Pasture lands are an under-utilized and under-managed resource in Minnesota. Rotational grazing systems, when combined with adequate fertilizer use, will improve pasture productivity and animal performance. However, there is still a high percentage of cow/calf producers who use continuous grazing systems.

To respond to this educational challenge, a demonstration project was conducted in 2005 to compare animal performance in a continuous grazing system, using no inputs; to animal performance on a pasture that was fertilized and rotationally grazed.

The demonstration was conducted with a cow/calf producer in Cass County. One pasture was divided into four fenced paddocks that were fertilized according to University of Minnesota guidelines. Electric fence and a watering system were installed so that rotational grazing could be used. This pasture consisted of 41.5 acres. For comparison, a non-fertilized continuous 400 acre pasture without fertilization was used.

The rotationally grazed paddocks was fertilized with 60 lb. N, 30 lb. P2O5, and 90 lb. K2O per acre at a cost of $40 per acre.

When results from the two grazing systems were prepared, there were several obvious differences in pasture carrying capacity and animal performance. The rotationally grazed paddocks was able to support one cow/calf pair on 2.1 acres of land for 143 days. The pasture that was continuously grazed provided support for one cow/calf pair on 5 acres for 87 days before these cattle had to be moved because of lack of available forage.

The measure of animal performance was important. During the same 87-day grazing period, cows on the rotationally grazed paddocks gained 0.38 lb. per head per day more than cows on the continuously grazed pasture. It is estimated that suckling calves gained approximately 60 pounds per head more on the rotationally grazed paddocks. This added weight translates to more profit from the weaned calves.

The additional weight of the cows and calves was not the only advantage. Cows on the rotationally grazed paddocks had a greater body condition score after 87 days. This increase in body condition helps to stimulate efficiency of forage utilization and allows cows to breed earlier in the breeding season. This translates to older and heavier calves at weaning. Cows from the rotationally grazed system will go into winter in better body condition, which ultimately can reduce winter feed cost.

The results of this demonstration from the summer of 2005 show the positive value of combining fertilization with rotational grazing. There are many pastures where the use of these management practices could improve forage production, reduce feed cost, and ultimately increase profits.