Whether raising five, 50 or 500 calves, quality colostrum is vital for giving calves a strong start. Calves are born with an immature immune system and have little to no immunity against diseases. That’s why they need to receive quality colostrum soon after birth.

Colostrum contains antibodies, known as immunoglobulins (Ig), such as IgG, that help protect calves against diseases. Compared to whole milk, colostrum has twice as much dry matter, three times as many minerals and five times as much protein. It is also higher in energy and vitamins. The high nutrient content of colostrum is especially important because newborn calves have low reserves of these nutrients.

“Quality colostrum helps set calves up for long-term health, growth and productivity. The care and detail that go into delivering colostrum to newborn calves in their first hours of life is crucial to future performance,” said Dr. Julian "Skip" Olson, technical services manager for Milk Products.

Olson suggested four areas to keep in mind for colostrum success:

1. Quality is key. “While high-quality colostrum containing a large percentage of IgGs is usually thick and creamy, don’t rely on appearance alone to predict quality,” Olson said. “A Brix refractometer or a hydrometer-based colostrum tester can help you quickly estimate colostrum quality.”

The Dairy Calf & Heifer Assn. Gold Standards recommend the following IgG levels:

* Brix refractometer — 22 or greater for large breeds, and 18 or greater for smaller breeds like Jerseys. A Brix value of 22 corresponds to about 50 mg/mL, or 50 g per liter.

* Colostrum tester (Colostrometer) — about 50 mg/mL if in the “green” zone. The instrument rises as colostrum cools and sinks in the colostrum as it becomes warmer.

For greatest accuracy, measure colostrum cooled to 72°F. At lower temperatures, colostrum testers can overestimate levels; at higher temperatures, they can underestimate levels.

2. Quantity matters, too. Within the first two hours of life, a calf should receive colostrum equal to 10% of its bodyweight. For example, a 90 lb. calf should receive four quarts of colostrum, which weighs about 9 lb.

“Ideally, after the first colostrum feeding, feed (the calf) quality transition milk harvested up to 72 hours after calving — about six feedings,” Olson said. “While colostrum contains the highest concentration of beneficial factors, transition milk will continue to be higher in solids, fat, protein, vitamins and immunoglobulins than standard milk. After feeding transition milk, you can begin feeding milk replacer or whole milk.”

3. Timing is everything. Within 24 hours after birth, a calf’s gut begins to close, making it difficult to absorb antibodies in colostrum. Studies have shown that calves absorb 66% of IgGs from colostrum at six hours after birth but only absorb 7% of IgGs 36 hours after birth.

“This information shows how important it is to feed newborn calves colostrum as quickly as possible,” Olson said. “The first two hours is the ideal time window for calves to absorb antibodies. If this is not possible, aim for four hours.”

4. Options for when there isn’t enough. When maternal colostrum isn’t high enough quality or there isn't enough of it, there are other options. In these situations, frozen colostrum or colostrum replacer can be used.

“It’s an emergency situation when you do not have the proper amount of colostrum for a newborn calf. Colostrum replacers can help if you don’t have access to quality frozen colostrum,” Olson said. “Colostrum replacers are a viable alternative to build the immune system of a calf. Keeping colostrum replacer on hand will help you stay prepared for the arrival of newborn calves.

“Your role in helping protect calves from disease by properly feeding colostrum is important,” Olson added. “Pay close attention to the details to help calves build immunity and get off to a healthy start.”