Making sure a heifer is fully prepared before weaning reduces the chance she will need preferential treatment post-weaning. Preferentially managing small groups of animals to try and “catch them up” to the group is time-consuming and can be difficult to manage, so it is best avoided by good early management.

Factors to consider before weaning

Is the calf:

• Consuming the desired amount of feed? Is its rumen sufficiently developed?
• Meeting its weight-for-age target, based on its breed and/or the rearing system?
• At the minimum age for the rearing system?
• Able to compete within a group?

• Rumen development

  A calf's rumen development is the most important factor to consider when making the weaning decision. The only way this can be assessed is by measuring the amount of concentrate or pasture they are readily eating, which should be at least 1 kg/day of meal or 2 kg/day of pasture.

  Calves should be supplied with clean water and feed for rumen development. Calf meal and high quality herbage together provide the energy, protein and volatile fatty acids necessary for rumen development and animal growth.

  Grain have different fatty acid profiles and higher levels of butyrate which stimulates papillae growth, papillae increase the surface area of the rumen and aids in digestion.

  Good quality hay can be used as a roughage if a grain-based meal is also being used, and should be offered from birth.

  Calves given large quantities of milk will have slower rumen development. This is primarily because the milk satisfies their appetite, so they eat less forage and concentrates, which decreases the requirement for digestion in the rumen.

  Any change to the quantity or type of feed needs to be measured. Just as it takes time to develop the rumen, time is key in transitioning from calf meal to a full pasture diet. Farmer experience indicates that two week gap between each diet change (e.g. weaning off milk with meal concentrate to full pasture diet) will help transition heifers to a full pasture diet.

  New-born calves have high dietary protein requirements, this requirement declines as they age. A  higher crude protein intake should lead to higher growth rates. If using calf meal, look for products that contain 20% crude protein for calves on milk and 17% crude protein for weaned calves to meet total dietary requirements.

Nutritional guidelines for calves

Sometimes animals do not thrive post-weaning so weigh them within 7-10 days to make sure they have gained weight from weaning. If they’re not thriving post-weaning they may need continued access to calf meal, regardless of weight or age.

Weaning weight

Individual heifers should reach a minimum weight prior to weaning. No specific weaning weight has been defined by research.  The type of rearing system will affect the target weaning weight. Although, common weights used for weaning are 70kg for Jerseys, 80kg for Fr x J Crossbreds, and 90kg for Friesians. 

Competing within a group

Heifers need to be competing with the group before they are weaned. Any that are not should be held back.

Relocating recently weaned calves

Relocation can result in growth checks or be a trigger for animal health issues including pneumonia, scouring and parasites.

Recently weaned calves are at particular risk as they will be undergoing changes in diet, rumen development, and moving from individual or small group care to larger mob management. Relocation adds to the risk; the younger the animal, and the more recently they have been weaned, the higher the risk.

More information

• Weaning decisions 
• Younger or lighter calf management