Rumination and Activity Patterns in Angus and Angus-Cross Beef Calves: Influences of Sex, Breed, and Backgrounding Diet.

The objectives of this study were to evaluate the influences of sex, breed, and backgrounding diet on rumination and activity patterns in Angus and Angus-cross beef calves; and the daily variations in rumination and activity in Angus and Angus-cross beef calves under different backgrounding systems. A total of 62 freshly weaned calves were vaccinated and randomly stratified by sex (heifers and steers), breed (Angus and Angus × Simmental cross), and assigned randomly to 3 backgrounding treatments for 55 days. The peak values for rumination and activity in heifers, steers, Angus, and Angus × Simmental cross occurred during the dark and light phases of the dark/light cycle, respectively. Beef calves backgrounded on cover crops had higher (p < 0.05) rumination (45.33 ± 1.57 min) compared with calves backgrounded on a perennial pasture (43.96 ± 1.47 min) diet. Similarly, drylot calves (24.16 ± 0.68 min) had higher (p < 0.05) activity compared to perennial pasture (23.49 ± 0.72 min). The results showed that sex and breed did not influence rumination and activity of Angus and Angus-cross beef calves during the study period. We concluded that the time of the day and backgrounding diet influenced rumination and activity patterns of Angus and Angus-cross beef calves.