TY - JOUR AU - Ríos-Utrera, Ángel AU - Calderón-Robles, René Carlos AU - Rosete-Fernández, Jorge Víctor AU - Lagunes-Lagunes, Juvencio PY - 2010/12/01 Y2 - 2024/03/29 TI - Genetic and phenotypic correlations among reproductive traits of dairy cows. JF - Agronomía Mesoamericana JA - Agron. Mesoam. VL - 21 IS - 2 SE - Articles DO - 10.15517/am.v21i2.11835 UR - https://revistas.ucr.ac.cr/index.php/agromeso/article/view/11835 SP - 235-244 AB - <p>The objective of this</p><p>work was to estimate the genetic and phenotypic correlations</p><p>among fertility traits of 317 Holstein Friesian and Brown</p><p>Swiss cows. Cows were born and reared under subtropical</p><p>conditions, during a 20-year period (1986 to 2006), and were</p><p>daughters of 116 sires and 199 dams. The study was carried</p><p>out in Las Margaritas research station, in Hueytamalco,</p><p>Puebla, México, which belongs to the Instituto Nacional de</p><p>Investigaciones Forestales, Agrícolas y Pecuarias (INIFAP).</p><p>Fertility traits studied were: days to first service after calving</p><p>(DFS), calving interval (CI), days open (DO), number of</p><p>services per conception (NSC) and conception rate at first</p><p>service (CR). Genetic correlations were estimated with a</p><p>two-trait animal model (bivariate analysis), which included</p><p>individual additive genetic effect as a sole random effect.</p><p>Main fixed effects were: calving year, calving season and</p><p>breed of cow. Analyses were carried out with restricted</p><p>maximum likelihood, using an algorithm free of derivatives.</p><p>In general, fertility traits were favorably and strongly</p><p>correlated genetically. Estimates of genetic correlations for</p><p>DFS-CI, DFS-DO, DFS-NSC, CI-DO, CI-NSC, and DONSC</p><p>were positive (0,89, 0,89, 0,25, 0,90, 0,59 and 0,97,</p><p>respectively), while all estimates of genetic correlations that</p><p>included conception rate to first service (DFS-CR, CI-CR,</p><p>DO-CR, NSC-CR) were negative (-0,45, -0,62, -0,72, -0,85).</p><p>The high estimates of genetic correlations between CI and</p><p>DFS or DO indicate that selection for less DFS or DO would</p><p>reduce CI.</p> ER -