title: Effect of copper on performance, carcass characteristics, and muscle fatty acid composition of meat goat kids.
abstract: An experiment was conducted to determine the effects of dietary Cu on performance, carcass characteristics, and muscle fatty acid composition in meat goats. Thirty five Jianyang Big-ear goat (JYB) kids (average BW 20.3 ± 0.6 kg and age 3 to 4 mo) were stratified by weight and randomly assigned to 1 of 7 experimental treatments (n = 5 goats per treatment). Treatments consisted of: 1) control (no supplemental Cu; 14.3 mg Cu/kg DM), 2) 20 mg supplemental Cu/kg DM, 3) 40 mg supplemental Cu/kg DM, 4) 80 mg supplemental Cu/kg DM, 5) 160 mg supplemental Cu/kg DM, 6) 320 mg supplemental Cu/kg DM, and 7) 640 mg supplemental Cu/kg DM. Copper was supplemented from CuSO4•5H2O (25.2% Cu). Goats were individually fed a concentrate-hay based diet for 96 d. Performance was not affected by Cu concentration. Liver Cu concentration was increased (P < 0.01) with Cu supplementation. Goats supplemented with 0 or 20 mg Cu/kg DM had lower (P < 0.01) liver Cu concentrations than the other treatments. Backfat depth (P < 0.01) and intramuscular fat (IMF) content (P < 0.01) were also increased with Cu supplementation. However, Cu-supplemented goats had lower (P = 0.04) longissimus muscle area (LMA) compared with control. Dietary Cu supplementation increased the percentage of C14:0 (P < 0.01), C20:4 (P < 0.01), and total polyunsaturated fatty acids (P = 0.03), decreased C18:1 trans (P = 0.04), and tended to decrease C18:0 (P = 0.08) in LM. Other fatty acids detected were not affected by dietary Cu supplementation (P > 0.10). These results indicate that JYB goats can tolerate up to 640 mg Cu/kg DM for 96 d without adverse effects on performance, but fat deposition and fatty acid composition in the body could be altered by Cu supplementation as low as 20 mg/kg of diet with high concentrate-hay. Copper supplementation increased backfat depth, IMF, and percentage of polyunsaturated fatty acids in LM and decreased LMA in the carcass of JYB goats.
authors.affiliation: College of Life Science and Technology, Southwest University for Nationalities, Chengdu 610041, P. R. China.
authors.forename: Y L
authors.initials: YL
authors.lastname: Huang
authors.forename: Y
authors.initials: Y
authors.lastname: Wang
authors.forename: J W
authors.initials: JW
authors.lastname: Spears
authors.forename: X
authors.initials: X
authors.lastname: Lin
authors.forename: C H
authors.initials: CH
authors.lastname: Guo
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001823:Body Composition / Q000187:drug effects*; D003300:Copper / Q000494:pharmacology*; D004032:Diet / Q000662:veterinary; D005227:Fatty Acids / Q000235:genetics / Q000378:metabolism*; D006041:Goats / Q000254:growth & development* / Q000502:physiology*; D008297:Male; D018482:Muscle, Skeletal / Q000737:chemistry / Q000378:metabolism*; D012016:Reference Values
chemical_list: D005227:Fatty Acids; D003300:Copper