Are You Managing Your Endotoxin Risk?
Endotoxins and negative effects in swine
Lipopolysaccharides (LPSs) are cell wall components of Gram-negative bacteria such as E. coli and Salmonella. They are also called endotoxins and are released during bacterial replication or death (lysis). LPSs vary depending on the originating bacteria, being more or less aggressive or pathogenic according to the variability of the O-specific polysaccharide chain. They also serve as a potential entry barrier to antimicrobials on the outer membrane of Gramnegative bacteria. Pigs are continuously exposed to LPSs throughout their lives. While the main route for swine LPS exposure is via the gastrointestinal tract, the concentration of endotoxins in the air and dust should not be overlooked: endotoxins are a major component of biological dust. In healthy animals, the intestinal and other epithelia such as the skin or lungs represent an effective barrier preventing the passage of LPSs into the bloodstream. However, if they do gain entry, endotoxins can elicit strong immune responses, weakening immune systems and impairing performance. In swine species, endotoxins cause an inflammatory cascade that increases a pig’s maintenance requirements due to fever. This, coupled with reduced feed intake, leaves less energy available for growth. Moreover, a severely pronounced immune response can lead to septic shock.
Endotoxins and feed efficiency
Endotoxins also impair feed efficiency. A recent study of common challenges in pig farms reported a decrease in growth response due to decreased feed intake for a number of reasons as listed in Table 1.
Table 1. Percentage decrease in feed intake associated with various reasons
Reason for decrease in feed intake
Poor housing conditions
Digestive bacterial infections
Mycotoxicoses (mycotoxin-induced diseases)
The results are also displayed along with feed efficiency differences in Figure 1.
Figure 1. Metabolic consequences expressed in negative growth response of an activated immune system due to different challenges
Prevention and management of endotoxin risk
In recent years, new concerns have emerged about nutritional, environmental, and social factors that may disrupt the gut barrier function and/or increase exposure to LPSs. The gut is the first line of defense against endotoxins and, if compromised with anti-nutritional, stress or metabolic factors, e.g. in times of heat stress, mycotoxin contamination or inflammation, endotoxin transport can increase. In several livestock species, it is commonly accepted that a 1 - 2°C increase in body temperature causes the intestinal tight junction proteins to be affected, increasing intestinal permeability and allowing more LPSs to enter the blood stream. High calorific and high fat diets increase serum endotoxin concentrations and induce acute low-grade inflammation. Starvation depresses the expression and function of intestinal alkaline phosphatase (IAP), a brush–border enzyme that detoxifies LPSs.
A BIOMIN solution for the management of endotoxins
Mycofix® is a state-of-the-art, market-leading product for the deactivation of mycotoxins, which utilizes the three strategies of adsorption, biotransformation and bioprotection to provide 360° mycotoxin counteraction. The product has also demonstrated effectiveness against of feed was included in the diet. The duration of the trial was 28 days. Several parameters were evaluated including average daily weight gain and ileal endotoxin permeability (Figures 2 and 3).
In the second trial conducted at CAN, 36 piglets (at 21 days of age) were assigned to two treatment groups: a control group or a group fed a diet containing 2.5 kg of Mycofix® per ton of feed. The duration of the trial was 56 days. Several parameters were evaluated and included performance (average daily weight gain in kg/d) over the whole feeding period, gut permeability during heat stress measured via the sugar permeability assay (lactulose: rhamnose (L:R) ratio), and endotoxin concentration (Units/mL) in the blood during heat stress (Figures 4, 5 and 6).
The results of both trials demonstrate that Mycofix®, at a concentration of 2.5 kg per ton of finished feed, is able to:
- counteract the negative effects of increased intestinal permeability induced by heat stress in weaning pigs
- decrease endotoxin concentration in the blood
All the results suggest that when Mycofix® is used, a counteraction of the triggering effects of endotoxins is observed, which leads to an improvement in performance during times of heat stress.
- The gut is the first line of defense against endotoxins, but if gut integrity is compromised, endotoxins can enter the blood stream.
- Endotoxins cause an immune response and impair feed efficiency, both of which reduce the amount of energy available to the animal for growth.
- Mycofix® is an effective solution against endotoxins as shown in two international trials.
De Jong, J.A., DeRouchey, J.M., Tokach, M.D., Dritz, S.S. and Goodband, R.D. (2014). Effects of dietary wheat middlings, corn dried distillers grains with solubles, and net energy formulation on nursery pig performance. Journal of Animal Science. 92(8). 3471-3481.