R. Bras. Zootec.01/Oct/2000;29(5):1578-87.
Growth curve analysis of Guzera and their crossbreds fed under grazing with or without supplementation: 2. Evaluation of growth curve parameters
DOI: 10.1590/S1516-35982000000500040
This paper evaluated the parameters of Gompertz nonlinear function to describe Guzera male and female growth curve, and their crossbreds (3/4Guzera – 1/4Brown Swiss, 1/2Nellore – 1/4Brown Swiss – 1/4Guzera, 1/2Brown Swiss – 1/2Guzera, 1/2Chianina – 1/4Brown Swiss – 1/4Guzera, 1/2Caracu – 1/2Guzera, 1/2Caracu – 1/4Brown Swiss – 1/4Guzera) submitted to three levels of supplementation: without supplementation, supplementation only during the dry season, and year-round supplementation. There were significant interactions between supplementation and breed, and breed and sex on mature weight and maturing rate; supplementation and sex on maturing rate and integration parameter; and breed effect on integration parameter. The dry season supplementation did not change mature weight. Increasing the energy content of the supplement increased the maturing rate estimates. Supplementation during year-round decreased the estimates of mature weight but increased maturing rate values. Calving status had a significant effect on mature weight and maturing rate estimates. An allometric equation with an r2 of 0.68 was derived to predict maturing rate from mature weight estimates.
Keywords: beef cattle; mature weight; maturing rate; nonlinear function