.With the levels of OPS-Zn rising,the excrement zinc content of weaned piglets decreased.(7)Intestinal morphology:The villus length in duodenum was observed and measured.It was no significant difference between A group and B group(P>0.05),significantly different between C,D,E groups and B group(P<0.05).Crypt depth:It was significantly different between B group and A,C groups(P<0.01),the other groups were not significantly different(P>0.05).Villus/crypt:It was significantly different between A,B and C groups(P<0.05).It had no significant difference between D and E groups(P>0.05),significant difference between B,E and D groups(P<0.05),and the other groups had no significant difference(P>0.05).The villus length in ileum and jejunum was significantly different between A group and B group(P<0.05),significant difference between B group and C,D,E groups(P<0.05),but no significant difference in C,D and E groups(P>0.05).Crypt depth:it was significantly different between A group and B group(P<0.05),the other groups were not significantly different(P>0.05).Villus/crypt:Compared with A group,the jejunum was not significantly different between B,C,D and E groups(P>0.05).Compared with B group,it had significant difference between A,C,D and E groups(P<0.05),but the other groups had no significant difference(P>0.05).The results showed that OPS-Zn could improve the morphological structure of villi,increase the absorptive cells and decrease the secretory cells to some extent.Conclusion:OPS-Zn can effectively alleviate the immune stress of weaned piglets induced by LPS injection,and the effect of remission is better between 0.8%and 1.2%. |
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