The first 90 days of a calf’s life are important for future performance and in this period calves should reach 15% of their mature body weight.

Calves should also double their birth weight in the first 60 days of life. These are all targets Bianca Theeruth, Cargill Calf and Heifer Specialist, works towards.

Action starts at birth with the newborn calf getting its first feed of high-quality colostrum within two hours of birth and more than 150g of immunoglobulins (IgG) in the first 24 hours of life.

The calf relies on this colostrum as a springboard to a healthy start.

Introducing a quality milk replacer maintains growth rates, providing concentrations and quantities are correct. Five or six litres a day, in two feeds, is recommended.

It’s worth checking concentration rates. A litre of milk at 12.5% concentration means 125g of milk powder in 875ml of water not 125g of powder in one litre of water which would give a concentration of 11.1%.

Encouraging rumen development essential

Encouraging rumen development straight after the colostrum phase is vital if growth rates are going to be maintained.

A high-quality calf starter and fresh water will encourage intakes, providing milk replacer rates are not exceeded, which may suppress the calf’s interest in dry food.

Cargill trials have shown that a modified accelerated programme, that accurately balances quantities of milk replacer and dry feed, will maximise growth rates alongside rumen development and help to maintain linear growth rates pre and post-weaning.

Calves on milk. Photo O'Gorman Photography.

Too often producers are encouraged to drive for higher pre-weaning weight gains by feeding more milk.

Current research shows that exceeding 750g/calf/day of milk replacer delays rumen development and reduces starter feed digestion by 6-9% Dry Matter (DM).

This compromises post-weaning growth rates, as calves face a more abrupt and stressful change in diet at weaning resulting in a growth check.

The benefits of extra growth from the milk replacer are soon lost.

The importance of intake targets

Intakes of dry feed should be 1.5-2kg a day by weaning, with the volume of milk replacer at the same concentration but reduced to one feed a day of three litres in the week before weaning.

Good quality straw will also help rumen development.

Calves on this modified, accelerated feeding programme are well equipped to increase concentrate intake post-weaning to 2.5-3kg.

Supported with good management and a healthy environment, these calves should be on course to meet their 90-day target.

dairy calves

Are your heifer calves on target?

It is advisable for producers to follow growth targets to ensure that their heifer calves meet the desired weights to allow for calving at 24 months of age.

Holstein heifers should gain 750-800g/day and Jersey heifers should gain 500-600g/day the whole way through to 24 months of age.

These targets are important, as heifer weight determines the onset of puberty and oestrus and so it is necessary to ensure that heifer birth weights double by the time the calf is 60 days of age.


  • Targets expressed as a percentage mature body weight (MBW) and can be applied to any breed.
  • Within breed, height is a good predictor of weight and can be used as a reference point.
  • If you cannot measure it, you cannot monitor it and you certainly cannot manage it.

When to weigh your heifers

Ideally, producers should weigh heifers at a time to coincide with the seven phases of the Nuture with Provimi programme – Gold Standard.

Target weighing times under the programme include:
  • At birth
  • At weaning
  • Post-weaning (to determine if there is a ‘check’ in growth)
  • Turnout (usually 6 months of age)
  • Puberty/Bulling – are my heifers heavy/tall enough?
  • Pregnancy

Weighing can be incorporated with another activity on-farm that requires handling such as worming, dosing or artificial insemination. This keeps handling to a minimum to prevent additional stress.

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