Effects Of Amino Acid Chelated Zinc On Growth Performance And Tissue Zinc Deposition In Weaned Piglets

The purpose of this experiment was to investigate the effects of replacing inorganic zinc?ZnSO₄?with different levels of organic zinc?zinc-methionine and zinc-glycine?on growth performance,serum biochemical indexes,hematological parameters and tissue zinc deposition in weaned piglets.The optimum addition level of amino acid chelated zinc in diet was further determined.This study also provides theoretical basis and technical support for the improvement of Zn feed efficiency in weaned piglets.Thirty-five weaned piglets with average body weight of?12.0±1.0?kg were randomly divided into 5 treatment groups,7 replicates in each treatment group and 1 pig in each treatment group.Piglets were housed in individual pens?one piglets per pen?.The control group was fed with 80 mg/kg ZnSO₄,and the experimental group was supplemented with 80mg/kgZn-Met?40mg/kgZn-Gly?80mg/kgZn-Met?40mg/kgZn-Gly in basal diet,respectively?according to Zn?.The pre-feeding period was 7 days,and the experimental period was 28 d.The results showed that:?1?compared with the control group,dietary Zn-Met or Zn-Gly had no significant effect on the average daily feed gain?ADFI?,?ADG?and feed-to-weight ratio?FG?of weanling piglets?P>0.05?.The feed-to-weight ratio?FG?of80mg/kgZn-Gly was lower than that of other groups,and there was a significant difference between the two groups?P<0.05?.?2?.Compared with the control group,the dietary addition of Zn-Met or Zn-Gly increased the serum total protein in weanling piglets.The content of?TP?and creatinine?CREA?in serum decreased to a certain extent,but the difference was not significant?P>0.05?.The serum IGM activity of 80mg/kgZn-Gly was the highest,which was significantly different from that of 80mg/kgZn-Met and40mg/kgZn-Gly?P<0.05?.?3?.Dietary addition of Zn-Met or Zn-Gly increased the total number of?LYM?,erythrocytes?RB?in?NEU?,lymphocytes of blood neutrophils in weanling piglets.C),mean platelet volume?MPV?,eosinophils?EOS?,basophils?BAS?,basophils ratio?BAS%?,among which 40mg/kgZn-Met blood RBC was the highest,compared with the control group.The difference between 80mg/kgZn-Met and80mg/kgZn-Gly group was significant?P<0.05?.Compared with the control group,the Mean Corpuscular Hemoglobin?MCH?in 80mg/kgZn-Gly and 40mg/kgZn-Gly groups was significantly lower?P<0.05?,while 40mg/kgZn-Met and 80mg/kgZn-G were significantly lower than those in the control group?P<0.05?.The mean hemoglobin concentration?MCHC?in the ly group was significantly lower than that in the control group?P<0.01?.Compared with the control group,the dietary supplementation of Zn-Met or Zn-Gly significantly decreased the blood PLT and PCT%?P<0.05?.?4?the muscle calcium levelof in 40mg/kgZn-Gly group was the highest,which was significantly different from that in the control group and Zn-Met group?P<0.01?.The muscle iron level in80mg/kgZn-Gly group was the highest,which was significantly different from that in80mg/kgZn-Met and 40mg/kgZn-Gly groups?P<0.01?.Liver zinc level in the content of80mg/kg Zn-Met group was the highest,which was significantly higher than that of control group and Zn-Gly group?P<0.01?,and kidney iron level in the content of iron and zinc in kidney of 80mg/kgZn-Met group was the highest,but there was no significant difference among the three groups?P>0.05?.Compared with the control group,the calcium content in the spleen of the 80 mg/kg Zn-Met group was significantly lower?P<0.01?,and the calcium content in the spleen of the 40 mg/kg Zn-Gly group was significantly increased?P<0.01?,zinc methioninate and zinc glycinate.The content of copper in the spleen was significantly decreased?P<0.01?.The content of spleen iron and spleen magnesium was the highest in the 40mg/kg Zn-Gly group,and significantly different from the 80mg/kg Zn-Met group and the 80mg/kg Zn-Gly group?P<0.05?,the zinc content in the spleen of the zinc glycinate group was significantly higher than that of the control group and the methionine zinc group?P<0.01?.In conclusion,adding Zn-Met and Zn-Gly instead of inorganic zinc sulfate can improve the growth performance and serum biochemical indexes of weaned piglets,especially when feedingwith 80 mg/kg Zn-Gly.The replacement with Zn-Met and Zn-Gly also promotes Zn deposition in tissues,especially when feeding with 80 mg/kg Zn-Met and40 mg/kg Zn-Gly.