Dr. Denise Beaulieu-Prairie Swine Centre:
We don't think the nutrient requirements are different.
From what we can see so far we don't see big differences in requirements between sows housed in stalls and those housed groups.
We know that feeding sows in gestation a higher amount of fibre increases their sense of satiety.
They feel fuller longer and also we know that the type of fibre, whether that fibre is soluble or non-soluble, how much it ferments, the fermentability of that fibre in the sow has an effect on how long she feels full.
Researchers for quite awhile actually, especially in Europe have been looking at this, feeding sows in group housing in gestation, diets with a higher fibre content and this makes them calmer, they're not hungry as much, they're not out looking for food and so it decreases a lot of related aggression.
It's more apparent with sows housed in groups so it's more of a problem.
Dr. Beaulieu notes research conducted at the prairie Swine Centre comparing the calcium and phosphorus requirements of sows housed in stalls to those of sows housed in groups found no difference.
However, she acknowledges, nutritional requirements may change in group housing systems in which the sows get higher levels of exercise.
Source: Farmscape