For decades, dairy producers have fed newborn calves based on standard protocols for first-milking colostrum, but as Dr. Donald Sockett and Dr. Ryan Breuer from the University of Wisconsin noted on a recent Raising Your Best Dairy Heifer webinar, the underlying assumptions might be due for revision.
“The current colostrum feeding guidelines that are considered best practices today were developed a little more than two decades ago,” Breuer says. “So we’ve had some time to observe what’s going on with it and whether we need to make some changes or not.”
Sockett explains that the conventional gold standard of 50 grams of immunoglobulin G (IgG) per liter, which the guidelines are based on, was reasonable back then, but times have changed.
“The average here is 75 g to 95 g per liter,” he says. “Why would we build a program around fair [quality] colostrum?”
Because calves are receiving colostrum of higher quality than what the older guidelines are built around, feeding volumes and methods might need adjustment.
In a recent case report, Sockett and Breuer described a Holstein heifer that received what is considered best practice for colostrum delivery based on 10% body weight: 4 liters of first-milking colostrum 30 minutes after birth and an additional 2 liters six hours after the first feeding. Shortly after the second feeding, the calf developed colic and was in apparent pain. This animal was humanely euthanized less than 24 hours later after a lack of response to on-farm medical care.
According to the attending veterinarian, this was not a one-off case.
“This wasn’t the only calf at this dairy,” Breuer says. “The veterinarian had also seen similar situations at other dairies where these calves, after the recommended colostrum feeding, had distress or colic.”
Upon necropsy, they noticed incidents of aspiration in the lungs. It was concluded aspiration pneumonia killed the calf after some colostrum was regurgitated due to a distended abomasum from colostrum volume.
This report emphasizes the need to reevaluate colostrum feeding standards.
In September, Frederick and colleagues from Cornell University published a study looking into the effects of feeding colostrum at 6%, 8%, 10% or 12% of a calf’s body weight on IgG absorption, gastric emptying and postfeeding behavior.
Gastric emptying is an important factor as no colostrum absorption occurs in the abomasum. Passage to the small intestine in a timely manner before absorption efficiency goes down is key. Calves fed at 10% and 15% of their body weight had significantly lower apparent efficiency of absorption of IgG rates and showed significantly more behavioral signs of discomfort (abdomen kicks) than those fed 6% and 8%.
“So yes, you’re feeding a bigger mass of immunoglobulin when you feed these larger body weight [percentages], but if your efficiency of absorption is going down and you have these health complications, is that really the best thing for the calf?” Sockett says.
A study of 818 calves across 61 Holstein dairy farms by Morin and colleagues at the University of Montreal looked into how colostrum management practices impacted transfer of passive immunity (TPI). They found that the No. 1 factor affecting apparent IgG absorption was the concentration of IgG in the colostrum, or colostrum quality. Calves fed colostrum with a Brix value over 24.5% were almost three times more likely to have received adequate TPI. Additionally, calves fed equal to or greater than 2.5 liters of colostrum at their first meal (notably less than 10% of the calves body weight) within three hours of birth had the highest odds of receiving adequate TPI.
This adds weight to Sockett’s assertion.
“Think about our recommendation standards,” he says. “We haven’t even been talking about the two most important variables of effective efficiency of colostrum absorption. We have to start thinking about the quality of the colostrum and the mass of colostrum being delivered.”
If you’re creating a colostrum feeding program for a dairy operation, Sockett and Breuer recommend collecting a database of information of what’s going on in the herd. Answer the following questions to tailor the program to your farm:
- What is the average birth weight of the calves? What are the lightest and heaviest animals?
- Are you feeding pooled or individual colostrum?
- What is the normal weight of the colostrum?
- What is the mean and standard deviation of the Brix scores?
- What is the timing of first colostrum delivery?
- What are your TPI goals?
The idea is not to abandon colostrum best practices but to update them strategically. By refining colostrum feeding protocols, verifying colostrum quality, aligning volume with body weight and monitoring outcomes, dairy operations can create their own evidence-based practice. The result? Healthier calves, fewer complications and better use of that liquid gold.
