Dairy Grazing Program Has Benefits

October 13, 1999

An ongoing project in Pennsylvania, conducted by USDA, the American Farmland Trust and others, shows that grazing dairy cows on pasture, instead of using confinement facilities only, can increase net income per cow.

The project is being conducted at the cove Mountain Farm, a 300-acre dairy farm owned by AFT in south-central Pennsylvania. Researchers visit the farm each week to monitor the instruments used in the project, including stream gauges for recording nutrient losses from pasture where 150 Holstein and jersey cows graze. Grass-based systems for grazing small herds of cattle on intensively managed pastures was popularized in New Zealand and Europe.

In the United States, however, large dairy operators usually confine their herds of 1,000 animals or more to feed regimens of hay, grain or cut forage like alfalfa.

Some estimates indicate that grazing-based systems of small to medium sized dairies can increase net incomes by $50-100 per cow per year. While full confinement operations produce higher milk yields, grazing-based farms profit by reducing operating and labor costs associated with growing, harvesting and storing crops like corn as year around feed. Another benefit is the reduced capital investment needed to house and manage large herds.

One problem faced by grazing operations is animal waste. Only about 15% of the nutrients contained in pasture herbage leaves the pasture as milk or meat; the rest is recycled onto the pasture in urine or manure. Concentrations beneath urine or manure patches are very high.

USDA researchers say that under certain conditions, waste-borne nutrients can outpace what pasture plants, soil microbes and other biological processes can recycle or convert into forms less damaging toe water quality. For example, excess phosphorus in runoff can harm recipient streams, lakes or reservoirs by triggering algal blooms.

Researchers closely monitor various instruments at the farm. One site is a 10-acre paddock where nutrients from cows' urine and manure can be monitored. About 10,000 feet of underground piping is used at the paddock.

That piping network captures water flowing beneath the paddock and directs it to five keg-sized sampling devices. Each is located in a flume house a few hundred yards from a creek and about a mile or so from the Cove and Cross Mountains.