Resumen
- The aim of this study was to evaluate the productivity of a synthetic guinea pig breed created by mating two breeds, a native breed from Nariño Colombia and other with peruvian origin, through alternate diallel crossesuntil 5/8 breed proportion. Weight measurements at different ages, litter size at birth and calving interval were analyzed in pure and synthetic breeds using a linear fixed effects model. Breed effect influenced the weight of individuals, being peruvian the heaviest for all ages. Synthetic breed showed heavier weight than native breed during early stages of growth, but were overcome by the latter from the eighth week. In addition, animals with higher proportion of peruvian breed reached higher weights at all analyzed ages and heterosis retention ranged from -10.97 to 5.83% for eighth and fourth week weight, respectively. No differences attributable to the breed effect in reproductive variables were found. Evaluation of different breed proportions is recommended to determine a specific genetic composition according of breeding objectives and modeling maternal and environmental effects to obtain more accurate heterosis estimation. © 2016, Fundacion CIPAV. All rights reserved.