2004 Annual Report for GNC03-024
Systems Evaluation of the Components of Reduced Input Dairy Farms
Summary
The impacts of herd characteristics measured on 10 diverse grazing dairy farms on the long-term economic sustainability of a representative grazing dairy were evaluated through simulation modeling. Preliminary findings indicate that the impact of the range observed across farms for the rates of replacement mortality (stillbirth plus death of replacement heifers), adult mortality, and involuntary culling on long-term economic gross margin are greater than the impacts of the range observed in the rates of clinical mastitis incidents or amount of feed supplemented to the lactating herd during the grazing season.
Objectives/Performance Targets
The primary objective of this project is to identify important herd characteristics of reduced-input dairy operations located in the upper Midwest which might impact the long-term sustainability of these operations. An objective is to locate a number of dairy farms within Minnesota that are utilizing a range of management strategies typically used on reduced-input dairy farms including one or more of the following: management intensive grazing, outdoor winter housing of the dairy herd, group rearing of calves, cross breeding, and value-added sales. Samples of pasture and feeds supplemented to the lactating herd will be collected on each of these farms to test nutritional quality. Data pertaining to the management and performance of the herd will be collected from the farm operators by conducting interviews and analyzing available records. The long-term impacts of the range observed for important herd characteristics in the participating herd will be evaluated through simulation modeling.
Accomplishments/Milestones
A number of important herd characteristics of reduced-input dairy farms have been identified and include the rates of replacement mortality (stillbirth plus death of replacement heifers), adult mortality, involuntary culling, mastitis incidents, and quantity of feed supplemented during the grazing season. Ten reduced-input dairy operations have participated in the project. The collection of pasture and supplemented feed samples and the nutrient composition analysis of those samples has been completed. The pasture samples were collected biweekly from June 1, 2003 through the end of the 2003 grazing season, which ranged from the end of August on some farms to the middle of November on other farms. Samples of feeds supplemented were collected on a semimonthly basis from June 1, 2003 until the date in the spring of 2004 when the farmer operators stated that the cows in the lactating herd were receiving a significant amount of their forage dry matter intake from pasture. This ranged from the end of March to the end of May. A large amount of management data was collected on each of the operations including the amounts of each feed supplemented during the grazing and non-grazing season and rates of mortality, involuntary culling, and clinical mastitis for 2003. Information has also been collected pertaining to the quantity and quality of the milk sold during the data collection period. The range of herd characteristics as compared across the farms has been calculated. The long-term impacts of the range calculated across farms for a number of herd characteristics has been evaluated through simulation modeling with SIMHERD, a dairy herd modeling program developed by Danish researchers to evaluate the long-term impacts of herd management strategies on annual milk yield per cow, other technical effects, and economic gross margin. Currently, the results of the simulations are being summarized.
Impacts and Contributions/Outcomes
This project will be summarized in Eb Ballinger’s Masters thesis, which is due to be completed in the spring of 2005. Current outcomes of this project include the development of good working relationships between the farmers in this project and University of Minnesota personnel, facilitating the collection of valuable data. The long-term outcome for this project will be the identification of herd characteristics for reduced-input dairy farms which have will likely have large impacts on the long-term sustainability of these types of farms. The identification and analysis of these characteristics will likely lead to further research on the impacts of these and other characteristic and lead to the adoption of management practices which can increase the sustainability of moderately sized dairy farms in the Upper Midwest.