The aim of this study was to evaluate the seminal characteristics and the physical and functional conditions of native and introduced sheep breeds under the environmental conditions of the Colombian Caribbean. In total, 117 Santa Inés, Dorper, Katahdin and Ovinos de Pelo Colombiano (OPC) rams older than 11 months were evaluated for 14 months. The animals were from 18 farms of the departments of Córdoba, Sucre, Bolívar, Cesar and La Guajira. The physical-functional examinations of the males were carried out, as well as the macroscopic and microscopic characteristics of the semen. There were no differences (p>0.05) between breeds, departments and collection methods for the variables testicular volume, testicular length and width, scrotal circumference and testicular tone. In the humid Caribbean, mass motility was 76.36 ± 6.13% and the sperm concentration was 2707 ± 573x106 sperm/ml...

The sheep populations of the Colombian Caribbean Region are characterized by having a high phenotypic heterogeneity mainly due to the use of Creole animals in crossbreeding with exotic breeds. The aim of this study was to estimate the genetic diversity and the population structure of sheep in this region. In total, 459 sheep from 26 farms in 19 municipalities were selected. The DNA samples were genotyped with the ovine low-density chip (15K). Analyses of molecular variance, genetic diversity and population structure were performed. At the phenotypic level, 65.8% of the sampled animals were assigned to the Criollo population, while 15.7% showed signs of introgression with other commercial breeds (mestizos). The populations presented a high degree of genetic diversity within individuals (90.6%) and low levels of genetic variation between populations (FST = 0.075). This low differentiation,...

The effect of energy and protein densities of diets on homeostasis, metabolic profile and productive performance during pre and postpartum periods of Romosinuano cows was evaluated. Thirty grazing cows were assigned to three nutritional supplementation groups: TC: 0.0, T1: 2.35 and T2: 2.8 kg/animal/day of energy-protein supplement. The experiment ran from 30 days before calving to 60 days postpartum. Body weight (BW), body condition (BCS) and serum concentrations of glucose, cholesterol, total protein, β-hydroxybutyrate, non-esterified fatty acids (NEFAs), urea, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were evaluated. The prepartum supplementation did not affect BW (p=0.4557) nor BCS (p=0.1893). In the postpartum period, there was a significant effect of supplementation on BW (p=0.0343) and BCS (p=0.029) in T1 and T2 and on glucose at prepartum in T2 (p=0.001...

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...