Scholars

Walker, John

Agrilife Center Director

Positions:

Professor, Ecology and Conservation Biology, College of Agriculture and Life Sciences
Agrilife Center Director, San Angelo Research and Extension Center, Texas A&M AgriLIFE Extension, Texas A&M AgriLife Research

education and training

Ph.D. in Range Science, Texas A&M University - (College Station, Texas, United States) 1988

selected publications

Academic Articles67

Walker, J. W., Shoemake, B. M., Quadros, D. G., Thorne, J. W., & Cahill, N. C. (2023). Selecting goats for juniper consumption did not improve their liver Phase I detoxification.. Journal of Animal Science. 101, skad180.
Seidel, D. S., Walker, J. W., Musser, J. M., Whitney, T. R., & Callaway, T. R. (2022). Impact of camphor on the in vitro mixed ruminal microorganism fermentation from goats selected for consumption of low and high levels of Juniperus spp. 1.. Translational Animal Science. 6(3), txac097.
Seidel, D. S., Walker, J. W., Musser, J. M., Lourenco, J. M., Welch, C. B., Whitney, T. R., & Callaway, T. R. (2022). Impact of concentrations of camphor on the in vitro mixed ruminal microorganism fermentation from goats selected for consumption of low and high levels of Juniperus spp.-2.. Translational Animal Science. 6(3), txac098.
Wilcox, B. P., Fuhlendorf, S. D., Walker, J. W., Twidwell, D., Ben Wu, X., Goodman, L. E., Treadwell, M., & Birt, A. (2022). Saving imperiled grassland biomes by recoupling fire and grazing: a case study from the Great Plains. Frontiers in Ecology and the Environment. 20(3), 179-186.
Walker, J. W., & Kronberg, S. L. (2022). Nature, nurture, and vegetation management: Studies with sheep and goats.. Animal. 16(1), 100434-100434.
Leite, P., Wilcox, B. P., McInnes, K. J., & Walker, J. W. (2021). Applicability of soil moisture sensors for monitoring water dynamics in rock: A field test in weathered limestone. Vadose Zone Journal. 20(6),
Altangerel, N., Ashley, C., Hemmer, P. R., Kraemer, D., Scully, M. O., Walker, J. W., & Quadros, D. G. (2021). Raman spectroscopy of fresh feces is a practical tool for identifying animal species and estimating diet characteristics. Animal Feed Science and Technology. 281, 115081-115081.
Walker, J. W., Pope, R., & Pfeiffer, F. A. (2021). On-farm testing of FibreLux Micron Meter and OFDA2000 compared to Sirolan Laserscan in the laboratory. Small Ruminant Research. 200, 106401-106401.
Tolleson, D. R., Welsh, T. H., & Walker, J. W. (2020). Metabolic and endocrine indicators in male goats differing in genetic propensity to consume juniper.. Journal of Animal Science. 98(Supplement_2), 32-33.
Tolleson, D. R., Welsh, T. H., Garza, N., Hollingsworth, K., & Walker, J. W. (2020). Proportional tissue weights in male goats differing in genetic propensity to consume juniper.. Journal of Animal Science. 98(Supplement_2), 33-34.
Bailey, D. W., Mosley, J. C., Estell, R. E., Cibils, A. F., Horney, M., Hendrickson, J. R., ... Burritt, E. A. (2019). Synthesis Paper: Targeted Livestock Grazing: Prescription for Healthy Rangelands. Rangeland Ecology and Management. 72(6), 865-877.

