By Emma Stuart
With dairies calling for reduced milk supplies, drying cows off early may be one way to achieve this but it should not be seen as the easy option.
The risk of these cows becoming over-fat in the dry period is enormous. Careful management and planning their diet are both paramount to minimising post-calving metabolic disorders such as fatty liver, ketosis, left displaced abomasa (LDAs) and milk fever. As well as affecting health, these cows are more likely to have reduced fertility and lower milk yield through the lactation, thus savings made now may turn to losses in the future.
If you already have a short dry period, for example, 42 days, then you should be able to safely extend the dry period to 60 days without much issue. Try to avoid going above 90 days if possible. If you feel this is necessary, these cows must be kept on a low-energy, high fibre diet. (Discuss with your nutritionist/Promar consultant, etc to formulate a diet to meet their needs). Unless you have very old or bare pasture, avoid putting them out to grass entirely as they will quickly put on body condition which they will struggle to shift. When selecting cows for an extended dry period avoid heavily conditioned cows (body condition score of greater than 3.5).
Choosing which cows to dry off
The main candidates for an extended dry period should be high cell count cows (>250,000 cells per ml). This will not only bring down bulk tank results to preserve bonuses but will also give these cows longer to regenerate udder tissue and clear infections.
However, it should be noted that for the average cow, there is some evidence to show that extended dry cow periods (beyond 80 days) can increase the risk of cows developing mastitis in early lactation. Work closely with your vet to review your dry cow protocol as appropriate selective dry cow antibiotic therapy and teat sealant are vital for repairing and preserving udder health through this risk period.
It is inevitable that some cows may be giving too much milk (more than 20 litres) when you want to dry them off so consider putting them on the far-off dry cow diet for a week or two to drop yields first before drying them off abruptly.
As an alternative to early drying off, it may be worth considering cutting cake from cows that have been confirmed pregnant. On the average 100-cow herd, cutting late lactation (pregnant) cows from 4kg cake to 2kg could cut milk by about 250 litres. Removing it entirely should reduce it by about 500 litres and will save you about £44 a day!
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