Submitted to: Alfalfa National Symposium Proceedings
Publication Type: Proceedings
Publication Acceptance Date: March 4, 1996
Publication Date: N/A
Interpretive Summary: Costs of feed production and manure handling are increasing more rapidly than the price of milk placing an economic squeeze on dairy farmers. Decreasing profitability is causing many to look for alternatives to reduce their costs. One option of growing interest is the use of rotational grazing. A major deterrent though is the lack of good information on the long-term economic benefits of grazing. Although many farmer testimonials are heard on the benefits of grazing, well documented comparisons of grazing and confined feeding systems are seldom found. Such comparisons are difficult because variations in weather across locations and years obscure the data that must be compared. Computer simulation provides a useful tool for comparing systems over similar conditions. A simulation model of the dairy farm was set up to describe a typical farm in Southern Michigan. An intensive rotational grazing system was used to meet most of the herd's forage needs during six months of the year. When the farm was simulated over 25 years of weather for both the grazing system and an all confined feeding system, grazing was found to improve farm profit by $100 to $240/cow. These results will encourage more dairy farmers to adopt rotational grazing systems.
Technical Abstract: The Dairy Forage System Model, DAFOSYM, was used to model a representative dairy farm in Southern Michigan. The farm used intensive rotational grazing of alfalfa to supply a major portion of the forage needs of a high producing Holstein herd. Additional forage was harvested, stored and fed in a total mixed ration. Using the model, the performance and economics of the farm using a grazing system were compared over many years of weather to those using a confined feeding system. The net cost of feed decreased with grazing through reduced use of conserved forages, corn grain and soybean meal. Because grazing animals spent less time in the barn during the grazing season, less bedding was required with 34% less manure hauled each year. Altogether, these effects provided a 12% reduction in the average feed and manure handling cost. Grazing of an 18,000 lb herd reduced the total feed and manure handling cost by $0.83/cwt of milk produced compared to the confined feeding system. At a production level of 20,000 lb/cow, the reduction in the feed and manure cost was slightly less at $0.73/cwt. The net return or profit margin of the farm increased by $146/cow or $58/acre. Thus, grazing of alfalfa is an economically viable option for dairy farms in Michigan. The grazing strategy used and other assumptions of the analysis influence the benefit received.