Blood chemistry, nutrient metabolism, and organ weights in fetal and newborn calves derived from in vitro-produced bovine embryos.
Calves born after in vitro production (IVP) of embryos often show reduced perinatal viability. The present experiment investigated a series of physiological variables in the immediate prenatal and postnatal period of IVP dairy calves. Fetal IVP and control calves (each n = 7) were prepared with vascular catheters at 248+/-1 day gestation (term = 280 days), and blood samples were taken for five days before premature delivery by cesarean section. IVP fetuses compared with controls had significantly elevated arterial hemoglobin and oxygen content (8.41 vs. 7.52% and 5.75 vs. 3.79%, respectively) whereas lactate level was lowered (1.89 vs. 2.26 mM). The umbilical venous-arterial concentration differences in oxygen, lactate, and glucose indicated that IVP fetuses relied more on lactate and less on glucose as oxidative substrates. The fetal glucose tolerance, and the basal and adrenocorticotropin-stimulated cortisol levels were similar between the groups. In the immediate postnatal period, IVP calves showed elevated venous blood pH (7.294 vs. 7.270), hemoglobin (9.06 vs. 8.25%), oxygen contents (6.33 vs. 4. 64%), K(+) levels (4.89 vs. 4.56 mM), and rectal temperature (38.9 vs. 37.4 degrees C), and lowered blood Na(+) (139.9 vs. 141.0 mM), Cl(-) (100.2 vs. 103.1 mM) and glucose levels (2.86 vs. 3.11 mM). There were no differences in body dimensions and organ weights, except that the fore legs and hind legs were slightly longer in the IVP group (76.1 vs. 72.4 cm and 93.4 vs. 88.8 cm, respectively). Although prenatal and neonatal IVP calves differed from control calves in a number of variables, the effects were relatively minor and provide no direct evidence for the hypothesis that IVP calves have an impaired capacity to adapt to life ex utero. In fact, several parameters indicated enhanced rather than retarded maturation of IVP calves when data from premature calves were compared with data from a group of control calves delivered at term.
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Department of Animal Science and Animal Health, Division of Nutrition, Royal Veterinary and Agricultural University, DK-1870 Frederiksberg C, Denmark.
Schmidt
M
M
Jacobsen
H
H
Fowden
A L
AL
Forhead
A
A
Avery
B
B
Greve
T
T
D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D000831:Animals, Newborn / Q000033:anatomy & histology / Q000378:metabolism*; D001158:Arteries; D001783:Blood Flow Velocity; D001786:Blood Glucose / Q000032:analysis; D001835:Body Weight; D002417:Cattle / Q000196:embryology*; D005260:Female; D005307:Fertilization in Vitro; D005333:Fetus / Q000033:anatomy & histology / Q000378:metabolism* / Q000601:surgery; D007751:Labor, Induced / Q000662:veterinary; D019344:Lactic Acid / Q000097:blood; D009929:Organ Size; D010100:Oxygen / Q000097:blood; D011247:Pregnancy; D014471:Umbilical Veins; D014680:Veins
D001786:Blood Glucose; D019344:Lactic Acid; D010100:Oxygen