Jay Heeg, Owner-Heeg Brothers Dairy
Jay Heeg, Owner-Heeg Brothers Dairy

Marathon County, Wis., saw record-cold temperatures this past winter, but calf growth rates didn’t skip a beat at Heeg Brothers Dairy in Colby, Wis. Owner Jay Heeg credits the farm’s seasonal feeding approach for maintaining calf gains.

Seasonal feeding, which involves feeding different milk replacer formulations as the seasons change, is still a relatively new concept. However, the benefits to calf performance – and farm profitability – are quickly racking up for the early adopters. Here’s what they have to say about it.

The concept of seasonal feeding is based on the principle that a calf’s energy needs are different at different times of the year, explanied Tom Earleywine, director of nutritional services for Land O’Lakes Animal Milk Products. This is why producers like Heeg switch from one formulation to another as seasons change.

Energy reserves are extremely limited in the young calf. During cold stress, energy for growth and other functions becomes limited, or even nonexistent, when the calf draws on its very limited reserves to maintain its core body temperature. For the calf, cold stress occurs at 60 degrees F and below. During heat stress (which begins at 78 to 80 degrees F), the calf burns energy as it tries to drive heat from its body, leaving less energy available for growth. In both cases, the calf needs greater and more rapidly available energy.

Seasonal formulations take this into account, but accomplish it in different ways. For example, cold weather formulations may contain a greater percentage of fat than warm weather formulations. The fat is designed in such a way that, when stored, it can be drawn upon more efficiently by the calf. That doesn’t mean warm weather formulations provide less energy. In these formulations, lactose is providing a greater percentage of the energy, and this type of carbohydrate is something the body can utilize quickly.