Growth of Grasses and Legumes: Impact on Grazing

The primary, cool season, perennial pasture grasses used in Kentucky are orchardgrass, bluegrass, and tall fescue. When not grazed or harvested, each of these passes through successive stages of growth in the spring: 1) leafy vegetative; 2) boot with seed heads enclosed in leaf sheath; 3) heading when the seed heads begin to show and, 4) bloom when pollination has occurred ( Figure 2). Since fiber and lignin contents increase steadily beyond the vegetative stage, while percent protein and digestibility decrease, a major goal in grazing management is to maintain these grasses in the leafy, vegetative stage at all times. Once the spring season is past, these grasses do not go through this series of growth stages until the next spring. Therefore, the regrowth after each grazing period is leafy and high in quality