Genotype × environment interaction in individual performance and progeny tests in beef cattle

Abstract

The study reported here evaluated genotype × environment interaction in individual performance and progeny tests in beef cattle. Genetic parameters for final weight (FW), ADG, and scrotal circumference (SC) of 33,013 Nellore young bulls tested on pasture or in feedlots were analyzed. The posterior means (and highest posterior density interval with 90% of samples [HPD90]) of heritability for traits measured on pasture-raised and feedlot-raised animals were 0.44 (HPD90 = 0.40 to 0.48) and 0.50 (HPD90 = 0.43 to 0.56) for FW, 0.26 (HPD90 = 0.23 to 0.29) and 0.26 (HPD90 = 0.20 to 0.32) for ADG, and 0.53 (HPD90 = 0.48 to 0.59) and 0.65 (HPD90 = 0.55 to 0.74) for SC, respectively. The posterior means (and HPD90) of genetic correlations for FW, ADG, and SC on pasture and in feedlots were 0.75 (HPD90 = 0.66 to 0.87), 0.49 (HPD90 = 0.31 to 0.66), and 0.89 (HPD90 = 0.83 to 0.97), respectively. When the selection intensity was kept the same for both the environments, the greatest direct responses for FW and ADG were exhibited by the animals reared and selected in feedlots. The correlated responses relative to production on pasture and based on selection in feedlots were similar to the direct responses, whereas the correlated responses for production in feedlots and based on selection on pasture were lower than the direct responses. When the selection intensity on pasture was higher than the selection intensity in feedlots, the responses to direct selection were similar for both the environments and correlated responses obtained in feedlots by selection on pasture were similar to the direct responses in feedlots. Analyses of few or poor indicators of genotype × environment interaction result in incorrect interpretations of its existence and implications. The present work demonstrated that traits with lower heritability are more susceptible to genotype × environment interaction and that selection intensity plays an important role in the study of genotype × environment interaction in beef cattle.

Interação genótipo x ambiente via modelos de normas de reação para características de crescimento em bovinos Nelore

“…Com esta metodologia, vários autores têm verificado a presença da IGA na raça Nelore, em diferentes regiões do Brasil, entre os quais se podem citar: Santana Jr. et al (2015), quanto ao ganho de peso pós-desmama, circunferência escrotal e produtividade média anual; Chiaia et al (2015), quanto ao de ganho de peso e reprodução; Raidan et al (2015), quanto ao peso final e circunferência escrotal em animais Nelore jovens; e Ribeiro et al (2015), quanto ao peso à desmana.…”

Genotype×Environment Interactions in Growth Performance of Brahman Crossbred Cattle in Bangladesh

“…These results are fairly consistent with the present findings. In comparison to present results, relatively less interaction effects were reported by Raidan et al (2015) for final weight with heritability values of 0.44 and 0.50, respectively for feedlot-raised and pasture-raised Nellore bulls while Espasandin et al (2011) reported similar direct heritability (0.35 and 0.34) for weaning weight in Asian J. Anim.…”

“…These authors also found that the genetic correlations between each trait expressed in an intensive fattening system and the same trait expressed in a pasture spanned from 0.31-0.93. Raidan et al (2015) reported genetic correlation to be 0.75 for final weight between Nellore cattle reared in feedlot and on pasture. On the contrary, Beffa et al (2009) found high genetic correlation estimates (0.96-1.00) for different weight traits across different management environments and Boettcher et al (2003) reported minor effects of G×E in dairy cattle with genetic correlations of 0.93 for milk yield trait.…”

“…For example, Assenza et al (2010) found that the genetic correlations between each trait expressed in an intensive fattening system and the same trait expressed in a pasture spanned from 0.31-0.93 while Raidan et al (2015) reported genetic correlation to be 0.75 for final weight between nellore cattle reared in feedlot and on pasture.…”

“…Earlier studies have reported the existence of significant G×E in growth traits between production systems (Bradfield et al, 1997;Amelie, 2007;Assenza et al, 2010;Raidan et al, 2015), among regions (Van Niekerk et al, 2004;Guidolin et al, 2012;Bresolin et al, 2015), between countries (Espasandin et al, 2011) and between seasons of birth (De Alencar et al, 2005;Williams et al, 2012). For example, Assenza et al (2010) found that the genetic correlations between each trait expressed in an intensive fattening system and the same trait expressed in a pasture spanned from 0.31-0.93 while Raidan et al (2015) reported genetic correlation to be 0.75 for final weight between nellore cattle reared in feedlot and on pasture.…”