Quick facts
- Hunger often results from optimizing reproductive performance by feeding less during gestation.
- Chronic hunger can lead to aggression and cause fight-related injuries in sows.
- Feeding high fiber diets can help satisfy the sow’s hunger without affecting reproductive performance.
- Selecting against skin lesions during mixing can reduce aggression among gestating sows.
Why is hunger an issue in sows?
![Sows Two sows](https://extension.umn.edu/sites/extension.umn.edu/files/styles/caption_medium/public/sow%20feeder%20SROC.jpg?itok=Rq_onhUo)
![Sows Two sows](https://extension.umn.edu/sites/extension.umn.edu/files/styles/caption_medium/public/sow%20feeder%20SROC.jpg?itok=Rq_onhUo)
Sow feeding challenges occur from the contrast between nutrient needs during gestation and lactation. For optimal reproductive performance, sows should eat less during gestation and more during lactation.
- Often during gestation, sows receive enough feed to maintain their body condition but not enough to satisfy their hunger.
- Limited-feeding leads to chronic hunger, which is a major welfare issue for gestating sows.
Hunger leads to unwanted behavior
Hungry sows confined in gestation stalls develop unwanted behaviors including such as bar biting, sham-chewing and aggression. In group-housing systems, limited-fed sows sustain more injuries from fighting than sows that had enough food to satisfy their hunger.
Feeding more fiber to solve hunger
![Sows looking out of a housing system Sows looking out of a housing system](https://extension.umn.edu/sites/extension.umn.edu/files/styles/caption_medium/public/WCROC%20sows.jpg?itok=99bErScp)
![Sows looking out of a housing system Sows looking out of a housing system](https://extension.umn.edu/sites/extension.umn.edu/files/styles/caption_medium/public/WCROC%20sows.jpg?itok=99bErScp)
Feeding high-fiber diets to gestating sows may enhance sow welfare during both gestation and lactation.
- Feeding high-fiber diets to fill the gut is an effective way to satisfy hunger and maintain body condition and reproductive performance in gestating sows.
- Feeding appropriate fermentable dietary fibers, such as sugar beet pulp, during gestation can increase voluntary feed intake during lactation.
- Increased feed intake during lactation may be a carry-over effect of gut fill during gestation.
Controlling sow aggression through genetics
Selecting against skin lesions at mixing can result in reduced aggression among sows. Genetic selection can be a solution to limit aggression among group-housed sows.
- Aggression in pigs is heritable, with a heritability of 0.31.
- Aggression among sows is difficult to measure.
However, aggression can be assessed through skin lesion scoring because there’s a strong genetic correlation between aggressiveness and skin lesions in sows.