Summer mastitis: Fly control, costs and protection

As fly populations reach their peak, farmers are reminded that prevention is better than cure to combat summer mastitis. According to Nadis, losing a quarter to summer mastitis can reduce a cow’s future milk production by 10% and the infection may cause up to 100kg liveweight loss, states a recent press release by MSD Animal Health.

Cases tend to surge in July and August, as warmer temperatures encourage fly activity, and wet weather makes the problem worse.

Photo: MSD Animal Health

With the Met Office predicting an unsettled summer with above average temperatures, NFU dairy board chairman and Disease? Not On My Farm! ambassador Michael Oakes recommends carefully considering fly exposure to avoid costly illness in your herd.

Flies like mild, damp and sheltered spots, so we’re more likely to find transmitted infections in dry cows or heifers next to a wood or brook,” says Oakes.

The first sign of mastitis infection is usually a swollen teat with thick, clotted discharge. Large numbers of flies are often clustered around the udder, irritating the cow and causing her to kick frequently.

Within a week, visible swelling can develop into isolated behaviour, joint stiffness and reluctance to graze, rapidly impacting a cow’s body condition.

“I’ve found you often have to accept a loss in milk yield and sacrifice the infected quarter to save the cow, so it’s critical to act fast with treatment, or better still, implement preventative measures before flies strike,” he adds.

Fly control and preventative measures

Steph Small, MSD Animal Health dairy veterinary adviser, recommends farmers invest in preventative measures to reduce the chance of cows becoming sick.

“Fly control is the first line of defence against summer mastitis and is especially important if there’s no other option but to use grazing pastures next to woodland,” says Small.

“A pour-on suspension such as Butox Swish will deter biting or nuisance flies for 8 to 10 weeks, allowing cows to graze contently,” she advises.

“For most effective protection, apply this early in the grazing season before eggs and larvae start to develop to prevent the fly population spiraling out of control. Small concludes that diligent monitoring is crucial to spot early signs of infection.

“Checking cows regularly for swollen teats, and monitoring fly numbers surrounding the udder will help ensure prompt effective treatment. If you suspect a case of summer mastitis, contact your vet immediately for treatment advice,” she adds.

Source and for more information, visit MSD Animal health