RESUMO
This experiment was conducted to determine the effect of high levels of supplemental Cu (as (CuSO4).5H2O) on the serum lipid profile and carcass traits of goat kids. Fifteen Boer x Spanish wether goat kids (BW = 21.3 +/- 0.7 kg) were housed in individual pens and were assigned randomly to 1 of 3 treatments. Treatments consisted of 1) control (no additional supplemental Cu), 2) 100 mg of Cu/d, and 3) 200 mg of Cu/d. Copper sulfate was placed in gelatin capsules and inserted into the esophagus via a balling gun before the morning feeding. Animals were fed a high-concentrate (70:30 grain:hay) diet for 112 d. Serum lipid profile was determined on d 14 and 112, and BW was recorded after 4-h withdrawals from feed and water. After 112 d, animals were slaughtered, and carcass traits were measured. The left half of 12 carcasses and 9th to 11th rib sections from the right side of 15 carcasses were dissected into separable soft tissue and bone portions. The soft tissue portion was analyzed for moisture, ether extract, CP, and ash. Average daily feed intake decreased (linear; P = 0.05), and G:F increased (quadratic; P = 0.02) in the 100 mg of Cu/d group. Serum cholesterol and triglycerides did not change (P > 0.10); however, NEFA decreased (linear; P = 0.01) as supplemental Cu increased. No differences were observed (P > 0.10) in HCW, chilled carcass weight, or kidney and pelvic fat; however, 12th rib fat (linear; P = 0.01) and adjusted fat thickness (linear; P = 0.03) decreased as Cu supplementation increased. No differences (P > 0.10) in LM area were observed; however, percentage of boneless closely trimmed retail cuts increased (linear; P = 0.04) as Cu supplementation increased. The moisture (%) of the 9th to 11th rib sections increased (linear; P = 0.03), ether extract (%) decreased (linear; P = 0.02), and CP and ash (%) tended to increase (linear; P = 0.09 and 0.06, respectively) as Cu supplementation increased. Carcass composition measured using the left half of the carcass confirmed the values obtained through the 9th to 11th rib sections. Results of this study indicate that supplemental Cu can alter the serum lipid profile, carcass characteristics, and carcass composition of goat kids.
