A wet harvest imposes strict requirements on crop storage to prevent the growth of yeast and fungi, which can increase the risk of mycotoxin growth, according to Jacob Dall, Technical Manager, Pig Nutrition, Vitfoss/Vilofoss.
If you suspect problems relating to toxins, you can take a number of samples of ready-mixed feed from different parts of the housing unit
In Denmark, we use pig feed ingredients that are generally of good, reliable quality. Despite a wet growing and harvesting season in 2017, the level of toxins found has generally not given cause for concern. But a wet harvest imposes high demands on crop storage to prevent the growth of yeast and fungi, which would increase the risk of mycotoxin growth.
Despite this, an increasing percentage of Denmark’s on-farm mixers use toxin binders anyway, many in the form of a preventive, constant admixture of low doses or specifically in response to symptoms arising in the herd. Toxin binders are not only admixed due to the possible presence of fungal toxins in the ingredients, but also in an attempt to counteract the effect of endotoxins, i.e. toxins formed by bacteria in pig intestines.
"Although there are currently good assays for determining the level of a wide variety of toxins, getting a clear overview of toxin prevalence can still be difficult." - Jacob Dall, Technical Manager, Pig Nutrition, Vitfoss/Vilofoss.
- Swollen labia (zearalenone)
- Generally poor immune system
- Intestinal bleeding
- Kidney damage (ochratoxin)
To-do list if toxins are suspected
- Contact your Landmix consultant
- Add a toxin binder to the feed
- Inspect/clean feeding systems/bins
- Take a representative sample for analysis, if necessary.
Keener focus on toxin binders
An analysis over the past five years shows how often toxins are suspected of causing problems in a housing environment that prompted a need to use a toxin binder. Table 1 above shows not only an increasingly widespread focus on toxin binders, but also a clear profile of consumption over the year.
Consumption in May–July is 20% higher on average than the rest of the year.
This is attributable to the fact that these months are typically when feed bins are emptied, and the grain used has a significantly higher percentage of dust and husk components, which are the parts of the grain with the highest concentration of mycotoxins, if they are present at all. At harvest, when freshly harvested grain is brought into the feed cycle, consumption declines again, after which it increases again for a few years. This can be interpreted to mean that the year’s harvest was more problematic than first assumed after all or possibly that any problems in the herd are related more to endotoxins than mycotoxins.
Actions to take if toxins are suspected
If a toxin strain in a herd is suspected, different strategies can be applied. Often the issue of analyses will be raised.
Although there are currently good assays for determining the level of a wide variety of toxins, getting a clear overview of toxin prevalence can still be difficult. As fungi usually grow in colonies in grain, it can be very difficult to take a representative sample. Another option is to take a number of samples of the ready-mixed feed from various parts of the housing environment and pool them afterwards. This is the best method for studying the actual toxin strain to which the pig is exposed, but the method will not provide any information about which ingredients are the source or whether the feed system itself is contaminated.
If grain samples are taken, a large number of sub-samples should be taken and pooled. Occasionally we also see blood or bile samples being taken for subsequent analysis. This method is problematic as the samples often yield incorrect results because the analysis method is not developed for bile or blood. In addition, levels in bodily fluids fluctuate greatly and they will be high relatively soon after feed intake, and then fall again.
Often, the simplest approach is to add a good toxin binder to the feed for a while. If the situation improves, it is likely that toxins were involved. Analyses take two or three weeks and – for the same price of an analysis – it is often possible to add a toxin binder for a while, which is enough to get an idea of its effect.
Vitfoss/Vilofoss has extensive experience of dealing with mycotoxin-like problems, including expertise in choosing toxin binders, and we can also help with analyses of feed and ingredients. Contact us for further details.