title: Estimation of genetic parameters and variance components for growth traits in Romosinuano cattle in the Colombian humid tropics.
abstract: (Co)variance components and genetic parameters were estimated for body weights of a Romosinuano herd located in Sinú Valley, Cordoba, Colombia. Restricted maximum likelihood methods were used with a univariate animal model for birth weight, weaning weight (270 days), 16-month weight (480 days), weaning daily gain, and post-weaning daily gain. Models included random animal direct and maternal genetic effects, maternal permanent environmental effect (c2), and sex-year-month of birth and age of dam, as fixed effects. Estimates of direct effect for birth weight, weaning weight, 480-day weight, weaning daily gain, and post-weaning daily gain were: 0.25 +/- 0.0001, 0.34 +/- 0.063, 0.33 +/- 0.066, 0.32 +/- 0.062, and 0.17 +/- 0.052, respectively. Estimates of direct maternal genetic effects were low and ranged from 0.06 +/- 0.003 for birth weight to 0.20 +/- 0.054 for weaning daily gain. The genetic correlations between direct and maternal genetic effects were negative and low for 480-day weight (-0.05 +/- 0.219) and showed values of -0.37 +/- 0.007, -0.34 +/- 0.133, -0.33 +/- 0.135, and -0.38 +/- 0.232 for birth, weaning weight, weaning, and post-weaning daily gain, respectively. Permanent environmental maternal effects were not significant; the highest values were found for weaning weight, and weaning daily gain (0.086 +/- 0.031 and 0.078 +/- 0.031, respectively). We conclude that direct and maternal effects should be included in a selection program for all of these traits, and also that selection of weaning weights would be the most productive way to improve performance in Romosinuano cattle.
authors.affiliation: Animal Genetics Resource Group, Tibaitatá Research Center, Corporación Colombiana de Investigación Agropecuria CORPOICA, Bogotá, Colombia. rodrigomartinez19@yahoo.com
authors.forename: R M
authors.initials: RM
authors.lastname: Sarmiento
authors.forename: J P
authors.initials: JP
authors.lastname: Garcia
mesh_terms: D000465:Algorithms; D000818:Animals; D001835:Body Weight; D002417:Cattle / Q000235:genetics* / Q000254:growth & development*; D003105:Colombia; D005260:Female; D014644:Genetic Variation; D008297:Male; D008957:Models, Genetic; D010641:Phenotype; D012044:Regression Analysis; D012737:Sex Factors; D013997:Time Factors