News & Advice

Feeding calves- what to feed, when to feed it and when to wean

Jun 8, 2017 | Dairy, Young Stock

Colostrum for the best start 

Feed enough high quality colostrum quickly to newborn calves

Calves need 10% of their bodyweight in high quality, first milking colostrum within the first 6 to 12 hours of life. This is because a calf is born without a fully functioning immune system, and needs to absorb antibodies from its mother’s colostrum across their guts, into the bloodstream.

Colostrum needs to be high in antibodies (greater than 50g/L of antibody) and low in bacteria (less than 100 000CFU/ml total bacteria count). Colostrum that is low in antibody and/or high in bacteria can result in calves that have low blood antibody levels. And, research has proven that these animals are more susceptible to disease and death, don’t grow as well or conceive as well, and they don’t produce as much milk in their first lactation. A 40kg newborn calf needs 4 litres of colostrum within the first 12 hours of life, but their abomasum (stomach) capacity is only about 2 litres, so you can’t physically feed this all in one feed. Ideally, a 40kg calf should be fed 2 litres of first milking colostrum within 6 hours of birth and another 2 litres of first milking colostrum within the first 12 hours of life. Calves should also be fed second, third and fourth milking colostrum for 4 days if possible.

New Zealand data suggests that pooled colostrum for feeding to newborn calves is highly contaminated and very low in antibody. In fact, only 2% of colostrum samples collected from over 100 dairy farms met antibody and bacteria targets. This is bad news for our highest genetic merit stock-out calves.

What can we do to improve colostrum quality

  • You can check your colostrum antibody level easily on farm, by using a device called a Brix refractometer; you can get one from your local Vet clinic. You can also measure bacterial contamination in your colostrum through your Vet. 
  • All colostrum collection and storage equipment needs to be scrubbed thoroughly with hot soapy water after each use. Test buckets, colostrum storage vats and calf feeders are often very dirty and aren’t cleaned properly allowing bacteria to build up. 
  • First milking colostrum is the only colostrum suitable for feeding to newborn calves; don’t mix first milking colostrum with later milking colostrum as this lowers the antibody level of the pool. 
  • Collect colostrum from cows as soon as possible after calving to ensure antibody levels are maximised. 
  • Feed your calves with fresh, first milking colostrum as soon as possible after birth. 
  • Select the cows in your herd that are likely to be giving you the best quality colostrum- if you don’t know who they are; test colostrum from individual cows with the Brix refractometer. 

Stored colostrum for older calves should be kept in a clean storage vat with a stirrer and a loose fitting lid to prevent contamination and bacterial proliferation. You may also like to use a colostrum preservative like Potassium sorbate to control bacterial growth if it is to be stored for more than 12 to 24 hours. You can get this from your local Anexa FVC Vet clinic.


Milk feeding calves 

Feed calves enough milk

Calves need to be fed 10% of their bodyweight in milk, preferably split into two feeds, until they are consuming enough grass, meal and roughage to meet their energy demands.
New Zealand based work has shown that calves that are fed twice daily for the first three weeks of life are less likely to get sick and less likely to die than calves fed once a day before they are they weeks old.
Offer meal and hay to calves from birth
Calves are born to ruminate! When young calves are being milk fed, they use only one (the abomasum) of their four stomachs; but the aim of successful calf rearing is to develop the calf rumen quickly and to produce a well grown, healthy, ruminating animal. It’s much cheaper to feed a calf meal and grass than it is to feed milk.
In order to develop the calf’s rumen quickly, calves need to be offered meal from birth. Calf meal aids in the development of the lining of the rumen.

Calf starter meal should contain

  • Ideally 23 – 25% crude protein (CP) (definitely at least 18 – 20% CP) 
  • Minimum 11.5 – 12.5 MJ/kg DM ME 
  • Rumensin or Bovatec to protect against coccidiosis 
  • Vitamins and minerals 

As well as meal, calves also need to be offered fibre or roughage in the form of hay. Research has found that 6-7 week old calves fed concentrate ruminated for fewer minutes (6 minutes per hour) compared to calves fed forage such as hay (18 minutes per hour).

The hay should ideally be short chopped and offered to calves in small amounts (10-15% of their diet). Hay should be fed ideally in hay nets or feeders to prevent calves from soiling it or using it as bedding. Fibre makes the rumen bigger and promotes the development of the rumen muscles by stimulating the receptors that trigger muscle contractions. Fibre also helps to develop the rumen epithelium and maintains the health of the rumen lining by “un-clumping” rumen papillae thereby improving energy absorption.
Since calf meal is responsible for developing the lining of the rumen, and hay is responsible for developing rumen size and strength and for stimulating rumination; calves need BOTH roughage and grain to prepare them for weaning.


Weaning calves off milk 

When to wean calves

Milk should not be withdrawn until the nutrients from ruminal digestion of calf starters can provide the protein and energy needs for both maintenance and growth. Traditionally calves have been weaned on age, but it is better practice to wean on weights and meal consumption. Calves should be eating an AVERAGE of the following for 3 consecutive days:
• Friesians: 1.5 – 2 kg grain per day
• Jerseys: 1 – 1.5 kg grain per day

It is best to wean calves at 30% of their mature liveweight. Each herd will have its own genetic liveweight potential targets, so work out how much your weaned calves should weigh based on your mature cow liveweights.
Anexa FVC stocks high quality, carefully formulated calf meal for all stages of calf rearing. See your local clinic to place an order and give your calves the best start.

If you are interested in a more detailed calf rearing plan, talk to your Vet about a Calf Rearing Consult – we’re here to help.

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