The sex-relation in calves produced by artificial insemination

Abstract

The AA., utilizing 1048 cattle births coming from the artificial insemination, during 1952 to May 1956, studied the probable influences of different factors (semen age, sire, month in which was carried out the insemination, dry — April to September — and rainy — October to March — seasons and females breeds), on the sex ratio. The sex ratio found on 523 males and 525 females was 49.9 ± 50.1 ± 1.5%. In connection with the semen age, the sex ratio showed apparent predominance of females in the 24th hours and in the 96th hours of conservation, but in the interval from 48 the to 72th hours and 120 to 252th hours, there were predominance of males. However, these differences were not significant statistically (Chisquare). The arrangement of the data in I, II and I I I tables, is such as to lead to the conclusion that the factors studied do not materially affect the sex ratio. The data were submitted to the statistical analysis (Chi-square). During that period, were born 23 twins (2.2%) being 25 males and 21 females.