You gotta know when to dose ’em
Faecal sampling is the foundation for a targeted dosing strategy, writes
THE Lleyn ewe is a medium sized lowland sheep weighing up to 75kg at maturity, renowned for their hardiness, prolificacy, easy lambing, strong mothering instinct, milkiness and easy handling.
It was with these attributes in mind that Clifford Richardson, who farms outside the village of Carrigallen in south Leitrim, chose the Lleyn breed as the foundation stock for his expanding sheep enterprise.
Clifford is focused on having a labour-efficient flock which, when combined with good fencing, housing and handling facilities, enable him to work full time off farm.
The 2016 profit monitor analysis for the farm shows lambs reared per ewe at 1.76, a sales figure of €157 per ewe from 97kgs of liveweight output per ewe.
This resulted in a gross margin of €61 per ewe. Clifford plans to increase this to over €90 in the next three years which, when combined with an increase in stocking rate, will dramatically increase the overall gross margin on the farm.
Like most other flock owners in the west of Ireland, stocking rate is the main factor limiting overall farm profitability when technology and farm efficiencies are maximised.
Clifford recently hosted an extremely well-attended Lleyn society open day on the farm, promoting the attributes of the breed. Lambing went well on the farm this year, with 1.79 live lambs on the ground for mature ewes and 1.25 lambs for ewe lambs mated.
This was Clifford’s first year to lamb down ewe lambs. No major problems occurred and he plans to continue breeding ewe lambs next year.
Feeding a ration with 20pc soya bean meal prior to lambing and feeding the single bearing ewes an additional 100g of soya per day ensured that ewes and ewe lambs lambed down with an adequate colostrum supply for twin lambs.
The majority of multiple born lambs were cross fostered on to single bearing ewes. The challenge for Clifford from now on is to ensure that post lambing losses are kept to a minimum and lamb performance from grass is maximised. The main reasons for post-lambing losses up to weaning are starvation, ewes with inadequate milk supply, clostridial diseases and pasteurella pneumonia, coccidiosis and parasites nematodirus and strongyles.
An outbreak of orf or mineral deficiencies, while they may not result in lamb mortality, can severely affect lamb thrive if not addressed. Clifford treated all lambs with Scabivax at turnout.
The earliest born batch of lambs were given a white worm drench for nematodirus on April 17 when the nematodirus warning was issued and were also treated for coccidiosis with a toltrazuril-based product.
Clifford also vaccinated the lambs with their first injection of Heptavac P to protect against pasteurella pneumonia. The younger batch of lambs were given the same treatments two weeks later. All lambs will be given a six month cobalt and selenium bolus when they are gathered for their booster Heptavac P vaccination.
Clifford plans to change his dosing strategy for lambs this year from routine dosing as practiced in previous years to dosing only when required. Routine dosing is like gambling — it’s a shot in the dark and you may get it right sometimes.
Future dosing for strongyles on the Richardson farm will be based on faecal sampling carried out every three weeks over the summer months.
“I would have routinely dosed the lambs last week if I hadn’t taken faecal samples.” On May 24, five weeks after their first dose for nematodirus, lambs were faecal sampled. This was carried out in the field where they were grazing. Ten individual random samples were taken from lambs as they passed faeces on to the grass.
It is best to lift samples in the field when sheep are settled or lying. When the lamb gets up, it stretches and normally passes faeces. It is vitally important that you keep a good eye on the spot the lamb defecates as you need to ensure that the faeces are fresh and, more importantly, come from a lamb with no cross contamination with ewe faeces.
Place the faeces in the plastic sealable containers provided by the lab you have selected, collecting an amount similar to a large marble — the circumference similar to a €2 coin.
Samples should not be mixed from different lambs — this will be carried out in the lab where three grams from each sample is taken and pooled prior to testing.
This is done to avoid a large proportion of faeces coming from a single lamb with a high count influencing the final pooled sample count. Lifting 10 individual samples normally takes 20-30 minutes.
However, as in Clifford’s case, it could save a lot of time and effort if the result shows that the lambs do not require a dose. It will also influence the long term efficacy of the drug used as reduced use will reduce the onset of drug resistance. It is important that the samples are lifted early in the week, are properly sealed for posting using the three-layered system to avoid leakage, and are posted or delivered to the lab as soon as possible after they are taken.
The results of faecal samples are sent to your local vet, with whom the future dosing strategy based on the findings should be discussed. The parasitology report from Clifford’s lambs showed they had a strongyle count of 350, a nematodirus count of 150 and showed few coccidia present.
The lambs sampled were born from the last week of February to the first week of March and should have built up their own resistance to nematodirus at this stage.
However, if there were younger lambs on the farm beginning to eat grass and becoming exposed to nematodirus for the first time, then they will require a dose, preferably a white drench.
The coccidia count is evidence that the toltrazuril dose has done its job. Lambs will require a dose for strongyles when the egg count reaches the 500-1,000 eggs per gram.
Clifford will sample every three weeks and dose again when the count indicates that the dose is necessary.
ROUTINE DOSING IS A GAMBLE — IT’S A SHOT IN THE DARK AND YOU MAY GET IT RIGHT SOMETIMES
Tom Coll is a Teagasc business and technology advisor based in Mohill, Co Leitrim