Effects of controlled time of ovulation on apparent duration of gestation and day of farrowing

摘要

The ability to accurately predict farrowing dates would facilitate improved supervision and could potentially lead to a decrease in piglet mortality. Generally a predicted farrowing date is calculated from the day a sow is first bred, even if the sowis bred the following day as well.3 There is no practical way of knowing the time of conception in a sow, particularly when more than one breeding per service occurs. This uncertainty with respect to conception adds to the inaccuracy of estimating farrowing day. The use of equine chorionic gonadotropin (eCG) at weaning and porcine lutenizing hormone (pLH) 80 hours later for synchronization of estrus and ovulation allows for single timed insemination.1 This protocol has been shown to synchronize a groupof weaned sows to ovulate within a few hours of each other. The result of instituting such a protocol is to greatly reduce the variation in when sows are bred and when conception occurs.