Maintaining high levels of feed during lactation benefits both the current litter, subsequent letters as well as the sows overall productivity. Most problems arise in the first or second parity if the sow does not consume enough feed to meet energy requirements. If not enough feed is consumed milk production will decrease and body condition is lost as fat reserves are mobilized to synthesize milk. Loss of body fat can also compromise reproductive performance.
There are several management practises to help ensure sows are consuming enough feed during lactation to avoid weigh loss. Feeding levels and intake during gestation is unlikely to influence litter size unless feed intake is restricted significantly. The target for weight gain should be based on backfat thickness at time of weaning and her weight at weaning. All sows should have 18-20mm of backfat at time of farrowing and should be fed an extra 1kg/day at 100 days from breeding. Protein levels in the diet have shown to have an influence on feed intake as well as piglet weaning weight. For example, sows fed 12-14% CP consumed less than sows fed 16-18% CP. Several other factors have been shown to influence feed intake during lactation such as environment, number of daylight hours as well as the form in which the ration is fed. It is possible that the differences in sow productivity may be a result of feed and feeding programs over a sows reproductive lifetime.