Dairy heifer calves: how to manage the first 60 days
As dairy farmers across the country gear up for the busy spring ahead the main focus is on how to best manage the next 120 days to make sure cows are fit and healthy after calving to be ready for service come April 24.
Irish farmers know that managing the transition cow period after calving is critical to getting cows back in calf in time.
But what of the calves that will land over the next couple of months and why is the first 60 days so important for their future production in the herd?
The First 60 Days: What the research says:
- Increased weight gain during the first 60 days increases milk yield in the first lactation
- 225kg increase expected in the 1 lactation for every additional 100g of daily weight gain in The First 60 days of life
- Heifers that grow best in the first 60 days survive longer
Studies have shown that additional average daily live weight gain (ADLG) during the first 60 days will result in additional milk yield in the first lactation. For every additional 100g of ADLG during the first 60 days of life, about 225kg of additional milk yield in the first lactation can be expected.
Average daily liveweight gain pre-weaning has been shown to account for a 22% variation in first lactation yield. In addition growth during the first 60 days is linked to survival, with studies showing that heifers that reached second lactation grew significantly more in the first two months compared with those that did not make it through to the second lactation.
Anything that has a negative effect on growth rates in the first 60 days will consequently have a negative effect on both a) ability to produce milk and b) survival through to mature cow.
Pneumonia in calves in the first 60 days will reduce growth rates and so will impact on future production. Studies from Northern Ireland have shown that one single case of pneumonia in the first 60 days reduces first lactation yield by 4% and second lactation by 8%.