Spring parasite risk ‘hugely variable’ on sheep farms 

Staying vigilant for signs of liver fluke and worms is paramount for sheep farmers, as the risk of parasites becomes increasingly variable, say advisers.

Traditional risk periods for parasites are no longer applicable and regular monitoring is the only way to know if – and when – treatment is required, says Matt Colston, ruminant technical consultant at Elanco.

“An example of this variability can be seen with liver fluke,” he explains. “Deaths caused by acute fluke infection were seen well into January this year, and historically we’d expect these to happen in late autumn and early winter.”

Peak periods for parasite infection have varied so much in the past five years that a ‘typical year’ no longer exists, says Mr Colston. Doing tests on your own farm is the only way to know what is going on with parasites.

For liver fluke, Mr Colston says producers should find out if – or when – the infectious stage has appeared on a pasture by using some of this season’s lambs as sentinels and checking blood samples at intervals throughout the season.

“Once the sentinel lambs have shown fluke is active with a positive antibody result, follow-up dung samples can be used to show what stages of the parasite are present.”

A coproantigen test will pick up fluke at the late immature, ‘teenager’ stage, while an egg detection test will show when fluke have reached the adult stage, which is 10-12 weeks after infection.

“Using the right test at the right time in the right animals is necessary to get a true picture of what’s happening on the farm so it’s worthwhile speaking to your vet to get the right testing plan for your farm,” adds Mr Colston.

Worm larvae

For worms, Mr Colston says the cold snap in January is likely to have reduced the number of worm larvae active on pastures, however, it is worth testing mob samples to see if any groups of ewes might benefit from treatment.

“Farmers were previously advised to treat the whole flock at lambing,” says Mr Colston. “We now know we can have the same impact by targeting ewes that might be struggling to maintain body condition up to and around lambing.”

“Thin ewes, older ewes, those carrying injuries or any other illness, and those with multiple lambs would fall into this group.”

Lastly, Mr Colston says ectoparasites – in particular, sheep scab – can cause serious problems for a flock if not identified and dealt with effectively before lambing time.

“If any sheep are even slightly itchy when gathered for scanning, this offers the opportunity to blood test a set number for scab antibodies, to either rule out or confirm the need for further action,” says Mr Colston.

“Plunge dipping in an organophosphate (OP) is the only treatment option likely to be fully effective, and modern dipping waggons mean even pregnant ewes can be effectively treated without causing undue stress.”

Diet is ‘soya-free success’ for dairy cows

Dairy cows can consistently thrive on an optimised, soya-free diet, producing more milk from forage while maintaining milk quality, say researchers.

Trials at Nottingham University saw a 4.8kg increase in milk per cow  among the university’s  400-head herd of Holstein Friesians. Additionally, milk urea levels dropped from 249mg/litre to 176mg/litre, signalling improved protein efficiency.

Lower emissions

The goal was to reduc farm emissions and improving its overall carbon footprint per kg of fat and protein corrected milk (FPCM), in line with milk buyer expectations.

The diet shift, fully implemented in March 2024, replaced soya with rumen-protected amino acids, protected rapeseed meal and rumen energy sources, while reducing crude protein levels from 17.5% to 16.7%

Starch content increased from 18% to 22.5%, further supporting milk yield and fertility.  Since moving to a 100% soya-free diet the cows have consistently outperformed their previous production levels thanks to a better balance of nutrients.

Supporting yield

Forage intake rose by 14%, leading to a boost in milk from homegrown forage. This contributed to more than a 10% reduction in CO2e per kilo of milk, and a decrease in the diet impact per portion from 37kg CO2e to 21kg CO2e.

The trial was undertaken in partnership with Wynnstay and Trouw Nutrition. Feed has a big impact on carbon footprint and the result is seen as a quick win to reduce emissions.

Wynnstay head of dairy David Howard said: “We’ve proven that cows can thrive without soya  – a huge step forward in reducing the carbon footprint of dairy farming.”