Nutrition
Nutrition Articles
Mouldy Feed Risks
I was talking with a farmer from Alberta about some late term abortions he experienced in his herd. There are several common causes for this and some can be vaccinated for where there are pathogens
involved but others can be feed related. Moulds can develop in grain and hay when high humidity or high moisture content in the feed is not handled properly. Some moulds are toxigenic and these are
the ones which can hurt production in the herd. This producer had his vet update all his cows’ vaccine status so our discussion centred on vomitoxins and aflatoxins which can be found in common
ingredients.
Vomitoxins include DON, deoxynivalenone which is a potent metabolic substance when consumed in quantity. Once detected by a simple feed test it serves notice there are storage problems so other
toxins may be present also. Pigs that consume sufficient amounts of DON will throw up but cattle don’t. Signs of illness in cattle include reduced feed intake and poor overall appearance, lactating animals will reduce milk production. If there is rain and cool weather at flowering time of the grain there is a good possibility that DON will be present in the grain. Over a long period of time of feeding anorexia will develop with a lowered immune status.
A mycotoxin which can interfere with pregnancy and reproductive performance is Zeralenone which is an aflatoxin with pseudo estrogenic effects. It develops during cool wet weather as in storage or
late field harvest situations.It can be associated with pink mould at times in corn. This substance plays havoc with females causing swollen vulvas in prepubertal females and can cause testicular atrophy in males. Fed during pregnancy it can cause abortions at any time. Aflatoxins from Aspergillis sp. are most likely the culprit where mouldy feed causes abortions. Calves born from affected mothers are weak and survival
is reduced.
Mycotic abortions can be diagnosed by the veterinarian when the calf and placenta are examined. These types of abortion are not uncommon but can be reduced by proper harvesting and storage of
grain and forages but most contaminations begin in the field. For grain products be sure to test all grain intended for feed when sending in the fall samples. Feed contaminated with DON can be
used in limited amounts by blending down the amount of toxin to an allowed amount. No contaminated grain should be fed to pregnant animals. Feed affected with Zearalonone should not be fed to
females destined for the breeding herd as it can negatively affect reproduction. Other toxins in the feed may also be present such as Ochratoxin, T2, fumonisin and penicillin moulds and these can
be added to the feed test request.
Accurate mixing with clean grain can be accomplished with one of the many models of Highline® TMR mixers ready for use this fall.