Chasing the target: Changes in colostrum benchmarks

Editor’s note: This article is excerpted from a presentation during a Vita Plus Growing the Modern Calf workshop on March 27, 2026.

One thing I’ve learned working in the dairy industry is that we love to swing the pendulum. We pick a target, we chase it hard and then a few years later we move it again. Colostrum management is no exception. What used to be “good enough” has evolved, and now we’re asking new questions: Are we truly hitting the right benchmarks, and are there unintended consequences along the way?

When we talk about colostrum, everything still starts with the fundamentals — the “five Q’s”: quantity, quality, quickness, cleanliness, and now, increasingly, quantification. These are the pillars we’ve relied on to drive successful passive transfer. Historically, that’s meant feeding 3 to 4 quarts, targeting 22% Brix (about 50 g/L IgG), delivering it within the first two hours, and keeping it as clean as possible.

Those targets were designed to deliver about 200 grams of IgG to the calf, which we know is critical. Passive transfer outcomes tell the story. Calves that fall into the “poor” category are 1.5 times more likely to get sick and up to four times more likely to die. That’s why we’ve pushed hard to hit — and exceed — those colostrum goals.

But here’s where the pendulum comes in.

In the pursuit of maximizing IgG delivery, we’ve pushed both volume and quality higher. And with that, we’re starting to see some unintended consequences, particularly in smaller calves. Feeding large volumes of very dense colostrum can lead to excessive curd formation in the abomasum, which may translate to discomfort, colic and in severe cases, mortality.

This doesn’t mean we need to overhaul every colostrum program overnight. But it does mean we need to think more critically. Instead of focusing solely on volume, we should be asking: How do we efficiently deliver IgG without overwhelming the calf gut?

The emerging consensus is to slightly rebalance that equation. Rather than pushing maximum volume, we can target a more moderate feeding rate — around 8 to 10% of body weight — while increasing colostrum quality closer to 24% Brix, or roughly 70 g/L IgG.

At the same time, we should lean more heavily on a second feeding. I’ve always been a strong proponent of that second dose, ideally within the first 8 to 12 hours. The gut isn’t completely closed, and we can still improve total IgG absorption. More importantly, splitting intake reduces the risk of overloading the digestive system in a single feeding.

Think of it this way: The calf’s gut has a limited number of receptors. Throwing more IgG at it impairs absorption efficiency and creates more stress. Smaller, well-timed feedings often make more biological sense.

The updated benchmarks reflect this shift. We’re not abandoning the five Q’s, we’re refining them. Volume becomes a range, quality increases and the second feeding is no longer optional in progressive systems. It’s an insurance policy.

Beyond that first day, there’s another opportunity I think we’ve overlooked for years: transition milk.

We’ve treated colostrum like a switch — on for one day, then off. But biologically, it’s more of a slope. Transition milk still contains meaningful levels of immunoglobulins, growth factors and bioactive compounds. In fact, feeding only the first milking captures just a fraction of what the dam produces.

Extending the feeding of colostrum or transition milk — even for a few days — can support gut health, improve immune defense at the intestinal level and contribute to better early growth.

Of course, these strategies aren’t free. There are real costs, whether it’s labor, inventory management or opportunity cost of saleable colostrum. That’s where each operation must step back and ask: Does it fit our system, and does it deliver value?

If you’re already achieving strong passive transfer with low morbidity and mortality, you may not need to change much. But if you’re seeing variability — or pushing for incremental gains — these updated benchmarks and strategies are worth considering.