Cattle often graze foothill rangelands in northern latitudes as a cost-effective alternative to being fed hay. In a 2-yr study, we determined whether exposure to winter wind elicits a stress response in pregnant cows (5–7 yr old) grazing a foothill rangeland. We measured several indicators of stress-response of cows which had (windbreak) or did not have (non-windbreak) access to windbreaks. In Winter 1 (1966–1997), backfat thickness increased on windbreak and non-wind-break cattle. Body condition scores of both groups were lower at the end of the trial. In Winter 2 (1997–1998), backfat thickness decreased for windbreak and non-windbreak cattle. Body condition scores did not change. Weight changes were minor both winters. Changes in backfat thickness indicated that cattle in Winter 1 were catabolizing more lean muscle tissue, whereas cattle in Winter 2 were catabolizing more fat. Cattle entered Winter 1 in lower body condition and mass than in Winter 2. Cattle with access to windbreaks tended to have a stronger cell-mediated immune response than non-windbreak cattle. Birth and weaning weights of calves, and calving interval were similar for windbreak and non-windbreak cattle. Neither winter elicited a strong stress response from cattle grazing this foothill rangeland, with or without access to windbreaks. Key words: Beef cattle, backfat, body condition, weight loss, immune response
Effect of Body Condition Score of the Dairy Cow on the in vitro Immune Response of Peripheral Blood Mononuclear Cells to Progesterone Stimulation