Dairy calves that are fed higher-protein milk replacement produced more milk and had earlier weaning dates, improved health and better fertility rates, according to a new paper by University of Missouri Extension specialists.

Before weaning calves, producers feed them a milk replacement, a concentrated powdered milk diluted with water. In a two-year study on a pasture-based dairy, calves fed higher-protein milk replacers showed fewer health problems, says dairy veterinarian Scott Poock. As calves matured, they had higher conception rates at first breeding, and they bred at a younger age. They also gave 1,000 pounds more milk at first lactation. All of this translates into more money for the producer, says extension dairy specialist Stacey Hamilton.

In the study, researchers fed 28.5:15 protein-fat accelerated milk replacer to one group of heifer calves and traditional replacer to others. They used a mob feeding system of multiple calves per feeder at MU's Southwest Research Center near Mount Vernon.

Poock says conventional milk replacer feeding programs limit dry matter intake of milk to 1-1.5% of body weight at birth. Higher-protein milk replacer allows dry matter intake of 2-3%.

"The higher level of milk feeding is counterintuitive to the goal of increased grain feeding and subsequent rumen development," says Poock. However, the study shows that calves eat more grain after weaning when the milk ration is reduced one to two weeks before weaning.

A 2005 University of Minnesota analysis of feeding of high-protein milk replacers to dairy calves reported an 18% decrease in calf mortality. A Cornell University study found that calves inoculated with cryptosporidium and fed accelerated milk replacer had fewer days of diarrhea, less dehydration and improved feed efficiency than traditionally fed calves.

Hamilton recommends the accelerated milk replacer to push calves to weaning sooner and improve overall herd health. "We've seen the extra growth and health benefits," he says.

He says it is important to mix the replacer thoroughly with the right ratio of powder to water. Clumps of undissolved powder can cause gut issues in the calves.

Poock, Hamilton and MU College of Agriculture, Food and Natural Resources interim associate dean Rob Kallenbach are authors of the paper.