Sow Satiety in Pen Gestation Housing – Can Nutrition Help?

As group housing systems for gestating sows continue to increase in the U.S. swine industry, strategies to manage social interactions have become increasingly important.

Because gestating females are limit fed to prevent excessive weight gain rather than being fed to satiety, motivation to express foraging behavior often goes unmet. In response, sows may become increasingly frustrated, developing stereotypic behaviors that result in aggressive interactions towards pen mates.

Here are three ways nutrition may be able to help.

1.    Feeding System
Feeding systems should offer protection to avoid high levels of aggression during mealtime. This is particularly important for submissive sows due to the potential of leading to feeder displacement and subsequent reductions in feed intake and body condition compared to dominant sows. In general, electronic sow feeders (ESF) or free access stalls with hind gates provide greater eating protection and therefore more equal feeding opportunities between sows compared to short stanchions or floor feeding. Conversely, ESF systems require sows to eat in sequence rather than simultaneously, which more closely reflects their natural eating habits. This presents a unique set of challenges regarding feeding order and potential aggressive interactions around ESF systems. A more detailed summary of the advantages and disadvantages of different sow gestation housing options can be found at porkgateway.org/resource/sow-housing-options-for-gestation.

2.    Feed Allowance
Limit feeding gestating sows leads to increased activity around the feeder prior to feeding time. Hence, daily feed allowance and number of feedings per day are important considerations. The amount of feed individual sows receive depends on the diet energy concentration and should be based on achieving a target body condition score. Unfortunately, the optimal number of feedings per day to meet the target daily allowance is less clear. In group-housed sows, it appears that increasing meals from one to two or two to five times per day has limited effects. This may be related to the natural eating habits of gestating sows who eat on average 1.17 meals per day when given a choice. Sows should be allowed to consume their entire meal during a single visit to the ESF or stanchion rather receiving multiple meals per day.

3.    Dietary Fiber
Outside of providing sows ad libitum feed, which can have negative consequences on body condition, dietary fiber concentration has the greatest potential to increase sow satiety. Present data indicate that fermentability or solubility, fatty acid production, water-holding capacity and digesta passage rate are the most important characteristics when selecting a fiber source. Shortly after feeding, bulkiness or potentially abdominal discomfort, appears to elicit satiety, whereas solubility has the greatest influence on long-term satiety. Sows fed slowly fermented or soluble polysaccharides such as sugar beet pulp, soybean hulls, or resistant starch exhibit prolonged reductions in physical activity (increased satiety) compared to other fiber sources. In general, 30% neutral detergent fiber is recommended to increase satiety, but these levels are challenging to achieve through regular ingredients.