The objective was to evaluate the productivity and production uniformity of Wistar female rats (Rattus norvegicus) submitted to three mating systems: permanent monogamous, with a couple permanently maintained in each cage, permanent polygamous, with two females and one male permanently maintained in each cage, and temporary polygamous in which a male was maintained in a cage with two females until each mating was verified and was removed afterwards, returning after both litters were weaned. For that, 69 90-days-old females were randomly assigned to three groups. The evaluations comprised five reproduction cycles per dam. Litters that were heavier at weaning were obtained in the temporary polygamous systems. In addition, dam mortality was null in this system, which is an important animal welfare indicator. In the permanent monogamous system, the interval of time required to produce one weaned pup per dam was shorter than in the polygamous systems. One should consider, however that this system requires twice as many cages and sires than the polygamous systems. Therefore, the temporary polygamous mating system may be recommended for the expansion and production Wistar rats colonies, provided that qualified personnel is available to identify copulation in breeding females and to perform male rotation.
monogamous mating; polygamous; mortality; litter weight; Rattus norvegicus
