Genotype-environment interaction for productive traits of Holstein cows in Brazil described by reaction norms

• Published in: Tropical animal health and production Vol. 52; no. 5; pp. 2425 - 2432
• Main Authors: Santos, Jarbas Corrêa, Malhado, Carlos Henrique Mendes, Cobuci, Jaime Araújo, de Rezende, Marcos Paulo Gonçalves, Carneiro, Paulo Luiz Souza
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-09-2020; Springer Nature B.V
• Subjects: Animal models; Animals; Biomedical and Life Sciences; Brazil; Cattle; Cattle - genetics; Cattle - physiology; Cow's milk; Dairy cattle; Environmental gradient; Female; Gene-Environment Interaction; Genotype; Genotype-environment interactions; Genotypes; Heritability; Life Sciences; Male; Mathematical models; Milk; Milk - chemistry; Models, Biological; Norms; Phenotypes; Phenotypic plasticity; Reclassification; Regular Articles; Statistical analysis; Statistical models; Veterinary Medicine/Veterinary Science; Zoology; Brazil; Genetic correlation; Genetic evaluation; Heritability; Environmental sensitivity; Dairy cattle
• ISSN: 0049-4747; 1573-7438
• DOI: 10.1007/s11250-020-02269-8

Brazil is the world’s fourth largest milk producer; this activity extends throughout the national territory, with productions of approximate 34 billion liters of milk per year. The objective of this work was to evaluate the genotype-environment interaction (GEI) in purebred Holstein cows for milk (M), protein (P), and fat (F) yields. The statistical models used were the standard animal model (AM), which disregards the GEI, and hierarchical reaction norm models with homoscedastic (HRNMHO) and heteroscedastic (HRNMHE) residual variance, and one (HRNMHO1S and HRNMHE1S) and two (HRNMHO2S and HRNMHE2S) steps. HRNMHO1S presented a better fit of the data for all traits, with higher heritability for the best environments. Most bulls presented robust phenotypes; however, GEI was found with a reclassification of the bulls in the environmental gradient. Although few, and less used, bulls with plastic phenotypes were found for all traits, and the use of them can optimize genetic gains in specific environments.