We do not expect that the mating ratio will substantially change the impact of IGE on the rate of inbreeding in sib selection schemes.
The rates of genetic gain and inbreeding were examined in alternative breeding designs of rainbow trout with different mating ratios, variable number of individuals measured and different number of traits included in a selection index in a closed nucleus-breeding scheme.
After mating, the sex ratio of the resulting cross-progeny was 99.7% hermaphrodite (Table 2).
Female and male mice were housed for mating in the ratio of 3 : 1 and examined every morning for vaginal plug.
The accuracy of the breeding values differ only little among the different mating ratios explored, whereas the inclusion of information from relatives at the sea station in the selection index increased the accuracy, and thus, the genetic gain.
The objective of using different mating ratios was to compare between different selection intensities among males.
The analysis showed that the rate of genetic gain can be improved as much as 20% by changing the mating ratios from the traditional nested designs (e.g., ratio of sires to dams 1M : 3F) to factorial mating (e.g., 3M : 5F).
Thirty-sex pairs of 18 24-month-old 18 24-month-old 18 24-month-oldgeons "belong to Rock dove, Columbai livia" were parentsed from a pigeon fancier in Assiut Governorate, Egypt, and were distributed according to its consistent mating systems (sex ratio of pigeons 1:1).
In populations where aggressive males confer net indirect benefits, these benefits are most likely to be realized during the fertile stage of a woman's cycle; at other times, the cost-benefit ratio of mating with an aggressive male will be higher, making them less attractive.
Indirect approaches comprise population studies that test the null hypothesis of random mating and include analysis of gametic disequilibrium, mating type ratios, genotypic diversity and phylogenetic analysis [ 19, 20].
