Many farms will experience reduced fertility over the next few months due to summer and autumn infertility, warns Paul Thompson, veterinary consultant to pig-breeding company ACMC Ltd.
Summer infertility is related to periods of heat stress in boars and sows due to hot conditions while autumn infertility is triggered by falling day lengths. On many units analysis of farm records show that this is a predictable event, though severity can vary from year-to-year.
To maintain output it is essential to have the correct number of sows farrowing each week/batch and therefore it is necessary to lift the service numbers to compensate. It is better not to let herd parity drift by retaining older sows which would have been culled, he points out.
Instead, the available gilt pool needs to be increased, which producers should discuss in good time with their breeding stock supplier.