|Title||Landscape use of Angus Crossbred vs. Raramuri Criollo cattle on desert rangeland|
|Publication Type||Conference Paper|
|Year of Publication||2021|
|Authors||Nyamuryekung'e S., Cibils AF, Estell RE, Gonzalez AL, McIntosh MM, Spiegal S.|
|Conference Name||Society for Range Management Meeting Abstracts|
|ARIS Log Number||383810|
We conducted a replicated study (in both space and time) to validate previous findings reporting differences in grazing patterns of Raramuri Criollo (RC, heritage breed) vs. Angus Hereford crossbred (AH, commercial breed) cows grazing Chihuahuan Desert rangeland. We monitored cows of both breeds that grazed desert pastures separately during summer and winter in three consecutive years. GPS positions were acquired from 5 to 11 randomly selected cows of each breed and were classified based on movement velocity. Presumed grazing locations were used to calculate Ivlev’s electivity index to determine preference (E>0) or avoidance (E<0) of pixels relative to thirteen pasture attributes including topography, vegetation, facilities, temperature, and moisture variables. Statistical mixed models were used to determine the effects of breed and season on selection of pixels. Separate analyses were conducted for each pasture attribute. Both breeds avoided areas far from water, but RC cows showed higher preference for pixels close to the drinker during the dormant season. RC cows appeared to exhibit a keener ability to select pixels with differing surface temperature, and greenness compared to AH counterparts. RC cows showed greater preference for pixels with high shrub density than AH counterparts in summer. During the dormant season, both breeds preferred sites with high shrub density. AH cows exhibited a strong preference for black grama pixels and higher avoidance of pixels with high density of other grasses. RC cows, did not select pixels with high black grama cover. Average electivity values for each pixel (grazing likelihood) revealed remarkable season differences between breeds. In summer, both breeds appeared to prefer similar portions of the pasture, whereas in winter, pixel preference (and hence spatial distribution) of breeds diverged significantly. Our study confirmed previously reported differences in landscape use patterns of RC vs. AH beef cattle.