2006 Annual Report for LNC03-237
Nutrient Management Planning for Dairy Farms Practicing Management Intensive Rotational Grazing
Summary
Data needed to estimate dry matter intake and manure production on seven Wisconsin dairy farms was collected in the summers of 2003 through 2005. Three methods were used to estimate dry matter intake, clipping, a pasture plate, pasture height or energy balance. The energy balance method proved to be the most accurate Dry matter intake based on this method were 20.9, 20.5 and 20.0 lbs/cow/day for 2003, 2004 and 2005 respectively. Milk production averaged 51 lbs/cow/day. Feces production average of 86 lbs/cow/day. This is significantly less than values currently used for nutrient management planning for cows in confinement. However when urine is included the total manure production values were similar to those used for confined animals.
Producers using Management Intensive Rotational Grazing (MIRG) will increase their awareness of the need for Nutrient Management Planning (NMP) and will become more knowledgeable of what is required to develop accurate plans.
Other audiences (agencies and private consultants) involved in the process will be more knowledgeable about NMP issues for grazing farms and improve their ability to assist/support the NMP process.
Accuracy of estimates of manure production by grazing dairy cows will be improved to facilitate NMP by MIRG farms.
Nutrient management plans for the participating farms will be developed, implemented, and monitored to demonstrate to the NMP process to other MIRG farms.
Development and demonstration of a nutrient management planning framework which will enable grazing dairy farms in the north central region to meet current and future nutrient management standards.
Development/modification of supporting NMP software and related tools that provide farmers and their support network with a means for accurately planning and documenting nutrient flows throughout the farm in accordance with nutrient management standards.
MIRG farms in the North Central Region will develop and implement nutrient management plans that enhance their environmental stewardship and improve the natural resource base on which they depend.
Objectives/Performance Targets
Producers using Management Intensive Rotational Grazing (MIRG) will increase their awareness of the need for Nutrient Management Planning (NMP) and will become more knowledgeable of what is required to develop accurate plans.
Other audiences (agencies and private consultants) involved in the process will be more knowledgeable about NMP issues for grazing farms and improve their ability to assist/support the NMP process.
Accuracy of estimates of manure production by grazing dairy cows will be improved to facilitate NMP by MIRG farms.
Nutrient management plans for the participating farms will be developed, implemented, and monitored to demonstrate to the NMP process to other MIRG farms.
Development and demonstration of a nutrient management planning framework which will enable grazing dairy farms in the north central region to meet current and future nutrient management standards.
Development/modification of supporting NMP software and related tools that provide farmers and their support network with a means for accurately planning and documenting nutrient flows throughout the farm in accordance with nutrient management standards.
MIRG farms in the North Central Region will develop and implement nutrient management plans that enhance their environmental stewardship and improve the natural resource base on which they depend.
Accomplishments/Milestones
Data was collected form seven farms in 2003, 2004 and 2005. Data collected included pasture dry matter availability before a grazing event and after a grazing event. This data provided information on dry matter intake. Pasture quality was measured by taking grab samples at each sampling time. Milk production was also measured during the time that animals were in each sampled pasture. Data was collected three to five times each season on each farm. 68 for the three years of the study. Manure was sampled five times at each farm to provide average nutrient content. Supplemental feed levels and quality were also recorded. Information on total intake levels of P and N and total P and N excreted in milk allowed us to estimate manure production required to excrete the remaining P and N.
Three methods were used to estimate dry matter intake, clipping, a pasture plate, pasture height or energy balance. The energy balance method proved to be the most accurate. The other methods, while providing a similar overall average DMI were highly variable and reliable indicators of animal intake. Pasture dry matter intake averaged 20.5 lbs/cow/day using using the energy balance method.
Average crude protein level was 21%, average neutral detergent fiber level was 43%, and average relative forage quality was 201. Average milk production was 52 lbs/cow/day. Manure nitrogen content was 10.5 lbs/ton and P2O5 averaged 7.9 lbs/ton. Feces production was estimated to be85 lbs/cow/day using P2O5 excretion as an estimator. This value is well below the 124 lbs/cow/day currently used to estimate manure production of 1200-lb cows. When urine production is included the total manure production increases to 120 pounds which is similar to the manure production estimates currently used for nutrient management planning purposes.
Impacts and Contributions/Outcomes
Information generated from this project was incorporated into seven grazing schools held in Wisconsin in 2003, 2004 and 2005. Results were presented at the 2004 Upper Midwest Grazing Conference in LaCrosse, WI and the Central Wisconsin Grazing Network Annual Conference in Marathon, WI. As well as the Wisconsin Grazing Conference in 2006.
An article summarizing some of the results appeared in the Winter 2004 issue of Forage Focus, a publication of the Midwest Forage Association.
A meeting of all participants was held at Wisconsin Dells in March 2005. Results obtained thus far were presented and discussed.
Articles have been included in the Midwest Forage Association Forage Focus Magazine and the UW Extension Grazing Web site.
Results were presented at he International Grasslands Congress in Dublin, Ireland in 2005. The primary nutrient management planning software SNAP Plus has been updated to reflect the information generated form this study. Nutrient management plans fore each farm are under development and information will be shared statewide.
The project is providing participating producers information regarding dry matter intake of their cows on pasture. It also is providing pasture utilization percentages, milk production figures, and pasture quality values. These types of values have not previously been available and are being shared with others as representative of typical grazing dairy farms. At the conclusion of the project, this information will represent a unique and valuable database for grazers in the north central region.