Changes of Embryonic Wastage during Pregnancy in Rats Fed Low and High Energy Diets

Abstract
Embryonic wastage rates were determined at different stages of pregnancy in Wistar strain rats fed low and high energy diets (digestible energy: 2.3 and 4.8 kcal/g, respectively). Feeding of experimental diets was started on the day sperm were noted in vaginal washings (0 day of pregnancy). The embryonic wastage rates in the low energy group were 3.1, 8.8 and 9.6% until day 7, 14 and 19 of pregnancy, respectively. On the other hand, those in the high energy group were 19.4, 21.6 and 22.8%, respectively. Most of the total embryonic wastage in the high energy group occurred in the first third of pregnancy, and the major part of this loss occurred at the process of egg cleavage (until day 3). Fetal and placental weights on day 19 of pregnancy were higher in the high energy group.