Interaction genotype-environment for dairy production in Mambi cattle from Cuba

Abstract

A total of 40 042 records of milk production accumulated up to 305 d (L305), of 15 260 Mambi de Cuba cows (3/4 Holstein ? Zebu), from four genetic enterprises and 177 herds were used. The study purpose was assessing the existence or not of interaction genotypeenvironment (IGE) for dairy production in two production levels: normal (P1, of the calving years 1981- 1990) and low (P2, of the calving years 1991-2006). A univaried animal model was applied for estimating the genetic parameters and values (GV) in both production levels and years (P3, of the calving years from 1981 to 2006). The combination herd-year-four-month period of calving, age at calving as linear and square co-variable, the animal random effects, the effect of the permanent environment and the residues were included as fixed effects. The Pearson?s correlations between the GV of the 39 sires represented in both production levels were estimated. The heritability and repeatability were: 0.227 ? 0.029 and 0.473 ? 0.008, 0.059 ? 0.015 and 0.266 ? 0.014, 0.170 ? 0.020 and 0.418 ? 0.006, for the levels P1, P2 and P3, respectively. The correlation between the GV of the sires in P1 and P2 was of 0.66, so the effect of the interaction genotype-environment was proved. It is concluded that the environmental conditions should be considered for using the Mambi de Cuba sires.
Key words: genotype-environment interaction, Mambi de Cuba cattle, dairy production, genetic parameters, genetic values.