A recent study has found that traditional and conservation based grazing systems can produce differences in livestock production.
The study compared traditional livestock grazing systems with the conservation practice of pyric-herbivory, or fire and grazing.
The technique of fire and grazing involves lighting controlled fires for the purpose of tree and shrub management, to establish and manage pastures and manage grazing distribution, among others.
Fire and grazing can increase biodiversity, and effectively removes dead grass material, which makes the pastures more nutritious and appealing to livestock.
The study employed two separate sites in Oklahoma, United States, with one being a tallgrass prairie and the other a mixed-grass prairie respectively.
Traditionally managed grazing pastures at the tallgrass prairie site were burned in their entirety on a three year basis.
On the contrary, conservation managed grazing pastures at the tallgrass prairie were burned in patches on a seasonal basis, with a burn rotation being completed every three years.
Meanwhile at the mixed-grass prairie, traditionally managed grazing pastures were not subjected to the method of fire and grazing, while the conservation managed grazing pastures at this site were spring burned every four years.
For the first four years of the study the livestock, whom in this case were stocker cattle, carried out seasonal grazing, and individual weights were recorded at the beginning and end of each season. At the end of these four years, the livestock were removed from the mixed-grass prairie and replaced with cow-calf pairs from the tallgrass prairie.
The body condition of each cow was assessed on a monthly basis; meanwhile calves were weighed at both birth and weaning to determine average livestock weight gain.
The study found that for the first four years, livestock performance was the same at both sites regardless of whether traditional or conservation grazing methods were employed.
This pattern continued at the mixed-grass prairie for the following four years. Interestingly, at this stage differences began to appear at the tallgrass prairie.
The study identified that where conservation grazing methods were employed, calf weaning weights were very consistent.
Furthermore, at the mixed-grass prairie the livestock weighed approximately 22 kilograms or 48 pounds more than those who were subjected to traditional grazing methods.
The study found that the weight gain is directly attributed to the practice of fire and grazing, because as mentioned earlier, it provides livestock with more nutritious, vitamin rich pastures.
At the tall grass site the traditional and conservation grazing methods did not produce differences in livestock weight, behaviour or grazing practices.
To summarise, in some cases conservation-based grazing systems can promote livestock performance as cattle weight can increase and calf weight may be more uniform.
A summary of this study was provided by Wesley Hartmann, contributing author for SDSU Extension, a division of South Dakota State University. It can be found here.
Photo: a Creative Commons Attribution (2.0) image from James Nedresky photographer’s Flickr photo stream