by Dr. Don Ball

Auburn University scientists have conducted numerous steer grazing experiments involving various forage species. These studies have generally involved crossbred animals of similar breeding and weights, and were conducted over multiple years. Therefore, they provide a good basis for comparison of both the animal production potential and the production cost of various forage species commonly used in Alabama.

In the interest of providing a way to get a clearer view of the performance of stocker cattle on forages, performance criteria for stocker steers grazing the 37 different pasture treatments used in these Auburn University grazing studies were summarized from various research reports and articles. Subsequently, Auburn University 2008 budget estimates for the various forage species or species mixtures involved in these studies were used to determine both the approximate pasture costs per acre and the pasture costs per pound of gain. Notable points revealed include the following:

* The seven lowest total pasture costs per pound of gain and eight of the ten lowest total pasture costs per pound of gain involved legumes.

* Forage yield is an important economic factor, as evidenced by a study at the Wiregrass Station in which pasture costs per pound of gain for Coastal Bermudagrass were less than those of bahiagrass, and those for bahiagrass were less than those of common Bermuda-grass. The forage quality of these three is similar, so the primary difference in pasture cost per pound of gain was production per acre. Data from this test also indicate that application of nitrogen (N) is a more cost efficient practice (results in more dry matter production per pound of N applied) on some forages than on others.

* Coastal Bermudagrass overseeded with vetch was a lower-cost treatment than any of the other warm-season perennial grass treatments, which suggests overseeding a legume can be a cost effective practice.

* Use of a sorghum/sudangrass hybrid was a very expensive option. Both average daily gain and calendar days of grazing provided by this grass were low as compared to most other treatments.

* In general, the higher the percentage infection by toxic endophyte in tall fescue, the more costly the gains. For example, among treatments at a study at the Black Belt Station the total pasture cost per pound of gain was almost double ($1.12/lb vs $0.65/lb) in high versus low endophyte treatments.

* Adding legumes to either tall fescue or orchardgrass substantially lowered pasture cost per pound of gain. In fact, this management practice resulted in the lowest three pasture costs per pound of gain of the 37 forage alternatives evaluated.

* It appears both improved forage quality and reduction of the amount of fertilizer N used were factors in substantially lowering total pasture cost per pound of gain when forage legumes were included in pastures for stocker cattle. An important concept is stocker cattle producers who are able to increase animal performance via providing higher quality pasture and/or who are able to lower fertilizer inputs (with legumes or by other means) can achieve lower pasture costs per acre and lower costs per pound of gain.

* Of the 37 forage treatments, only five treatments had less than a $0.50 total cost per pound of gain. Careful assessment of performance and pasture cost per pound of gain are the crux of sound pasture decisions.

The data summarized pertains to stocker-steer tests. Nonetheless, it has some relevance to other types of livestock operations, as it should facilitate obtaining a better understanding of the relative level and duration of nutrition provided by these forage species and mixtures. The pasture cost values were calculated assuming the application of recommended management practices with commercially purchased inputs as reflected in 2008 Auburn University forage crop budgets. In addition, although pasture cost per pound of gain is an important measure of production efficiency, it is not the only factor affecting profit.

However, this exercise provides much insight regarding both the approximate levels of performance expected from various forage species or species combinations as well as the relative cost of using them in livestock production. The publication from which the information in this article was excerpted is available at www.alabamaforages.com.

Don Ball is an Extension Forage Crop Agronomist with Auburn University.