The effects of seasonality on ram fertility.

摘要

The objective was to determine how seasonality affects reproductive activity in rams of different breeds, comparing wool, black face, and hair sheep. Fourteen rams were included: 5 Rambouillet, 5 Suffolk, 2 Black-headed Dorper, and 2 St. Croix. Once a month, semen was collected, and the rams were evaluated for a body condition score, scrotal circumference, and rectal body temperature. Samples were evaluated for color, motility, and sperm concentration. A libido test was performed two weeks after every collection. It involved counting ewes a ram heat checked within a two-minute period. The experiment covered 12 months to cover all variations in season, temperature, and day length. Because of small sample size, differences were considered significant at P ≤ 0.10. It was concluded that there is more variation among individuals within a breed than among the three breeds as shown by high standard errors.