Many heifer calves on farms will now be approaching 10-12-weeks-of-age, meaning that they should be strong enough to be completely weaned off milk.
The key to weaning calves off milk is gradually cutting back the amount of milk fed in conjunction with gradually upping the amount of concentrates fed.
With the start of calving nationally starting a week or later than usual this year, there may be a number of heifer calves only eight weeks old that still should be gradually weaned off milk.
The last thing you want when weaning calves is to inflict stress on the calf, as it can upset their digestive system and predispose them to illness such as pneumonia and subsequent growth checks.
Calves go from monogastrics to ruminant animals during the weaning process, as they adjust from getting all their nutrients from milk to solid food such as grass, straw, hay, or concentrates.
In order for heifer calves to reach their weight targets, there needs to be a balance between milk intake and rumen development when gradually weaning them.
Heifer calves
Most heifers would have been on a once-a-day (OAD) feed for the last number of weeks to reduce labour and to help with the gradual cut-back of milk fed to calves.
Calves need to drink water to help ensure bacterial growth and require 4-5L of water for every 1kg of concentrates, so provide calves with clean, fresh water at all times.
Weaning can be achieved at week 8-9 of the calves’ life if the gradual reduction of milk and increase in concentrates is done in conjunction with each other.
Hwoever, if there are a few heifers behind target and under performing, it would be advised to keep these calves on a OAD feed for another two to three weeks.
Heifer calves should only be weaned after they have been eating at least 1kg of starter concentrates/day for a number of consistent days.
Some may argue and say that calves should be eating at least 1.5kg of concentrates/day before weaning – the more you can get them to eat before completely shutting off milk offered, the better.
Heifer targets
Weaning can safely take place when the heifer has reached approximately 15% of her target mature weight.
The predicted mature weight and target weaning weight of replacement heifers of different maintenance sub-indexes as per Teagasc are as follows:
Maintenance sub index
Mature cow weight (kg)
Target weaning weight (kg)
€0
640
94
€10
590
88
€20
540
82
Calves should ideally be weighed before getting fully weaned off milk to give the farmer comfort in knowing that the calf is at right weight and eating enough meal.
However, many farmers will solely wean calves by the amount of concentrates they consume daily along with a visual assessment of weight gain, health, and so on.
Heifer calves should be weighed so that ones on target are weaned off milk completely. If there are a few behind target, the farmer should keep them on milk for another week or two and slowly add more concentrates to their diet.
Heifer rearing is one of the most expensive costs for a dairy enterprise and if calves are behind target before they are even weaned, it is going to be costly and difficult to try and catch them up.
Feeding more milk for another two weeks might seem like a cost at the minute, but it will be nothing in the long run as it is much easier to get a calf back on target than a yearling or a maiden heifer.
