Is your wormer still working?

Charles Chavasse, area veterinary manager with Zoetis, outlines the importance of effectively treating worm infections in livestock 

In 1981, Kerry won the four in-a-row and Offaly claimed its first Senior All-Ireland Hurling Championship. That year also saw a massive breakthrough in the treatment of worm infections in livestock when ivermectin became available for use by farmers all over the world.

At that time, ivermectin offered better and more convenient control of worm infections compared to the white and yellow drench products that were already available.

Fast forward 37 years and farming practices have changed considerably, with higher stocking densities, tighter grazing schedules and much less labour.

This has led to increased production, with better grass management and genetics. But at a cost; there is now an increased exposure to worms on pastures and resistance to some of the wormers is occurring.

Recent research on 16 of the BETTER Farm Beef Programme farms looked at the effectiveness of some wormers and the daily live weight gain when worms were controlled effectively.

On all 16 farms studied, it was clear that ivermectin was not working. The ivermectin products used simply were not providing the level of worm control required because the worm populations on these farms have become resistant to ivermectin.

On one of the farms studied, the ivermectin-treated calves were 7kg lighter at the end of the month long trial. In the bunch of 39 calves, this was equivalent to a loss of 273kg or almost the same loss as having a dead calf every month.

So, resistance to wormers is an issue and there’s evidence that the ivermectin products – regardless of brand – are simply not working as well as they once did.

What are the alternatives? Reduce stock numbers? Organic farming?

Well, the older white and yellow drenches are still available; but as they only kill worms on the day of use, they don’t offer the most practical solution given farmer’s existing workload.

Newer products such as Cydectin and Dectomax are viable alternatives; offering persistent killing of worms and no evidence of resistance.

Cydectin contains moxidectin, which is very different to ivermectin. It is available in both a long-acting injection which provides worm cover for 120 day or a pour-on formulation.

Cydectin 10% Long Acting wormer injection is a convenient, labour-efficient, one-shot wormer for animals over 100kg.

A single 1ml/100kg injection – under the skin – gives 120 days (four months) persistent protection against both stomach worms and lung worm, so no need to round up the calves every four-to-six weeks.

Convenient and effective

Niall Kelleher, a dairy farmer from Aherla, Co. Cork, started using Cydectin 10% Long Acting wormer on the recommendation of one of his vets Edmund Walsh of Glasslyn Veterinary Clinic.

I have found it very convenient. It lasted for up to four months and it did a great job on the lung worm and stomach worm in my calves this year.

The Cork-based farmer was very happy with the overall growth and performance of his cattle and they “haven’t looked back since”.

Charles Chavasse, area veterinary manger with Zoetis, said: “Our experience over the last few years is that farmers start using Cydectin 10% Long Acting for the convenience and labour saving; but the reason they keep using it year-after-year is that they see the improved performance for themselves.

“It is an obvious choice for all calves and weanlings at grass this summer. It is easy to use in all calves – be they dairy replacements, dairy-to-beef, or suckler calves.

It is also a good option for worming yearlings and it’s an obvious choice if they are going to an outside farm with no crush or poor facilities.

“Farmers can use it with confidence, knowing that there have been no known cases of resistance,” he added.

Good value and cost effective

Calves are treated at lower weights, so not as much product is required and yet the dose still works when they have more than doubled their weight (e.g. a calf treated at 100kg in mid-June could expect to be 200-220kg in mid-October and would still be protected against stomach and lung worms).

The cost would be about 2.5c/day of protection. It should also be remembered that the most expensive product is the one that does not work (e.g. where ivermectin resistance has been found).

There is no known resistance to Cydectin 10% Long Acting and it offers the longest persistent effect of any product – 120 days against stomach and lung worms. Click here for more information