title: Body temperature around induced estrus in dairy cows.
abstract: The overall objective of this study was to study the influence of induced estrus on body temperature, comparing 5 distinct intervals around induced estrus and to determine the diurnal pattern from 4 ± 1 d before to 4 ± 1 d after induced estrus. Sixteen estrous cycles of 9 postpartum dairy cows were synchronized with 2 injections of PGF(2α), 10 d apart. After the second PGF(2α) injection on d 10, temperature loggers were inserted into the vaginal cavity for a 12 ± 1-d period. Two days later, a third dose of PGF(2α) was injected to induce estrus. After confirmation of a corpus luteum, loggers were removed on d 5 ± 1. Observation of estrus, rectal palpation, and ultrasound scanning to determine ovulation were carried out every 4 ± 1h, beginning at 12h after the third PGF(2α) injection. Blood samples from the vena coccygea mediana were collected twice daily from d 11 to 12 and every 4 ± 1h after the third PGF(2α) injection until ovulation. Vaginal temperature was recorded every 5 min and averaged to hourly means for the following 5 periods: 1) 48 h preceding the third PGF(2α) injection, 2) from the third PGF(2α) injection to first signs of estrus, 3) estrus to ovulation, 4) a 4-h interval in which ovulation occurred, and 5) a 96-h post-ovulation period. High body temperatures (39.0 ± 0.5 °C) and low progesterone (P4) concentrations (<0.5 ng/mL) were observed during estrus, whereas low body temperatures were observed from PGF(2α) injection to estrus (38.6 ± 0.3 °C) and around ovulation (38.5 ± 0.2 °C), respectively. An association between body temperature and serum P4 concentrations did not exist. However, P4 concentrations on d 11 and 12 were high (5.0 ± 1.5 ng/mL) and decreased (0.9 ± 0.2 ng/mL) after ovulation. Diurnal temperature rhythms were similar before and after estrus. Vaginal temperature before estrus (d 11 and 12) was slightly (0.1 °C) higher compared with the post-ovulation period.
authors.affiliation: Clinic of Animal Reproduction, Faculty of Veterinary Medicine, Freie Universität Berlin, Koenigsweg 65, 14163 Berlin, Germany.
authors.forename: V S
authors.initials: VS
authors.lastname: Suthar
authors.forename: O
authors.initials: O
authors.lastname: Burfeind
authors.forename: J S
authors.initials: JS
authors.lastname: Patel
authors.forename: A J
authors.initials: AJ
authors.lastname: Dhami
authors.forename: W
authors.initials: W
authors.lastname: Heuwieser
mesh_terms: D000818:Animals; D001831:Body Temperature; D002417:Cattle / Q000502:physiology*; D002940:Circadian Rhythm / Q000502:physiology; D015237:Dinoprost / Q000008:administration & dosage; D004973:Estrus Synchronization / Q000187:drug effects / Q000502:physiology*; D005260:Female; D011374:Progesterone / Q000097:blood; D013997:Time Factors; D014621:Vagina / Q000502:physiology*
chemical_list: D011374:Progesterone; D015237:Dinoprost