Sustainable Livestock Management

Defining Sustainability
My definition for "sustainable" mostly refers to environmental sustainability, although economic and social sustainability are also important.  My aim is to develop a livestock management system that 1) protects and enhances soil quality (physical and biological), 2) protects water quality, 3) enhances on-farm biodiversity, 4) provides a humane and healthy environment for the livestock, and 5) minimizes greenhouse gas emissions.  Fortunately there are strong positive linkages between all these goals, so working toward any one of them usually helps with all the others.

Healthy Soils and Water
Keeping permanent pasture in place and managing it with intensive rotational grazing is one of the best forms of agriculture known to prevent soil erosion and build healthy soils. I move each group of animals every 24 hours in the summer to a fresh paddock where animals are concentrated using portable electric fencing - polywire for the cows and Premier's Electronet for the sheep.  Paddocks are grazed to 3-4 inches then allowed to "rest" for approximately 3 weeks before the next group grazes again when it is recovered to 8-10 inches in height.   By making sure I don't allow the animals to graze too low, the soil surface remains covered and is
kept moist and cool so microorganisms and macro fauna stay healthy and happy.  Also, by allowing the field to "rest", manure can breakdown and roots can grow deep into the soil again, improving nutrient cycling.  This practice also protects water quality - when erosion is avoided, siltation of waterways does not occur and by keeping nutrients cycling in the pasture, those nutrients do not runoff.

I utilize a wide range of plants in my pastures, including orchard grass, perennial rye, meadow brome, timothy, white clover, red clover, alsike, birdsfoot trefoil, alfalfa, and chicory.  Each of these plants has its own set of qualities - some fix nitrogen, some are deep rooted and therefore drought resistant, some do well in wet years, and all have their own nutrient profile, providing a balanced diet for the sheep and cows grazing them.  Having a range of plants makes the pastures more resilient to climate extremes so no matter what the weather is like each year, there is always something growing well, both for the livestock but also for the soil microorganisms that need living plants to provide carbon and nitrogen into the soil profile.

Biodiversity and Parasite Management
Using a variety of plants is only one of the ways I use biodiversity to improve the health and sustainability of the farm.  In fact, the reason I introduced cows to the system back in 2004 was to help me do a better job of managing internal parasites in my sheep flock.  "Worms" in sheep are a major problem for most shepherds because of the over-use of anthelmintics, or wormers, in modern agriculture.  Parasites have developed resistance to most of the drugs on the market.  Additionally, a healthy, sustainable livestock system should not have to rely on drugs to manage a common problem.  I use a range of practices to manage parasites:  I alternate cows and sheep on each paddock as they rotate through the farm because they do not share the same species of parasites and by alternating, the parasite load on the pastures is reduced to a level that the flock can handle.  I also select for sheep that have natural resistance to parasites.  My original flock was a mix of Finn, Dorset and East Friesian
breeds but I have been using pure Icelandic rams for many years now and am increasing the percentage of Icelandic genetics in the flock because they show a good tolerance of parasites, however I only save replacements from the ewes that show the best resistance.  Finally, I include plants in the pasture mix that contain condensed tannins (especially chicory and birdsfoot trefoil), which have been shown to reduce the rate of infection by parasites in the sheep.  Work is on-going to refine the set of practices that help manage internal parasites in sheep.

Humane Treatment
I follow a number of practices endorsed by "Animal Welfare Approved" - I lamb on pasture in early May, I do not dock tails on sheep or cows, and I provide shade and fresh water in every paddock.  At left, the flock lambing on the north hill in early May 2010.

Greenhouse Gas Emissions
Managing for climate change mitigation and adaptation is a priority on my farm.  My fossil fuel energy usage on the farm is low but not zero - I use diesel in my tractor and I do clip the pastures 2-3 times a year to manage unwanted weeds.  I also buy all my hay for winter which was made using tractors.  But, with the help of my graduate students in the Bard Center for Environmental Policy,  I am in the process of estimating my total greenhouse gas emissions from the farm.  This will include an estimate of soil carbon sequestration in trees (about 100 planted the fall of 2010) and soils, methane emissions from the animals and manure, and nitrous oxide emissions from manure.  Having the full inventory based on current management practices will provide me with information that could be used to fine-tune the system to reduce impacts.  Stay posted!