Abstract #T55
Section: Animal Health
Session: Animal Health: Lactating cows
Format: Poster
Day/Time: Tuesday 7:30 AM–9:30 AM
Location: Gatlin Ballroom
Session: Animal Health: Lactating cows
Format: Poster
Day/Time: Tuesday 7:30 AM–9:30 AM
Location: Gatlin Ballroom
# T55
Correlation of ACTH test results with hormonal, metabolic and cardiac stress responses during stress challenge in dairy cows.
Lea Fieguth1, Lena Locher1, Anja Schacht1, Akos Kenez2, Asako Kinoshita1, Ulrich Meyer3, Sven Dänicke3, Juergen Rehage*1, 1Clinic for Cattle, University of Veterinary Medicine Hannover, Hannover, Germany, 2Department of Physiology, University of Veterinary Medicine Hannover, Hannover, Germany, 3Department of Animal Nutrition, Friedrich-Loeffler-Institute, Braunschweig, Hannover.
Key Words: ACTH test, stress reactivity, dairy cow
Correlation of ACTH test results with hormonal, metabolic and cardiac stress responses during stress challenge in dairy cows.
Lea Fieguth1, Lena Locher1, Anja Schacht1, Akos Kenez2, Asako Kinoshita1, Ulrich Meyer3, Sven Dänicke3, Juergen Rehage*1, 1Clinic for Cattle, University of Veterinary Medicine Hannover, Hannover, Germany, 2Department of Physiology, University of Veterinary Medicine Hannover, Hannover, Germany, 3Department of Animal Nutrition, Friedrich-Loeffler-Institute, Braunschweig, Hannover.
Cows react to stressors with release of cortisol and catecholamines after activation of the hypothalamic-pituitary-adrenal axis (HPA) and of the hypothalamic-adrenal medullary axis, respectively. Increases in heart rate, hyperglycemia, and hyperlipidemia are typical metabolic responses. The extent of the individual stress response depends on individual experience and stress responsiveness. ACTH-test results are assumed to reflect the individual HPA reactivity. The aim of the study was to compare results of the ACTH test with hormonal, metabolic and cardiac stress responses of cows on claw trimming as a typical acute non-painful stressor. In 18 pluriparous German HF cows claw trimming (CT) was performed in lateral recumbency 40 d postpartum (pp). Blood level of cortisol, glucose, and nonesterified fatty acids (NEFA) and heart rate (HR) and heart rate variability (HRV; standard deviation of R-R intervals: SDNN, root mean square of successive differences: RMSSD) were measured at T1: 30 min before CT in the herd, T2: standing at the surgical table, T3: end of claw trimming, T4: 30 min after CT in the herd. ACTH tests were performed on d 110 pp (80 µg/cow ACTH; repeated blood samples for cortisol measurement over 120 min) from which the area under the cortisol time curve (AUC) were assessed. AUC was correlated (SPEARMAN, SAS package) with cortisol, glucose and NEFA blood concentrations as well as HR and HRV at T1-T4and with differences between time points during the CT procedure. AUC correlated positively with T3 cortisol (r: 0.76, P = 0.002) and DiffT4-T1 cortisol (r: 0.75, P = 0.002), and negatively with T4 NEFA (r: −0.64, P = 0.014), T4 HR (r: −0.64, P = 0.014), T4 SDNN (r: −0.59, P = 0.027), DiffT4-T3 glucose (r: −0.56, P = 0.037), DiffT4-T1 NEFA (r:-.73, P = 0.003), DiffT4-T1 HR (r:-.71, P = 0.005), DiffT4-T1 SDNN (r: −0.65, P = 0.012). High ACTH test reactivity was associated with high cortisol level during but a quick decrease to baseline values in blood NEFA and glucose concentrations and in HR, and HRV after CT, which may indicate a close association between individual stress responsiveness and metabolic and cardiac adaptability to stress challenges in cows.
Key Words: ACTH test, stress reactivity, dairy cow
