- Agronomic: barley, corn, oats, potatoes, sugarbeets, sunflower, grass (misc. perennial), hay
- Animal Products: dairy
- Animal Production: feed/forage, housing, animal protection and health, grazing - multispecies, pasture fertility, pasture renovation, grazing - rotational, stockpiled forages
- Crop Production: application rate management
- Education and Training: display, mentoring, networking, on-farm/ranch research
- Farm Business Management: new enterprise development, budgets/cost and returns, feasibility study, agricultural finance
- Production Systems: agroecosystems, integrated crop and livestock systems
- Soil Management: organic matter, soil quality/health
- Sustainable Communities: new business opportunities, sustainability measures
This study involved analysis of monthly data collected from ten diverse reduced input dairy operations and a prototype farm. Practices utilized on these dairy operations included management intensive grazing, outdoor winter housing of the dairy herd, group rearing of baby calves, cross breeding, and value added sales. Data pertaining to pasture production, feed supplementation, reproductive performance, mortality rates and involuntary culling rates was collected and analyzed. A large amount of variability was observed across the operations. The impact of this variability on the long-term economic sustainability of a prototype dairy was estimated with stochastic simulation modeling. Results showed that the long-term impacts of high rates of involuntary culling and mortality outweighed the long-term impacts of feed supplementation.
Many dairy operations located in the upper Midwest use grazing systems to meet a portion of their annual forage needs. Buttel et al. (2003) found that 23% of all Wisconsin dairy farms surveyed utilized some type of management intensive rotational grazing system. However, the survey didn’t specify whether this grazing system was used for lactating cows, non-lactating cows and/or heifers. The United Stated Department of Agriculture (USDA, 2002) found that 15.1% of United States’ dairy operations, representing 9% of the lactating cows in the U.S., used rotational grazing systems. Thirty three percent of dairy operations, representing 16% of lactating cows used other grazing systems.
An important goal of any grazing dairy is to be profitable. Many studies have examined the impact of feed supplementation level on profitability. Soder and Rotz, (2001) conducted a farm simulation study testing the effects of various levels of concentrate supplementation under different management constraints. They found the highest net return to management was achieved at the highest concentrate supplementation level the tested, a maximum of 9 kg dry matter (DM) per cow per day in early lactation. Tozer et al. (2004) used partial budgeting to compare income over feed costs of high yielding Holsteins fed 2 different pasture allowances and either supplemented with 1 kg of concentrate per 4 kg of milk produced or not. Regardless of pasture allowance, higher income over feed costs was realized for concentrate supplementation.
While level of feed supplementation may impact the level of profitability in a grazing herd, other herd characteristics, such as the rates of replacement mortality (stillbirth and replacement heifer deaths), adult mortality, involuntary culling, and incidents of clinical mastitis, also influence profitability. Survey studies found that the rates of herd health characteristics were quite variable across herds (Gardner et al., 1990; Kelton et al., 1998; Rougoor et al., 1999; USDA, 2002; Ingvartsen et al., 2003).
The long term effects of different levels of herd characteristics on production and profitability may be estimated through simulation modeling. SIMHERD III, a dairy herd simulation model developed by researchers in Denmark, is an analytical tool which can be used to investigate dairy cattle production management, production systems and production diseases (Østergaard et al., 2004). SIMHERD III uses a set of decision variables, to define a management strategy, and an initial herd, to simulate the application of a management strategy for up to 10 years. Generally 10 or more iterations, replicate simulations, of the same time period, with the same management strategy, can be conducted. Output summarizing the mean values for economic and production results for a particular management strategy or scenario are generated. Comparisons can then be made between the outputs of different scenarios to test for significant differences (Østergaard et al., 2004).
- Identify herd characteristics that may impact the long term sustainability of reduced input dairy operations located within the upper Midwest.
Estimate long term production and economic effects of 5 herd characteristics through simulation modeling.