title: Ultrasonographic fetal parameters and neonatal survival in somatic cell nuclear transfer-derived beef calves.
abstract: The objectives of this study were to identify prognostic indicators of calf survival in SCNT-derived beef calves. Ultrasonographic parameters of fetal well-being and development, maternal clinical parameters, and neonatal parameters were evaluated as predictors of calf survival in cows carrying SCNT-derived beef fetuses (n = 38). Calf survival was 61.5% (88.2% female and 40.9% male calves; P = 0.0026). Cow respiratory rate and cow temperature were significantly greater in the nonsurviving (NS) group 1 week prepartum. In surviving (S) calves, fetal heart rate (FHR) decreased during the last 2 weeks of gestation (P < 0.01). However, this final deceleration was not observed in NS calves, resulting in higher FHRs in this group (P < 0.0001). Fetal movement and fluid scores did not differ with calf classification. Mean amniotic fluid depth was smaller in S (5.5 ± 0.7 cm) than NS (8.7 ± 1.4 cm) calves (P = 0.0398). However, mean allantoic fluid depth did not differ (P = 0.6120). There was a significant association between the body weight of calf and the diameter of the fetal aorta (P = 0.0115; r(2) = 0.3762). Surviving calves were lighter at birth (P = 0.0028) and were born later (P = 0.007) than NS calves. Calves born vaginally had a smaller fetal aorta (2.1 ± 0.1 cm vaginal and 2.4 ± 0.1 cm Cesarean) (P = 0.0487) and a lighter birth weight (41.4 ± 4.2 kg vaginal and 60.4 ± 2.1 kg Cesarean) (P = 0.0001) than calves born by Cesarean. Also, calves that underwent spontaneous labor (52.2% S and 0% NS; P = 0.0029) had a lighter birth weight (44.9 ± 3.8 kg) than calves that did not initiate labor (61.6 ± 2.2 kg) (P = 0.0004). Frequent ultrasonographic fetal monitoring allowed identification of differences between S and NS calves. Calves without a final decrease in FHR or with a large aortic diameter were more likely to require a Cesarean because of failure to initiate labor or fetomaternal disproportion. Parameters of fetal well-being and development during the last 3 weeks of gestation were first described in SCNT-derived beef calves.
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas, USA. Electronic address: mferrer@fvet.uba.ar.
authors.forename: M S
authors.initials: MS
authors.lastname: Ferrer
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas, USA.
authors.forename: M
authors.initials: M
authors.lastname: Miesner
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas, USA.
authors.forename: D E
authors.initials: DE
authors.lastname: Anderson
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas, USA.
authors.forename: M
authors.initials: M
authors.lastname: Rousseau
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas, USA.
authors.forename: M C
authors.initials: MC
authors.lastname: Sardoy
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000893:Anti-Inflammatory Agents / Q000494:pharmacology; D001724:Birth Weight; D001831:Body Temperature / Q000187:drug effects; D002417:Cattle / Q000196:embryology* / Q000502:physiology*; D002585:Cesarean Section / Q000662:veterinary; D003907:Dexamethasone / Q000494:pharmacology; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D008297:Male; D053652:Nuclear Transfer Techniques / Q000662:veterinary*; D011247:Pregnancy; D012119:Respiration / Q000187:drug effects; D016216:Ultrasonography, Prenatal / Q000662:veterinary*
chemical_list: D000893:Anti-Inflammatory Agents; D003907:Dexamethasone
keywords: Bovine; Cloning; Fetus; Nuclear transfer; Ultrasound