Genetic parameters for milk, growth, and reproductive traits in Guzerá cattle under tropical conditions

Genetic study of quantitative traits supports the use of Guzerá as dual-purpose cattle

“…Overall, heritabilities were moderate (0.16 to 0.32), indicating that all traits studied could respond to selection with lesser or greater intensity and could achieve a satisfactory genetic progress rate in the breeding program of Guzerá cattle. The heritability estimate for MY305 (0.32) was similar to that reported by Brito et al [10] (0.29), and it was higher than those reported by Santos et al [17] (0.24) and Gama et al [18] (0.24) in studies also conducted on Guzerá cattle. It must be highlighted that heritability is a property of a population and its mating system in a specific environment and time.…”

“…A r t i c l e by Brito et al [10] is the only study reporting the genetic correlations among milk, growth, and reproductive traits in this breed. In the present study, however, a larger number of animals and important traits, such as milk components and SP, for the genetic improvement of dual-purpose Guzerá were included in the analyses.…”

“…Additionally, age at first calving (AFC) is highly correlated with fertility and reproductive efficiency in both beef and dairy cattle, thus affecting heifer precocity [8,9]. The AFC exhibits heritability of moderate magnitude, approximately 0.20, and favorable (i.e., negative) genetic correlation with milk yield and growth traits in Guzerá cattle [10].…”

“…Although the genetic improvement programs of the Guzerá breed for milk and beef are developed independently, joint genetic evaluation is feasible due to the high genetic association between pedigree datasets of the breeding programs [2]. In addition, favorable genetic correlations among dairy (milk yield), growth (weaning weight, yearling weight, and weight at 550 days), and reproductive (age at first calving) traits were previously reported in Guzerá cattle [10].…”

Efeito da taxa de crescimento nos períodos de pré-desmame, pós-desmame e engorda sobre os atributos da carcaça e carne em sistemas de recria e engorda de bovinos Nelore

“…Assim, o ganho de peso dos animais reflete o próprio potencial de crescimento determinado pela genética em um sistema de produção, sendo influenciado pela quantidade e qualidade de pasto, produção de leite das vacas, raça, sexo, idade ao desmame, manejo e o tipo de suplemento durante a vida do animal (BRITO et al, 2020;CÔNSOLO et al, 2020). Logo, a avaliação genética, dessa característica é normalmente avaliada por períodos, como ganho pré e pós-desmama (BRITO et al, 2020;).…”