Colostrum

Calves are born with a non-developed immune system and must absorb antibodies from colostrum until their own immune system becomes functional. At 24 hours old, the calf gut "closes" and becomes unable to absorb antibodies. Calves that fail to absorb enough antibodies in the first 24 hours are said to have suffered Failure of Passive Transfer (FPT).

All calves, including bobbies, must receive adequate fresh colostrum within the first 12 hours of life and should be fed colostrum, or a colostrum substitute, for at least the first four days of life.

Giving your newborn calves the correct amount of high-quality colostrum will help ensure:

• Less scours and disease.
• Reduced death rates.
• Better growth rates.
• Improved lifetime productivity and fertility.

You can achieve this by:

• Feeding newborn calves 4 litres (or more for heavier calves) of gold colostrum within the first 6-12 hours of life.
• Testing the quality of colostrum and feeding newborns gold colostrum with brix readings over 22 percent.
• Scrubbing all calf rearing equipment with hot soapy water.
• Storing colostrum in a lidded drum or vat, stirring regularly.

While research completed in 2015 showed that about a third of calves in New Zealand suffered from failure of passive transfer (FPT), there have been significant improvements in colostrum management practices since then. The increased adoption of Brix refractometers has helped farmers better assess colostrum quality on-farm, leading to improved calf health outcomes.

However, FPT remains a concern on some farms. If you have concerns about your calves' colostrum intake or passive transfer status, talk to your veterinarian about IgG blood testing to assess your herd's performance. Blood samples of 12 healthy calves between one and seven days of age can be sent to the lab to estimate the antibody levels. Doing this at the beginning and peak of calving will give you the best insight into how it is going on your farm.

Brix refractometry has become increasingly popular as a practical on-farm tool for assessing colostrum quality. Colostrum measuring 22% Brix or higher is considered good quality and should be prioritised for newborn calves.

Colostrum storage

Feeding fresh colostrum is best but if you need to keep it for any length of time, even two or three hours, it is important to ensure the quality doesn’t decrease.

• Store colostrum in a lidded drum or vat and stir regularly.
• Ideally, colostrum should be refrigerated (at 4°C) or frozen.
• If refrigeration or freezing is not possible, add a chemical preservative agent to the colostrum, such as potassium sorbate at a rate of one percent by volume of a 50 percent solution.

How to preserve colostrum with potassium sorbate

Potassium sorbate is a chemical food preservative. Its anti-microbial properties stop the growth and spread of harmful bacteria. When used correctly, it inhibits bacterial growth in colostrum and milk. It can also be used to preserve antibody levels in 'gold' (first milking) colostrum.

All equipment MUST be clean and sterile

1. Gather safety equipment (glasses, mask, gloves).
2. Potassium sorbate (preferably granules).
3. Water (as clean as you can get it).
4. Scale.
5. Very clean container with millilitre measurements.
6. Stirrer.

Colostrum podcast

Are your calves getting the colostrum they need? How are you supposed to know and what can you change to make sure they do? And what are some of the common myths about colostrum? Find out in this episode of Talking Dairy, featuring veterinarian and researcher Emma Cuttance.

Colostrum webinar

Find out about what management practices can help make sure your calves get quality colostrum when they need it.