Sarah Mikesell, editor with The Pig Site, spoke to Neil Jaworski, global nutritionist with Trouw Nutrition, about kinetics and the impact rate of nutrient digestion has on growth in piglets. Neil joins the podcast from Trouw Nutrition’s nutrient digestion kinetics laboratory in Boxmeer, the Netherlands. Neil grew up in the Chicago suburbs and is a PhD graduate of the University of Illinois, where he grew his skills in feed ingredient evaluation. He is excited to follow his passion, managing Trouw Nutrition’s nutritional database and matrix.
What's missing from a weaned pig’s diet?
“The answer is the subject of today - nutrient digestion kinetics or the rate of nutrient digestion,” he said. “Currently piglet feed formulation, piglet diets, and all pig diets are formulated on the extent of digestion, and that's based on two different boxes - the stomach and small intestine is one box, and the whole pig is another box. What’s missing is the rate (how fast or how slow) of digestion.”
Trouw Nutrition’s lab research shows that the nursery pig is about to become a stressed post-weaned piglet that’s experiencing many challenges. Switching from sow’s milk to solid feed really changes the rate of digestion of feed ingredients compared to a growing pig. Research indicates that some of these stressful conditions, which can be simulated in lab tests, cause some traditional pig feed ingredients, like fish meal and corn, to be more slowly digested compared to other ingredients that would never be fed to a piglet.
“A lot of nutritionists have a gut feeling about their feed ingredients that is developed over many years of experience and trial and error and anecdotal evidence from farmers or other nutritionists in the field,” he explained. “They fall in love with certain ingredients or certain inclusion rates. By looking at the nutrient digestion kinetics in this weaned pig model in the lab, we helped explain some of that gut feeling. The most exciting discovery - was that we used to say 3% of a certain ingredient all the time in all our piglet diets. Now, we learned it's because that protein is rapidly digested, or perhaps the fiber is very resistant to fermentation. Then, we put that information together to try to achieve the goal of improving piglet performance and/or reducing reliance on antibiotics to minimize post-weaning diarrhea.”
Role stress plays in digestion
One eye-opening moment related to stress came during an in vitro system that was set up for the stressed pig and a normal growing pig. A soy protein concentrate was added into those two systems, and the difference in digestion rate or the kinetics of that protein digestion was startling. One system basically produced tofu that was slowly utilized because the conditions were so stressful and so different that it didn’t behave as expected. Thus, it was eye-opening and helped to explain that the feed ingredient contained specific kinetics in a stressful situation.
“Then, we took it to the farm, and you let the pigs tell you what happens. Indeed, the rate of protein digestion impacted performance and gut health dramatically,” he explained. “We saw more incidents of diarrhea with pigs fed this slowly digested protein, which confirmed what we saw in the lab. This kind of information and our lab and on-farm process are critical when we study kinetics.”