Carlson Grassland Management Project

2004 Report
Carlson Grassland Management Project

The Carlson ranch in Kingsbury County employs a management-intensive grazing system with five paddocks on 168 acres of established pasture with two dominant grass species: Smooth Brome and Kentucky Blue Grass. The paddocks are separated by a single wire electric fence and range from approximately 31 to 43 acres in size. The size of the paddocks has proven to allow ample time for regrowth between rotations. On May 15, 2004, the first paddock was stocked with fifty cow/calf pairs.
	Because the Carlson system employs set paddock sizes, the grazing periods are variable and forage monitoring is performed to determine the periods for each paddock. Those monitoring efforts, which include collecting forage weights before and after the cattle occupy a paddock, determined that an adequate amount of forage was available throughout the grazing season. Forage weights ranged from 900 – 2580 pounds/acre before the cattle entered a paddock and from 200 – 2330 pounds/acre when they were rotated out.
The cattle were on the system for a total of 141 days, through 4 rotations. The 1st rotation was for 43 days, the 2nd for 43 days, the 3rd for 41 days, and the 4th rotation for 14 days. During the rotations, a total of eight random fecal samples were collected and tested for crude protein, digestible organic matter, fecal nitrogen, and fecal phosphorus. The average percentages of the test results were: CP 13.75%, DOM 62.72%, FN 1.65%, and FP 0.44%. Throughout the grazing season, the crude protein (CP) remained at a satisfactory level, ranging from 12.39% to 14.28%.
	Because fresh drinking water has been shown to contribute to improved weight gains in calves, the ranch has installed a water line into the center of the pasture so one water tank can be used by four of the paddocks that would otherwise have an unreliable water supply.The watering system consists of a large tank with three posts and cross boards that prevent calves from getting into the tank and also aid in reducing contamination. A float connected to the water source ensures the cattle have a constant supply of water. Although there is only one water source, the cattle have a method of avoiding crowding and conflict during watering periods –– they simply take turns. The Carlson site received a good amount of precipitation in 2004. During the grazing season (May through September), a total amount of 22.35 inches of precipitation was recorded. The amount of rainfall by month and inches received was: May - 3.75, June - 5.6, July - 5, August - 2, and September - 6.
The cattle were pulled from the system on October 3, 2004.