| Autor: |
de Paula C; Department of Animal Science, Universidade Federal de Viçosa, Peter Henry Rolfs Avenue, Viçosa 36570-900, Brazil., Rennó LN; Department of Animal Science, Universidade Federal de Viçosa, Peter Henry Rolfs Avenue, Viçosa 36570-900, Brazil., Ferreira MFL; Eastern Oregon Agricultural Research Center, Department of Animal and Rangeland Sciences, Oregon State University, Burns, OR 97720, USA., Moreira SS; Department of Animal Science, Universidade Federal de Viçosa, Peter Henry Rolfs Avenue, Viçosa 36570-900, Brazil., Martins HC; Department of Animal Science, Universidade Federal de Viçosa, Peter Henry Rolfs Avenue, Viçosa 36570-900, Brazil., Rodrigues II; Department of Animal Science, Universidade Federal de Viçosa, Peter Henry Rolfs Avenue, Viçosa 36570-900, Brazil., Detmann E; Department of Animal Science, Universidade Federal de Viçosa, Peter Henry Rolfs Avenue, Viçosa 36570-900, Brazil., Valadares Filho SC; Department of Animal Science, Universidade Federal de Viçosa, Peter Henry Rolfs Avenue, Viçosa 36570-900, Brazil., Paulino MF; Department of Animal Science, Universidade Federal de Viçosa, Peter Henry Rolfs Avenue, Viçosa 36570-900, Brazil. |
| Abstrakt: |
Most studies investigate the impact of stress at weaning on calves; however, little is known about the responses of cows, and whether they would differ according to parity. This study aims to investigate whether parity would influence the weaning stress response in beef cows. Thirty pregnant Nellore cows with their respective calves were randomly allocated to five paddocks and two females from each parity group were placed in the paddocks. There was an interaction ( p < 0.05) between parity and evaluation days regarding cortisol, where on d + 7, the higher concentration was observed for multiparous cows. There was an interaction ( p < 0.05) between parity and evaluation day for red blood cells (RBC), hematocrit (HCT), and hemoglobin (HB), whereby higher RBC counts on d + 4 were observed for multiparous cows. For HCT and HB, on all post-weaning collection days, higher values were observed for multiparous cows. The day of evaluation had an ( p < 0.05) effect on all recorded behaviors, except for rumination ( p > 0.05). Nellore cows, regardless of parity, underwent behavioral and physiological changes on abrupt weaning. Physiological parameters indicated that the magnitude of stress was greater in multiparous cows. |
