Colostrum

Colostrum: The first milk after calving

Calves are born without antibodies in their bloodstream and have no natural immunity. Colostrum provides maternal antibodies for the newborn calf that help it fight disease.

A calf begins to develop its own immune system from four weeks of age, but it takes months to fully develop. Without good quality colostrum, they are highly vulnerable to disease, which could result in illness and ongoing impacts. 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). There may not be obvious differences in calves with FPT, especially when there is a low disease challenge, but they will have an increased risk of disease and death prior to weaning.

Providing the correct amount of high-quality colostrum as soon as possible after birth to newborn calves will help ensure:

Less scours and other diseases.
Reduced death rates.
Better growth rates.
Improved lifetime milk production and fertility.

All calves, regardless of their end destination, require adequate, fresh colostrum.

Ways to avoid FPT and ensure a great start for your calves

Feed newborn calves 10-12% of their bodyweight of good quality colostrum (around 4 litres for a 40kg calf). Feed colostrum as soon as possible after birth, but within the first 6-12 hours of life. Split into two feeds to avoid feeding more than 2L at a time.
Test the quality of colostrum using a Brix refractometer and only feed newborns colostrum with Brix readings at 22% or higher.
Clean all feeding equipment regularly with hot soapy water.
Store colostrum in a lidded drum or vat, stirring regularly. Preserve, refrigerate, or freeze if colostrum is not used immediately.

Past research has shown that about a third of calves in New Zealand suffered from failure of passive transfer (FPT), but there have been significant improvements in colostrum management practices since then. The use of Brix refractometers helps you better assess colostrum quality on-farm, leading to improved calf health outcomes.

Calves Colostrum Fpt Test Image 1500X1000

Calves Colostrum Brix Test Image 1500X1000

FPT remains a high 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 colostrum management.

The ‘5 Qs’ - key to ensure calves get the best start in life

Quantity: 10 percent of bodyweight

Newborn calves need at least 10 percent of their bodyweight of good quality colostrum (4 litres for a 40kg calf). Calves can only take 1.5-2 litres in their stomach (abomasum), so two feeds within the first 12 hours is the target.

Quality: 22 percent or higher - tested with the Brix refractometer

First milking colostrum is the highest quality colostrum and should be fed to newborns, but quality can vary. Brix refractometers can be used to measure the antibody level in colostrum. Colostrum that measures 22% or more is considered high quality. For the best results, feed the highest quality colostrum you have available to newborns.

Quickly: feed calves as soon as possible (within 6-12 hours of birth)

It’s most effective to feed colostrum in the first 6-12 hours of life as antibodies cannot be absorbed after 24 hours. Every hour counts when it comes to feeding colostrum.

sQueaky clean: good hygiene is essential

Bacteria in colostrum can decrease its quality and prevent calves from absorbing antibodies. Contamination can occur during colostrum harvest, storage, and feeding:

Wash and dry dirty teats, check for mastitis, and keep everything as clean as possible before collecting colostrum.
Clean collection buckets and feeding equipment before use with hot soapy water.
Bacteria multiply quickly, especially in warm weather. Use colostrum immediately and if storing, use a preservative, refrigerate, or freeze it.

If colostrum becomes contaminated, a calf’s uptake of antibodies falls and can lead to illness.

Quantify: reviewing colostrum management on farm is important

Review colostrum management by evaluating colostrum quality and the immune status of your calves.

Measurement of colostrum quality: Regularly test colostrum quality using a Brix refractometer and aim for 22 % or higher. Seek advice from your vet if readings are consistently below this level.
Evaluation of calf immunity: A calf’s immune status is measured by the total solids in serum (STS), using blood samples collected from calves aged 24 hours to 7 days. This test evaluates the transfer of antibodies from cow to calf through colostrum. Doing this at the beginning and peak of calving will give you the best insight into how effective your colostrum management is. Work with your vet to decide on the best time to evaluate calf immunity.

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.

Equipment required (all equipment MUST be clean and sterile)

Safety equipment (glasses, mask, gloves).
Potassium sorbate (preferably granules).
Water (as clean as you can get it).
Scales.
Very clean container with millilitre measurements.
Stirrer.

How to make a 50% solution of potassium sorbate

Potassium Sorbate	to	Water (stir thoroughly)
50 grams	to	100 mls
500 grams	to	1 litre
5,000 grams	to	10 litres
10 kg	to	20 litres

How to add a 1% potassium sorbate mix to colostrum

Potassium Sorbate (50% solution)	to	Colostrum
1 ml	to	100 mls
10 mls	to	1 litre
100 mls	to	10 litres
200 mls	to	20 litres
1 litre	to	100 litres

Do's and Don'ts

Always mix at the recommended rate – overdosing can be harmful to calves.
Only use food-grade potassium sorbate and clean water.
Treat each additional volume of colostrum with 1% potassium sorbate before you add it to your vat.
Don't use any potassium sorbate solution that has been mixed up for more than a week.
Colostrum can be preserved with potassium sorbate and then stored at room temperature or refrigerated at 4 °C.

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.

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