Facial Eczema threatens ewe fertility

Warm, wet weather is creating perfect conditions for Facial Ezcema (FE) and given the right conditions the risk could continue through until May.
Monday, 3 April 2017

This is according to agricultural scientist Neale Towers, who says damp weather coupled with mild night and warm daytime temperatures are ideal for the FE-causing fungus. This fungus lives in dead and decaying grass in the base of a pasture sward. 

The recent rise in FE spore counts in many parts of the North Island has coincided with ewe mating and if animals are exposed to the toxin, Towers says FE can impact negatively on fertility and scanning results.

“The number of dry ewes will increase and the number of multiples decrease.”    

FE Treatment

Towers says zinc – preferably in the form of a zinc oxide bullet – is the only direct FE treatment available for livestock and it is probably too late in the season to be spraying paddocks with fungicide.

As the FE- causing fungus only lives in pasture, feed crops can minimise livestock’s exposure to the disease although grassy headlands can be source of contaminationTowers urges farmers in FE risk areas to keep an eye on weather and regional FE spore count reports.

“If you see the district averages rising then it is highly likely that counts on your farm will be rising.” 

FE affects the liver and Towers says by the time clinical symptoms appear – swollen ears and eyes caused by photosensitivity – then the damage has already been done. 

“You are two weeks too late.”

Few animals will display clinical symptoms, a much greater proportion of a flock will be affected sub-clinically and while the symptoms of FE may not be visible, the disease will still impact on productivity and fertility.

Genetic component

Towers says there is a large genetic component to FE susceptibility in sheep and he urges farmers in high FE risk areas to ensure their ram breeders are testing and selecting for FE tolerance.“It is the only long-term strategy.”