The aim of this study was to estimate the values of direct and maternal heritability and the variances due to the permanent environment from 1990 to 2012 in the Colombian Creole Blanco Orejinegro breed. In total, 10 698 data on growth variables were analyzed for birth weight (BW), adjusted weight at 240 days (PAJ240) and adjusted weight at 480 days (PAJ480). The derivative-free restricted maximum likelihood methodology (DFREML) was used, adjusting an animal model that included direct genetic effects, maternal and variations due to the permanent environment, assuming as fixed effects the year, time of birth, the sex of the calf and as covariate the mother's age at delivery. The heritability for BW were h²d = 0.31, h²m = 0.03 and σ²c = 0.07. the heritability values for PAJ240 were moderate and low (h²d = 0.18, h²m = 0.05, σ²c = 0.04) while for PAJ480 they were h²d = 0.17, h²m = 0...

The aim of this study was to determine by SDS PAGE the protein profile of the seminal plasma of Romosinuano (ROMO) and Costeño con Cuernos (CCC) bulls and their relationship with sperm quality parameters in fresh and thawed semen. Three ejaculates per bull were collected by electro-ejaculate from 10 ROMO and 10 CCC sires. Viability (VF), mass motility (MMF), individual rapid progressive motility (MIRPF) and sperm concentration (CE) were determined in fresh semen. Seminal plasma (PS) was obtained by double centrifugation. Individual motility of rapid progressives (MIRPPC), progressivity (PRPC), rapid progressives (RPPC) and medium progressive (MPPC) were determined in thawed semen, in both cases using the CASA computerized analysis system. Additionally, viability (VPC) and membrane integrity were determined by the hypoosmotic test. Proteins were separated by polyacrylamide gel electropho...