Peso vivo final, ganho de peso, características de carcaça e concentrações plasmáticas de IGF-I e hormônios tireoideanos de bezerros mestiços Angus-Nelore recebendo somatotropina bovina recombinante (rbST) até a desmama
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Data
2005-12-01
Autores
Cervieri, Rafael da Costa
Arrigoni, Mario de Beni [UNESP]
Chardulo, Luis Arthur Loyola [UNESP]
Silveira, Antonio Carlos [UNESP]
Oliveira, Henrique Nunes de [UNESP]
Martins, Cyntia Ludovico [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Sociedade Brasileira de Zootecnia
Resumo
Objetivando estudar o efeito da somatotropina bovina recombinante (rbST) sobre o desempenho, as características de carcaça e as concentrações plasmáticas de IGF-I e hormônios tireoideanos, 36 bezerros mestiços ½ Angus-Nelore com idade de 63 ± 17 dias e pesando 76,8 ± 14,7 kg, criados em pastagens de Brachiaria decumbens e suplementados em creep feeding, foram submetidos a dois tratamentos até a desmama (217 dias): I) 18 bezerros receberam 1,4 mg/kg de rbST (Boostin®) a cada 14 dias; II) 18 bezerros controle receberam solução salina. As pesagens e colheitas de sangue foram realizadas a cada 28 dias e, à desmama, foram abatidos cinco animais de cada tratamento, para avaliação das características de carcaça. Os animais tratados apresentaram maior ganho de peso médio diário e peso vivo final, maiores concentrações plasmáticas de IGF-I e T4 que os bezerros controle. Os parâmetros peso de carcaça quente, rendimento de carcaça, pesos de traseiro e dianteiro, gordura peri-renal, peso de fígado, área de olho de lombo, espessura de gordura subcutânea, pesos dos músculos do quarto do traseiro e concentração plasmática de T3 não diferiram entre os tratamentos. A utilização de rbST proporcionou aumento de 7,9% no ganho de peso vivo e alterou o perfil hormonal de bezerros suplementados em creep feeding durante a fase de cria, não refletindo, entretanto, em maior peso ou rendimento de carcaça.
The objective of this study was to evaluate the effects of recombinant bovine somatotropin (rbST) on production, carcass traits, and plasmatic concentrations of IGF-I and thyroid hormones on crossbred Angus-Nellore male calves. Thirty-six calves averaging 63 ± 17 days old and 76.8 ± 14.7 kg of body weight (BW) grazing Brachiaria decumbens and creep fed were randomly assigned (18 calves per treatment) to one of two treatments until weaning (217 days) as follows: I) 1.4 mg of rbST (Boostin®)/kg of BW every 14 days or II) similar dosage of saline solution. Every 28 days calves were weighed and blood samples collected; at weaning, five animals from each treatment were slaughtered for carcass evaluation. The rbST-treated calves had greater average daily weight gain, final weight, and plasmatic concentrations of both IGF-I and T4 than those receiving saline solution. Weights of hot carcass, forequarter, hindquarter, hindquarter muscles, and liver as well as dressing percentage, kidney and pelvic fat, rib eye area, backfat thickness, and plasmatic concentrations of T3 were all not affected by rbST. Use of rbST increased body weight gain (7.9%) and changed the hormonal status of pre-weaning creep-fed calves compared to the use of saline solution but did not improve carcass weight or dressing percentage.
The objective of this study was to evaluate the effects of recombinant bovine somatotropin (rbST) on production, carcass traits, and plasmatic concentrations of IGF-I and thyroid hormones on crossbred Angus-Nellore male calves. Thirty-six calves averaging 63 ± 17 days old and 76.8 ± 14.7 kg of body weight (BW) grazing Brachiaria decumbens and creep fed were randomly assigned (18 calves per treatment) to one of two treatments until weaning (217 days) as follows: I) 1.4 mg of rbST (Boostin®)/kg of BW every 14 days or II) similar dosage of saline solution. Every 28 days calves were weighed and blood samples collected; at weaning, five animals from each treatment were slaughtered for carcass evaluation. The rbST-treated calves had greater average daily weight gain, final weight, and plasmatic concentrations of both IGF-I and T4 than those receiving saline solution. Weights of hot carcass, forequarter, hindquarter, hindquarter muscles, and liver as well as dressing percentage, kidney and pelvic fat, rib eye area, backfat thickness, and plasmatic concentrations of T3 were all not affected by rbST. Use of rbST increased body weight gain (7.9%) and changed the hormonal status of pre-weaning creep-fed calves compared to the use of saline solution but did not improve carcass weight or dressing percentage.
Descrição
Palavras-chave
creep feeding, crescimento, superprecoce, creep feeding, growth, calves
Como citar
Revista Brasileira de Zootecnia. Sociedade Brasileira de Zootecnia, v. 34, n. 6, p. 2009-2019, 2005.