Attributes related to maternal ability in three improved guinea pig genotypes resulting from a genetic reconversion process were evaluated. The guinea pigs belonged to the Yauris Agricultural Experimental Station (Junín, Peru). Litter size at birth (LSB) and weaning (LSW), litter weight at weaning (LW), pup weight at birth (LBW) and at weaning (LSW), and pup survival rate (PSR) were evaluated. Genotypes were differentiated by their coat colour: red-R (n=68), white-R (24), and bay-R (19). Dams were monitored for five months in their respective breeding pens under a mating system. The bay-R genotype had the highest weight at birth (162.2 ± 28.5 g) and weaned (325.4 ± 40.1 g) offspring, but a lower PSR (79.1%). The red-R and white-R genotypes stood out for their higher LSB (3.76 ± 1.05 and 3.45 ± 0.9), LSW (3.13 ± 0.88 and 3.20 ± 0.91) and LW (839.0 ± 247.0 and 826.5 ± 215.9 g), wh...