|Title||Movement and spatial proximity patterns of rangeland-raised Raramuri Criollo cow-calf pairs|
|Publication Type||Conference Paper|
|Year of Publication||2016|
|Authors||Nyamuryekung'e S., Cibils AF, Estell R.E., Gonzalez AL, Roacho-Estrada J.O., Rodriguez-Almedia F.A|
|Conference Name||Journal of Animal Science Supplement|
|Publisher||Journal of the Animal Science|
|ARIS Log Number||331679|
The objective of this study was to compare movement patterns of nursing vs. nonnursing mature cows and to characterize cow-calf proximity patterns in two herds of Raramuri Criollo cattle. Herds grazed rangeland pastures in southern New Mexico (4355 ha) and west-central Chihuahua, Mexico (633 ha)'' At each site, five nursing and four nonnursing adult cows weighing approximately 325 kg were fitted with Lotek 3300 LR GPS collars which recorded animal position at 10-min intervals for 25 d during March to April 2015. Nursing cows and their calves were also fitted with Sirtrack proximity loggers that recorded number and length of dam-calf contact events (<m distance). All calves were <2 wk old at the onset of the study. Collared animals grazed with a herd of 30 and 68 adult cows at the NM and Chihuahua sites, respectively. Distance traveled and path sinuosity of cows and time spent by calves within 3 m of their dam and number of dam-calf contact events during day and nighttime hours were calculated. Movement data were subjected to ANOVA to determine effect of cow state (nursing vs. nonnursing) on distance traveled and path sinuosity. ANOVA was also used to determine if calves spent similar amounts of time within 3 m of their dam during day vs. nighttime hours. PROC MIXED (SAS 9.3) with a randomized complete block design was used for statistical analyses. No differences were detected in distance traveled by nursing and nonnursing cows over a 24-h period (8.43 vs. 8.56 ± 0.29 km; P = 0.67), daytime (5.47 km vs. 5.75 ± 0.24 km; P = 0.24), or nighttime hours (2.96 vs. 2.80 ± 0.15 km; P = 0.32). However, nighttime/daytime ratio of distance traveled was greater for nursing cows (0.62 vs. 0.55 ± 0.08; P = 0.05). Nursing cows exhibited more sinuous 24 h travel trajectories compared with nonnursing counterparts (0.13 vs. 0.18 ± 0.05 km; P < 0.01). Calves spent on average 66.9 ± 3.41 min/d within 3 m of their dam, distributed over 86.4 ± 3.7 proximity events/d. Minutes spent by calves within 3 m of their dam were not different for day vs. nighttime periods (P = 0.07); however, more contact events occurred during daytime hours (predawn = 13.8; AM = 26.1; PM = 22.0; postsunset = 24.5 ± 2.02 contact events). Physiological state of Criollo cows affected their movement patterns in large rangeland pastures.