Video: Perfect weather this June for flies; have you protected your herd?

Rainfall for the month of June, 2019 (up to June 23), ranges from 56mm in Shannon to 111mm in Ballyhaise, which is 42mm and 71mm more rainfall that fell in the entire month of June in 2018, respectively.

Most attention has been focused on silage making with many farmers across the country struggling to get two days of good weather in order to make first-cut silage and/or remove surplus bales.

Although mean temperature so far for June 2019 (11.0°C) is lower than June 2018 (15.90°C), it is expected to rise for the remainder of June with a heatwave forecast for the end of this week.

Increased temperatures combined with the high level of rainfall provide the perfect environment for nuisance flies. While silage quality is essential for animal performance next winter, it is important not to lose focus on current animal performance.

Flies cause a significant amount of irritation to cattle, most noticeably by the swish of the tail or shake of the head while at pasture and flying clusters in the parlour. There are also a number of performance-related negative effects of flies such as reduction in milk and butterfat production and reduced growth rates.

More noticeably, flies are implicated in the spread of common diseases such as “summer mastitis” and “pink eye”. However, their impact does not end there; they are also capable of transmitting viruses, bacteria and certain parasites.

There are a number of different flies in Ireland including house or stable flies, face flies, head flies, warble flies (rare) and blowflies.

Face flies are the top offenders for annoyance of cattle at pasture. Face flies and head flies are linked to the transmission of Moraxella bovis; the bacteria responsible for “pink eye” and there is strong evidence to suggest head flies are also involved in the spread of “summer mastitis”.


Areas such as paddock entrances, roadways and collecting yards that have an accumulation of manure provide the perfect environment for flies to breed and subsequently gather. Avoiding the use of fields bordering woodlands is advised in the peak risk period (June-September) where possible.

Removing or at least reducing the source of infection is the most useful approach in controlling stable flies. Examples of this include using multiple paddock entrances where possible and cleaning the collecting yard after each milking.

However, these control techniques are most effective when implemented with fly repellent in a total fly control programme.

Pour-on and spray preparations, repellent creams together with insecticide impregnated ear tags are widely used to reduce fly annoyance. Pour-on products applied at the dosing intervals recommended by the manufacturer will also aid control.

To ensure correct product usage read the guidelines supplied by the manufacturers and adhere to instructions regarding administration, dose, frequency of use and withdrawal periods.

Butox Pour-on

This product contains deltamethrin. In cattle it is indicated for the control of flies and lice. It is advised to pour the dose along the animal’s spine from the base of the head to the tail.

The person applying should wear gloves. It is safe to use during pregnancy and lactation.

Butox Pour-On has 18-day meat and 12-hour milk withdrawal periods for cattle. The time to apply this product is after evening milking and ensure that the full withdrawal period is respected.

Butox Pour-on

Indications for flies in cattle:

  • Prevention and treatment of flies on calves and other cattle;
  • For fly control a single application provides protection for six to 10 weeks (depending on the infestation, fly species and weather) at which time treatment should be repeated.

Avoid animal irritation and the unseen cause of reduced animal performance by starting your fly control programme now.