SDG 15
Stewart, W. C., Whitney, T. R., Scholljegerdes, E. J., Waldron, D. F., Walker, J. W., Adams, R. P., & Musser, J. (2019). Ruminal fermentation characteristics of goats selectively bred to have greater consumption of juniper foliage. Animal Feed Science and Technology. 256, 114240-114240.
Toniecek, J. M., French, J. T., Walker, J. W., & Bromen, N. A. (2019). Factors influencing the movement of livestock guardian dogs in the Edwards Plateau of Texas: implications for efficacy, behavior, and territoriality. HUMAN-WILDLIFE INTERACTIONS. 13(1), 16-28.
Bromen, N. A., French, J. T., Walker, J. W., & Tomecek, J. M. (2019). Spatial relationships between livestock guardian dogs and mesocarnivores in central Texas. HUMAN-WILDLIFE INTERACTIONS. 13(1), 29-41.
Garnick, S., Barboza, P. S., & Walker, J. W. (2018). Assessment of Animal-Based Methods Used for Estimating and Monitoring Rangeland Herbivore Diet Composition. Rangeland Ecology and Management. 71(4), 449-457.
Walker, J. W., Stewart, W. C., Pope, R., Spear, S. L., Ebert, M., & Murphy, T. W. (2018). Evaluation of mean fiber diameter measurements by FibreLux micron meter and OFDA2000 in Texas and Intermountain west wool. Small Ruminant Research. 159, 31-37.
Altangerel, N., Walker, J. W., Gonzalez, P. M., Bailey, D. W., Estell, R. E., & Scully, M. O. (2017). Comparison of Near Infrared Reflectance Spectroscopy and Raman Spectroscopy for Predicting Botanical Composition of Cattle Diets. Rangeland Ecology and Management. 70(6), 781-786.
Stewart, W. C., Whitney, T. R., Scholljegerdes, E. J., Hallford, D. M., Walker, J. W., Adams, R. P., & Naumann, H. D. (2017). Effects of feeding ground redberry juniper (Juniperus pinchotii) to gestating ewes on pre- and postpartum performance, serum metabolites and hormones, milk fatty acid composition, and progeny preweaning performance.. Journal of Animal Science. 95(9), 4113-4123.
Stewart, W. C., Whitney, T. R., Scholljegerdes, E. J., Hallford, D. M., Walker, J. W., Adams, R. P., & Naumann, H. D. (2017). Effects of feeding ground redberry juniper (Juniperus pinchotii) to gestating ewes on pre- and postpartum performance, serum metabolites and hormones, milk fatty acid composition, and progeny preweaning performance. Journal of Animal Science. 95(9), 4113-4123.
Stewart, W. C., Whitney, T. R., Scholljegerdes, E. J., Naumann, H. D., Cherry, N. M., Muir, J. P., ... Estell, R. E. (2015). Effects of Juniperus species and stage of maturity on nutritional, in vitro digestibility, and plant secondary compound characteristics. Journal of Animal Science. 93(8), 4034-4047.
Stewart, W. C., Whitney, T. R., Scholljegerdes, E. J., Naumann, H. D., Cherry, N. M., Muir, J. P., ... Estell, R. E. (2015). Effects of Juniperus species and stage of maturity on nutritional, in vitro digestibility, and plant secondary compound characteristics.. Journal of Animal Science. 93(8), 4034-4047.
Walker, J. W., Waldron, D. F., Campbell, E. S., Taylor, C., Lupton, C. J., & Landau, S. (2013). Intermediate Periodicities in Juniper Consumption and Sampling Strategies to Estimate the Diet of Free-Grazing Goats. 66(2), 209-215.
Frost, R., Walker, J., Madsen, C., Holes, R., Lehfeldt, J., Cunningham, J., ... Sullivan, J. (2012). Targeted Grazing: Applying the Research to the Land. Rangelands. 34(1), 2-10.
Glasser, T. A., Landau, S. Y., Ungar, E. D., Perevolotsky, A., Dvash, L., Muklada, H., Kababya, D., & Walker, J. W. (2012). Foraging selectivity of three goat breeds in a Mediterranean shrubland. Small Ruminant Research. 102(1), 7-12.
Surber, L., Rude, M. E., Roeder, B. L., Mosley, T. K., Grove, A. V., Walker, J. W., & Kott, R. W. (2011). Percent Spotted Knapweed (Centaurea stoebe) in the Diets of Grazing Sheep. Invasive Plant Science and Management. 4(1), 95-101.

Chapters1

Muir, J. P., Butler, T. J., & Ocumpaugh, W. R. (2005). Pastoral systems in marginal environments, Proceedings of a satellite workshop of the XXth International Grassland Congress, July 2005, Glasgow, Scotland. Milne, J. A. (Eds.), Pastoral Systems in Marginal Environments: Proceedings of a Satellite Workshop of the XXth International Grassland Congress, July 2005, Glasgow, Scotland. 107-79. Wageningen Academic Publishers.