Relationships between Libido, Semen Characteristics and Fertility in Range Rams

Publisher Website
Google Scholar
Abstract
The relationships of libido, semen characteristics and other factors to breeding performance of 1109 rams, consisting mainly of the Rambouillet, Columbia, Targhee and Corriedale breeds, mated in 1309 pens to 31,473 ewes over a 15-year period were studied. The data indicated that libido, as measured by the time required to produce successive ejaculates and by the number of ejaculates produced in a 30-minute period, had a significant relationship to fertility. Of the various semen characteristics studied (including viscosity, pH, volume of semen, motility score, percentage of motile sperm, estimated motility count, or EMC, sperm concentration, total sperm produced per trial, percentage of normal sperm, percentage of abnormal heads, percentage of live sperm and percentage of live-normal sperm) only volume of semen, EMC, percentage of normal sperm, percentage of abnormal heads and percentage of live-normal sperm were significantly correlated with the percentage of ewes lambing. The inbreeding of the ram had a significant depressing effect on the percentage of live lambs and the percentage of lambs weaned but not on the percentage of ewes lambing. The percentage of ewes lambing was significantly correlated with the percentage of live lambs and with the percentage of lambs weaned. The percentage of live lambs was also significantly correlated with the percentage of lambs weaned. Copyright © . .