How to Avoid Costly Mistakes in Pasture Management

By Sarah Flack, Organic Consultant; Dr. Cindy Daley, California State University Chico; and
Kathy Soder, USDA’s Agricultural Research Station in Pennsylvania

Added September 10, 2012. Well-managed pasture-based grazing systems are key to economic sustainability in the organic dairy industry. However, while well-managed pasture is an asset to a dairy farm, poorly managed pasture can create serious problems, including reduced milk production and poor animal performance. Let’s step back from the day-to-day routine for just a moment and look at some of the areas that have been identified as the most common costly mistakes made by dairy graziers.

Badly Designed Grazing System and Infrastructure: Producers often “inherit” a grazing system that may be outdated, or designed for a different herd size and management system. Often this type of infrastructure does not meet the farm’s grazing management goals and needs to be updated. Mistakes often made in the design aspects include:

  • Lane construction & location preventing easy cattle flow
  • Poor proximity to water and water access
  • Fences which are overbuilt ($$) or under-built (no control)
  • Poorly grounded electric fence systems (no control)
  • Incorrectly sized paddocks
  • Too few acres of pasture, which can lead to overgrazing and low dry matter intake [DMI]
  • Too many acres, particularly during the times of rapid forage growth when pastures become over mature and less digestible
  • Dairy pastures on poor quality land instead of on high quality crop land.

Failure to develop an effective grazing design ends up costing time and labor, and leaves a lot of lost profit potential in the paddock. There are new technologies and grazing system resources to improve grazing systems including:

  • Mapping & satellite imagery using freeware such as Google Earth, which can provide the bird’s eye view of their farm as well as linear measurements for effective planning and design.
  • Cost effective electric fence technology, lane building techniques and portable water troughs
  • NRCS programs to assist with design, management and cost of improvements.

Poor Grazing Management Techniques: Poor grazing management can happen even in a well-designed system, so a good understanding of how pasture plants grow and how they respond to different types of grazing management is important. Poor grazing management will result in a whole list of pasture problems including:

  • Overgrazing damage to pastures
  • Increasing numbers of weeds
  • Soil erosion
  • Less productive pasture plants, uneven growth, low density pasture
  • Lower quality pasture
  • Internal parasite problems.

Continuous grazing or set stock grazing is the most common grazing system in the United States. Unfortunately, it most often results in overgrazing damage and an increase of less-desirable plant species. When cows graze without restriction, they eat the most palatable forage first, leaving the less desirable/less palatable plants behind to go to seed and proliferate.

Managed Intensive Grazing, or MIG, is a style of grazing where a paddock is grazed by a large group of animal and then rested for 21 -30 days before it is grazed again. Rest periods allow plants to recover before the next grazing cycle. Likewise, the roots are allowed to reestablish. A well-designed MIG system can significantly increase forage production and quality and improve weed management as cows are encouraged to eat a diversified diet because of competition with other cows and the limited amount of forage made available at a time.
Overgrazing Damage: Overgrazing damage happens by returning livestock to a pasture where the plants have not yet had time to fully regrow, OR by keeping livestock in a paddock for too long. Overgrazing can rob pastures of future production and when it is repeated, results in desirable forages dying, and being replaced by undesirable weeds.

Overgrazing most often results from a few common mistakes including:

  • Removing interior fences in the fall and letting cows “clean up” pastures
  • Having a “rotational” system of 6 or 7 paddocks, with each grazed for 1-2 days
  • Leaving animals in the same pasture for more than 3 days
  • Returning animals to the pasture before all of the plants have regrown
  • Not adding additional acres into the grazing rotation when plant growth rates slow
  • Having too many ‘leader-follower’ groups without leaving sufficient plant residue.

Pasture Nutrition Problems: The two most common nutritional pitfalls during the grazing season are feeding too much protein, and inadequate DMI due to poor pasture quality.

Overfeeding Protein: As soon as cows are grazing daily on cool season perennial pastures in the spring, the grain and other supplemental feed must be adjusted to ensure that protein is not being overfed, particularly the soluble fraction called rumen degradable protein. This type of protein is easily converted to ammonia within the rumen, which increases blood and milk urea nitrogen concentrations that can impair milk and reproductive performance.Adjusting the ration to achieve a balance in protein fractions between rumen degradable and undegraded (bypass) protein will improve DMI, grazing behavior and overall performance of cows. Testing pasture forage quality and monitoring milk urea nitrogen can go a long way toward improving animal performance. Other helpful indicators of balanced nutrition include monitoring body condition and the overall consistency of the manure.

