Continuous vs. Rotational Stocking of Steers on Mixed Endophyte-Infected Tall Fescue-Bermudagrass Pastures Fertilized with Broiler Litter

Rotational stocking (RS) may be useful in alleviating nutrient runoff problems from high rates of broiler litter application while improving animal performance of steers grazing mixed grass pastures of endophyte-infected (E+) tall fescue (Festuca arundinacea Schreb.) and common bermudagrass [Cynodon dactylon (L.) Pers.J. Six 2.0 acre bermudagrass pastures no-till seeded with E+ ‘Georgia 5’ tall fescue were fertilized annually with approximately 6 tons (dry weight)/acre of broiler litter, allowing three replications each of continuous stocking (CS) and RS methods. Broiler litter was applied on 16 Mar. and 30 Oct. 1995, and 4 Mar. and 25 Sept. 1996, to follow generally recommended guidelines for fertilization of tall fescue-bermudagrass pastures in the Southern Piedmont. Rotationally stocked pastures with eight paddocks each allowed 3 d of grazing and 21 d of rest per paddock. Two crossbred beef steers (Bos taurus) were maintained on each pasture treatment year around for 2 yr with additional steers added to maintain similar forage availability between grazing methods. With both CS and RS there was a decrease (P< 0.10) of 21 and 26% in bermudagrass basal cover and frequency, respectively, accompanied by a 21% increase (P < 0.10) in frequency oftall fescue. Grazing method had no effect (P > 0.10) on tall fescue or other species basal cover, or frequency of other species. Grazing method had no effect on monthly harvested forage samples measured for crude protein (CP), neutral detergent fiber (NDF), or acid detergent fiber (ADF) content. Rotational stocking resulted in increased (P < 0.10) forage available oftall fescue in January and November. Rotational stocking had no effect (P > 0.10) on stocking rate the first year, but increased it 24% (P < 0.10) during the second year. Steer average daily gain and gain per acre of 1.04 and 551 lb, respectively, were unaffected by grazing method (P > 0.10) and were in the expected range for steers grazing E+ tall fescue pastures. Rotational stocking maintained bermudagrass better than CS in the aggressive heavily fertilized E+ tall fescue of the mixed pastures. Rotational stocking did not improve steer performance and was similar to CS in utilizing nutrients from broiler litter. Research QuestionMixed endophyte-infected tall fescue-bermudagrass pastures are commonly fertilized with high rates of broiler litter in the southeastern USA. The results of this are excessive nutrient runoff from pastures and poor cattle performance because of fescue toxicity. We studied the effect of rotational compared with continuous stocking of steers in reducing these problems. Literature SummaryRotational stocking has been shown to increase cattle carrying capacity and maintain a better balance of species in mixed grass pastures. Bermudagrass can dilute the effect of fescue toxicity in pastures under normal fertilization practices. However, beef cattle farms in many areas of the southeastern USA also have broilers and generate more litter than is needed to meet pasture needs, often resulting in rates well in excess of 5 tons/acre annually. Rotational stocking has been suggested as useful in reducing nutrient runoff and maintaining a better balance of other species to dilute the effects of fescue toxicity. Study DescriptionWe compared year around rotational and continuous stocking of beef steers on mixed endophyte-infected tall fescue-bermudagrass pastures fertilized annually with approximately 6 tons (dry weight) per acre of broiler litter where nutrient runoff was measured for 2 yr in central Georgia. Split applications of broiler litter were applied during early autumn and late winter of each treatment year. Applied QuestionsHow do steers perforin under the two grazing methods? As expected, daily steer gains were only about 1 lb/d because of fescue toxicity. Grazing method had no effect on average daily gain, gain per acre, or nutrient runoff from pastures. Stocking rate was increased 24% the second year with rotational stocking, a result of additional tall fescue being available during November and January. How did grazing method affect plant species cover in the pastures? With both grazing methods, there was a decrease in bermudagrass and an increase in tall fescue, which dominated pastures over most of the year at this high rate and timing of broiler litter application. While not adequate to mediate animal performance, rotational stocking maintained the relatively more stable species mixture. RecommendationLivestock producers should apply broiler litter according to a nutrient management plan. The timing of broiler litter application to endophyte-infected tall fescue-bermudagrass pastures to favor bermudagrass production and persistence must also be considered. This should be beneficial in reducing fescue toxicity problems.