Efficacy of RESURRECT
Before explaining the graphs in this section, I would like to briefly explain the type of test that was used – called a fecal egg count reduction test, or FECRT. The test involves identifying groups of 10 sheep – one group for each active you would like to test, plus an additional “undrenched” or “control” group. The sheep are marked in a way that makes it easy to identify the active which those sheep were drenched with. On the day of drenching, fecal egg counts are taken from each individual sheep. 10 – 14 days later, fecal egg counts are again taken for each sheep. Reductions in fecal egg count are recorded and drench efficacies are calculated as a percentage fecal egg count reduction compared with initial fecal egg count results. This fecal egg count reduction is averaged across all animals within a treatment which gives the efficacy of each particular drench active. The control or “untreated” group is used to observe any change in the fecal egg counts had the sheep not been drenched. These is also a large degree of variability between animals using this type of test. In some cases a 95% confidence interval (CI) is given to show how variable the records were for a particular treatment.
In May 2016 we knew we had drench resistance with Nilverm, Closantal, Abamectin and some in Q drench & Duocare, but wasn't sure what to do about it, we knew Josh was working on a possible solution that may help. We agreed to be one of Josh's trials. He needed 100 merino lambs for this trial. in early July we cleaned them out with Zolvix and two weeks later dosed with Resurrect. The results spoke for themselves. So early 2017 we used Resurrect on all our 2016 drop lambs. Clean out drench on 22/4/17 Resurrect on the 6/5/17 their next dose was Duocare in late August then nothing for 8 months when they got a Closantal. These sheep have grown well, they are much healthier and stronger sheep and much better than other previous years, we didn't expect it especially given the horrible seasons they were dished up. We will definitely be using Resurrect again, it's a real game changer!
In 2014, I realised I was having trouble with Barbers pole worm resistance. Rametin was starting to lose efficacy, most of the other drenches were operating at 80% and Nilverm was at zero. However, Zolvix had just been released but had a withholding period of 120 days.
Mustering for summer drenching involved carrying a backpack to drench the tailenders that could not travel back to the yards and this could occur in as little as 4 weeks since the last drench! It was depressing.
Josh had been working on an solution that he had wanted to try, so in 2015, after preparation we inoculated our sheep with the first Resurrect barbers pole worms. The difference was beyond our expectations.
At first, I thought it was just the use of Zolvix being so effective, but we went for months without needing to drench. I would muster to drench but on inspection let the sheep go without drenching because they looked so healthy.
After 12 months we repeated the efficacy tests on the drenches and we found marked improvement with Nilverm’sefficacy returning to over 95%.
My experience now with running sheep is our worm control is more in line with our cattle operation and the stress levels are negligible. The major benefit for our business has been a significant increase in productivity and reduced cost input making the business more rewarding.
Thanks Josh and Resurrect.
In a nut shell, the Resurrect system has saved our sheep enterprise here at NEGS. We run Dohne and Dohne/ White Suffolk ewes with terminal Poll Dorset or Poll Dorset/ Suffolk rams to breed quality prime lambs from multiple births. Over the years we have absolutely struggled to control barbers pole worm with traditional drenches and paddock rotations. To be honest, drench resistance nearly put us out of sheep! Josh really has enabled us to successfully continue with our sheep enterprise for the purpose of Agricultural education at NEGS, to the point where commonly used drenches such as Q-drench is highly effective with a recent 50kg lamb autopsy showing no sign of worms.
I’ll now draw your attention to Trial 2. These are the results from another trial conducted in the same way as the previous trial. First we established the drench efficacy of Moxidectin, Albendazole and Levamizole. The Resurrect product was then applied according to instructions. Some months passed and the sheep were drenched with a Closantel, Abamectin, Albendazole and Levamizole combination (available as Q Drench) to kill the artificial infection. Once worm egg counts had increased again, drench efficacies were re-evaluated using an FECRT. As can be seen in Trial 2, the drenches reduced the FEC by a greater amount after the treatment had been applied.
I would now like to draw your attention to Trial 3. In this trial the efficacies of three drenches were evaluated, they were Levamizole, Closantel and a combination of Levamizole and Albendazole. Initially the Levamizole worked at 78%, the Closantel worked at 88% and the Levamizole Albendazole combination worked at 95.9%. After applying the resurrect treatment, the Levamizole worked at 99.78%, the Closantel worked at 99.69% and the Levamizole and Albendazole combination worked at 99.9%. It is also important to note that when undertaking the larval differentiation only 6 Haemonchus contortus (barbers pole worm) larvae were retrieved from approximately 15g of dung culture from the combination drench treatment.
Trial 1. This data represents the average worm egg counts 10 – 14 days after drenching with Levamizole as compared with the undrenched group. The graph shows that there is little apparent difference between the Levamizole treated sheep and the untreated sheep. In fact the worm egg counts had increased to almost 400% of what they were when the sheep were drenched 2 weeks prior.
After identifying that Levamizole didn’t work, the sheep were treated with “Resurrect” according to recommendations. Some months passed, the sheep were drenched several times with Napthalaphos (Rametin). Another resistance test, or FECRT, was performed, using Levamizole. The results are presented in Figure 1. Again the data shown is the average fecal egg count 10 – 14 days after drenching. The control group FEC had increased to over 900% of what it was measured at the time of drenching. The Levamizole group however showed only 2.5% of the initial FEC, demonstrating over 97% efficacy of Levamizole.