In 2020, Oceania Dairies in the South Island banned the use of abamectin based drench products in lactating dairy cows after abamectin residues were detected in UHT milk products imported into China.
Abamectin is commonly used in dairy cows as low-cost pour-on and these products currently have a nil milk withhold claim. These products while primarily aimed at the control of internal parasites, also control lice.
Now MPI is in the process of implementing a 35-day milk withhold for these pour-on products.
Given this decision, our advice is to start removing these pour-ons from your dairy farm; there are other safer and more effective options.
The risk of retaining the supply of abamectin pour-ons for use in non-lactating cattle on a dairy farm, is the unintentional application onto animals in milk. The detection of these residues in products, is not the story we wish to be reading about.
So, what to use in adult dairy cattle instead of abamectins?
The first question to ask is, does your herd suffer from lice? If the answer is “no”, then we will recommend either Eprisure™ or Eprinexa®.
Episure™ comes as either a pour-on or as a low-dose injection (5 mL for a 500 kg cow) applied subcutaneously under the skin. The low-dose injection will provide a higher and longer level of the eprinomectin active in the blood plasma. Eprinex® comes as a pour-on only.
Both products have a nil milk withhold as well as a nil withhold for bobby calves fed milk from treated cows.
If you are injecting with Multmin® three to four weeks prior to calving as an aid for reducing sub-clinical and clinical mastitis early in the season, either Eprisure™ or Eprinexâ can be applied at the same time.
While Episure™ and Epinexa® have a label claim for the control of lice, these are not the preferred products you should be reaching for.
For lice control, use a specific lice product. Options available include Pouracide NF which comes with a six-week claim for both biting and sucking lice. This length of control is important as it allows time for the lice eggs to hatch; this occurs around 10 days after the eggs are laid. The other advantage of Pouracide use in dairy herds is the nil milk withhold and nil withhold for bobby calves fed milk from treated cattle. The meat withhold is seven days.
Other pour-on options include Lypora® (milk withhold 14 days and meat 10 days), Coopers Blazea® (nil milk withhold and 28 days for meat), and Delmax (nil milk, 28-day meat and nil Bobby Calf withhold).
There is much to think about when using these products so either speak with one of our vets, farm techs or to one of our commercial managers to get clarity on the right approach.