ABSTRACT
BACKGROUND: Five hundred 8-d old male broilers Cobb500 were randomly allotted into 10 treatments in factorial arrangement with 5 Cu levels (0, 4, 8, 12, and 16 mg/kg), and 2 sources (Cu proteinate, CuPro and Cu sulphate, CuSO4.5H2O) for a 10-d-experiment. RESULTS: Feed conversion ratio (FCR) was better (P < 0.05) in CuPro fed chicks compared with CuSO4.5H2O group. Average daily feed intake (ADFI) decreased linearly (P < 0.05) as dietary Cu increased. A quadratic response (P < 0.05) to Cu levels was found for FCR, being optimized at 9.87 and 8.84 mg Cu/kg in CuPro and CuSO4.5H2O diets, respectively. Copper supplementation linearly increased liver Cu content (P < 0.05) and tended to linearly increase (P = 0.07) phosphorus (P) and copper in tibia. Manganese and zinc were higher (P < 0.05) in tibia of CuPro fed birds. Broilers fed CuPro exhibited lower liver iron (P < 0.05) content, lower activities of Cu, Zn superoxide dismutase (CuZnSOD) in breast muscle and liver, and glutathione peroxidase in liver. Glutathione peroxidase reduced linearly (P < 0.05) with CuPro levels and increased linearly (P < 0.05) with CuSO4.5H2O levels and were lower (P < 0.05) in all CuPro levels in breast muscle. Breast muscle malondialdehyde concentration tended to be higher (P = 0.08) in broilers fed CuSO4.5H2O. Copper levels linearly increased (P < 0.05) metallothionein (MT) and malate dehydrogenase (MDH) expression in liver, and six-transmembrane epithelial antigen of the prostate-1 (STEAP-1) in the intestine. Copper elicited a quadratic response (P < 0.050) in AKT-1 and mammalian target of rapamycin (mTOR) in breast muscle, CuZnSOD in liver and antioxidant 1 copper chaperone (ATOX 1) in intestine. Broilers fed CuPro exhibited higher mRNA expression of mTOR in muscle breast and lower CuZnSOD in liver and ATOX 1 in intestine. Interaction (P < 0.05) between levels and sources was found in mRNA expression for GSK-3ß, MT, and CuZnSOD in breast muscle, FAS and LPL in liver and MT and CTR1 in intestine. CONCLUSIONS: CuPro showed beneficial effects on feed conversion and bone mineralization. Organic and inorganic Cu requirements are 9.87 and 8.84 mg Cu/kg, respectively.
Subject(s)
Chickens , Copper , Animal Feed/analysis , Animals , Antioxidants/metabolism , Copper/metabolism , Diet/veterinary , Dietary Supplements , Glutathione Peroxidase , Glycogen Synthase Kinase 3 beta , Lipids , Male , Mammals , Minerals , RNA, Messenger , Superoxide Dismutase , TOR Serine-Threonine KinasesABSTRACT
SUMMARY This study was conducted to determine the ideal ratio of digestible threonine: lysine in diets for laying hens at 42 to 58 weeks of age. Two hundred forty Hy Line W-36 laying hens were used at 42 weeks of age for 16 weeks. The treatments were distributed in a completely randomized design with eight replicates and six birds each. The experimental diets were formulated with five levels of digestible threonine (0.461; 0.515; 0.569; 0.622 and 0.676%) providing the five ratio of digestible threonine: lysine (60; 67; 74; 81 and 88%) studied. The variables analyzed were: egg production; feed intake; lysine intake; threonine intake; mass egg; average egg weight; lysine use efficiencies by mass and produced eggs; feed conversion per mass and dozen eggs; Average weights yolk, albumen and shell; weight gain and final body weights of birds; and nitrogen balance. The digestible threonine: lysine ratio in the diet did not influence the analyzed variables except consumption of threonine which showed a linear effect. The ideal ratio of digestible threonine: lysine in diets for white laying hens at 42 to 58 weeks of age is 60%, which corresponds to the level of 0.461% of digestible threonine in the diet and daily intake of digestible threonine 446mg/bird.
