Agriland Media is delighted to collaborate with Elanco Animal Health to bring you the ‘Flock Forwards, not Backwards’ Series.
Farming just outside the village of Claudy in Co. Derry, sheep farmer Clement Lynch and his family run a flock of 530 breeding ewes and 140 replacement ewe lambs over 215ha of mixed-quality land.
The closed flock consists of Scottish Blackface-type, Suffolk and Texel-cross, and mule ewes, with rams only being purchased for the breeding season each year.
All lambs, with the exception of replacements, are brought to slaughter, which usually commences in July.
Around 60% of the lambs are finished by the end of September, with the hill lambs sent to the factory by Christmas.
Given the fragmented landscape and the mixed-quality terrain, the sheep enterprise is the only viable option for Lynch.
With this in mind, he places a major emphasis on flock health and protecting the system for future generations.
“Anthelmintic and antibiotic resistance are the two biggest challenges we’re facing on the farm. We’re in a situation where the landscape will only allow me to graze sheep; I can’t turn to cattle or grow any crops.
“So, it’s imperative for me to stay on top of flock health and welfare to help ensure we’re able to farm for generations to come.
“This includes protecting the anthelmintics that are currently on the market. Because if I don’t, there will be no option left but to give up farming the land,” he said.
Consistent monitoring
Lynch aims to make the best use of his cheapest available feed source – grass. However, grazing sheep are naturally exposed to gut worms and, if left uncontrolled, these worms will have a negative effect on lamb performance.
While this causes an animal welfare issue, it also has a detrimental effect on a farm’s bottom line, mainly due to poor lamb growth rates.
In a bid to maximise productivity and performance, Lynch regularly weighs his lambs at certain times throughout the grazing season.
This, coupled with regular Faecal Egg Counting (FEC), allows him to make the most accurate decisions when it comes to dosing.
“My whole dosing programme is based on FEC tests, weighing, looking at daily live weight gain, and using this data to inform what drench I use and when I use it,” he added.
“Lambs that would be gaining 320-330g/day wouldn’t be dosed at all.
“Then I’d divide the remaining lambs up into two batches. The poor-thriving ones would definitely get dosed, and I’d decide whether or not to dose the middle batch,” he said.
By implementing this strategy, Lynch avoids wasting time and money on wormers that are of no benefit if a significant worm burden is not present.
Additionally, overuse of anthelmintics leads to resistance being accelerated.
Dosing regime
Only when a worm burden has been identified will Lynch look to anthemintics.
Early in the season, for Nematodirus worms, he will monitor the health of the lambs, look at the Nematodirus Forecast online and the weather, before doing all lambs with a class 1 white wormer aged six to seven weeks.
Industry best practice advises only using white wormers to treat Nematodirus in lamb. This is because of a high level of resistance among other worm species to this wormer class.
Any further dosing should be determined by FEC results and lamb daily live weight gain (DLWG).
Lynch explained he generally varies his dosing programme though the season, using either a class 3 clear or a class 2 yellow dose, just not to be using the same product all the time.
“A few years ago, I’d have dosed for a season with the same product, but in the last two or three years, I’ve moved away from that approach, as guidance has changed,” he said.
Importantly, Lynch carries out a follow up FEC either seven or 14 days after dosing, depending on what colour drench was used. By doing so, he can be sure the product has worked to a satisfactory level.
It was by conducting these post-drench tests that he learned of his farm’s resistance to ivermectin.
Class 4 orange wormer
Growing increasingly worried about wormers not working on the farm, and the problems this poses, Lynch now incorporates a newer generation product into his dosing programme – the class 4 orange wormer.
Using this as a mid-to-late season break dose removes worms left behind by previous treatments, allowing lambs to reach growth potential.
Long-term, this will prevent lambs carrying a higher percentage of resistant worms from contaminating paddocks with resistant worm eggs in the autumn.
“After I dose with the orange wormer, I’d continue to lift faecal egg samples every couple of weeks and generally find a very low or completely clear worm burden,” said Lynch.
He adds: “My lambs thrive better, and I get them away quicker.”
Lynch also uses the wormer as a quarantine dose after purchasing rams for the breeding season. After treatment, the rams are turned out onto pasture recently grazed by the resident flock.
“I use it for a quarantine dose to make sure I’m not bringing in worms that are going to cause me problems in years to come,” he noted.
Rotational grazing is also employed on the farm in a bid to minimise worm burdens, with groups moved every three days allowing lambs access to top-quality grass.
The weighing scales are not only used to assess DLWG, but Lynch is meticulous at avoiding under-dosing, as this also accelerates the rate of resistance on farm.
“After weighing the lambs, I always calibrate my gun for the heaviest individual to ensure each one is given the correct dose rate.”
Farm facts
- 670 sheep – Scottish Blackface, Mules and Suffolk-Texel cross ewes;
- 60ha of grassland;
- 155ha of hill and rough grazing;
- Regular weighing throughout the grazing season;
- FEC pre- and post-dosing;
- Inclusion of class 4 orange wormer as a break dose and quarantine dose;
- Closed flock, only buying in rams.
Flock Forwards, not Backwards Series
Stay tuned to Agriland for episode two next week, when Elanco Animal health technical consultant, Brian McConnell, speaks with vet Kieran Devaney of Ormonde Veterinary in Co. Kilkenny.
References available here.