The Dynamic Relationships Of Growth Performances And Copper Residues In The Body Tissues With The Dietary Copper Supplementation In The Growing～Finishing Pigs

The Dynamic Relationships of growth Performances and Copper Residues in the Body Tissues with the Dietary Copper Supplementation in the Growing ~ Finishing Pigs were investigated in this study . In the experiment , Sixty DurocXLandranceXYorkshire(DLY) piglets averaging 20kg were assigned to five dietary treatment in a single factorial arrangement during 20~100kg weight stage. Pigs received a diet containing about 0, 100, 200, 300, 400mgCu/kg diet, respectively.The results showed that the supplementation of 100~300mgCu /kg diet could increase average daily gain (ADG) and decrease F/G of growing-finishing pigs. Compared to the control group, ADG increased by 7. 67 -10.59% (p>0. 05) , F/G was reduced by 4. 58-11.76% (p>0. 05) . The regression equations of the ADG(y,,g) and F/G(y2) with the copper supplementation(x, mg/kg) is : y, = 737.21+ 0.9343 x-0. 0025 x2 (R2=0.900, p=0. 100) ; y2 =3. 1063- 0.0036x+8.7E-06x2 (RJ=0. 795, p=0. 205) . According to the regression equations,the highest ADG could be achieved when the copper supplementation is 186mg/kg, the lowest F/G could be gotten when the copper supplementation is 206mg/kg.The supplementation of 100-400mgCu/kg diet did harm to the body tissues in different extent. The copper content in the liver and kidney tended to increase with the increase of the copper supplementation. When the pigs were slaughtered at the body weight of 100kg, the copper content in the liver of the tested groups is 1. 37 (p>0. 05). 3. 48 (p<0. 05X 14. 34 ( p<0.01 ) and 27.42 times ( p<0.01 ) as much as the control group respectively. The copper content in the spleen, heart, blood serum andmuscle didn' t change too much with the dietary copper supplementation.The regression equations of the copper content in the liver(y3, mg/kg) with the copper supplementation (x, mg/kg) is : 80kg, y3 =5.4697 - 0. 08l4x +0. 0009x2 (R2=0. 930, p=0. 07) ; 100kg, y4= 11.3963- 0. 2920x + 0. 0022x2 (R2=0. 814, p=0. 036) . According to the regression equations, if "y3" and "y4" don' t exceed 10mg/kg, "x" couldn' t exceed 129 mg/kg when the pigs were slaughtered at 80kg, and "x" couldn' t exceed 128 mg/kg when the pigs were slaughtered at 100kg. The regression equations of the copper content in the kidney (y5, mg/kg) with the copper supplementation (x, mg/kg) is : 100kg, y5 = 8. 7583 - 0. 0043x +0. 0002x2 (R2=0. 975, p=0. 025) . According the equations, if the copper content in the kidney don' t exceed 10mg/kg, the copper supplementation couldn' t exceed 90 mg/kg.