Key factors to improve production and longevity of primiparous sows

Abstract

Energy and protein needs during lactation are substantial and since many sows have a limited feed intake capacity, protein and fat reserves are severely depleted during lactation. This results in post-weaning fertility problems like prolonged weaning to oestrus intervals, lower ovulation rates and higher embryonic mortality. Especially in first litter sows feed intake is often suboptimal, resulting in a second litter syndrome (lower litter size and/or lower farrowing rate) as found in average farm records and within farms. Sows suffering from a second litter syndrome may have lower life time productivity. An adequate feed intake during lactation, preventing high losses of body stores, is therefore important. Feed intake can be stimulated through good management in which attention should be given to gilt development, feed intake during pregnancy, water intake, ambient temperatures in the farrowing room and the feed intake and feeding pattern during lactation. Reducing the number of piglets during (part of) the lactation can be successful in improving reproductive results after lactation, but a risk is the occurrence of lactational oestrus. Post weaning feeding strategies or management strategies can also be used to improve fertility. Extending the time of first service after weaning by using Altrenogest or skipping-a-heat improves pregnancy rate and litter size. In early pregnancy sufficient feeding levels should be given to sows to optimize litter size in the next parity.