The Effects Of Different Levels Of Copper In Diets On The Growth Performance And Biochemical Parameters In Growing Pigs

Abstract: This experiment using 60 揓unmu No.1?pigs (average initial weight of 19.26 kg) was conducted to examine the effects of feeding different levels of dietary Cu from copper sulfate (CuSO4) on growth performance and serum biochemical parameters. Dietary treatments were 0 (4.6 mg/kg of Cu in basal diet), 100, 150, 200, 250, or 300 mg/kg of supplemental Cu from CuSO4. Pigs were allotted by weight, sex, and given ad libitum access to corn-soybean feed and water during the lOO-d trials. Pigs were weighted and pen feed intakes were recorded on dO, 20, 40, 60, 80. and 100 of the trial. Blood samples were collected for measurement of biochemical parameters on d 0, 20. 40, 60, and 80 of the experiment. Overall, absolute weight (AW), average daily gain (ADG) and feed:gain (FIG) were improved by feeding 150, 200, 250, or 300 mg/kg of Cu as CuSO4 during the growing stage (live weight 20-60 kg). However, different levels of Cu in diets showed no effect on ADO and FIG during the finishing stage (live weight 60 kg-90 kg). The addition of 200 and 250 mg/kg of Cu improved (P less than .01) performance (ADG attained 720.7 g/d and 725.8 g/d, AW attained 90.81 kg and 92.02 kg, FIG attained 3.08 and 3.06, respectively) significantly throughout the 100-d trial. Supplementation of 100 and 0 mg/kg of Cu (control group) did not affect pig performance. Feed intake was not affected by adding Cu in the diets. Concentrations of urea N in serum in pigs supplemented with Cu decreased on d 20, 40, 60, and 80 (10.3%, 12.0%, 9.7%, and 5.6%) by supplement Cu. Serum urea N decreased (P less than .05) significantly on d 60 in pigs supplemented with 200 and 250 39 H4t~J4IJf)~ mg/kg of Cu. Addition of Cu increased serum total protein and albumin. The average increased percentage of total protein on d 40, 60, and 80 were 5.4, 7.2, and 3.2, and albumin on d 20, 40, 60, and 80 were 14.6, 15.5, 16.9, and 0.23, respectively. The concentrations of triglycerides and cholesterl in serum were not influenced by Cu treatment. The activities of ceruloplasmmin, CuZn-superoxide dismutase, alkaline phosphatase, and alanine aminotransferase in serum were increased by supplement with various levels of Cu in diets. In contrast, there was little or no variation in serum lactate dehydrogenase and cholinesterase activity by Cu treatment. Treating pigs with Cu enhanced serum growth hormone, insulin, free thyroxine, and free triiodothyronine. Growth hormone and insulin had increased (P less than .05) significantly by supplement with 200 or 250 mg/kg of Cu in the diets. Pigs fed the supplemental Cu diets had higher Cu concentrations and lower Zn concentrations in serum, however, Fe concentrations had not been affected by adding Cu to the basic diets. These data indicate that pharmacological addition of 150, 200, 250, or 300 mg/kg of Cu (sulfate) play a role of stimulating growth in pig with living weight ranges from 20 kg to 60 kg, and addition of 200 mg/kg or 250 mg/kg of Cu has the greatest improvement in growth performance. The effects of supplemental Cu in diets on serum hormones, enzymes activities, biochemical parameters, and trace elements in pig depend on the phrases of pig growth. The role of Cu in stimulating growth in pig is derived from increasing the efficiency of nutrient utilization rather than increasing feed intake. The effects of Cu stimulating growth on performance and on the serum biochemic...