Overgrazing pasture or cutting hay too frequently damages forage stands, limits stocking rates and prevents optimum utilization by livestock.
Forage producers who over-graze or cut hay too frequently harm the forage plant’s root system, says Texas AgriLife Extension forage specialist Vanessa Corriher. “The root system dies back and the plant will not survive drought or persist through the winter,” Corriher said during the recent Ag Technology Conference at Texas A&M-Commerce. “Forage managers must allow the roots to rest and grow back. Adequate rest is essential.”
She said different grazing and mechanical harvesting systems offer a wide range of efficiency ratings.
Continuous stocking results in only 30 percent to 40 percent forage efficiency. That improves to 50 percent to 60 percent with a slow rotation program using three or four paddocks. With six to eight paddocks and moderate rotational grazing, efficiency improves to 60 percent to 70 percent.
Strip grazing offers 70 percent to 80 percent efficiency.
With mechanical harvesting, cutting hay provides 30 percent to 70 percent efficiency; silage is 60 percent to 85 percent efficient. Green chop, at 70 percent to 95 percent is the most efficient mechanical harvest method.
Corriher said fencing is the key to efficient grazing but adds to expense. Forage managers also have to assure water availability in each fenced-in area. “Movable fencing is one option,” Corriher said. A producer would move the fence forward as cattle graze, keeping water available to the rear.
“This does require more time and labor,” she said.
Livestock perform selective grazing if left in the same pasture, picking the newest, most tender and most palatable grass. “That depletes the root system as livestock continually return to the same spot to get new growth,” Corriher said. “Rotational grazing forces cattle to take advantage of all forage.”