Grass-based dairy farming can work anywhere cool-season grass and clover pastures grow.

So says Darrell Emmick, a state grazing land management specialist with USDA's Natural Resources Conservation Service (NRCS) based in Cortland, NY. Emmick also holds a doctoral degree in animal behavior, which gives him a unique perspective on the foraging behavior of bovines. He shares four tips to enhance grass-based dairy efforts:

Change your mind before changing your management. “The biggest challenge farmers face when converting to a grass-based production system is in changing their mindset,” says Emmick. Many bring the “maximum production equals maximum profit” equation with them to grass farming, when they need to start thinking of “optimum production equals optimum profit.”

“Sometimes optimum production does mean maximum production, but certainly not all of the time. When the cost of feed is higher than the milk price, optimum production means feeding less of the costly items and letting the cow consume more low-cost pasture. Producing less may well provide greater profits through cost reduction.”

Recognize that foraging behavior and diet selection are learned. What livestock learn to eat, they learn early in life — usually from their mothers, explains Emmick. “Dairy calves tied to calf hutches learn nothing about being grazers, grazing or selecting their own diets.”

When a grazing-dairy system is implemented, calves need to be taught to graze at an early age. Emmick recommends getting them on grass as soon as possible for eight to 10 weeks — with their mothers or nurse cows. These cows with calves should be in a separate pasture away from the milking herd.

Be cautious of overfeeding protein. When it comes to monitoring animal performance, he calls the cow “the lie detector.”

“Regardless of what a computer ration says we should feed cows on pasture, if they are not eating well, are not producing lots of milk or are losing body condition, it is probably not the pasture's fault.”

Instead, he suggests that it's likely they're being overfed protein in the barn ration.

“Pasture forages range from 20 to 34% crude protein,” he explains. “A cow only needs about 16 or 17% protein in her diet. Overfeeding protein results in subclinical ammonia toxicity, which causes cows to go off feed and divert energy away from milk production to detoxify and eliminate the ammonia.”

Pastured dairy cows don't need to be fed protein unless the pasture is in short supply. If that's the case, then all nutrients will be in short supply. Generally, pastured cows should be supplemented with energy.

Monitor when and what cows are eating. A cow's dry matter intake from a pasture hinges on three things: the number of bites she takes per unit of time, the amount of forage taken in with each bite and the amount of time she spends grazing.

“Anything that gets in the way of this formula will result in a loss of intake and milk production,” Emmick says.

To ensure animals' opportunities to optimize intake, he offers three simple rules:

  • Cows should graze pastures that are 6-8” tall. Forage heights below 4” reduce intake per bite. Forages taller than 10-12” have higher fiber levels, which increase tensile and shear strength, reducing bite rate.

  • Pastures should be at least 50% legumes to optimize bite rate and intake per bite. Cattle and sheep prefer legumes over grass by a 70-30% ratio.

  • Legumes are higher in protein, higher in energy, are more digestible, and animals can eat legumes faster than they can eat grass. Thus, legumes are their preferred food,” he says.

  • To ensure high dry matter intakes, allow cows to graze during the first and last four hours of daylight. Ruminants are most active during the gray light hours at dawn and dusk. Accommodating this natural foraging behavior may mean shifting milking times, says Emmick.