Cool season annual grasses provide high quality forage at a time that warm season forages are dormant, low in crude protein, and high in fiber. Although tall fescue grows at the same time of year as most of our small grains, forage intake and animal performance of tall fescue is much lower than with annuals because of the toxicity of tall fescue in most of the acreage in Arkansas (unless novel endophyte tall fescue has been planted!). Small grains, such as rye (cereal rye not annual ryegrass) and wheat grow well in the fall and early winter and are extremely productive in the spring. Annual ryegrass is not as productive in the fall and winter but is also extremely productive in the spring. Oats are very productive but are not cold tolerant and can have stand losses due to freeze damage most years in northern Arkansas and some years in southern Arkansas. Cool season annuals provide excellent forage for growing stocker calves and developing replacement heifers and can be an excellent supplement for mature cows by limit grazing a few hours a day or for several hours on alternating days.
Our recommendations are to plant a mixture of 100 to 120 pounds of small grain (cereal rye or wheat) and 20 to 25 pounds of annual ryegrass in the fall. This should be done in early to mid-September in crop fields or in early to mid-October when interseeding into warm-season grass sod. After cool-season annuals are planted, cattle should be kept off the pastures until the annuals are at least 6 to 8 inches tall, which is about 1200 to 1600 pounds of forage dry matter per acre. In most years interseeded cool season annuals have enough forage growth for grazing to start in late November or early December, while cool season annuals planted in crop fields can be grazed in late October or early November. This is enough forage for about 2 pounds of gain per day with ¾ to 1 calf per acre stocking rate until mid-February or early March, when spring growth patterns begin. When spring forage growth patterns begin, stocking rate can be increase to 2 calves per acre until mid-May. In this system small grains provide forage from November to May, while the annual ryegrass will provide forage from March to mid-May (or sometimes early June). If forage is intended for use by spring calving mature cows, later planting dates can be considered because the high quality forage is not necessary until later in the year (late January or early February depending on when calving season starts).
Every year dry conditions in the fall give producers pause when considering where to plant cool season annual or not. There is risk involved, but by using a no-till drill that can penetrate hard soils and place seeds at least ½ inch deep beneath the sod, the Stocker Unit at the Southwest Research & Extension Center at Hope has been very successful in getting stands of small grains and ryegrass in these harsh conditions. This year bermudagrass pastures at the SWREC were interseeded with a mixture of rye and annual ryegrass from October 1 to October 20. When the rains came finally on October 24th the cool-season annual seedlings began to emerge by October the 28th and very good stands of grass was evident by November 1. With the late emergence, pastures were not (quite) ready to graze by Thanksgiving, but were ready to graze before Christmas.
For this system to work, fertilizer needs to be supplied to these pastures to drive forage growth. Soil test results should be used to determine the optimal rate of phosphorus and potassium and nitrogen fertilizer should be supplied in the fall at a rate of about 50 pound of actual nitrogen per acre. Clover, vetch or other legumes may be helpful for spring grazing but should not be relied on to supply nitrogen for fall growth. Although, production expenses (total pasture cost of $150 per acre) may be considerable the productivity of these annual pastures provide for gains costing around $0.35 per pound.