Effect of lying behavior on uterine blood flow in cows during the third trimester of gestation.
Seven Holstein cows (BW = 639.4 +/- 28.8 kg, age = 62.6 +/- 6.9 mo, parity = 3.1 +/- 0.4 yr) (mean +/- SE) were used to measure uterine blood flow using a transit time ultrasonic flow meter. Ultrasonic flow probes were implanted (d 218 +/- 4 of gestation) around both uterine arteries (n = 3) or the gravid uterine artery (n = 4) to measure variations in uterine blood flow through this vessel in response to postural change (standing and lying). Implantation of the ultrasonic blood flow probe was successful in all 7 cows. Uterine blood flow was measured for 22.9, 23.1, and 21.4 h/d on d 226, 248, and 269 of gestation, respectively. Cows exhibited normal durations of gestation (272.8 +/- 1.6 d), gave birth to normal healthy calves (birth weight = 41.5 +/- 3.0 kg), and did not retain their placenta. Uterine blood flow to the gravid horn during lying was greater than during standing on d 226 (standing vs. lying, 8.04 vs. 8.79 L/min, respectively), d 248 (9.87 vs. 11.06 L/min), and d 269 (8.15 vs. 9.74 L/min) of gestation. Cows spent nearly 50% of their time lying during our observations at all gestational ages. Greater blood supply to the gravid uterus was observed during lying than during standing in this study.
Nishida
T
T
Department of Animal Feeding and Management, National Institute of Livestock and Grassland Science, Nishinasuno, Tochigi 329-2793 Japan. nishtake@affrc.go.jp
Hosoda
K
K
Matsuyama
H
H
Ishida
M
M
D000818:Animals; D001522:Behavior, Animal; D001783:Blood Flow Velocity; D002417:Cattle / Q000502:physiology*; D005260:Female; D005865:Gestational Age; D011187:Posture; D011247:Pregnancy; D014599:Uterus / Q000098:blood supply*