Original scientific paper

The effects of increasing number of strange male mice on the Bruce effect.

Izuchukwu S. Ochiogu ; Department of Veterinary Obstetrics and Reproductive Diseases, Faculty of Veterinary Medicine, University of Nigeria, Nsukka, Enugu State, Nigeria
Chike F. Ogoejiofor ; Department of Veterinary Obstetrics and Reproductive Diseases, Faculty of Veterinary Medicine, University of Nigeria, Nsukka, Enugu State, Nigeria
Chinaza C. Okafor ; Department of Veterinary Obstetrics and Reproductive Diseases, Faculty of Veterinary Medicine, University of Nigeria, Nsukka, Enugu State, Nigeria

Abstract

This study investigated whether the increasing number of strange male (SM) mice influences the Bruce effect. Thirty females and 27 males were used. The females were divided into 6 groups of 5 each. Of the 27 males, 12 were introduced, 2 each to the 6 female groups as mating males (MM). The remaining 15 males, which were SM, were divided into graded numbers of 5, 4, 3, 2, 1 and 0 for groups A F females. Two days after any female was mated, it was transferred to the cage of the corresponding SM. Within both the first round of matings and the second round of matings, the following parameters were assessed: the number of matings before conception or the number of matings through the duration of the study, the length of time before conception, gestation length, litter size at birth, litter weight at birth and average weight of new-borns at birth. The results showed a significant (P<0.05) number of SM-dependent increases in the number of matings before conception or the number of matings through the duration of the study for both the first round of matings and the second round of matings. There was also a number of SM dependent significant (P<0.05) increases in the length of time before conception for the first round of matings. In the second round of matings, only group F showed a significantly (P<0.05) reduced length of time before conception. Litter size at birth, litter weight at birth and average weight of new-borns at birth for group F were only significantly (P<0.05) higher than those of group D in the first round of matings, and all the groups in the second round of matings. Considering primarily the result of the number of matings before conception and probably that of the length of time before conception, it was concluded that increasing the number of SM mice exhibited an enhancing effect on the Bruce effect.

Keywords

mice; mating; strange male; Bruce effect

Hrčak ID:

77411

URI

https://hrcak.srce.hr/77411

Publication date:

6.2.2012.

Article data in other languages: croatian

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