The University of Arizona

College of Agriculture and Life Sciences

V Bar V Range Program

Research Projects


Research is obviously a critical function of the V Bar V Range Program for several reasons: 1) Research is one of the 3 primary missions of a land grant university, 2) We are based out of a research ranch, and 3) There is so much to be learned about rangeland ecosystems, especially those in arid regions. As you will discover below, we have taken a broad approach to rangeland research here at the V Bar V. Our “laboratory” is generally defined as northern Arizona. How’s that for diversity? Keep reading and I’ll bet you find something you are interested in.

Alkanes in Arizona range grasses

N-alkanes are plant cuticular wax compounds used to determine forage intake and digestibility. The objectives of this study were to: 1) determine the content of 12 different n-alkanes (carbon chain length from 22 to 37) in 7 perennial range grasses, and 2) determine the effects of climate/...

Read more at: Tolleson, et al. 2012. Proceedings: Society for Range Management annual meetings, Spokane, WA.

Parasite Stress in Grazing Animals

Ticks are external parasites which pose a significant economic burden to domestic animal agriculture. The effects of ticks on grazing animals may be exacerbated during periods of low nutrition such as those encountered during drought. It is not completely understood how plane of nutrition...

Read more at: Tolleson, et al. 2012. Chapter 1. In: Ticks: Management, Disease Control and the Environment. Nova Science Publishers, Inc.

Kaibab Mule Deer Diet Quality

The Colorado Plateau is one of the most biodiverse ecoregions in the US. Within this landscape, the Kaibab Plateau on the north rim of Grand Canyon supports a mule deer (Odocoileus hemionus) herd with historical, ecological, and economic significance. Management of the Kaibab mule deer herd has...

Study in progress.

Range Cow Mineral Boluses

A long acting rumen trace mineral bolus containing Cu, Se, and Co has been developed in the United Kingdom and has shown promise for helping alleviate trace mineral deficiencies. One advantage of the long acting rumen boluses is the capability to provide a trace mineral supplement on rugged...

Read more at:
Sprinkle, et al. 2011. Proceedings of the Western Section American Society of Animal Science. 62:349-353.

Fecal Starch NIRS

Feedlot nutritionists routinely analyze diet samples for nutrient composition including DM, CP, NDF, ADF as well as estimates of starch availability. Samples are often analyzed at commercial laboratories using wet chemistry procedures. However, commercial analyses may be expensive and time...

Read more at:
Allen et al. 2010. Proceedings of the Western Section American Society of Animal Science. 61:96-99.

Range Cow Individual Mineral Intake

Mineral supplementation is an essential part of all beef production systems. It is not usually that difficult to provide a mineral supplement to range cattle in most management settings. It is also not usually difficult to determine herd or pasture level intake rate of mineral supplement. What is...

Read more at: Dal Molin et al. 2012. University Department of Animal Science. Producers Update and Research Highlights. pp 49-54.

Range Cow Early Pregnancy Determination

Pregnancy determination is an important tool for managing range cow reproductive and nutritional efficiency. Pregnancy determination is accurately determined via rectal palpation conducted by trained individuals, often at weaning. At such time, decisions can be made regarding culling of non-...

Read more at: Tolleson and Schafer. 2012. Journal of Animal Science 90:426 (Suppl. II).

Range Soil Carbon:Nitrogen

Southwestern rangelands may function as carbon sources or sinks depending on location and annual precipitation. These shrub dominated lands may have greater carbon sequestration potential than previously estimated but there is uncertainty in quantifying and accounting for carbon dynamics in such...

Read more at:
Tolleson and Kava. 2011. Proceedings: Society for Range Management annual meetings, Billings, MT.

Phygrow Validation

Rangeland managers deal with large extensive landscapes. Real-time information about landscape scale vegetation conditions can inform planning and decision making for grazing, fire, or restoration management. The Phytomass growth simulator model (Phygrow) has been applied alongside remote sensing...

Read more at:
Rhodes, et al. 2012. Proceedings: Southwest Fire Ecology Conference, Santa Fe, NM.

Range Cow Nutrition

Nutritional status of free-ranging animals is more difficult to monitor than it is for their pen-fed counterparts. Fecal analysis, be it the “old school” method of visual observation of color and consistency, or modern chemical assays of nitrogen content has been used by cowboy and biologist alike...

Read more at: Tolleson and Schafer. 2014. Journal of Animal Science
(see Papers in Press Dec 4 2013).