Data comprising 68,523 test day milk yield of 8,536 cows of the Holstein breed, daughters of 537 sires, distributed in 266 herds, calving from 1996 to 2001, were used to compare random regression models, for estimating variance. Test day records (TD) were analyzed by different random regression models regarding the function used to describe the trajectory of the lactation curve of the animals. Legendre orthogonal polynomials function of second, third and fourth order were used. The random regression models included […]