| In order to explore the effects of dietary copper levels on hair production performance,hair follicle development and intestinal microorganisms of Angolan long-haired rabbits,180five-month-old long-haired rabbits with good health were randomly divided into 5 groups,each group had 36 replicates,each replicate was 1 replicate,the copper additions were 0,5,10,20 and 40 mg/kg,respectively,and the samples were taken on the 76 th day of the test to determine the hair production performance,trace element digestion and metabolism,serum biochemistry,hair follicle development and intestinal microorganisms,and the test results were as follows:(1)The dietary copper concentration significantly affected the gross yield(P < 0.01),among which the gross yield of the 5 mg/kg copper addition group was significantly different from that of the control group,the copper concentration of the diet significantly decreased the material-to-gross ratio(P < 0.01),and the feed conversion efficiency of the 5 mg/kg copper addition group was higher.Dietary copper concentration significantly affected the elongation,elongation and shoulder hair length of angora rabbit hair(P < 0.05),and the dietary copper concentration significantly affected the rabbit hair breaking strength,breaking strength,breaking work,coarse hair rate,back hair length and shoulder hair length(P < 0.01).Dietary copper concentration significantly affected the total hair follicle density of Angora rabbit skin(P < 0.05),with the increase of copper concentration,the total hair follicle density showed a trend of first increasing and then decreasing,when the copper addition amount was 5 mg/kg,the total hair follicle density was significantly different from that of the control group,and the dietary copper concentration significantly affected the secondary hair follicle density of Angolan rabbit(P < 0.01),and with the increase of copper concentration,the secondary hair follicle density showed a gradual increase trend.The concentration of dietary copper significantly affected the expression of Wnt10 b and Kap6.1 genes in the skin of Angora rabbit(P < 0.05),and the concentration of dietary copper significantly affected the m TOR gene(P <0.01)in the skin of Angora rabbit,and the expression of Wnt10 b,Kap6.1 and m TOR genes in the skin of Angora rabbit was significantly different from that in the control group when the amount of copper was 5 mg/kg.(2)Effect on the apparent digestibility of trace elements: there was a significant effect on the apparent digestibility of iron in the control group and the group with a copper addition of5 mg/kg(P < 0.01),the apparent digestibility of zinc in the control group and the copper addition of 5 mg/kg group(P < 0.05),and the apparent digestibility of iron and zinc in the group with a copper addition of 5mg/kg was significantly different from that in the control group.(3)Effects on blood routine and immune performance: dietary copper concentration significantly affected Angolan rabbit triglycerides(P < 0.05),when the copper content was 20mg/kg,the content of triglycerides was significantly increased,and the dietary copper concentration significantly affected the content of uric acid,alanine transferase and glutamate transferase in Angolan rabbits(P < 0.01),with the continuous increase of copper concentration,uric acid showed a trend of first decreasing and then increasing,and the content of alanine transferase and glutaminase was significantly increased when the copper content was 40mg/kg.Dietary copper concentration had no significant effect on Angora rabbit immunoglobulin A(Ig A),immunoglobulin G(Ig G),and immunoglobulin M(Ig M)(P > 0.05).(4)Effects on intestinal microbiota: dietary copper concentration significantly affected species number(P < 0.05),and dietary copper concentration significantly affected Chao index and coverage rate(P < 0.01).Dietary copper concentration had no significant effect on aroma index,Simpson index,evolutionary diversity and uniformity(P > 0.05).The addition of copper reduced the richness and diversity of intestinal microbiota in Angora rabbits,and combined with the columnar stacking plot at the Venn diagram and the phylum and genus levels,it was found that the addition of copper had no significant effect on the structure of beneficial intestinal bacteria(P > 0.05). |
