Funções para descrever o crescimento corporal de fêmeas Nelore e cruzadas

Abstract

To study the adjustment of a function to describe the entire growth in the productive life of females considering simultaneously age, pregnancy and lactating effects, data from Instituto Agronômico do Paraná (IAPAR) were used.Data set were composed by observations of weight of 19 Nellore females (NN); 7 F1 Guzerá x Nellore (GN); 19 F1 Red Angus x Nellore (RN); 4 F1 Marchigiana x Nellore (MN) and 17 F1 Simental x Nellore (SN). The model was composed of three functions: the weight gain yearly, weight gain during pregnancy and the weight lost during lactation. When adjusting simultaneously the functions was observed the multiple coefficient of determination adjusted (R2a) varying from 0.996 to 0.998, with standard deviations smaller than the parameter estimates and the Durbin-Watson statistical value higher than 0.8 when adjusted the function to the information from the NN, MN, RN and SN groups. It's indicate a good adjustment of the function. It was concluded that the function that consider simultaneously the age, pregnancy and lactating effects, even though with little data, described best all the growth in productive life of females.