Poor Pasture/Forage Quality: Another problem in many dairy production systems is the care and management of pasture forage quality. While producers seem to get their mind around the issue of tonnage (how much dry matter they are producing), many are less clear about average protein, energy or fiber levels in pasture.

Tracking forage quality is not difficult: benchmark where you are and monitor improvements over time. If the soil is deficient, the forages will be deficient. Testing soil goes hand in hand with testing forages. The investment in the analysis is insignificant compared to the information you get in return.

High quality forages that are designed to optimize herd performance will have some of the following characteristics.

  • Crude Protein 18 – 21%
  • Acid Detergent Fiber (ADF) 28-30%
  • Neutral Detergent Fiber (NDF) 40-45%
  • Neutral Detergent Fiber Digestibility (NDFd) 40-60%
  • Net Energy for lactation (NEL) 0.70 (Mcal/lb)
  • Calcium > 1-1.5%; K < 2.5%; Mg > 0.35%; P >0.35%; S>0.30% (N:S 10:1).

Chances are, if you are way off these marks, you need to address soil deficiencies, change your grazing/forage management program or add some improved forage species.

Maximizing Pasture DMI: In order to maximize DMI from pasture:

  • Plant density in the pasture needs to be high enough to allow cows to harvest enough pasture dry matter.
  • Pastures must be managed to the correct pasture plant height and stage of maturity
  • Pastures which are too short will limit the cow’s ability to consume enough DMI
  • Pastures which are too tall/over-mature can also limit a cow’s ability to get enough DM into her rumen due to physical space restrictions
  • Pastures must have a good selection and diversity of pasture plant species.

Poor Soil Fertility: A well-balanced soil will produce high quality pasture. This point is most often overlooked by dairy producers.

A basic soil analysis will cover soil pH, soil organic matter (SOM), and overall mineral composition. Maintaining the correct soil pH and building SOM will allow soils to be biologically active and teaming with good bugs. The higher the SOM in your soil, the more potent the forages.

Composted animal manure might also be an excellent investment because it adds fertility and benefits soil microbes. However, if manure is applied to the same pastures over many years, phosphorus or potassium can build up and cause issues.

Finally, good MIG grazing practices create nutrition from the growth and dieback of grass root systems. After each grazing period or hay harvest, some of the forage roots die, becoming food for the organisms in the soil. In addition, a well designed grazing system will allow for a more even distribution of manure and urine by grazing cattle. Amending soils for deficiency and implementing a sound rotational grazing system will build SOM, creating more fertility, and therefore more profitability over time.

Inadequate Recording Keeping: There are many organic dairy farms who are meeting the organic standards requirement for DMI and length of the grazing season, but who don’t yet have the records to show the certifier that they are meeting the rule. Ideally, the record keeping system should be as simple as possible while still able to be useful and able to provide information required by the organic standards. The organic standards are not the only reason to keep records, however. Grazing records can be very helpful in tracking pasture regrowth periods, number of acres used and needed, and tracking livestock productivity and pasture quality/quantity.

Sarah Flack is a consultant specializing in grass based livestock production systems & organic certification. She is the author of ‘Organic Dairy Production’, co-author of ‘The Organic Dairy Handbook – a comprehensive guide for the transition and beyond’, as well as many articles on farming and food.

Kathy Soder is a Research Animal Scientist with the USDA-ARS Pasture Systems & Watershed Management Research Unit, University Park, PA. Her research interests include the nutrition, behavior and management of pasture-based dairy and livestock systems.

Dr. Cindy Daley is a Professor within the College of Agriculture at California State University, Chico, where she manages an organic dairy program along with her team of 10 students. The applied research program focuses on the economic impact of amending soil on forage quality and the effect of grazing and pasture DMI on milk nutrients important to human health.

Editor’s Note: This topic will be covered more in-depth by the authors at the 2012 NODPA Field days.