Wintering Beef Cattle on Mixtures of ‘Georgia 5’ Tall Fescue and Warm-Season Perennial Grasses on Coastal Plain Soils

A persistent, perennial cool-season grass could reduce winter feed costs for beef production in the lower South. ‘Georgia 5’, is an endophyte-infested [Neotyphodium coenophialum (Morgan-Jones and Gams) Glenn, Bacon & Hanlin] tall fescue (Festuca arundinacea Schreb.) cultivar developed for improved persistence in the Coastal Plain. Two experiments were conducted to define the response of overseeded Georgia 5 to fall grazing deferment varying in starting date and duration, and to evaluate its potential contribution to winter feed for beef production. Plots of this tall fescue, overseeded on a warm-season grass pasture on upland Coastal Plain soils in 2 yr, were grazed continuously after establishment except for 60-, 90-, or 120-d fall grazing deferments beginning at 15-d intervals after 31 August. Deferments beginning mid-October or later provided benefit to Georgia 5 survival. Deferments longer than 60 d allowed greater herbage accumulation, but did not further enhance persistence. Georgia 5 tall fescue was overseeded on ‘Coastal’ bermudagrass [Cynodon dactylon (L.) Pers.] or ‘Pensacola’ bahiagrass (Paspalum notation Flüegge van saurae Parodi) flatwoods pastures in October of 2 yr. Continuous stocking (1.9 heifers/acre in the first and 1.2 in the second year) of pastures began in the following April. Performance of heifers grazing overseeded pastures from December to April was compared with heifers fed bermudagrass hay ad libitum and 6.8 lb/head of a ground corn-cottonseed mixture three times weekly. Tall fescue herbage mass ranged from about 200 to 600 lb dry matter/acre from December through April. Growth of hay-fed heifers was faster (P < 0.05) than non-supplemented grazing heifers (1.51 vs 0.50 lb/d) in the first year, but similar for both treatments in the second year (0.99 lb/d). Foliar cover of tall fescue was stable in bermudagrass pastures and averaged 51%. Tall fescue declined in bahiagrass pastures from 61% in spring of 1990 to 35% in spring of 1992. Minor, but transient, fescue toxicosis symptoms were observed. Georgia 5 overseeded on warm-season grass pastures can be used for winter grazing and contribute to reduced beef production costs in the lower South. Research QuestionBeef production in the lower South is dominated by cow-calf production utilizing warm-season perennial pasture as the primary feed source. Winter feed for the cow herd is expensive because it must be provided by stored hay or from annuals planted for grazing every year. This study evaluated methods by which Georgia 5 tall fescue might provide an alternative to conventional winter feeding programs. Literature SummaryPoor persistence of cool-season perennial grasses has been observed repeatedly in the lower South. The range of adaptation of tall fescue extends farther south than other cool-season perennial grasses. Presence of the tall fescue endophyte improves the persistence of tall fescue cultivars in stressful environments. Georgia 5 tall fescue, containing the endophyte, was selected for improved adaptation and persistence in the Coastal Plain region. Superior fitness of Georgia 5 has been demonstrated in several clipping experiments in the region. Study DescriptionGrazed Small Plot Experiment Georgia 5 tall fescue planted in October into existing warm-season grass pasture. Plots grazed continuously, except for fall deferment maintained with electric fence. Nine deferment treatments (60, 90, or 120 d) initiated at 15-d intervals beginning 31 August. Soil: Carnegie loamy coarse sand (clayey, kaolinitic, thermic Plinthic Kandiudults). Fertilization: November—60 lb N, 26 lb P, 50 lb K per acre; February—100 lb N, 44 lb P, 83 lb K per acre. Grazing Trial Responses to continuous grazing of Georgia 5 tall fescue overseeded into bermudagrass or bahiagrass pastures were monitored. Pastures were grazed continuously except during 2-mo fall deferment. Animals: British yearling heifers (515 lb) Soils: Leefield and Alapaha loamy sands Fertilization: Single November application—1000 lb/acre 10-10-10 Winter feed: Free choice bermudagrass hay and 6.75 lb/head of corn-cotton seed meal mixture fed three times a week or grazing overseeded Georgia 5 tall fescue. Applied QuestionsWas Georgia 5 tall fescue persistent in the Coastal Plain when overseeded into warm- season perennial pastures and grazed continuously for 10 months of the year? Stands declined in continuously grazed small plots established on upland soils. Sixty-day grazing deferment beginning in mid October provided improved persistence. On flatwoods soils, stand ratings indicated that the contribution of Georgia 5 tall fescue to pasture vegetation was stable during three years when overseeded into bermudagrass pasture (Fig. 1). Overseeding into bahiagrass resulted in initial stands comparable to those in bermudagrass, but percentage cover of tall fescue decreased with time. Fig. 1Botanical composition of (a) bahiagrass or (b) bermudagrass pastures overseeded with Georgia 5 tall fescue and grazed continuously for 10 mo per year by yearling heifers. What was the performance of heifers grazing Georgia 5 tall fescue over- seeded into warm- season perennial grass pasture? During the first grazing season, when yearling heifers were stocked at an average rate of 1.9 heifers/acre, they gained 0.50 lb/d. During the second season, gains were 0.93 lb/d with an average stocking rate of 1.2 heifers/acre. Heifers fed hay and supplement gained 1.51 and 1.05 lb/d the first and second seasons, respectively. When stocked conservatively, Georgia 5 tall fescue supported heifer growth comparable to a conventional wintering program of hay and grain supplement.