Growth rates and patterns of organs and tissues in the bovine fetus.
Ninety-two purebred Jersey fetuses from clinically normal dams derived from a variety of sources but unexposed to experimental infection, were killed between 80 and 260 days after conception and dissected to provide basic parameters of a normal population. Organs and tissues were weighed and measured and the equations for the regression of the values on fetal age evaluated. Growth followed a sigmoid curve with rapid changes in growth rate between 140 and 170 days' gestation. While a few variables increased their growth rate over the late fetal period, the majority maintained a low even rate of growth. Thyroid and cerebellum weights showed a marked reduction in growth rate at this time. Long bone length and crown-anus length were the most predictable parameters for a given gestational age.
Richardson
C
C
Central Veterinary Laboratory, Weybridge, Surrey.
Barnard
V
V
Jones
P C
PC
Hebert
C N
CN
D000818:Animals; D001835:Body Weight; D002417:Cattle / Q000196:embryology*; D002531:Cerebellum / Q000196:embryology; D005865:Gestational Age; D009929:Organ Size; D012044:Regression Analysis; D013961:Thyroid Gland / Q000196:embryology