As we head into the next transition of weaning calves, here are a few things to remember and some tips that might help making your calves transition easier.
"Minimising weaning stress is one of the most critical aspects of rearing calves. Every change should be carefully planned and gradually implemented to avoid abrupt changes in feeding practices, such as removing milk or meal suddenly."
Avoid any major changes in the environment and provide shelter for the calves (e.g. use the same paddock if weaning off milk outside onto pasture, and don't wean off milk indoors and then abruptly put your calves outside into a foreign environment).
A calf's rumen development is the most important factor to consider when making a weaning decision. The only way this can be assessed is by measuring the amount of solid feed your calves are readily eating, which should be at least 1kg of meal or 2kg of pasture per day when commencing the weaning process.
The best time to start implementing "step-down weaning" will depend on your milk feeding system, but three good rules of thumb are:
• Weight-for-age target met (common weights used for weaning are 70kg for Jerseys, 80kg for Crossbreds, and 90kg for Friesians)
• Eating more than 1kg of meal or 2kg of good quality forage (e.g. pasture) per day
• Calves are in good health and not receiving animal health treatments.
Prior to weaning monitor calves closely to establish whether all calves are consuming solid feed (i.e. eating at the feed trough and demonstrating rumination behaviour). Monitor closely for signs of illness and consider separating and reintroducing milk for any calves that don't seem to be coping.
Once a day feeding with restricted milk allowance can be used as a weaning method. Low milk allowance calves can be weaned over 3-4 days, while high milk allowance calves (>6L/day for an average-size calf) need 2-3 weeks, to increase solid feed intake and thereby help prepare the rumen for better post-weaning performance. Ideally, the step-down weaning procedure should be implemented in 4-5 steps where 20-25% of the milk offered is reduced every 4-5 days. If using automatic feeders, a 5% linear reduction of milk offered daily over 20 days is ideal.
If you have the equipment, weigh a sample of calves to monitor target growth rates before making a weaning or management decision. And as always, make sure shelter and water are easily accessible post weaning. Good calf management is setting the animal up for success.
For more information, tune in to NZAgBiz's free live Q&A on weaning on 1 September, or see the calf rearing video series. Visit nzagbiz.co.nz/nz/en/animals/calves.