Seasonal infertility can manifest itself in various forms but reports typically concentrate on reductions in farrowing rate and litter size. In herds that suffer reproductive loss during summer months, either through reduced farrowing rates or pigs born per litter, or a combination of both.

Management strategies have been adopted to maintain pig flows such as mating more sows during the warmer months of the year to counteract this dip in reproduction. However, there are currently very few management strategies that can address a dip in piglet birth weight, or an increase in litter weight variation. An increased weight variation is associated with increased piglet death and increased variation in weaning weights. This last point can impact time to slaughter, carcass weight variability and meat quality. Thus, effects on birth weight and birth weight variation are far reaching across the production chain.

Dextrose has been linked to improved egg development when fed to sows during the insemination period, reducing the variation in piglet birthweight. This project assessed whether adding dextrose to sow diets during the wean to mate period in summer would help reduce seasonal infertility and variation in birthweight within litters.