Efeito da seleção para peso pós-desmama sobre indicadores da eficiência produtiva de vacas da raça Nelore
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Data
2000-08-01
Autores
Silva, Josineudson Augusto II de Vasconcelos [UNESP]
Razook, Alexander George
Tonhati, Humberto [UNESP]
Figueiredo, Leopoldo Andrade de
Título da Revista
ISSN da Revista
Título de Volume
Editor
Sociedade Brasileira de Zootecnia
Resumo
O objetivo deste estudo foi avaliar indicadores da eficiência produtiva de vacas Nelore selecionadas para peso pós-desmama, enfocados nas relações peso bezerro e peso da vaca, nos rebanhos controle (NeC), não-selecionados para peso pós-desmama, seleção (NeS) e tradicional (NeT). As análises envolveram 3929 e 3906 pesos dos bezerros aos 120 (P120) e 210 (P210) dias de idade, respectivamente. Os pesos das vacas àquelas idades também foram considerados, obtendo-se 3824 (PV120) e 3777 (PV210) registros, respectivamente, para 120 e 210 dias. A análise incluiu 183, 375 e 554 vacas dos rebanhos NeC, NeS e NeT, respectivamente. Para as análises utilizou-se o procedimento GLM/SAS, em modelos que incluíram os efeitos fixos de rebanho, ano e mês de nascimento, sexo do bezerro, idade da vaca ao parto e as interações rebanho x ano de nascimento e ano x mês de nascimento. Todos os efeitos foram significativos. Os resultados mostraram respostas correlacionadas positivas na seleção para peso pós-desmama nos pesos dos bezerros e, em menor magnitude, no peso das vacas. As relações peso bezerro e peso da vaca apresentaram valores médios ajustados de 249,0±2,1; 253,7±1,6; e 255,8±1,2 g/kg para R120 e 362,9±2,8; 368,5±2,1; e 374,6±1,7 para NeC, NeS e NeT em R210, respectivamente, indicando que, nas duas idades, os rebanhos NeS e NeT produziram mais quilogramas de bezerro por quilogramas de vaca, quando comparados ao NeC.
The objective of this study was to evaluate the productivity efficiency indicators of cows selected for post-weaning weight, with emphasis in the calf-cow weight ratios, in a controlled herd (NeC), unselected for post-weaning weight, selection (NeS) and conventional (NeT). The analysis involved 3929 and 3906 calves weights at the 120 (P120) and 210 (P210) days of age, respectively. The cow weights at those ages were also considered, and the recorded numbers were 3824 (PV120) and 3777 (PV210), respectively, for 120 and 210 days. The analysis included 183, 375 and 554 cows from NeC, NeS and NeT, respectively. The SAS/GLM procedure was used in the data analyses. The model included the effects of herd, year and month of birth, and sex of calf, age of cow at calving, and the interactions herd x year, and year x month of birth. All effects were significant. The results showed a positive correlated response in the selection for post weaning on the calf weights and, low response, on cow weights. The calf weight/cow weight ratios showed average adjusted values of 249.0±2.1, 253.7±1.6 and 255.8±1.2 g/kg for R120, and 362.9±2.8, 368.5±2.1 and 374.6±1.7 g/kg for NeC, NeS and NeT at R210, respectively, and indicated that, at both ages, the NeS and NeT herds produced more kg of calf by kg of cow when compared to NeC.
The objective of this study was to evaluate the productivity efficiency indicators of cows selected for post-weaning weight, with emphasis in the calf-cow weight ratios, in a controlled herd (NeC), unselected for post-weaning weight, selection (NeS) and conventional (NeT). The analysis involved 3929 and 3906 calves weights at the 120 (P120) and 210 (P210) days of age, respectively. The cow weights at those ages were also considered, and the recorded numbers were 3824 (PV120) and 3777 (PV210), respectively, for 120 and 210 days. The analysis included 183, 375 and 554 cows from NeC, NeS and NeT, respectively. The SAS/GLM procedure was used in the data analyses. The model included the effects of herd, year and month of birth, and sex of calf, age of cow at calving, and the interactions herd x year, and year x month of birth. All effects were significant. The results showed a positive correlated response in the selection for post weaning on the calf weights and, low response, on cow weights. The calf weight/cow weight ratios showed average adjusted values of 249.0±2.1, 253.7±1.6 and 255.8±1.2 g/kg for R120, and 362.9±2.8, 368.5±2.1 and 374.6±1.7 g/kg for NeC, NeS and NeT at R210, respectively, and indicated that, at both ages, the NeS and NeT herds produced more kg of calf by kg of cow when compared to NeC.
Descrição
Palavras-chave
cows, maternal hability, Nellore, Post-weaning weight, Selection, habilidade materna, Nelore, Peso pós-desmame, Seleção, vacas
Como citar
Revista Brasileira de Zootecnia. Sociedade Brasileira de Zootecnia, v. 29, n. 4, p. 1020-1027, 2000.