Briefs Column

"Background, News, and Updates"

Getting more out of grass with rotation

Westlock, AB: A three-year rotational grazing demonstration on a reclaimed mine site west of Edmonton is demonstrating to Alberta livestock producers that better grass management can benefit both beef production and the environment.

The project on a 100-acre parcel of TransAlta Utilities’ Whitewood Mine property is comparing the productivity of season-long grazing with rotational grazing, says Curtis Snell, a water management specialist with the Prairie Farm Rehabilitation Administration (PFRA) in Westlock.

“More grass translates into improved beef gains per acre,” says Snell. “Higher quality forage means improved feed efficiency and reduced methane gas production per pound of feed eaten. Through improved pasture management these forage stands should remain productive longer, which increases the amount of carbon sequestered in the soil.”

Area producer Kim Bamber who leases the Whitewood site for grazing, has provided 30 cow/calf pairs for the demonstration project. One group of 15 pairs is grazing the season-long pasture, while the other group is being rotated through the paddocks.

The project will also demonstrate how old pastures can be rejuvenated with proper management, says Arnold Mattson, a rural development officer with PFRA in Edmonton. He helped design this managed grazing system.

“We hope to be able to double the carrying capacity of these pastures over the next three to five years,” says Mattson.

While the 28-year-old pasture has been fertilized to “kick-start” forage growth, Mattson says managed grazing, which leaves plant litter behind on the soil surface, will begin to improve soil quality.

“Litter on the soil surface will begin to build soil organic matter,” he explains. “Improved moisture conservation and water cycling will help activate the mineral cycle in the soil. Over the next few years we should see improvement in soil quality and health and ultimately, productivity.”

How digestible is feed fibre?

Guelph, ON: A two-year demonstration project, ultimately aimed at improving feed and production efficiency in beef cattle, is evaluating an innovative method for testing fibre digestibility.

Improved testing of forage quality will help improve production efficiency says Dr. Vern Osborne of the University of Guelph, who is leading the project. Improved feed efficiency also means reduced production in the rumen of methane gas, a greenhouse gas with 21 times the “global warming potential (GWP)” of carbon dioxide.

“The quality of forage fed to beef cattle varies significantly and can have a major impact on production efficiency,” says Osborne.

The new test involves chemical analysis of Neutral Detergent Fibre digestibility (NDFd) that will measure fibre fractions in plant cell walls. The test will help livestock producers more accurately balance feed rations and predict an animal’s dry matter intake and performance. It can also help to improve forage harvesting management.

While Neutral Detergent Fibre (NDF) can be measured now, the new method is more affordable and practical for producers. The new test gives a much more accurate reading of digestibility and, therefore, the dry matter intake possible by the animal.

Working with 12 feedlots and 12 cow/calf producers, the team, which includes students from the University of Guelph, will determine appropriate feed rations based on NDFd testing results. After analyzing rations fed to cattle by producer co-operators in the cow/calf and feedlot sector, the team will develop management strategies, ration balancing and greenhouse gas reduction estimates.

Once the forage quality has been determined, recommendations for re-balancing feed rations will be made over the fall and winter of 2004 to 2005. Greenhouse gas emission reductions will also be predicted at this stage of the project.

Cover crops compete

Forestburg, AB: A common practice of using a cover crop in the establishment year of a new forage stand may be counter productive, suggests a central Alberta applied research group looking into the issue.

Competition by the cereal cover crop appears to cause a setback for the forage plants, says Jenifer Heyden, a forage and livestock agronomist with the Battle River Research Group at Forestburg, northeast of Red Deer. Initial establishment of a healthy, vigorous forage crop is not only important for the long term productivity of the field, but it can also increase the amount of carbon sequestered in the soils under the crop.

“In our demonstration plots, forage plants that were established with a cover crop tended to be spindly and had few leaves,” says Heyden. The plots with cover crops showed lower forage plant counts compared to the plots with no cover crop.

However, plots with no cover crops were initially more susceptible to weeds, says Heyden. The financial impact of this has yet to be determined. Once the forage stand is more established, mowing and crop competition suppress weed production, and over time, weed seeds in the soil will become non-viable.

The project involved three demonstration sites – one in the County of Beaver and two in the County of Paintearth. Heyden says they used barley, oats, triticale and annual ryegrass as cover crops seeded with meadow brome, smooth brome, tap rooted alfalfa and creeping rooted alfalfa as forage crops.