Farm Ireland

Tuesday 23 January 2018

Mid-season worm control - Use your ears and weighing scales or a weigh band

We are now half way through the grazing season and it is a good time to take stock as to how well weanlings, heifers and bullocks are doing at grass.

There have been a number of warnings in recent weeks about the high incidence of hoose this year. Hoose (lungworm) can cause, at the very least, a setback in growth but can also lead to large numbers of very sick and coughing animals, some of which will die.

It would appear that the unusual weather patterns we have experienced so far this year have not only led to difficult pasture management, due to erratic grass growth, but also to a higher incidence of hoose in both first season grazers i.e. calves &weanlings and in second season grazers i.e. heifers and bullocks.

The Regional Veterinary Labs report that herds were experiencing losses from hoose as early as April this year and Animal Health Ireland released a warning bulletin earlier this month highlighting the risks.

All animals at grass should be checked on a daily basis and close attention should be paid to their breathing rates and whether they are coughing or not. A farmer’s ears are the most effective early warning system for hoose.  

A slight ticklely cough in a few animals can develop into a full blown outbreak in a matter of days if prompt remedial action is not taken.

The white drenches (benzimadazoles), levamisole injections and the clear macrocyclic lactones (ivermectin type) injections and pour ons are all effective against lungworm infections but only the clear  macrocyclic lactones offer any persistent protection.

The reality is that at this time of year, once weanlings and heifers are treated they will be turned back onto pastures that will still have some level of worm burden, and as a result they will be quickly re-infected with lungworm again.

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Using long acting  products like Cydectin or Dectomax, both available as pour on or injection, will not only treat the current worm infections, but will also ensure that the animals will remain free of lungworm infections for up to six weeks. This will not only give the lungs a chance to heal but will also ensure that they maintain or improve their growth rates.

Even if animals are not showing any signs of disease it would be wise to weigh them and check their growth rates, ideally with electronic scales but weigh bands are also useful. Dairy heifer calves should be growing at 750grams per day and beef animals at 1kg per day.

By August 1, Friesian heifer calves that were born in the first week of February should weigh about 175kg (180 days x 750gms + 40kg (birth weight). It is important that all in the group are on track and it is not the average, as animals that are behind are less likely to reach their target weights in another 6 to 8 months when they will be going to the bull. 

However, if they are behind there is plenty of time to offer them some meal, better grazing and/or dose them to help them get back on track.

So remember, check animals daily,  particularly with your ears, weigh them when they are close to the yard and dose them with an effective persistent wormer like Cydectin or Dectomax when necessary.

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