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 two ranches in New Mexico and one in Montana. DNA samples were obtained from cows that used the highest and steepest terrain (hill climbers) and cows that used gentle terrain near water (bottom dwellers). Currently, cattle are being tracked in Arizona, and tracking efforts are planned for a cooperating ranch in Wyoming and New Mexico during 2011. Analyses of DNA samples and cattle tracking data are ongoing. Three presentations from this study will be given at the Society for Range Management (SRM) annual meeting during February 2011.

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 three ranches: 1) Hartley Ranch near Roy, NM; 2) Corona Range and Livestock Research Center near Corona, NM; and 3) Thackeray Ranch near Havre, MT. At least ten 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 210 cows.

Blood samples have been obtained from over 60 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). By the end of the study, we hope to increase the number of these extreme animals that we have both DNA samples and a characterization of the grazing patterns from 60 to 200 (100 hill climbers and 100 bottom dwellers).

We have conducted analyses of visual location data and GPS collar tracking data to verify that visual observations collected during the early morning provide an accurate indicator of where cattle graze during their primary grazing bouts. Steven Lunt (graduate student at New Mexico State University funded by this project) will give an oral presentation summarizing these analyses at the Society for Range Management annual meeting in February 2011.

We tracked six bulls during a six-week breeding season as part of Objective 2 of this project. Bull tracking data was incomplete because the bulls damaged GPS tracking collars while fighting each other. Preliminary analyses of the available bull tracking data suggests that bulls travel farther than cows during the breeding season and that distance traveled by bulls varies during the breeding season. 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) will give an oral presentation summarizing the bull tracking data at the Society for Range Management annual meeting in February 2011.

Cattle at the Todd Ranch located near, Willcox, AZ are currently being tracked in a 23,000 acre pasture with mountainous terrain. The extensive and rugged nature of this cooperating ranch is expected to provide outstanding research data and outreach opportunities.

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. 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 inheritable before implementing a selection program. This study will determine the extent that genetics affect cattle grazing distribution. If grazing is inheritable, 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 about ten days, ranchers can identify hill climber cows that consistently use rugged terrain and travel long distances from water and that would be potential candidates for selection. Similarly, horseback observations can be accurately used to identify bottom dweller cows that use gentle terrain near water that would be candidates to be culled.

Tracking data from this study show that bulls differ in their movement patterns during the breeding season. These differences among individual bulls show that there is selection differential, which is needed to ensure genetic progress during selection.

Collaborators: