Direct and maternal annual genetic changes for selected traits at weaning and yearling in beef cattle

Abstract

Heritability and direct and maternal genetic changes were estimated in Nellore cattle for the following traits: birth to weaning weight gain (BWG), weaning to yearling weight gain (YWG), weaning conformation (WC), weaning precocity (WP), weaning muscling (WM), yearling conformation (YC), yearling precocity (YP), yearling muscling (YM) and yearling scrotal circumference (SC). Direct and maternal heritability for weaning traits were 0.21±0.03 and 0.13±0.01 (BWG); 0.19±0.03 and 0.07±0.01 (WC); 0.22±0.03 and 0.07±0.01 (WP); 0.20±0.03 and 0.07±0.01 (WM), respectively. For yearling traits, direct heritability were 0.19±0.04 (YWG); 0.32±0.05 (YC); 0.37±0.05 (YP); 0.38±0.05 (YM) and 0.41±0.04 (SC). Positive and significant direct genetic changes (p < 0.05) were found for all traits, except for WC (p = 0.09), equal to 0.138 kg year-1 (BWG), 0.003 units year-1 (WC), 0.011 units year-1 (WP), 0.009 units year-1 (WM), 0.132 kg year-1 (YWG), 0.003 units year-1 (YC), 0.011 units year-1 (YP), 0.011 units year-1 (YM) and 0.020 cm year-1 (SC), indicating favorable genetic gains in the period. For weaning traits, we obtained negative and non-significant (p > 0.05) maternal genetic trends, with values of -0.084 kg year-1 (BWG), -0.004 units year-1 (WC), -0.004 units year-1 (WP) and -0.004 units year-1 (WM). Thus, greater emphasis should be given for maternal genetic merit of weaning traits in this population, if improvements in maternal ability were desirable.

Relationship between direct and maternal genetic effects on weaning weight of Limousin and crossbred beef calves

“…Obtained results are similar or somewhat lower than those obtained by Keeton et al (1996), Dodenhoff et al (1999), Crews and Kemp (1999), Splan et al (1998) and Lukaszewicz et al (2015). However, heritability values are somewhat higher than those published by Albuquerque and Meyer (2001), Tilki et al (2008), Martinez et al (2016) and Boligon et al (2018). According to several previous findings this result confirms that the environmental effect on weaning weight of beef calves is higher than the genetic effect.…”

“…Martinez et al (2016) published the value between 0.24 and 0.47 for direct heritability and between 0.15 and 0.21 for maternal heritability in the Brahman Zebu population. Boligon et al (2018) reported direct and maternal heritability for weaning traits of Nellore herd 0.21 ± 0.03 and 0.13 ± 0.01, respectively. The above-mentioned publications confirm that the heritability values of WW trait are low or moderate and indicate that direct heritability values are generally higher than the maternal heritability.…”

Polymorphisms Related to Bovine Leptin Gene and Association with Productive and Reproductive Traits in Nellore Heifers

“…This allele was associated with a lower weight in heifers and as observed in Figure 1, the curve for the allele 138 was lower when compared to the curve for the other alleles, in relation to the average asymptotic weight. It was observed that around the tenth month of the growth curves showed different behavior so the performance of the heifers was affected by the environment conditions and was not directly influenced by the maternal effects (Boligon et al, 2019).…”

Genetic selection indices for growth traits in Blanco-Orejinegro cattle

“…The most efficient way to achieve this goal is to use selection indices that allow assessing genetic values for various traits and combining them with their economic values, thus classifying individuals with a single figure and facilitating selection ( Marques et al, 2012 ; Stanojević et al, 2015 ). For example, Boligon et al (2018) showed positive and favorable direct genetic changes for the traits growth and reproductive in Nellore cattle when using selection indices.…”