By David Rosero, Iowa State University, and Amy Petry,
University of Missouri
Have you reached your daily goal of 35+ grams of dietary fiber? If not, consider adding 2 cups of boiled pinto beans and an apple to your diet. Meeting your daily recommended fiber intake can significantly extend your lifespan. This healthy habit becomes even more critical as we age, with recent studies showing that high fiber consumption can reduce mortality risk by 23%. These insights into human nutrition underscore the vital role of dietary fiber for sows, especially when developing nutritional programs aimed at enhancing sow longevity and lifetime productivity.
Once overlooked, dietary fiber in sow nutrition is now recognized as a critical component that influences intestinal functionality, gut microbiota and modulation of digestion and metabolism. Recent advancements in sow fiber nutrition highlight its importance in enhancing satiety, gut fill and weight control, while supporting energy metabolism, insulin sensitivity, reducing constipation, improving farrowing kinetics and increasing milk composition. These functional properties of fiber have the potential to improve sow welfare and lifetime productivity.
Due to regional differences in the availability of fibrous ingredients, gestating sow diets outside the U.S. often contain 40% to 120% more dietary fiber. Iowa State University and University of Missouri are actively engaged in innovative research to characterize the dietary fiber in available ingredients and to determine its physiological roles when fed to sows. Here’s a look at some of our research projects in progress.
Role of Fiber in Gestation
Growing evidence indicates dietary fiber’s satiety-enhancing effects ease stress and behavioral issues in group-housed sows and improve body weight maintenance. Fiber improves satiety through three main mechanisms. First, its physicochemical properties and bulk density within the gastrointestinal tract prolong the sensation of fullness after meals and slow the rate of passage. Second, fiber fermentation produces short-chain fatty acids that stimulate the release of satiety-related hormones such as GLP-1, CCK, and PYY, signaling the brain to curb hunger. Third, fiber slows glucose absorption in the bloodstream, resulting in a more stable post-feeding glucose and insulin response, preventing rapid fluctuations in blood sugar levels that can trigger hunger.
We recently showed that a high-fiber gestation diet (Total Dietary Fiber (TDF) 18% and 9% for high- and low-fiber diets, respectively) did not affect reproductive performance, litter size, individual piglet weight, or pre-wean mortality, but it did reduce weight loss during lactation. In a second study conducted in a group-housing sow farm, we formulated gestation diets using much higher levels of dietary fiber (TDF 32% and 14% for high- and low-fiber diets, respectively). Feeding high-fiber diets to gestating sows reduced their overall mortality, especially for those categorized as mortality due to lameness.
Role of Fiber in Peripartum Period
Constipation during the peripartum period can impact sow productivity through increasing farrowing duration and stillborn piglet rates. Dietary fiber can aid in alleviating constipation by increasing fecal bulk and promoting regular bowel movements. Recent studies in Petry’s lab have shown that supplementing gilts with dietary fiber from loading to farrowing can decrease constipation by 21%, improve farrowing kinetics and reduced pre-weaning mortality by 16%. Fiber sources with high water-holding capacity, such as soy hulls, lignocellulose and sugar beet pulp, can enhance fecal hydration and gut motility. Additionally, fiber fermentation can provide sustained energy, supporting the increased demands of parturition and better colostrum production. Applying these learnings, we designed a top-dress dietary fiber (targeting > 500 g TDF and > 100 g of soluble fiber) and fed to sows during the peripartum phase. Top-dressing dietary fiber reduced the wean-to-estrus interval post-weaning, enhancing overall reproductive efficiency.
Integrating dietary fiber into sow nutrition programs holds significant promise for improving digestive health, animal welfare and reproductive outcomes, increasing profitability for pork producers. However, further research is needed to study the complexities of dietary fiber in sow diets and effectively translate these insights into practical applications. By integrating the strengths of our research programs, we aim to address this research challenge head on and develop real-world solutions that improve both sow health and farm profitability.
