With reports of higher than usual worm burdens amongst livestock this year, dairy farmers are being urged to be vigilant for signs of infection in their cattle and take action to prevent costly dips in animal health and performance.

Many dairy producers have noticed a marked increase in the number of livestock suffering with parasitic worms this year, with both the weather and economic factors contributing to the scope of the problem.

"It's expected that there will be a level of worm burden on dairy farms, but it's particularly bad this autumn – and that's because there's been a 'perfect storm' of contributing factors," explains ForFarmers' Technical Manager, Philip Ambler. "The autumn weather so far has been warm and wet, providing perfect conditions for worm larvae to survive and thrive on grassland. We've not had the cold frosts needed to kill off parasites."

And this comes as many farmers have had cows out at grass for longer than usual due to lower milk prices and higher feed costs.

"As a result, cows have had more exposure to the risk of infection and to higher burdens of parasitic worms than normal," continues Philip. "Last year's weather was also beneficial for parasitic worms, so we're now experiencing a cumulative build-up of worm burden on land and it's having a significant impact on some dairy farms.

"Cows suffering from gut worm infection will show a dramatic reduction in feed intakes and performance. In a dairy cow, that can result in a drop of between 0.35-2.35 litres of milk a day, depending on the severity of infection."

To help prevent this drop in performance and keep animal health on-track, Philip stresses the importance of maintaining timely vaccination protocols.

"Most preventative treatments or vaccinations will have a recommended timeframe for treatment to ensure that an animal stays protected," continues Philip. "When margins are tight, it can be tempting to delay treatments – extending the time between doses and delaying the cost of treatment.

"But this is a risky approach, as the original dose of medication will be less and less effective over time. If the worm burden is low, farmers might get away with it, but when it's high, like this year, they won't. Medication obviously has a financial cost, but it's important to weigh this against the greater potential losses caused by reduced animal performance in both the short and long term."

Youngstock are particularly susceptible to worm infections and should be a key priority for preventative worming, along with high yielding dairy cows. 

"Heifers and higher yielders are the core cows on a farm and need to be worm-free before calving," continues Philip. "You don't want anything holding the performance of these cows back in their first 100 days in milk when they're going to be the most productive. If there's any doubt over whether these animals might be infected with worms, then vets need to be consulted as soon as possible."

Close cooperation with a farm's vet is very important when dealing with worm issues on farm, and any cows displaying signs of infection should be examined promptly.

"Cows suffering with bad worm infections can often be spotted coughing and lacking in energy when walking to the milking parlour or robot," says Philip. "During warmer, humid weather, it can be easy to mistake signs of worm infection for heat stress – this is especially the case in housed cows. But if the weather is cooler and less humid and cows are still coughing and looking under pressure, it's worth highlighting to the vet.

"Anyone concerned that worms might be an issue on their farm can ask a vet to do faecal egg counts and follow up blood tests, as required. A farm's veterinary practice really is the number one source of advice and practical help to prevent or solve worm-related problems."

Given the reported rise in worm burdens on farms, ForFarmers staff are being encouraged to pay close attention to livestock that may show signs of infection.

"When we're visiting farms and checking livestock, the issue of worms is higher up on our observation list at the moment," concludes Philip. "We know the negative impact that lung and gut worm infections can cause to livestock. It's vital that we talk to our customers about the increased risks and help identify any potentially infected animals."