A 30% increase in the feed provided to first and second parity sows during the first four weeks of gestation increases the size of the litter but also appears to increase the percentage of repeat breeders. This latter problem could be avoided by delaying the increase in feed level until a number of days after insemination. This is apparent from a study carried out by Wageningen UR on the request of the Product Board for Livestock and Meat, De Heus Voeders and Varkens KI Nederland.
Weight loss during lactation has a great effect on the fertility of sows. Sows that lose more than 10-12% weight during lactation have a lowered fertility in the next parity. This weight loss can have particularly great consequences for young sows. An adjusted feed level during early gestation can help the sow recover from lactation and, consequently, may improve fertility.
Reproduction results
For this reason, the objective of the study was to improve the reproduction results of first and second parity sows by adjusting the feed strategy during the first four weeks of gestation. This was carried out by providing 30% more feed (Plus Feed) or 30% extra protein (Plus Protein) from day 2 through to day 32 after insemination. The control group received the standard feed provided on the basis of the standard feeding curve. In addition, the researchers examined whether a lactation period of 3 weeks had an effect on the reproduction results of the next parity. In addition to the effects on reproduction, the researchers also measured the back fat and muscle thickness during the first four weeks of gestation.
Effect of protein and energy level
The study revealed that a 30% increase of the feed level during the first four weeks of gestation increased the size of the litter from the first insemination by two piglets as compared to the control feed level (15.2 as compared to 13.2 piglets). However, the percentage of repeat breeders also appeared to increase by 13% (23% as compared to 13%, although this was not significant). The increased number of repeat breeders could possibly be avoided by delaying the increase in feed level until a number of days after insemination. Neither the increased percentage of protein nor weaning after 3 weeks demonstrated a significant effect on reproduction results.
Download the report
Report 378. Voeding tijdens de vroege dracht: effecten op reproductie en lichaamsontwikkeling van jonge zeugen (Feeding during early gestation: Effects on reproduction and body development in young sows), L.L. Hoving et al. can be downloaded free from http://edepot.wur.nl/143702