CATTLE DIET QUALITY UNDER SHORT-DURATION GRAZING ON TALLGRASS PRAIRIE

Paddocks of tallgrass prairie were grazed at intervals similar to 8-pa ddock short duration grazing. Two replicates of a 2 x 3 factorial trea tment design were evaluated to determine the influence of stocking rat e and grazing schedule on crude protein and digestible organic matter content of cattle diets. Stocking rates were 1.3 or 1.8 multiples of t he rates recommended by the Soil Conservation Service for the study si te. Grazing schedules were 2, 3, or 4 complete cycles during a 152-day grazing season. Grazing and rest periods were lengthened as the seaso n progressed and forage accumulation rate slowed. Masticate samples we re collected from the experimental paddocks on alternate days during t he grazing periods in 2 consecutive years. No stocking rate by grazing schedule interactions were observed (P>0.10). Diet crude protein was depressed (P<0.05) slightly at the higher stocking rate. Diets collect ed from the 4-cycle paddocks contained more (P<0.05) protein than diet s from the 2- and 3-cycle paddocks. Diets from the 2- and 3-cycle padd ocks were not different (P>0.20). In vitro digestibility was not influ enced by stocking rate but tended (P<0.13) to be higher for the 3- and 4-cycle grazing schedules. The balance of crude protein and digestibl e organic matter was most favorable (P<0.05) for the 3-cycle diets. Ba sed on diet composition, more frequent grazing periods appeared to mai ntain a higher, more stable plane of nutrition than the slower rotatio n schedules.