Understanding udder health
Last month we talked about why dry cow management is critical, though often overlooked. This month I wanted to dive further into the dry period’s importance to udder health.
The price drop in 2008 triggered a range of responses, some teaching significant lessons which should not be forgotten.
In respect of milk quality and mastitis control there are three lessons that should be recalled now to avoid history repeating itself.
Dry-off
Many farms that made radical changes to their dry-off routine (mainly in product and cow selection) suffered a significant blow-out in cell counts and cases of mastitis in the following lactation, resulting in costs much higher than the saving made at dry-off. Many of these farms also suffered longer term effects on their milk quality and mastitis control.
This does not mean it is not possible to cut some costs at dry-off, but the lesson from 2008 is that understanding what effect each compromise has on the risk of mastitis will allow an informed decision, and give opportunity to potentially alter other management areas to reduce that risk.
Also consider that while every compromise has an effect, some changes carry a lesser risk than others, and some changes may have 'work-arounds' that will help to manage the change in risk.
If you think you need to make compromises at dry-off, make sure you discuss with your advisers how to minimise the risks, and how to best manage the changes in risk that are likely to result.
Items to talk about will include product selection (cure rates of existing infections and prevention of new infections), and cow selection (which cows should be treated and how to choose them).
As an example, if you were considering removing teat sealant from your dry-off treatment, the main effect will be to increase the risk of new infections, especially at calving.
After discussion, you may decide the increased risk is too great, or you may choose to limit the risk to a certain group of animals (eg the heifers) or you may choose to consider a 'work-around' -- altering your calving management for either the whole herd or that particular group of animals in a way that reduces that risk at calving.
Also, if you are considering selective treatment of cows, don't be surprised if your adviser suggests a different cell count threshold for treatment than you might have expected.
Culling
Already many herd managers are talking of reduced numbers for next season.
Selection of cows to cull is always based on many factors, but cell counts and mastitis are always in the mix to be considered.
Countdown has given us good guidelines to use when considering cows for culling. Cows that have had three or more clinical cases of mastitis in a lactation should appear on most preferential culling lists. However, the use of cell counts for culling requires a bit more thought, as just culling the cows with the highest cell counts at the most recent herd test may not give the best outcome.
A number of factors including a cow's age, production, udder conformation and history of dry cow therapy and clinical cases should also be considered.
As an example, an older cow with a history of high cell counts after having being treated with dry cow therapy should generally be higher on the preferential cull list than a young cow that has never had dry cow therapy, even though the younger cow's cell count may be considerably higher. This is because the cow that has never had dry cow therapy is likely to have a greater chance of cure with that therapy than a cow that has already failed to cure before.
It is likely that taking a little time to work through your cull list will give you a better outcome.
Replacements
Another lesson from 2008 is that some farms that chose to reduce costs and gain extra cash by selling replacement heifers subsequently found it to be a long hard road to rebuild the herd at a later date.
Not only that, but their ability to cull cows for any reason was also severely compromised for some years afterwards.
In summary, hard decisions are likely to be needed. Also, there is no single answer to any of these situations or questions, and every farm is different.
However, it is almost certain that an informed decision with forward planning to cover changes in the farm's milk quality and mastitis risk profile is likely to give a far better outcome.
History has given us lessons to learn from, and now is the time to heed those lessons.
• Rod Dyson is a vet with Dairy Focus in Victoria, Australia
