Abstract

ROMAN-PONCE, Sergio I. et al. Genetic correlations among milk yield and growth traits in a multibreed population. Rev. mex. de cienc. pecuarias [online]. 2018, vol.9, n.2, pp.316-327. ISSN 2448-6698.  https://doi.org/10.22319/rmcp.v9i2.4456.

In order to estimate the genetic parameters and correlations between total lactation milk yield and growth traits in a multiracial population of dual purpose cattle in tropical environments of Mexico, genetic variances and covariances were estimated between total milk yield during the first (PTL1L), second (PTL2L) and third lactations (PTL3L) and between PTL1L with birth weight (PN) and with weights adjusted to 205 (P205) and 365 (P365) days of age. To carry out this study, 1,349 records of lactations of females of cebuine breed crosses (CE) with Holstein (HS) [558], with Brown Swiss (SP) [444] and with Simmental (SM) [357] were used. Estimated heritabilties in both analyzes are presented. Genetic correlations found in the first analysis were 0.77 (± 0.16) between PTL1L and PTL2L, 0.47 (± 0.25) between PTL1L and PTL3L, and 0.73 (± 0.21) between PTL2L and PTL3L. Genetic correlations found in the second analysis were 0.10 (± 0.35) between PTL1L and PN, 0.20 (± 0.25) between PTL1L and P205 and 0.21 (± 0.32) between PTL1L and P365. It is concluded that the genetic correlations are positive between the first three lactations and a positive correlation is suggested between first lactation milk yield and growth traits, which makes feasible the genetic improvement programs that take into account both characteristics simultaneously.

Keywords : Crossbreeding; Tropical environments; Dual purpose.