Part two - Around calving
In our April newsletter we looked at the risk of inhibitory substance (IS) grades around drying off, this month we will consider steps that can be taken to minimise risk of grading around calving.
Critical to success is excellent record keeping. Maintaining clear and complete treatment records will go a long way to minimise any risk of an IS grade. However the ability to do this is dependent on accurate tagging and easy identification of individual cows - the dry period can be a valuable time in which to make improvements in this area if required!
Once calving has begun, ensure colostrum mob entry/exit dates for individual cows are recorded. It is vital to clearly identify and run colostrum and antibiotic treated cows separately from cows milked into supply and to milk these cows AFTER the main herd. Hot wash the milking machine after each milking (twice-a-day!) where cows treated with antibiotics have been milked through the plant.
Ensure you are aware of and that you follow label instructions of antibiotic treatments given at drying off and/or during the dry period, most importantly in regards to withholding periods (WHP). Remember that WHP are based on number of milkings NOT days, for example where cows are once-a-day milked, the WHP following dry cow therapy (DCT) is eight milkings, not four days. In addition, with DCT, it is also important to be aware of and adhere to the required length of dry period which varies according to which product has been used.
Two final points to remember are:
- that once-a-day or incomplete milk out following calving (such as for milk fever cases or low producing/skinny cows) has an effect on residue duration.
- that, where milk from multiple treated animals is to be returned to the vat on the same day, or the label dose rate or regime has been varied, it is important to follow the recommendations of your prescribing veterinarian as residue concentration may also vary.
With attention to detail and some organisation IS grades are avoidable, so take some time to meet with your team prior to calving and ensure you have a solid plan in place!