In most calf programs, success is defined by a simple, binary metric: Is the calf alive at the end of the risk period?
While measurable and easy to benchmark, this definition is dangerously incomplete.
“We’ve traditionally talked about calf success in binary terms. Did the calf live or did it die?” says Travis White, chief veterinary officer with Endovac Animal Health.
That framing overlooks a common, but less visible, outcome.
“A calf can still be alive at day 35 but be far behind on weight, intake, hydration status and overall resilience,” White says.
These calves are officially counted as successes, yet they represent a massive hidden loss.
To recapture this value, the industry must shift from a focus on survival to survivability — measuring whether a calf stayed on its productive path rather than simply whether it remained in the herd.
Subclinical Disease and Lung Lesions Halt Calf Growth Performance
The reason these survivors often fail to perform is rooted in the timeline of disease. By the time a producer identifies a sick calf, the window to preserve its growth trajectory may have already closed.
“Visible illness is often not the beginning of the disease process. It’s the stage where it’s advanced far enough for us to recognize it,” White says. “By the time we recognize that the animal is sick, we’re already far behind the eight ball.”
Recent research shows calves with subclinical lung lesions — undetected by routine clinical scoring — had reduced growth performance, with average daily gain decreased by approximately 0.1 to 0.13 kg/day. Even short disruptions in intake or hydration can permanently alter growth trajectories in young calves, whose development is highly sensitive to stress.
Why Early Immune Response and Passive Immunity Matter for Calves
Exposure to pathogens is a constant in calf systems. According to White, the difference between a high-performing calf and a functional failure isn’t the exposure itself, but what happens in the immediate aftermath.
“The bigger question is: What happens in the first phase after exposure? Does the immune system respond and engage early enough? Does the calf stay hydrated? Does it maintain intake?” White asks.
When a calf’s immune system engages effectively, it maintains stability. When that response is delayed, the calf enters a cycle of recovery that can extend well beyond the initial challenge. A study of nearly 400,000 calves found that early-life factors — particularly passive immunity and baseline health status — were strongly associated with subsequent growth and survival.
Subclinical Respiratory Disease Impacts Carcass Quality and Profitability
The financial impact of these lagging survivors is often felt long after the risk period ends.
“If the animal loses intake and spends weeks trying to catch up, that value erosion is still real,” White notes.
That erosion manifests in the final product. Work from Pensylvannia State University used lung ultrasound at weaning to identify subclinical respiratory disease in beef-on-dairy calves. Animals with early-life lung consolidation had roughly three times greater odds of grading Select rather than Choice or Prime at slaughter, despite showing little difference in feedlot growth performance.
Shifting Calf Management Priorities from Survival to Survivability
Focusing on survivability moves management priorities from restoring function to preserving it. Instead of waiting for mortality risks to drive decisions, producers should look to leading indicators like intake and daily gain.
“If we can keep more calves eating, hydrated, active and growing during that high-risk period, that’s where the real gains come from,” White says.
By shifting the definition of success, the industry can move away from simply counting losses and toward a more profitable goal: preserving the full potential of every calf in the system.
