Submitted to: American Forage and Grassland Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: April 20, 2001
Publication Date: April 25, 2001
Citation: Soder, K.J., Rotz, C.A. 2001. Economic and environmental implications of four levels of concentrate supplementation in grazing dairy herds. American Forage And Grassland Council Proceedings. 2001. v.10. p. 171-175. Interpretive Summary: Economic and environmental concerns are stimulating changes in dairy production. Inflation-adjusted milk prices have remained stable or declined for many years, while the cost of production inputs has continued to increase. As sustainable dairy farms are developed for the future, changes must be made to improve their productivity, profitability, and environmental impact. Low cost pasture-based forage systems are a viable management alternative to more traditional stored forages for dairy producers. Grazing dairy cows typically decrease input costs, but at the same time decrease milk production. Supplementation of these grazing cows decreases forage demand and increases milk production to more acceptable levels. However, maximum profitability may not occur at the highest level of supplementation due to the law of diminishing returns. In comparison to confined feeding systems, grazing dairy farms that supplement cows may have ehigher profitability, along with low N loss and soil P accumulation, at th higher levels of supplementation. The higher profits were due to decreased input costs associated with the grazing systems, even though income also decreased with grazing when compared to the confinement system. However, the net result was a greater profitability.
Technical Abstract: Low cost pasture-based forage systems are a viable management alternative for dairy producers. A whole-farm analysis was conducted to evaluate the potential long-term environmental impact and economic benefit of varying the level of concentrate supplementation on spring-calving, grazing dairy farms using a whole-farm model (DAFOSYM). A representative grazing farm in ncentral Pennsylvania was simulated with four levels of concentrate supplementation. These farms were then compared to a confinement farm producing corn and alfalfa on the same land base where total mixed rations were fed. Stocking rate was set on each farm so forage consumed equaled forage production on the farm. Profitability increased as supplementation level increased in the grazing systems, but at a decreasing rate with each successive level of supplementation. At the highest levels of supplementation, the grazing dairy farms showed greater profitability than the confinement farm. Nitrogen leaching remained relatively unchanged as supplementation increased, but soil P accumulation increased. Concentrate supplementation of grazing lactating dairy cows provided an increase in profitability and a mixed impact on nutrient balance of the farm.