The Role of Dietary Fiber in Improving Pig Welfare

SIMPLE SUMMARY: The restriction of feed intake in sows during the gestation period is important for the livestock producer due to the prevention of excess body weight gain and fat deposition, leading to low reproductive performance and detrimental effects at farrowing and during lactation. The frustration caused by feed restriction is the major factor in developing stereotypic behaviors in sows and the occurrence of this behavior may be associated with sows being hungry. Therefore, several strategies have been employed to ameliorate the stereotypic behaviors in sows. Feeding sows a high-fiber diet is the most effective method to increase postprandial satiety, thereby improving the welfare of sows subjected to feed restriction during pregnancy. There are a number of fibrous ingredients available, including wheat middlings, corn germ, sugar beet pulp, corn gluten feed, soy hulls, dried grass, and alfalfa meal. However, the effect of fiber-rich diets on satiety and behavior depends on the dietary fiber sources (physicochemical properties) or fiber inclusion rate in the diet. The objective of this review is to discuss the functional roles of dietary fiber sources with different inclusion levels reducing abnormal behaviors in sows. ABSTRACT: This review aims to discuss the effects of dietary fiber sources with various levels on stereotypic behaviors in sows. There are a variety of dietary fiber sources that are supplemented to feeds for sows. However, dietary fiber sources have different physio-chemical properties, leading to controversial results in feed motivation, nutrient digestibility, and behaviors in sows fed fiber-rich diets. Findings from previous studies indicated that soluble fiber delays nutrient absorption and decreases physical activity after feeding. In addition to this, it increases volatile fatty acid production, provides energy, and prolongs the feeling of satiety. It also prevents certain stereotypies and thus is paramount to sow welfare.