Management Strategies for Co-Grazing Steers and Sheep in Atlantic Canada

Sivakami K Muthusami, Dr. Ralph Martin and Dr. Nancy MacLean

Pasture systems represent a good opportunity to improve the efficiency of beef and sheep production in Eastern Canada and mixed grazing is one of the management tools available for improving both pasture and animal production. Mixed or multispecies grazing refers to the use of more than one livestock species in grazing a common forage resource. The basic principle of mixed grazing systems is that interspecific competition (i.e. among animals of different species) is always lower than intraspecific competition (i.e. among animals of the same species), because the different livestock species will utilize different forage species. Whereas single species grazing will put increased pressure on a small portion of the forage resources, mixed grazing typically results in a better utilization of all forage resources. Mixed grazing can therefore lead to a higher output per unit area than single species grazing and can also increase the sustainability of pasture production. The economic benefits of mixed grazing will include increased net income, improved cash flow from an extended marketing period, and reduced risks in a more diversified farm enterprise.

To evaluate the overall efficiency of a mixed grazing system, researchers at the Organic Agriculture Centre of Canada and the Nova Scotia Agricultural College are conducting pasture trials with sheep and beef steers. The study will assess forage yields and livestock growth rates under both mixed and single species grazing systems. The researchers also hope to develop a computer model for predicting the productivity of steers and sheep under mixed and single species grazing systems. The model will estimate both economic (e.g. pasture system profitability) and ecological (e.g. greenhouse gas emissions) indicators of efficiency for the different grazing systems.

The first field trial was conducted during the summer of 2002 at the Brookside pasture of the Nova Scotia Agricultural College. The predominant forage species in the pasture were white clover, timothy, and bluegrass, and no pesticides or fertilizers were applied to the pastures. Groups of sheep and beef steers were grazed either alone or mixed together on the same pasture, and within each grazing treatment the animals were rotated once every 10 days. Forage yields and live animal weights were recorded regularly, and slaughter weights for all animals were also recorded.

The results from the 2002 trial indicate that average daily gains were better for sheep in the mixed grazing systems than in the single grazing system. The most likely explanation is that sheep are more competitive with themselves than with steers when stocking rates are equal. More research is currently underway (summer 2003) to evaluate the different grazing systems over a second pasture season. The results will be posted as they become available.

Researchers:
Sivakami K Muthusami (MSc student), Dr. Ralph Martin, and Dr. Nancy MacLean
Department of Plant and Animal Sciences, NSAC
Organic Agriculture Centre of Canada
P.O. Box 550
Truro, NS B2N 5E3
Web site: www.nsac.ca
Contact: Ralph Martin
E-mail rmartin@nsac.ca
Tel: 902-893-6679

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