Spotting Mycotoxin Issues in the Dairy Cow

SUMMARY

Mould growth in feed materials is a common problem and so mycotoxins can pose a serious risk to animals.
Mycotoxicosis can lead to high economic losses, due to losses in milk yield and fertility as well as increased susceptibility to secondary diseases.
Mycotoxins are usually co-occurring (Streit et al., 2013) and so the cumulative deleterious effects of their presence can be at lower levels than recommended EU limits.

SWOLLEN HOCKS AND LAMENESS

There are several external signs of mycotoxicosis in dairy cows, including swollen hocks, lameness, swollen udders (especially in heifers) and teats, and rough coats. Lameness can cause a cascade of negative and costly effects on the cow, including poor feed intake, milk production, and fertility.
These are generic symptoms which can be caused by multiple different toxins, but are often associated with toxins from Fusarium molds (DON, Zearalenone, Fumonisin etc).

AFFECTED MILK PRODUCTION

A sudden drop in milk yield is one of the more costly effects of mycotoxicosis for dairy producers, but is easily spotted in individual animals.
Somatic cells are mostly white blood cells and are a sign of the animal’s immune response to a range of pathogenic issues. Different mycotoxins can cause an increase in somatic cell count (SCC) or incidence of mastitis, due to their immunomodulatory effects. A high SCC is another direct financial impact of mycotoxicosis, as milk with a high level can be rejected or penalised.

POOR FERTILITY

Zearalenone (ZEA) is the most common mycotoxin associated with signs of poor fertility, such as low conception rate, swollen vulva, vaginitis, silent/irregular heats or other irregularities in the oestrus cycle.
These signs have been seen at low levels of ZEA in feedstuffs, so it is important to monitor fertility alongside analysis of mycotoxins in feed.
Other mycotoxins which have also shown effects on fertility include aflatoxin, DON, and T2.

SAFEGUARDING PERFORMANCE

Monitoring silage and other feeds used in rations will help to understand the risks for the farm and allow for the segregation of high toxin containing materials which should not be used.
Poor fertility and milk production could be an indication of a mycotoxin contamination and will reduce profitability.
Feeding a broad-spectrum binder, especially one capable of providing protection against DON and ZEA, to the breeding herd will limit the deleterious effects of toxins.
For any further information please speak to your Anpario representative.