Enhancement of Sustainable Livestock Grazing through Selection and Training

Enhancement of Sustainable Livestock Grazing through Selection and Training

Summary

Cattle distribution patterns have been recorded by horseback riders and GPS collars at three ranches in New Mexico, two ranches in Arizona and one ranch in Montana. DNA samples were obtained from all collared cows and other cows observed to use high and steep terrain (hill climbers) or gentle terrain near water (bottom dwellers). We plan to track cattle from one or two more ranches in New Mexico during 2012. Analyses of DNA samples using High Density Single Nucleotide Polymorphism (SNP) technology are ongoing. Two presentations from this study were given at the 2012 Society for Range Management (SRM) annual meeting.

Objectives/Performance Targets

1) Evaluate the extent that genetics influence cattle distribution.

1a) Determine if cattle that use rugged terrain far from water are familialy related.

1b) Determine if cattle that use gentle terrain near water are familialy related.

2) Determine if the propensity for cows to use rugged terrain can be identified from the behavior of the bull that sired it.

3) Use identification and selection of adapted cattle at cooperating ranches as a forum and demonstration to train ranchers to develop and implement site-specific grazing management practices.

Accomplishments/Milestones

We have completed cattle tracking activities at six ranches:

1) Hartley Ranch near Roy, NM,
2) Corona Range and Livestock Research Center near Corona, NM,
3) Chihuahuan Desert Rangeland Research Center near Las Cruces, NM,
4) Todd Ranch near Willcox, AZ,
5) Carter Brangus Ranch, near Thatcher, AZ, and
6) Thackeray Ranch near Havre, MT.

At least 10 days of cattle location recording was completed at each of the ranches, which allowed us to characterize the grazing distribution patterns of the cattle in each herd. To date, we have characterized the grazing patterns of over 300 cows.

Blood samples have been obtained from over 110 cows that can be considered as extremes in grazing distribution. To evaluate if familial relationships affect grazing distribution, we must identify cows that are extreme hill climbers (use the highest terrain, steepest slopes and farthest areas from water) and bottom dwellers (use lowest terrain, most gentle slopes and areas close to water).

We have conducted analyses of GPS collar tracking data collected in 23,000 acre pasture at the Todd Ranch near Willcox, AZ to verify that there are large differences among cows in their use of extensive and rugged pastures. Clear differences in grazing patterns were observed during the three month tracking period. Steven Lunt (graduate student at New Mexico State University funded by this project) gave an oral presentation summarizing these analyses at the Society for Range Management annual meeting in January 2012.

In 2011, we tracked two sets of bulls during breeding season as part of Objective 2 of this project. We resolved most of the problems associated with tracking bulls that occurred in 2010. Preliminary analyses of the available bull tracking data suggests that younger bulls travel farther than older bulls during the breeding season, and that distance traveled by bulls is strongly affected by cow estrous activity. To our knowledge, this is the best available tracking data obtained for beef bulls during the breeding season. Adrienne Lipka (graduate student at New Mexico State University funded by this project) gave an oral presentation summarizing the bull tracking data at the Society for Range Management annual meeting in January 2012.

Preliminary results from this research were also presented at the Southwestern Brangus Breeders Association Field Day on June 25, 2011 in Gallup, NM. Over 40 producers attended the Field Day. On September 29, 2011, Bailey (project PI) presented the preliminary results from this project at the Spatially Enabled Livestock Management Symposium in Surfers Paradise, Queensland, Australia. Bailey was the keynote speaker at the symposium, and his travel was funded by Meat and Livestock Australia.

Impacts and Contributions/Outcomes

Grazing distribution is a critical factor in rangeland management. Many of the issues associated with cattle grazing on both public and private lands are associated with undesirable grazing distribution patterns. This project and an earlier Western SARE project show that individual cattle can have very different grazing patterns. If cattle with undesirable grazing patterns are culled and cattle with desirable grazing patterns are selected, most livestock grazing concerns can be alleviated and producers can potentially increase stocking levels while maintaining rangeland health. However, it is critical to know if a trait is heritable before implementing a selection program. This study will determine the extent that genetics affect cattle grazing distribution. If grazing is heritable, selection of cattle with desirable grazing patterns can improve grazing patterns and likely resolve most grazing issues without capital intensive improvements, such as water developments and fencing.

Results from this project have shown that visual observation of cattle locations by horseback observers can be an accurate method for determining where individual cattle graze. However, observers must be trained to readily recognize features of the pasture from a map. By riding and observing animals in their pasture during the early morning for 10 to 20 days, ranchers can identify hill climber and bottom dweller cows in pastures that contain rugged terrain.

Outreach efforts from this project will train ranchers and land managers how to manage livestock grazing distribution. Research results will provide a forum upon which approaches to modify cattle grazing patterns other than selection will be presented. This outreach effort will give ranchers and land managers in New Mexico, Arizona and other western states the tools needed to prevent localized overgrazing and sustainably increase grazing capacity of extensive and/or rugged rangeland pastures.

Collaborators: