WEANING-TO-FIRST SERVICE INTERVAL: IT’S IMPACT ON SUBSEQUENT REPRODUCTIVE PERFORMANCE IN SOWS AND ALTERNATIVE WAYS TO IMPROVE MATING EFFICIENCY IN WEANED SOWS

Abstract

The objective of this paper is to review current knowledge on the relationship between
weaning-to-first-service interval (WSI) in sows and subsequent reproductive performance, in order to optimize and improve mating efficiency. WSI is an important indicator of sows reproductive performance and is closely associated with subsequent fertility. Sows with a WSI of 4-5 days have a larger subsequent litter size, compared to those with a WSI of 7-10 days. Studies have demonstrated that the WSI influences the duration of oestrus, being shorter in sows with a longer WSI. In sows with a short duration of oestrous, the duration from the onset of oestrus to ovulation is also short. The negative influence of a prolonged WSI on subsequent reproductive performance has been linked to the timing of mating being suboptimal in relation to ovulation. A sound strategy to improve mating efficiency in weaned sows should therefore seek to increase the proportion of sows with a WSI within 4-5 days and concentration on oestrus stimulation, oestrus detection and an optimal mating time.