ABSTRACT
Summary Beef cattle supply a major portion of farm income of northern Minnesota, but the major resource supporting this enterprise, forage, is vastly underutilized. A 5-year on-the-farm demonstration was conducted by the Agricultural Extension Service of the University of Minnesota and the Upper Great Lakes Regional Commission to improve income in this area by improving management of the beef enterprise.
796We compared one or two improved pasture systems with an unimproved permanent grass pasture composed predominantly of Kentucky bluegrass (Poa pratensis L.), system A, on each of six ranches. Improved systems included use of a cool-season grass fertilized with 138 kg N/ha for spring and autumn grazing and either birdsfoot trefoil (Lotus comiculatus L.) or a legume-grass mixture (alfalfa [Medicago sativa L.], red clover [Trifolium pratensis L.], smooth bromegrass [Bromm inermis Leyss.], and orchardgrass [Dactylis glomerata L.]) for summer grazing. All pastures were rotationally grazed, with excess forage harvested for hay. System B involved use of 6 ha of birdsfoot trefoil and 8 ha of fertilized grass. System G contained 9.6 ha of legume-grass and 6.0 ha of fertilized grass. A fourth system, AA, had Kentucky bluegrass fertilized once a year with 35 kg N/ha. All pasture systems carried 25 to 30 animal units (AU), and we used cows and calves, except in one case, in which we used lightweight yearlings, to measure productivity. The introduced cool-season grass, smooth bromegrass, yielded more AUM (months)/ha than did the native Kentucky bluegrass when both received the same amount of N fertilizer. Legumes provided pasture during 70 to 90 days of the grazing seasons (100 to 132 days long). Harvesting of excess forage improved its utilization, but unless the excess was harvested early, fall pasturage was limited. Animal live-weight gains/ha increased from the use of improved pasture-management systems on all six ranches. Gain increases ranged from 182% to 480% from the best system compared with system A. When extra harvested forage was converted to extra calf gain, at least two ranches produced more calf gain/ha (93 to 126 kg) than was shown at an agricultural experiment station.
