Changing dry cow strategy slashes cell counts
Tom Carter, a sharemilker at a farm at Ohinewai near Huntly, has discovered a new way to get his 340-cow herd's somatic cell count down.
Having a reasonably well producing season, Tom found himself noticing that the milk from his dairy cows had uncomfortably high somatic cell counts, between 250,000 and 280,00. Somatic cells are found in fluids, like milk. The high count indicated a fairly high level of mastitis infection throughout the season.
His farm, on low-lying flats with a mixture of sandy and peaty soils, which gets very wet in spring, provided an ideal environment for mastitis infection during calving.
Tom has been with the herd on this property for five seasons and the annual pattern of mastitis infection was getting repetitive, costing the business money at a time of already low returns.
With the help of veterinarian Kris Brownlee of Franklin Veterinary Services, he reviewed the way he managed mastitis risk, focusing on the use of dry cow therapy.
This preventative treatment at the end of lactation clears up existing infections, protects against reinfection during the dry period and next calving, and should set up cows well to fight off mastitis well into the following lactation.
Tom was using Cepravin Dry Cow, a long-acting product widely regarded as a gold standard in dry cow therapy treatments. Whole-herd therapy at drying off is recommended, as it is not always easy to pick which cows are carrying infections or are susceptible to new infections by the end of lactation.
Tom had been treating about two-thirds of the herd. He dries off gradually, over about three weeks. It was his practice to not treat the first cows to dry off, introducing dry cow therapy to the cows that were dried off later on. Part of the motivation for this was to manage the risk of the first cows to be dried off getting back into the milking herd with freshly administered antimicrobials on board – potentially disastrous if residues got into the vat.
On his Kris's advice, Tom tried whole-herd dry cow therapy with Cepravin and he’s been blown away by the difference it made. He said infections during the dry period were much lower and that continued into calving. What really stood out for Tom was the huge drop in bulk tank somatic cell counts. The count went from around 250,000 last season to as low as 85,000 during the current lactation.
Vet Kris Brownlee said it’s impossible to eliminate all mastitis infections, but she’s noticed that the few cases that have occurred this season in Tom's herd have been much more easily curable than in past years.
Kris says Tom's approach is not unusual, with many farmers resisting the urge to cut costs by dropping or reducing dry cow therapy during the low payout period. “When they understand how well whole-herd therapy works and the difference it makes, they are happy to stick with it.”