sows-gilts stocking rates and their environmental impact in rotationally managed bermudagrass paddocks

Ground cover maintenance and nutrients management are key elements to reduce the environmental impact of outdoor swine production. The objective of this study was to determine the effects of sows-gilts stocking rates on vegetative ground cover and soil nutrient concentrations in rotationally stocked bermudagrass (Cynodon dactylon L. Pers) pastures. Three stocking rates (10, 15 and 25 sows-gilts ha⁻¹) were compared during three 8-week grazing periods. Increasing the stocking rate from 10 to 25 sows-gilts ha⁻¹ decreased the ground cover of the paddocks from 65 to 48%, and increased soil nutrient concentrations (ammonium 47%; nitrate 129%; phosphorus 53%; zinc 84%; and copper 29%).