By Adrienne Woodward, Ph.D., MBA, manager of Swine – Specialty Product Research at United Animal Health
Mycotoxins, produced by fungi and present on a variety of feed ingredients, can negatively impact performance in any phase of production when consumed by pigs. Some mycotoxins, such as deoxynivalenol (vomitoxin) and zearalenone, are easy to spot when pigs consume contaminate feeds. For example, high-deoxynivalenol diets lead to dramatically reduced feed intake and gain, while zearalenone causes swollen vulvas and reproductive inefficiencies. Producers can visually assess these performance issues, and it's easy to determine the culprits.
However, what about one of the other main players in the mycotoxin world, a.k.a. fumonisin? Fumonisin is typically measured in all mycotoxin panels, but it is not regulated, may not show any immediate impact on dietary intake, and has no signs of visual injury when consumed by pigs. Why, then, is fumonisin even an issue?
Fumonisin effects on gut health
Fumonisin is poorly absorbed through the gastrointestinal tract, remaining largely intact as it travels through the intestine. Fumonisin also has a slow excretion rate, so it remains in the animal for an extended time. This means fumonisin is in contact with the intestinal wall longer than other toxins, damaging villi and injuring the gut lining, priming the intestine for bacterial invasion. In fact, fumonisin levels as low as 5 parts per million can lead to pathogenic colonization of the intestine (1, Table 1).
When you combine the effects of fumonisin on the gut lining with other pig stressors, such as heat stress leading to reduced feed intake, the intestinal tract will lose efficiency of nutrient uptake and absorption, slowly reducing performance. Recent research has shown that mycotoxins reduce the digestibility of protein and energy (2), and fumonisin alone in the diet causes a loss of gain, feed intake, and feed efficiency (3, Table 2). Without an amelioration product present to defend gut health, fumonisin can wreak havoc on the intestinal lining, leaving producers to wonder why pigs are not reaching full growth potential.
How to stop the damage caused by fumonisin
One would guess that the best way of reducing fumonisin issues is to simply change grain sources; however, this may not be so easy. The United Animal Health Laboratory has been surveilling mycotoxins from across the Midwest for over three years, and, historically, fumonisin has been on the rise. Out of almost 900 corn samples tested since January 2020, 44% have been marked positive for fumonisin; with dried distillers grain with solubles, positives rise to 76% of approximately 500 samples tested. Just changing feed ingredients is not a whole solution.
Product intervention is another option to manage risks associated with fumonisin impact on gut health. United Animal Health fed high-fumonisin diets to grower pigs in an attempt to quantify the damage caused to the intestine. High-fumonisin diets (25 ppm fumonisin) were fed for a period of 14 days, then pigs were allowed to recover on a common, low mycotoxin diet for an additional 14 days. United Animal Health's M-Mobilize® was added both during the fumonisin challenge and recovery period to demonstrate how product intervention can do more than just recover performance. After the 28-day trial, villi height was reduced by 27.5% in the pigs fed high-fumonisin diets (Figure 1). However, when provided M-Mobilize, villi height showed a 71.9% improvement over pigs not receiving any gut health solution.
Figure 1. Effects of a high-fumonisin diet with or without product intervention on jejunum villi height after 14 days feeding and 14 days recovery. Lo FUM = the control, low mycotoxin diet. Hi FUM = 25 ppm added FUM diet. M-Mobilize = Hi FUM + 1.5 lb./ton M-Mobilize. Research conducted at United Animal Health to further understand the impact of mycotoxins on gut health.
Don't let fumonisin sneak up on you
Although fumonisin has historically been viewed as an issue, new research is bringing further understanding as to how even small doses of fumonisin can hurt the intestine and reduce performance. Combined with additional stressors that cause reduced feed intake, such as high heat, poor ventilation, over-crowding, etc., fumonisin can further damage gut health and allow bacterial colonization in the intestine. Reducing mycotoxins in the diet or adding products to assist in gut health and mycotoxin amelioration are the best solutions to fight any fumonisin problem.
1 Oswald, I.P., Desautels, C., Laffitte, J., Fournout, S., Peres, S.Y., Odin, M., Le Bars, P., Le Bars, J. and Fairbrother, J.M. 2003. Mycotoxin fumonisin B1 increases intestinal colonization by pathogenic Escherichia coli in pigs. App. Env. Microbiology. 69(10): 5870.
2 Kim, S.W., Holanda, D,M., Gao, X., Park, I. and Yiannikouris, A., 2019. Efficacy of a yeast cell wall extract to mitigate the effect of naturally co-occurring mycotoxins contaminating feed ingredients fed to young pigs: Impact on gut health, microbiome and growth. Toxins. 11(1): 633.
3 Rao, Z.X., Tokach, M.D., Dritz, S.S., Woodworth, J.C., DeRouchey, J.M., Goodband, R.D. and Calderon Cartagena, H., 2019. Efficacy of commercial products on growth performance on nursery pigs fed diets with fumonisin-contaminated corn. Kansas Agricultural Experiment Station Research Reports. Vol. 5: Iss. 8.
Statements are based on available published research or on independent trials conducted by or in conjunction with United Animal Health.