Colostrum – the essential first feed

Colostrum – the essential first feed

28 May 2020

Bovine colostrum delivers better calf health and performance according to a report by Ag Drs. Ajmal Khan and Sue McCoard, the Animal Nutrition and Physiology Team at AgResearch Limited, New Zealand.

Their report, Investing in best practice colostrum management delivers better calf health and performance, calls colostrum an "essential first feed" for calves as they are born with an under-developed digestive system and no ability to fight against disease-causing organisms.

To overcome this, immediately after calving, colostrum is produced in cows' udders for their calves to feed on. The colostrum gives the calf defense molecules critical for their survival for the first six weeks of their life before their immune system starts to develop.

"Colostrum is an essential first feed for the calf and is rich in nutrients and biologically active substances, such as immunoglobulins (defense molecules), hormones, and growth factors. Along with the importance of calves acquiring immune molecules from their mothers, colostrum has broad importance for the health, performance and development of calves," the report says.

AgResearch has found calves removed from cows within 24 hours of birth and fed high-quality colostrum have reduced incidence of scours and electrolyte use, and improved feed efficiency when compared to calves fed low-quality transition milk.

The production of transition milk follows that of colostrum in the first four days of calving and is a mixture of colostrum and milk.

Though this transition milk contains a substantial amount of nutrients and growth promoters to support health and growth of calves, it's recommended that transition milk is not used substitute for colostrum. Rather, it should be fed on days two to four after birth or longer if available.

High-quality colostrum has a Brix value of 22 percent or higher, while transition milk has a Brix value of 12 percent.

To ensure calves get the most from colostrum, Ajmal and McCoard suggest pooling colostrum from different cows before feeding it.

This is because "the concentration and type of defense molecules in colostrum can vary between cows because of their genetics, parity, stress, vaccination and nutritional status".

When pooled, Ajmal and McCoard suggest using a refractometer to measure colostrum quality.

Not only does pooling colostrum improve the quality fed to calves, it also helps to ensure calves get the required amount when they need it.A calf's ability to absorb antibodies decreases by 30 to 50 percent within six hours of birth and stops between 24 and 36 hours.

Because of this, Ajmal and McCoard say it's "a race against time because of the declining ability of the intestine to absorb antibodies into the bloodstream".

"Recent research indicates that leaving the calf to suckle on the cow for 24 hours does not guarantee sufficient colostrum intake. Recent research also shows that one-third of New Zealand calves fail to acquire the desired levels of antibodies (>10 mg/ml of immunoglobulin G or 52 g/L of serum total protein) in their bloodstream from colostrum."

This failure is known as "failure of passive transfer", and Ajmal and McCoard suggest it "may be the result of not feeding sufficient amounts of colostrum, feeding poor quality colostrum or transition milk, or feeding too long after calving".

Research recommends a calf should ideally have two feeds of high-quality warm colostrum, equivalent of 15 percent of its body weight, in its first 12 to 24 hours.

After colostrum is harvested, it should be stored in clean containers and can be kept in the fridge for 72 hours or in the freezer for a few weeks.

And while this early calf care and colostrum management can be logistically challenging with whole herds calving over a few weeks, it's worth the investment.

"Investing in calf care and good colostrum management will reduce labour and veterinary costs associated with treating sick calves and improved calf health and welfare with potential lifetime performance benefits."

Those lifetime performance benefits include improved lactation performance according to Ajmal and McCoard's research combined with other published international literature.

Article supplied by NZAgbiz.