Sows today produce more piglets per litter than ever before. The pressure to increase born alive is evident by the 30% increase in number of piglets born per litter in the U.S. from 2004 (11.5) to 2020 (15.0; Pigchamp). However, this increased sow production requires more resources from that sow to successfully farrow those piglets and subsequently provide adequate nutrients to ensure their growth and survival. A better understanding of sow nutrition will be needed as more weaned pigs are targeted, and data suggests that dietary fiber levels during sow gestation may be an important role in maximizing sow performance parameters and yielding more healthy pigs.
The Challenges of Measuring Fiber in Sow Diets
One of the challenges with including fiber in a sow’s diet is how to accurately measure it. Current methodologies like crude fiber (CF) and neutral detergent fiber (NDF) are readily available and affordable, however, they greatly underestimate the fiber in the diet by 70 to 80 percent. Furthermore, NDF can potentially overestimate fiber levels by measuring other insoluble nonfiber fractions while also failing to measure the soluble fiber component, which may be a key indicator of sow performance.
Today, through more advanced wet chemistry methods, the total dietary fiber (TDF; Figure 1), soluble dietary fiber (SDF), and insoluble dietary fiber (IDF) can be determined, providing a more complete understanding of the fiber components However, these measurements are not widely available and can be rather costly. Fortunately, the use of near infrared (NIR) technology is expanding our access to these measurements through rapid, affordable means.
Figure 1. The crude fiber (CF), neutral detergent fiber (NDF), and total dietary fiber (TDF) of feed ingredients*
*Data represent the average of all feed ingredients included in internal AB Vista database.
Research has shown additional TDF in the sow diet can provide potential benefits for sow performance parameters including more pigs weaned, increased litter weaning weight, reduced the number of stillborn piglets, and increase the viability of piglets[1].
Mode of Action of Fiber
Dietary fiber has been described as the portion of feed which cannot be digested by the animal. This undigested fraction likely supports sow productivity by two main mechanisms. The first relates to expanded capacity to consume feed and the movement of feed through the gi tract. When sows adapt to consuming more TDF in their diets, they are better able to maintain their feed intake during lactation, which helps maintain energy levels during the lengthier farrowing process[2]. This is likely because the farrowing time is reduced, which limits the chance of hypoxia for the piglet and allows the piglet to receive colostrum earlier; and because the colostrum’s lipid content is increased, which provides more energy to the piglets[3]. Gestating sow diets that include fiber have also shown a modification to sow behavior, including an increase in satiety and a decrease in aggression.
Perhaps the most undervalued contribution to sow productivity may be the shift towards more feed substrate for the bacteria present in the lower gastro-intestinal tract (Figure 2). These bacteria preferentially consume carbohydrates, generating short-chain fatty acids (SCFA), particularly butyrate.
[1] Fevera et al., 2017.
[2] Quesnel et al., 2009.
[3] Loisel et al., 2013; Feyera et al., 2019.
Perhaps the most undervalued contribution to sow productivity may be the shift towards more feed substrate for the bacteria present in the lower gastro-intestinal tract (Figure 2). These bacteria preferentially consume carbohydrates, generating short-chain fatty acids (SCFA), particularly butyrate.
The Roles of Insoluble and Soluble Fiber and Application of Stimbiotic
The TDF is comprised of SDF and IDF. The main fiber containing feed ingredients available for swine feed include corn, corn DDGs, sorghum, and rice bran, which are higher in IDF. These may help with reducing constipation. The SDF may have a greater role in feeding the microbiome and improving gut health and digestion. In fact, studies have shown that increasing SDF in the gestation diet can improve lactation intake, the number of piglets weaned, and weaning weights[1]. Sugar beet pulp (SBP) and soybean hulls have higher levels of SDF, but these can be cost prohibitive and difficult to source.
[1] Sun et al., 2015.
Polymeric networks of fiber are complex and not easily fermentable or soluble. Fiber becomes more fermentable and soluble as they break down into smaller fractions, either as polymers or oligomers (see Figure 3). The addition of a stimbiotic to the diet can signal the microbiome to ferment fiber, which would shift IDF into smaller, more SDF fractions like polymers or oligomers and lead to increased fiber digestion and SCFA production, thereby benefiting gut functionality[1].
[1] Cho et al., 2020.
Conclusion
Measuring fiber in sows’ diets is a balancing act. Research shows the inclusion of TDF, specifically SDF, can benefit sows and piglets in numerous ways. However, sourcing SDF can be challenging and cost prohibitive. The addition of a stimbiotic can react in a similar way as SDF, further aiding in fiber digestion and SCFA production, and can be more readily available and cost effective.
AB Vista created a fiber calculator that uses average values of raw materials to calculate the dietary fiber content of finished animal feed and has produced a reference guide that provides nutritionists with an introduction to the benefits of moving from conventional fiber methods to total dietary fiber analysis using Near Infrared Reflectance (NIR) technology. Learn more about the use of stimbiotics and find additional research at ABVista.com. Or, email NAM@ABVista.com to get started on your operation.
[1] Cho et al., 2020.
