Equações de predição da composição química corporal a partir do corte da 9-10-11ª costelas de bovinos castrados Nelore
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Data
2007-04-01
Autores
Galati, Rosemary Laís [UNESP]
Ezequiel, Jane Maria Bertocco [UNESP]
Silva, Octavio Guilherme da Cruz e [UNESP]
Watanabe, Pedro Henrique [UNESP]
Santos, Viviane Correa [UNESP]
Biagioli, Bruno [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Sociedade Brasileira de Zootecnia
Resumo
Objetivou-se obter equações de regressão linear simples para estimativa da composição química corporal de novilhos Nelore a partir da composição química do corte da 9-10-11ª costelas. Foram utilizados 27 bovinos em confinamento, com 21 a 31 meses de idade e 338,0 a 503,6 kg de peso corporal. do total, foram abatidos seis animais (referência) ao início do experimento para estimativa da composição química corporal. A composição química em água, proteína, EE e cinzas foi determinada no corte da 9-10-11ª costelas e nos tecidos corporais. As equações de regressão para estimativa do peso de corpo vazio (PCVZ) a partir dos pesos de jejum (PV) e carcaça quente (PCQ) foram PCVZ = 0,8726 PV - 2,7399 e PCVZ = 1,5350 PCQ + 13,598 (R² = 0,98). O ganho de 1 kg de PCVZ correspondeu a aproximadamente 1,15 kg de PV. A porcentagem de água no corpo vazio (CVz) esteve altamente correlacionada às porcentagens de água (R² = 0,98) e EE (R² = 0,91) no corte das costelas. A equação mais indicada foi a desenvolvida a partir da porcentagem de água no corte das costelas (Sx, y = 0,46). Verificou-se alta correlação entre a porcentagem de EE no CVz e a porcentagem de EE (R² = 0,95) no corte das costelas, portanto, a equação %EE CVz = 0,9662%EE costelas + 1,5294 pode ser utilizada para estimativa da composição do CVz em EE. O mesmo ocorreu para a porcentagem de cinzas, sendo recomendada a equação %MM CVz = 0,5915%MM costelas + 0,7619 (R² = 0,88). A composição química percentual em água, EE e minerais no corte das 9-10-11ª costelas permitiu estimar com acuidade a composição do corpo vazio.
The objective of this trial was to develop simple regression equations for estimating the chemical body composition of Nellore steers by using the chemical composition of the 9-10-11th ribs cut. Twenty-seven feedlot Nellore steers varying from 338.0 to 503.6 kg of BW and from 21 to 31 months of age were used. Six reference animals were slaughtered at the beginning of the trial to estimate the initial chemical body composition. Contents of water, protein, EE, and ash of the 9-10-11th ribs cut and body tissues were determined. Regression equations for estimating empty body weight (EBW) through measurements of BW and hot carcass weight (HCW) were: EBW = 0.8726 LW - 2.7399 and EBW = 1.5350 HCW + 13.598. The high R² values (0.98) in both equations indicated that the EBW of Nellore steers can be predicted by using BW and HCW. The gain of 1.0 kg of EBW corresponded to approximately 1.15 kg of BW. Water content of empty body (EB) was highly correlated with water (R² = 0.98) and EE (R² = 0.91) contents of the ribs cut; the equation based on the percentage of water in the ribs cut had the best fit (Sx, y = 0.46). Because the percentage of EB EE was highly correlated (R² = 0.95) with that of the ribs cut, the equation %EB EE = 0.9662% ribs EE + 1.5294 may be used for estimating EE content of EB. The same was true for ash, which can be estimated by the equation %EB ash = 0.5915% ribs ash + 0.7619 (R² = 0.88). It was concluded that the percentage of water, EE, and ash in the 9-10-11th ribs cut accurately estimated the EB composition of feedlot Nellore steers.
The objective of this trial was to develop simple regression equations for estimating the chemical body composition of Nellore steers by using the chemical composition of the 9-10-11th ribs cut. Twenty-seven feedlot Nellore steers varying from 338.0 to 503.6 kg of BW and from 21 to 31 months of age were used. Six reference animals were slaughtered at the beginning of the trial to estimate the initial chemical body composition. Contents of water, protein, EE, and ash of the 9-10-11th ribs cut and body tissues were determined. Regression equations for estimating empty body weight (EBW) through measurements of BW and hot carcass weight (HCW) were: EBW = 0.8726 LW - 2.7399 and EBW = 1.5350 HCW + 13.598. The high R² values (0.98) in both equations indicated that the EBW of Nellore steers can be predicted by using BW and HCW. The gain of 1.0 kg of EBW corresponded to approximately 1.15 kg of BW. Water content of empty body (EB) was highly correlated with water (R² = 0.98) and EE (R² = 0.91) contents of the ribs cut; the equation based on the percentage of water in the ribs cut had the best fit (Sx, y = 0.46). Because the percentage of EB EE was highly correlated (R² = 0.95) with that of the ribs cut, the equation %EB EE = 0.9662% ribs EE + 1.5294 may be used for estimating EE content of EB. The same was true for ash, which can be estimated by the equation %EB ash = 0.5915% ribs ash + 0.7619 (R² = 0.88). It was concluded that the percentage of water, EE, and ash in the 9-10-11th ribs cut accurately estimated the EB composition of feedlot Nellore steers.
Descrição
Palavras-chave
Beef cattle, coefficient of determination, empty body, Ether extract, Protein, Bovinos de corte, coeficiente de determinação, corpo vazio, extrato etéreo, Proteína
Como citar
Revista Brasileira de Zootecnia. Sociedade Brasileira de Zootecnia, v. 36, n. 2, p. 480-488, 2007.