- Animals: bovine
- Animal Production: free-range, grazing management, livestock breeding, preventive practices
- Education and Training: extension, farmer to farmer, networking, on-farm/ranch research, participatory research
- Sustainable Communities: new business opportunities
The goal of this project was to validate previously-identified genetic markers shown to be associated with cattle use of rugged terrain and areas far from water. We hoped to verify and enhance prototype DNA test(s) that could be used to identify cows and bulls with superior and inferior grazing distribution genotypes. Potentially, these tests can be used to identify bulls that will sire daughters that use more rugged topography and travel farther water.
Cattle tracking data and DNA samples were collected at eight ranches in New Mexico, Colorado, Nevada, Arizona and Wyoming and combined with data collected from our previous Western SARE study (SW09-54) for a total of 330 cows. BovineSNP50 genotyping data were used to explain tracking data using the BOLT software package with BayesC methodology. Quantitative trait loci detection was based upon posterior inclusion probability (PIP) and the percentage of total genetic variance explained by individual genomic windows. Analyses revealed 32 quantitative trait loci (QTL) that were previously associated with health and production traits in dairy and beef cattle as well as 29 putative candidate genes that function in oxygen homeostasis, environmental adaptation, and feed efficiency and growth. The QTL detected in this study support the polygenic nature of complex traits regulating beef cow terrain-use. Detection of genotype to phenotype associations in the current study was likely limited by the moderate sample size and lack of uniformity in the data. Therefore, a large independent population of beef cows, composed of one breed, grazing on the same pastures is needed to refine terrain-use measurements and further elucidate the role of genetics in terrain use in beef cattle.
Starting in December 2018, results and conclusions from this study as well as other grazing management tools were presented to over 620 ranchers and land managers at a total of 13 meetings located in New Mexico, Arizona, Nevada and California. A scientific symposium focusing on this project was presented the Society for Range Management 2019 Annual Meeting in Minneapolis, MN that was attended by over 60 scientists and land managers.
Project objectives:div style="margin-left:1em;">
A. Validate previously identified genetic markers discovered from previous Western SARE funded research project (SW09-054) shown to be associated with cattle grazing distribution.
A1. Track at least 200 cows with GPS collars for at least 2 months at 7 or more mountainous ranches in New Mexico, Arizona, Colorado, and Nevada.
A2. Collect DNA samples from tracked cows.
A3. Analyze DNA from tracked cows using High Density single nucleotide polymorphism (SNP) chip (BovineSNPHD; ~770,000 genotypes) and determine if previously identified genetic markers are similarly associated with grazing distribution traits as found in the previous Western SARE study SW09-054.
B.Verify and enhance prototype DNA test(s) for identifying superior and inferior genotypes for grazing distribution.
B1. Analyze genetic markers used in a small prototype (180 SNP) panel with cows tracked in this project and compare associations to previously studied cattle herds.
B2. Add or replace genetic markers in the prototype SNP panel so that the most predictive SNP are used in final DNA test.
C. Develop procedures and end user tools for estimating molecular breeding values (MBV) for grazing distribution.
C1. Develop statistical procedures for estimating MBV for grazing distribution from cattle DNA samples.
C2. Automate download of genotypes from DNA service providing company into CSU Center for Genetic Evaluation of Livestock (CGEL) software for estimating MBV.
C3. Develop web-based software so producers can easily obtain the MBV for grazing distribution for each animal.
D. Provide training to ranchers and seedstock producers specifically designed to increase their knowledge and ability to utilize MBV to select cattle for improved grazing distribution.
D1. Show ranchers how to collect DNA samples from cattle and how to submit the samples for analysis.
D2. Teach ranchers how to obtain MBV from web-based systems for their cattle and utilize this information to select for improved grazing distribution.
D3. Show how ranchers can incorporate grazing distribution goals and objectives into their ranch-specific breeding program.
E. Estimate the potential for improvement of grazing distribution through MBV and genetic selection.
E1. Estimate the potential for improvement in grazing distribution through genetic selection under varying scenarios.
E2. Deliver this information to ranchers and land managers via multiple kinds of extension programs so they will know the potential for improving on-the-ground grazing use.