Arquivo Brasileiro de Medicina Veterinária e Zootecnia
versão On-line ISSN 1678-4162
BARBOSA, P.F.; ALENCAR, M.M. e SILVA, A.M.. Mature weight, maturation rate and productive efficiency in Canchim beef cattle females. Arq. Bras. Med. Vet. Zootec. [online]. 2002, vol.54, n.5, pp.510-517. ISSN 1678-4162. http://dx.doi.org/10.1590/S0102-09352002000500009.
The objective of this research was to determine the relationships among mature weight and maturation rate with measures of lifetime productive efficiency of females Canchim beef cattle. The non-linear Von Bertalanffy model was used to describe growth in function of age. The parameters A (asymptotic weight) and k (maturation rate) of the growth curve were estimated for 486 females raised on pastures at the Southeast Cattle Research Center, São Carlos, SP. The relationships among the measures of productive efficiency (number of years in the herd, number of calves weaned, total weight of weaned calves, average weaning weight of calves and weaning weight per year in the herd) and the parameters A and k of the growth curve were analyzed through linear and quadratic regressions. The measures of productive efficiency of the Canchim females depend on both mature weight and maturation rate. In general, the relationships among A and k and the measures of lifetime productive efficiency were linear, positive and of the same shape, indicating that there is an optimum combination of mature weight and maturation rate in Canchim beef cattle females.
Palavras-chave : Beef cattle; Canchim; growth; longevity; reproduction; size; weaning.