CASE STUDY: Dairies using self-described ultra-high stocking density grazing in Pennsylvania and New York1

Proponents of ultra-high stocking density (UHSD) grazing emphasize increased forage-use efficiency and soil improvement by grazing mature forage with stocking densities up to 560,425 kg/ha of beef cattle on small paddocks with rest periods up to 125 d. However, it is unclear whether this management technique is appropriate for dairy farms in the northeastern United States. A case study was conducted to characterize management practices and forage and soil quality on dairy farms using self-described UHSD grazing. Data collected on 4 organic dairy farms in Pennsylvania and New York practicing UHSD grazing included pasture and soil nutrient analyses, stocking density, botanical composition, and pasture stratification. Herds were mixed breed with milk yields ranging from 11.9 to 17.7 kg/d per cow. Stocking density ranged from 49,421 to 377,912 kg/ha with 30 to 49 d of forage rest. Forage consumed was 46 and 45% of total available in 2012 and 2013, respectively. Within the available forage that was eaten, cows consumed 75% of forage from layers 33 cm and higher and 49% from below 33 cm. Across years, forage CP, NDF, and NEl averaged 24%, 44.7%, and 1.43 Mcal/kg, respectively. The increase in forage quality during 2012 was likely a result of forage being less mature at each successive grazing. Soil mineral content and pH were within recommended levels. Grazing dairies in Pennsylvania and New York have taken a modified approach to UHSD grazing by using forages more mature than recommended in management-intensive grazing systems by allowing longer periods of forage rest.