Semen characteristics and reproductive performance of native and improved guinea pigs in reciprocal crossing

Abstract

Guinea pig native genotype may not have high reproductive performance but may provide rusticity. In guinea pigs the offspring is born highly developed and gestation might be the most critical reproductive period in this specie. Therefore, objectives of the present investigation were comparing the characteristics of the semen of native and improved reproductive guinea pigs and evaluate reproductive performance and change of body weight of pregnant and lactating females of native and improved guinea pigs, in reciprocal crossing. A total of 48 first gestation female, 24 F2 native guinea pigs and 24 improved females (Cajamarca ecotype) were used in a reciprocal crossing with 6 Improved males and 6 native males, respectively. Genotype had a significant influence on reproductive results, while seminal quality did not affect reproductive performance of females. Guinea pigs born to native mothers exhibited significantly lower litter body weight and litter size at birth than those of improved mothers, while individual birth weight did not differ between groups. Total weight and litter size at weaning was lower in native mothers than in Cajamarca ecotype. Mortality rate of offspring was higher in the improved females. The maternal genotype, native and improved, lost not body weight during first lactation. In conclusion, native females had a lower productive performance than improved females; however, the incorporation of native genotype in crossing with improved guinea pigs produces greater rusticity, increasing survival of offspring at birth and weaning.

Keywords

• guinea pig
• reproductive performance
• semen characteristics