The objective of this work was to determine genetic parameters for body weight of tinamou in captivity. It was used random regression models in analyses of data by considering the direct additive genetic (DA) and permanent environmental effects of the animal (PE) as random effects. Residual variances were modeled by using a fifth-order variance function. The mean population growth curve was fitted by sixth-order Legendre orthogonal polynomials. Direct additive genetic effects and animal environmental permanent effect were modeled by using […]

Total numbers of 56,508, 35,091 and 8,326 records of milk, fat, and protein test-day yields, respectively, were used to estimate genetic parameters for six persistency measures on milk, fat and protein productions of Holstein cows reared in Minas Gerais state. Covariance components for additive genetic effects and permanent environmental effects were estimated by REML in random regression models using Legendre polynomials from the third to the sixth order. Overall, models with the highest orders of Legendre polynomials showed the best […]

It was evaluated data set of 19,303 weight records of Santa Inês sheep in order to evaluate distinct polynomial functions with different order for better adjustements of fixed and random regressions of growth trajectory and to estimate (co)variances components and genetic parameters of this trajectory. Fixed effects used in analysis were contemporary group, sex and birth type. Ordinary and Legendre polynomials, ranging from two to four orders, were evaluated for fixed regression of average growth trajectory. Legendre and quadratic b-spline […]

Random regression and Legendre polynomial (LP) of different orders were used for modeling the genetic, permanent environmental and residual variances of test day milk yield in dairy goats. The models included the fixed effects of contemporary group, age of dam at kidding as a covariate and the fixed regression of LP for the average lactation curve and the additive genetic, permanent environmental and residual as random effects. According to the values of the logarithm of the likelihood function, AIC and […]

Data consisting of 20,065 weights of 3,016 Nellore animals recorded from birth to 630 days of age were used to compare random regression on Legendre polynomials of age (LP) and on Legendre polynomials associated to a parametric correlation structure (PC) models for breeding value prediction of growth traits. Results from Standard bivariate analyses (SBA) using weights at standard ages were also compared to those from random regression models. Dependent variables in random regression analyses were Legendre polynomials of age at […]