Setting heifers up for success
November 21, 2024
The first 100 days in a dairy heifer’s life sets the precedent for the rest of her lifetime in dairying. Farmers received this strong message during a recent farm walk hosted by Richard Brown in Millisle, Co Down.
College of Agriculture, Food and Rural Enterprise (CAFRE) dairy advisers, Conail Keown and Anna Truesdale were there on the day. Along with Trouw Nutrition’s calf nutrition specialist, Aaron Brown. They discussed growth targets, nutrition curves and how to unlock the maximum potential of youngstock in their first months of life. Richard Brown calves his herd in an Autumn block. This year’s 70 Holstein replacement heifers already well on their way to achieving target weaning weights.
Table 1: Target weights from birth to 24-month calving. (Based on a 40kg birth weight and a mature cow weight of 685kg).
Age | Target Weight |
1 month | 55kg |
Post Wean (3 months) | 116kg |
Pre-Breeding (13/14 months) | 377kg |
Pre-Calving (24 months) | 582kg |
Mature Weight | 685kg |

On the farm, Richard implements a tight colostrum protocol. Each calf receives at least 10% of their body weight in the first few hours after birth. Richard then focuses on ensuring good intakes of first transition milk. This is followed by a changeover onto a good quality milk replacer. This is fed on a feed curve through an automatic feeder. The calves are kept in a light and airy shed, with plenty of fresh bedding, fresh water, straw and an ad lib nut which they have access to.

Aaron Brown provided a wealth of technical knowledge for the group on the day. He highlighted research showing that calves achieve higher growth levels when fed around 1kg of milk powder daily. This should be split into feeds of at least 4 litres, given twice a day.
The farmers also discussed the importance of providing a fibre source to young calves, with chopped straw being the forage of choice. This was because of its low energy density which encourages good simultaneous intakes of starter concentrate. Equally important is its ‘scratch mat’ properties, ensuring the calves rumen wall remains available for nutrient absorption.
Once the calf reaches 5-6 weeks, the higher level of milk feeding can be reduced. Aaron went on to explain how a gradual ‘step down’ approach encourages an increase in starter intakes. This method reduces stress for both the calf and the calf-rearer in the weeks both pre and post weaning. He continued that calves should ideally be weaned fully off milk by 10-12 weeks. By this stage, they should have consumed a total of 35kgDM/head of starter feed.

“Weaning based on starter intake is a good place to begin,” explained Aaron. “We need to ensure that calves are achieving an adequate amount of energy from their concentrate feed before we remove the energy source that is milk.” He explained that, instead of the traditional view on pushing concentrate intakes as early as possible, a higher level of milk feeding would be a more appropriate source of energy for the dairy calf in the first 3-4 weeks of life.
The group were asked to think about their own calf rearing, with a few leaving the meeting considering several potential changes to unlock even better performance in their own calf houses.
In a time when every little helps and every little counts, make sure you’re getting your getting calf rearing right!
Ask yourself – Is the environment correct? Low humidity, clean fresh bedding, good ventilation but no draughts and a clean source of water can have a massive effect on calf health and therefore growth in the first few weeks of life.
Is the mixing concentration correct? Aaron Brown pointed out that issues with incorrect concentrations can mean an imbalance in osmolality and an increase in gut problems for the developing calf.
Are you weaning gradually and ensuring a good level of concentrate feeding? Weaning stress can induce a growth check at a time when the animal is genetically programmed to have one of the best feed conversion ratios and growth rates of its entire life.
Are you meeting targets? The age old ‘measure to manage’, especially post weaning will provide a crucial insight into how well calf rearing is being managed on your own farm.
Speak to your local CAFRE adviser to help unlock the potential of your future herd.