Professor Peter H. Brooks looks at diet in relation to the gestating sows behaviour and diet salt content in relation to tail biting. It has been determined that feeding sows on high density, low fibre diets has a major effect on behavior and welfare and that providing sows with more bulky diets can have very positive effects on their well-being.

Today, bar biting in farrowing crates is attributed to hunger rather than the stress from inactivity. Researchers found that confined gilts who’s feed was increased from 1.25 to 4.00 kg/day showed almost no signs of these stresses. These gilts were motivated to a very high degree to work for their food. This was determined by making the gilts work for amount of food, and then increase the amount of work required to obtain the same reward. Gilts eventually spent more energy to get the food than the food provided them in return. When it comes to sow housing, sows housed individually and fed high-density diets meet their nutrient requirements but suffer welfare issues due to their inability to satisfy gut fill. Nutritionists now have to formulate diets to not only supply the sow with nutrient requirements but also to satisfy gut fill, which will satisfy their feeding motivation. Feeding sows with a high fibre diet will result in less stress and less fighting at feeding time while group housed. Feeding sows ad libitum with high fibre (unmolassed sugar beet pulp is suggested) will not compromise productivity. Tail biting is a serious occurrence as it can become infected, form abscesses in the spine, and lead to condemnation of the carcass. Simple practices such as adding straw to pens is shown to reduce tail biting, but there may be nutritional factors present as well. Salt is suspected and it is found that spreading salt on the floor of pens and feeding diets with higher than usual salt content reduces incidence. More salt results in more water consumption and urination, which helps maintain mineral balance. This could contribute to the reduction in tail biting.