title: Sympathoadrenal balance and physiological stress response in cattle at spontaneous and PGF2α-induced calving.
abstract: Increased cortisol release in parturient cows may either represent a stress response or is part of the endocrine changes that initiate calving. Acute stress elicits an increase in heart rate and decrease in heart rate variability (HRV). Therefore, we analyzed cortisol concentration, heart rate and HRV variables standard deviation of beat-to-beat interval (SDRR) and root mean square of successive beat-to-beat intervals (RMSSD) in dairy cows allowed to calve spontaneously (SPON, n = 6) or with PGF2α-induced preterm parturition (PG, n = 6). We hypothesized that calving is a stressor, but induced parturition is less stressful than term calving. Saliva collection for cortisol analysis and electrocardiogram recordings for heart rate and HRV analysis were performed from 32 hours before to 18.3 ± 0.7 hours after delivery. Cortisol concentration increased in SPON and PG cows, peaked 15 minutes after delivery (P < 0.001) but was higher in SPON versus PG cows (P < 0.001) during and within 2 hours after calving. Heart rate peaked during the expulsive phase of labor and was higher in SPON than in PG cows (time × group P < 0.01). The standard deviation of beat-to-beat interval and RMSSD peaked at the end of the expulsive phase of labor (P < 0.001), indicating high vagal activity. Standard deviation of beat-to-beat interval (P < 0.01) and RMSSD (P < 0.05) were higher in SPON versus PG cows. Based on physiological stress parameters, calving is perceived as stressful but expulsion of the calf is associated with a transiently increased vagal tone which may enhance uterine contractility.
authors.affiliation: Centre for Artificial Insemination and Embryo Transfer, Department for Small Animals and Horses, Vetmeduni, Vienna, Austria. Electronic address: christina.nagel@vetmeduni.ac.at.
authors.forename: Christina
authors.initials: C
authors.lastname: Nagel
authors.affiliation: Centre for Artificial Insemination and Embryo Transfer, Department for Small Animals and Horses, Vetmeduni, Vienna, Austria.
authors.forename: Lisa
authors.initials: L
authors.lastname: Trenk
authors.affiliation: Centre for Artificial Insemination and Embryo Transfer, Department for Small Animals and Horses, Vetmeduni, Vienna, Austria.
authors.forename: Christine
authors.initials: C
authors.lastname: Aurich
authors.affiliation: Centre for Artificial Insemination and Embryo Transfer, Department for Small Animals and Horses, Vetmeduni, Vienna, Austria.
authors.forename: Natascha
authors.initials: N
authors.lastname: Ille
authors.affiliation: Clinical Unit for Heard Health Management in Ruminants, Department for Farm Animals and Veterinary Public Health, Vienna, Austria.
authors.forename: Martina
authors.initials: M
authors.lastname: Pichler
authors.affiliation: Clinical Unit for Heard Health Management in Ruminants, Department for Farm Animals and Veterinary Public Health, Vienna, Austria.
authors.forename: Marc
authors.initials: M
authors.lastname: Drillich
authors.affiliation: Kremesberg Research and Teaching Farm, Vetmeduni, Vienna, Austria.
authors.forename: Werner
authors.initials: W
authors.lastname: Pohl
authors.affiliation: Division for Obstetrics, Gynecology and Andrology, Department for Small Animals and Horses, Vetmeduni, Vienna, Austria.
authors.forename: Jörg
authors.initials: J
authors.lastname: Aurich
mesh_terms: D000311:Adrenal Glands / Q000502:physiology*; D000818:Animals; D001724:Birth Weight; D002417:Cattle / Q000502:physiology*; D003612:Dairying; D015237:Dinoprost / Q000494:pharmacology*; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006706:Homeostasis / Q000502:physiology; D006854:Hydrocortisone / Q000032:analysis / Q000378:metabolism; D007751:Labor, Induced / Q000379:methods / Q000662:veterinary; D036801:Parturition / Q000187:drug effects / Q000378:metabolism; D011247:Pregnancy; D047928:Premature Birth / Q000378:metabolism / Q000503:physiopathology; D012463:Saliva / Q000737:chemistry / Q000378:metabolism; D013312:Stress, Physiological / Q000502:physiology*; D013564:Sympathetic Nervous System / Q000502:physiology*
chemical_list: D015237:Dinoprost; D006854:Hydrocortisone
keywords: Arrhythmia; Cattle; Cortisol; Heart rate; Heart rate variability; Parturition