Expert’s corner: When and how to wean your calves

By Lucas Mitchell, Ph.D., Vita Plus dairy calf and heifer specialist

Producers often ask me this question as I’m on farm or at meetings. The answer – albeit an unsatisfying one – is that it depends. The following steps contain key considerations that will help ensure a successful weaning strategy for your farm.

1. Pick the proper weaning age for your farm.
In my opinion, most farms should be able to successfully wean calves anywhere from seven to nine weeks of age. A couple questions need to be answered to determine the proper weaning age for your farm.

How much milk is being fed? Milk consumption is highly correlated to starter feed intake. Calves consuming less milk will consume much more starter and, therefore, be ready for weaning earlier than those consuming more milk. For example, a calf consuming 6 quarts of milk per day may be weaned as early as seven weeks of age without issue while a calf consuming 9 quarts of milk would likely benefit from being weaned closer to nine weeks of age.

How much pen space do you have? A good rule of thumb is to allow calves to stay in their nursery pens for at least one week after weaning. The goal here is to minimize stress by slowly making changes. This helps maintain feed intakes, which, in turn, keeps calves healthy and maintains good growth rates. If you do not have enough space to keep calves in nursery pens as long as desired, consider adjusting the feeding plan to potentially wean earlier or consider how to add more pen space.

2. Step down milk.
Stepping down milk involves either removing one feeding or reducing the amount of milk fed for a certain period of time prior to weaning. This practice helps drive up calf starter intake, which, in turn, eases the stress calves experience as they transition from a liquid to a solid diet. Calves should be stepped down at least one week prior to weaning, even in situations where they are fed lower levels of milk (4 or 6 quarts per day). In situations where calves are fed greater than 8 quarts of milk, it may be beneficial to incorporate multiple steps down. For example, a calf consuming 8 quarts may be stepped down to 6 quarts at two to three weeks prior to weaning and then further stepped down to 3 quarts for their last week on milk.

3. Ensure adequate starter intake.
Calves should consume at least 2 to 3 pounds of starter per day for at least three consecutive days before being weaned off milk. This should not be an issue for calves weaned between seven and nine weeks of age as long as appropriate milk step-downs occur. Starter intake is critical due to its role in rumen development and function. Calves with underdeveloped rumens will struggle to thrive after weaning. Furthermore, a couple studies have linked starter intake to first-lactation milk production.

Figure out a way that starter intakes can be easily estimated on your farm, whether that is using a feeding utensil that holds a known weight of starter or marking buckets. Adequate starter intake helps ensure that these calves will thrive after weaning and when they enter the milking herd.

4. Provide clean, fresh water.
Calves should be offered clean, fresh water from day one of age. The importance of water only increases as the calf ages. Water and feed intake are highly correlated. Calves will consume about 4 pounds of water per pound of calf starter. Therefore, starter intake cannot be maximized without proper water management. A successful weaning strategy relies heavily on providing calves with clean, fresh water.

The goal around weaning should be to minimize the amount of stress calves experience as they transition from a liquid to a solid diet. This helps ensure that calves stay healthy and maintain appropriate growth rates through the weaning transition phase. The preceding steps can help ensure successful weaning, but there is no “one size fits all” approach. Every situation has its own nuances to consider. Reach out to your Vita Plus consultant to discuss your farm’s current weaning strategy.