RESUMO Este estudo foi realizado para determinar a relação ideal de treonina:lisina digestíveis para poedeiras leves no período de 42 a 58 semanas de idade. Foram utilizadas 240 poedeiras Hy Line W-36 com 42 semanas de idade durante 16 semanas. Os tratamentos foram distribuídos em delineamento inteiramente casualizado, com oito repetições e seis aves por unidade experimental. As dietas experimentais foram formuladas com cinco níveis de treonina digestível (0,461; 0,515; 0,569; 0,622 e 0,676%) proporcionando as cinco relações treonina:lisina digestíveis (60; 67; 74; 81 e 88%) estudadas. As variáveis analisadas foram: produção de ovos; consumo de ração, de lisina e de treonina; massa e peso médio dos ovos; eficiências de utilização da lisina por massa e ovos produzidos; conversões alimentares por massa e dúzia de ovos; pesos médios de: gema, albúmen e de casca; ganho de peso; peso corporal final das aves; e balanço de nitrogênio. As relações treonina:lisina digestíveis na dieta não influenciaram as variáveis analisadas, exceto o consumo de treonina que apresentou efeito linear. A relação ideal de treonina:lisina digestíveis na dieta para galinhas poedeiras leves de 42 a 58 semanas de idade é de 60%, que corresponde ao nível de 0,461% de treonina digestível na dieta e ao consumo diário de treonina digestível de 446mg/ave.
ABSTRACT
SUMMARY This study was conducted to determine the ideal ratio of digestible threonine: lysine in diets for laying hens at 42 to 58 weeks of age. Two hundred forty Hy Line W-36 laying hens were used at 42 weeks of age for 16 weeks. The treatments were distributed in a completely randomized design with eight replicates and six birds each. The experimental diets were formulated with five levels of digestible threonine (0.461; 0.515; 0.569; 0.622 and 0.676%) providing the five ratio of digestible threonine: lysine (60; 67; 74; 81 and 88%) studied. The variables analyzed were: egg production; feed intake; lysine intake; threonine intake; mass egg; average egg weight; lysine use efficiencies by mass and produced eggs; feed conversion per mass and dozen eggs; Average weights yolk, albumen and shell; weight gain and final body weights of birds; and nitrogen balance. The digestible threonine: lysine ratio in the diet did not influence the analyzed variables except consumption of threonine which showed a linear effect. The ideal ratio of digestible threonine: lysine in diets for white laying hens at 42 to 58 weeks of age is 60%, which corresponds to the level of 0.461% of digestible threonine in the diet and daily intake of digestible threonine 446mg/bird.
RESUMO Este estudo foi realizado para determinar a relação ideal de treonina:lisina digestíveis para poedeiras leves no período de 42 a 58 semanas de idade. Foram utilizadas 240 poedeiras Hy Line W-36 com 42 semanas de idade durante 16 semanas. Os tratamentos foram distribuídos em delineamento inteiramente casualizado, com oito repetições e seis aves por unidade experimental. As dietas experimentais foram formuladas com cinco níveis de treonina digestível (0,461; 0,515; 0,569; 0,622 e 0,676%) proporcionando as cinco relações treonina:lisina digestíveis (60; 67; 74; 81 e 88%) estudadas. As variáveis analisadas foram: produção de ovos; consumo de ração, de lisina e de treonina; massa e peso médio dos ovos; eficiências de utilização da lisina por massa e ovos produzidos; conversões alimentares por massa e dúzia de ovos; pesos médios de: gema, albúmen e de casca; ganho de peso; peso corporal final das aves; e balanço de nitrogênio. As relações treonina:lisina digestíveis na dieta não influenciaram as variáveis analisadas, exceto o consumo de treonina que apresentou efeito linear. A relação ideal de treonina:lisina digestíveis na dieta para galinhas poedeiras leves de 42 a 58 semanas de idade é de 60%, que corresponde ao nível de 0,461% de treonina digestível na dieta e ao consumo diário de treonina digestível de 446mg/ave.