Worms - are they the real issue?
We started in 2021 with a goal of being NIL drench and lambing hoggets. Our SIL bureau at the time recommended that we do a weaning drench because it will remove some of the environmental noise from different set-stocking arrangements and general management through the lambing period. That all made sense to me at the time and is still a valid approach for some.
Something was nagging at me though, it felt unfinished to me. We want to see what effect this one drench is having and we had a goal of being NIL. The other aspect that seemed unexplored to me was, if a sheep is truly suited to its environment, should it matter if its left undrenched? Perhaps the science could come after we stopped drenching - the goal as an industry is to drench less afterall.
I heard many reasons why it wouldn't be doable — "you have Barber's pole worm they'll just die", "you'll make your evaluation less scientific", "you'll favour singles" — amongst many others. All of those things are easy enough to regulate.
I tell you one thing that excited me: if it worked, it meant we weren't tied to the hip of multi-national drug companies who love to sell us novel chemicals at a 1000% increased price over the old generic products just so we can stay in the same place as a production system. Surely if our genes are going to support commercial operations to drench less, we could take the last step available.
So in 2022 I didn't drench the ram lambs. They went as far as they could go, most needing some help at some stage but a solid group of 50 odd making it to sale time. The main ram that came from the '22 year group of significance was Albie 398/22, who as of writing this article has 700 progeny in the stud.
The problem we found with the year group, as proud as I may have been, was they were a bit tough for people to look at. That is when the commercial reality of stud breeding began to conflict my true beliefs. We know we need these sorts of breeding programs to push the boundaries, but purchasers quite rightly want to be proud of what they buy.
In the end leaving the females undrenched and putting the rams through the resilience protocol pushes the boundaries for each group. We have tried every measure of resistance and at this stage it looks like the new nextResist product will help reveal that side of the ledger.
We want to measure everything we can as it pertains to worms and how a NIL drench flock presents itself. The most important thing however is that we simply can't do any more than we already are to support good outcomes for your commercial flock.
I do think anthelmintic support will be needed for trade-stock and poor animals into the future across most farms, but I also know we can breed directly into the drench resistance storm around NZ and have breeding females that are totally capable of never needing a drench.
Journey of a NIL drench ewe lamb
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August
Birth
The ewe lamb is born sometime between mid August and mid September to a NIL drench mother.
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September
DNA Parentage
All lambs are brought in for marking, tagging and DNA sampling. They receive a B12 5in1 + Se.
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November
Weaning
Lambs are weaned between 80 and 90 days of age and given their second B12 5in1 + Se. Ewes and lambs are dag scored.
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December
Shearing
Lambs are shorn and put back on all grass pasture. Wool 29mic average.
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February
Growth
Ewe lambs are getting into the mid to late 40kg range about now, Toxo Vax and 2 Campy Vaccines will be given through this period. Barber's Pole worm begins to really get going. Poorest performers may lose 10kg over the next 30 days to worm burden. About 20% manage to grow through Barber's Pole infection, most will significantly slow down as they adjust.
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April
Mating
Many will have lost some weight over the last month. Regular weighing ensures we can build a picture of who has adjusted to worm burden. Truly worm tolerant sheep will begin to put weight back on for 3-4 weeks leading to the ram on 25th April. Eczema ramps up. Copper Multi-min + Depodine given pre ram.
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July
Scanning + Shearing
2026 we scanned 114% in our NIL drench ewe hoggets. Growth has slowed but good condition maintained. Dry hoggets are culled from stud. Tests have shown a mid winter B12 is useful at this point. Second Shear avg 31mic.
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September
Lambing
Pre-lamb 5in1 + Selovin LA Selenium. Hoggets begin lambing, improved pastures but still an all grass system. Weights are normally 65-75kg range depending on size at mating and litter size of pregnancy.
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January
Weaning
Lambs are weaned at 90-100 days if born to a hogget. Our hogget that we have followed from birth is now a freshly minted 2th and ready to join the ram mid March. Target weight to the ram is their pre-lamb weight as a hogget.