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 four 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%.
• Scrubbing all calf-rearing equipment with hot soapy water.
• Storing colostrum in a lidded drum or vat, stirring regularly.
Recent studies have shown about a third of calves in New Zealand suffer from FPT and do not get enough good quality colostrum soon enough after birth. This is caused by:
• Feeding colostrum with low levels of antibodies.
• Feeding too little colostrum.
• Feeding colostrum too late after birth.
• Bacteria contaminating colostrum at harvest, during storage or at feeding.
Are your calves getting what they need?
You can test to see if your calves are getting enough antibodies from colostrum by getting blood tests done by your vet. 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.
The 3 Qs of colostrum management
Quality: >22% Brix target
Gold (first milking) colostrum is the highest quality colostrum and should be fed to newborns, but quality can vary. Brix refractometers are small, simple tools that can be used to measure the antibody level in colostrum.
Gold colostrum that measures 22% or more with a Brix refractometer is considered high quality. For the best results, colostrum that measures 22% or more, or the highest quality colostrum you have available, should be fed to newborns.
Quickly: feed calves within 12 hours of birth.
It is 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.
Quantity: 4-6 litres.
Newborn calves need at least 10% of their bodyweight (4 litres for a 40kg calf) of gold colostrum within the first 6-12 hours of life. Calves can only take 1.5-2 litres in their stomach (abomasum), so two feeds within the first 12 hours is the target.
Bacteria in colostrum can decrease its quality and prevent calves from absorbing antibodies. Contamination can occur during colostrum harvest, storage, and feeding.
• Clean collection buckets before use.
• Feed calves from youngest to oldest (sick calves last).
• Use hot soapy water to clean all equipment and buckets after each use.
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 4degC) 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 1% by volume of a 50% 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.
• Gather safety equipment (glasses, mask, gloves).
• Potassium sorbate (preferably granules).
• Water (as clean as you can get it).
• Clean container with milliliter measurements.
Dos and Don’ts
• Use only 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 either stored at room temperature or refrigerated, if possible at 4degC.
This article first appeared in the August issue of our sister publication, Dairy Farmer.