“Culling” is generally viewed as a negative term.
But the act of culling can actually fuel a dairy herd’s productivity and profitability, depending on the reason for it. Michael Lunak, Extension Educator in Animal Systems/Dairy with Penn State University, explained in a recent bulletin how involuntary culling can drag a dairy down, but voluntary culling may boost overall herd quality.
Data from multiple sources indicates that the typical overall cull rate for dairies is about 37% -- or a little over a third of the lactating herd per year – including cow deaths. The most recent USDA/NAHMS data set for the Northeast shows that 26.8% of those culls were voluntary – primarily due to low milk production, poor temperament, or selling for dairy purposes.
The remaining 73.2 percent were involuntary culls. The two main causes were infertility (23.3%) and mastitis (18.6%), followed by lameness (9.1%), injuries (3.5%), respiratory disease (2.4%), metritis (2.2%), displaced abomasum (2.0%), and other (12.1%). Of those involuntary culls, 6.2% died on-farm.
Lunak noted that the more a dairy can shift its culling from involuntary to voluntary, the more likely it is to be successful. “Culling cows from the bottom of the herd makes room for more profitable cows,” he said. “A high percentage of voluntarily culled cows is required to maximize profits.”
Conversely, if a dairy is losing too many cows to involuntary culling, it will be forced to hang onto cows that would preferably be culled. Those kickers and low producers have to stay to maintain herd size.
Quite often, culling due to heath occurs early in lactation. More than half of the culls due to death in the USDA/NAHMS report occurred at less than 50 days in milk. Lunak noted that, unfortunately, cows culled early in lactation (60 days in milk or less) also represent the greatest economic losses.
The loss of young cows due to involuntary culling also weighs on dairies economically. Lunak said it takes more than 3 lactations to recoup the cost of raising a replacement heifer (about $2000/head), but the average productive life of a dairy cow is currently about 2.7 lactations. USDA data indicates that 70% pf cows are culled within their first 3 lactations. It’s a break-even proposition at best.
If a dairy can manage its way out of involuntary culling and shift to voluntary culling (or simply less culling overall, depending on the dairy’s goals), that’s where the magic can happen.
Voluntary culling can remove low producers and replace them with healthy, genetically superior heifers. Lunak did caution that herds with a high percentage of first-lactation heifers (40% or more) may sacrifice short-term milk yield because heifers typically produce less than older-parity herd mates.
By lowering involuntary culling, fewer replacement heifers are needed by the dairy to maintain its size. This provides the dairy with a number of flexible options, including:
- Growing its herd size;
- Selling excess replacement heifers, which currently are in high demand and fetching healthy prices; and/or
- Creating more beef-cross calves, which also are highly profitable in today’s marketplace.
Plus, healthier cows incur lower disease treatment costs and produce more milk. Lunak said much progress can be made if a herd focuses on the causes of involuntary culling – particularly transition health, reproduction, and mastitis. These and other culling factors can be recorded with herd management software and tracked for progress over time.
“Evaluating the reasons that cows are leaving the herd can help to target the management areas that need improvement,” he stated.
