Resumption of cyclic ovarian activity in postpartum ewes: a review

Abstract

The reproduction rate is considered a crucial factor that affects the ability of producers to meet the growing demand for ovines meat, and optimizing this factor will maximize the production rate and increase the efficiency of livestock. A reduction in the length of the postpartum anestrus period results in a shorter interval between lambing and conception and enables more lambs to be produced throughout the life of a ewe. This review discusses the current knowledge of several factors associated with the resumption of cyclic ovarian function in postpartum ewes and how the suckling management of ewes may affect this process. Factors that influence the resumption of cyclic ovarian activity include uterine involution, follicular development, occurrence of silent ovulation and short estrous cycles, breed, reproductive seasonality, nutrition and lactation. Controlled suckling and early weaning are management practices that may be used to obtain three lambings in a 24-month period. In the majority of the studies the interval between lambing and first estrus was reduced when a controlled suckling management strategy was used, therefore the controlled suckling appears to be the best alternative because it has produced good results and is easy to implement. Currently, however, this practice is still not widely used.