Genotype by environment interaction for fat and protein yieldsviareaction norms in Holstein cattle of southern Brazil

Abstract

Our objective was to evaluate the genetic merit of Holstein cattle population in southern Brazil in response to variations in the regional temperature by analyzing the genotype by environment interaction using reaction norms. Fat yield (FY) and protein yield (PY) data of 67 360 primiparous cows were obtained from the database of the Paraná Holstein Breeders Association, Brazil (APCBRH). The regional average annual temperature was used as the environmental variable. A random regression model was adopted applying mixed models with Restricted Maximum Likelihood (REML) algorithm using WOMBAT software. The genetic merit of the 15 most representative bulls, depending on the temperature gradient, was evaluated. Heritability ranged from 0.21 to 0.27 for FY and from 0.14 to 0.20 for PY. The genetic correlation observed among the environmental gradients proved to be higher than 0.80 for both traits. Slight reranking of bulls for both traits was detected, demonstrating that non-relevant genotype by environment interaction for FY and PY were observed. Consequently, no inclusion of the temperature effect in the model of genetic evaluation in southern Brazilian Holstein breed is required.

Genotype by Environment Interaction and Selection Response for Milk Yield Traits and Conformation in a Local Cattle Breed Using a Reaction Norm Approach

“…The degree of reranking of bulls is a widespread criterion to establish if the introduction of GxE is useful for routine selection practice or not: e.g., minor reranking of bulls for fat and protein yield [ 80 ] and for SCS [ 27 ] was observed in Brazilian Holstein bulls, suggesting non-relevant GxE. Despite a higher genetic response under intensive herd management, no reranking was found in French Holstein, Normande and Montbéliarde, despite a higher genetic response under intensive herd management [ 33 ].…”

Genotype by Environment Interactions in Livestock Farming

“…Similarly, Gerber et al [31], Huquet et al [32], Calus et al [21], and Schmid et al [33] studied macro-environmental plasticity for production traits in German Simmental, French Holstein, Dutch Holstein Friesian cattle, and German Brown Swiss cattle, defining the environmental conditions with different management parameters. Similarly, Santos et al [34] and Mulim et al [35,36] studied production traits in Brazilian Holstein, and Bohlouli et al [37] studied production traits as well as milk fat composition in German Holstein.…”

Interação genótipo x ambiente para produção de leite, gordura e proteína utilizando modelos de normas de reação em bovinos Guzerá

“…De acordo com Albuquerque (2004) Os modelos de normas de reação foram utilizados em diversos estudos que investigaram a ocorrência de IGA em características de produção de leite (SANTANA Jr. et al, 2016;SANTANA Jr. et al, 2019;CHERUIYOT et al, 2020;SANTOS et al, 2020;BOHLOULI et al, 2021;ERBE et al, 2021;MULIM et al, 2021a;TORO-OSPINA et al, 2022).…”