Seasonal growth model for animals from progeny tests

Abstract

The growth weight of bovines of the races Hereford and Charolais from progeny tests was studied. The model of Brody added of a periodic component was fitted to the cubic root of the weight. Data from progeny tests performed by the Instituto de Pesquisas Zootécnicas "Francisco Osório" of the Secretaria de Agricultura of the State of Rio Grande do Sul were used. The preliminary estimates of the parameters to start the iterative procedure were obtained by a specific method which is also presented. The square root transformation, adopted to attain the homogeneity of variance, facilitated the theoretical treatment of the model.