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Mob Grazing: Is It Right for My Farm? What We Learned from Dairies in the Northeast

Posted: June 28, 2013

Are you thinking about mob grazing? Take a look at this new study and comments from expert farmers.

Mob Grazing: What Is It?

Motivated by livestock farmers in dry or low soil quality environments, some farmers have been trying to improve soil quality through residue management. They allow pasture grasses to grow taller than the traditional 8-10 inches and allow animals to consume and trample the sward. In farm publications, growers report impacts such as increased weight gain, quicker finishing, less costs to feed animals, and improved soils. Unfortunately, there has been little research-based information to share with farmers and farm advisors regarding this practice.

Given the lack of research, there is some skepticism about its adaptation to dairy production. Dairy producers are looking for high quality feeds for lactating animals. In 2012 a study was initiated to analyze this practice on five dairy farms in the Northeast. Our conclusion is that some dairy graziers are allowing grass to grow taller and flower, but still are managing the pasture for quality standards. They are not allowing grass to brown.

The Take Home Points of the Study

-Experience Helps: If you are a beginning grazier, try to remain flexible when managing grass and animals. Do not lock yourself into thinking “it must be this way” as illustrated in a farm publication. Every farm will have an individual approach to grazing.

Forage Quality was Excellent

Does “tall grazing” give superior results for pastures? We did not find “superior” nutrition. Forage samples were taken in the same paddock at each rotation and sent to the Dairy One Forage Laboratory, Ithaca, New York. All forage sampled was excellent. With time, the forage quality actually improved.

Figure 1 shows that in 2012, farmers were able to maintain the % CP (crude protein), while the % NDF (neutral detergent fiber, a measurement of digestibility) and the NEL (net energy lactation, a measurement of energy) increased over the growing season. This may have been the result of growers having to rotate their animals sooner on paddocks toward the end of the summer due to a “mini-drought”.

Table 1. Grazing Comparisons, Dairies in the Northeast
High Density Stock Grazing Producer Applications in NE
250,000 lb/acre + stocking density 44,000-337,000 lb/acre
90 days forage rest 40-78 days of forage rest
Moving 2-3 times daily Moving 2 times, sometimes more per day

As a beginning grazier, learn more about forage quality. A good practice is to take pasture samples periodically to learn about the quality of forage on your farm. We sampled the same paddock through every rotation for one growing season. A “sample” was grab bag of 25 samples taken from the pasture. Care was taken to collect the sample, much like a cow eats grass with her tongue. The sample was put on ice, frozen and then mailed to the lab.

Trampling and Stocking Rate

Researchers evaluated the paddock before and following grazing by cows. They found that the forage consumed ranged from 50 to 70% of total forage available. Cows consumed the greatest percentage of the canopy cover in the top layers (averaging 75% consumption in the top 8” of growth), with lower layers (0-8”) having less total consumption (averaging 53%).

Most of the growers we worked with are aware that the “popular literature” says to leave a lot of residue to build the soil. Farmers told us they moved cattle more frequently if the forage quality was not ideal, leaving more grass as residue. Some of the comments about practices from dairy farmers in the study are as follows:

  • Tries to leave some forage standing - goal is 25%/50%/25% (standing, eaten, trampled).
  • “Take the leaf and leave half”- goal is to graze 60-70% and leave 30% behind.
  • Goal is to leave 50% behind, when actual is probably 25-50%.

On very small livestock farms, the availability of trampling is less. In our study, even some of the dairies periodically used high mowing to make sure plants continued to produce leaves to maintain quality forage, especially during droughty stress periods.

The study is being conducted in 2013 and a more complete report will be released at the end of the growing season, both in print and on the Northeast Pasture Consortium’s Website.

Acknowledgements

Mena Hautau, Extension Educator, CCA – Penn State Extension-Berks County, Dr. Kathy Soder, Melissa Rubano, Aimee Hafla – USDA Pasture-ARS-Pasture Systems and Watershed Management Research Unit, Brian Moyer, Program Assistant – Penn State Extension-Berks County
This study was funded by Northeast Sustainable Agriculture Research and Education Program – USDA, 2012, Partnership Grants Program.