07/28/1993

Animal Scientist Explores New Cattle Feed Options

AUBURN, Ala. - Johnsongrass and broiler litter often are considered nuisances for agriculture; however, Auburn University researcher Darrell Rankins is helping find ways to turn these and other feedstuffs into valuable nourishment for cattle.

Since Rankins, assistant professor in Auburn's Department of Animal and Dairy Sciences, joined the Auburn faculty in 1989 his research has focused on identifying new forage options for Alabama livestock producers and also on brood cow supplementation. He came to Auburn after completing the Ph.D. in animal science at New Mexico State University, where he had previously received a M.S. in animal science. Rankins, a native of Georgetown, Ill., earned his B.S. in agricultural science from the University of Illinois.

Rankins' johnsongrass studies have demonstrated that materials often considered worthless and troublesome can actually be useful to beef producers.

"I was looking for a summer forage that might help us with cow-calf production during the late summer when it gets very hot and dry in this part of the Southeast," he explained. "Summer annuals are usually not cost effective during that time period and the typical bermudagrass and bahiagrass pastures are usually low quality during August."

"Johnsongrass is common in the area and it is a perennial," he continued, "but only limited work had been done on it as a forage, and there was no data at all on how it performed under continuous grazing or how cattle performed on the forage." There also were concerns about possible prussic acid or nitrate poisoning problems.

To learn more about these issues, Rankins established a grazing study in 1990 at E.V. Smith Research Center in Shorter, the main research facility of the Alabama Agricultural Experiment Station. Results showed that johnsongrass produced average daily gains similar to other summer forages, though total gain per acre was lower and the grazing season was shorter.

Rankins also expanded his work to look at ensiling johnsongrass. In addition, the ensiling study gave Rankins a chance to combine johnsongrass research with another area of interest, the use of broiler litter as a cattle feed.

Small batches of johnsongrass were ensiled with various amounts of broiler litter. These batches were compared to corn silage and evaluated for several factors, including nutrient content and palatability. While johnsongrass silage will not replace corn silage for growing animals, such as stocker calves, Rankins believes it could be a high quality feed option for brood cows.

Rankins' brood cow supplementation work includes studies of two feedstuffs -- molasses and broiler litter. Most of his broiler litter research has centered around on-farm deep-stacking to preserve nutrient quality and minimize animal health problems. He is taking a new look at a better quality molasses-based supplement that may be economical to feed.

"Currently, we are trying to increase late-summer cow/calf performance by using these supplements for cows on summer pastures," he explained. "Performance and economic data will be forthcoming and we will be extending this work into winter supplements for brood cows and replacement heifers."

In addition to his research responsibilities, Rankins teaches graduate and undergraduate courses in feeds and feeding, sheep production and nutritional toxicology.

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Auburn, AL 36849
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Contact Jamie Creamer, 334-844-2783 or jcreamer@auburn.edu
Contact Katie Jackson, 334-844-5886 or smithcl@auburn.edu

July 28, 1993