Parasite Management Project - Monthly Update - May 2019

Nematodirus - the main focus for sheep this time of year:-

The major worm species that lambs first encounter is Nematodirus. This can be a particularly devastating worm for young lambs since most Nematodirus eggs hatch in the spring to coincide with when vulnerable young lambs start grazing. The norm across the country is to dose with a white wormer (Group 1BZ), there are 2 reasons for this –

1. Although white wormer resistance is widespread against the strongyle group (all worms other than Nematodirus), it seems to remain fully effective on most farms against Nematodirus (there a are only a few exceptions in the UK).
2. It’s a cheap option when there’s a lot of lambs on the ground to dose – and is a good option as will kill earlier stages of the parasite than other wormers.

Many will advise not to FEC test at this time of year as Nematodirus can cause significant problems for lambs before the adults start laying eggs. However, although we agree with the reasoning, we have been encouraging our project farmers to test as we can still get valuable information which may alter the wormer choice. This is highlighted in this extract of data from different farms over the last few weeks.

As you will notice, although Nematodirus is what we all focus on, the dominant worm species in these lamb counts are strongyles.  Many of our farmers know white drench isn’t fully effective against those strongyle worms, and are therefore able to change to use another group which would work better for both. We do however need to be doubly careful at this time of year when interpreting counts as even though the above results are in the low / medium category (below 500 epg), we still advise to worm against Nematodirus if there is a known history of it and the conditions are correct. The Nematodirus forecast on the SCOPS website (www.scops.org.uk) is also a useful resource in helping that decision making. If there are no significant strongyle counts then white wormer would be the most appropriate choice in these scenarios.

Note: Worming ewes in the spring does nothing to help the Nematodirus issue as most adult ewes have a complete or strong immunity against Nematodirus

Tracking of you cattle post turnout has now started: -

Below are some cattle results from two of our farms, Testing is not necessary on both these occasions with the advice of monitoring youngstock on a regular three-weekly basis – especially with the turn in the weather to wet and warm – ideal for worm hatch on the pasture.