Dietary deprivation induces fetal loss and abortion in rabbits

An Investigation on Restraining Effects and Acclimation to Protecting Jackets in Pregnant Rabbits -Wearing From Pre-Mating Through Fetal Organogenesis-

“…Apart from temperature changes, mated or pregnant rabbits are known to be insensitive to other distressing effects; housing in restraining cages exerted no effects on LH surge and ovulation (YoungLai and Dimond, 1976) and restricted feeding induced no effects on morphology of fetuses (Breslin et al, 2000;Matsuoka et al, 2006;Matsuzawa et al, 1981;Petrere et al, 1993). The present trial with restraining devices again confirmed previous results and revealed no effects on various parameters or fetuses morphology.…”

Effects of Stage and Degree of Restricted Feeding on Pregnancy Outcome in Rabbits

“…Conditions of restricted feeding required to induce some effects on reproductive performance in pregnant rabbits in the previous reports are inconsistent: restricted feeding at 15 g/ head/day from GD 6 to 18 or GD 7 to 19 induced abortion at low incidence (Clark et al, 1986;Petrere et al, 1993;Cappon et al, 2005). Restricted feeding at 20 g/ head/dam from GD 6 to 20 induced high incidence of abortion (Matsuzawa et al, 1981). Restricted feeding at 35 to 75 g/head/day from GD 6 to 18 or GD 7 to 19 induced no definite abortion (Clark et al, 1986;Petrere et al, 1993;Cappon et al, 2005).…”

“…As for embryo-fetal effects, restricted feeding at 15 g/head/day from GD 6 to 18 induced teratogenic effects, increased embryo-fetal lethality and decreased fetal body weight (Clark et al, 1986), decreased fetal body weight (Petrere et al, 1993) and restricted feeding at 15 to 75 g/ head/day from GD 7 to 19 induced decreased fetal body weight and high incidence of skeletal unossification (Cappon et al, 2005). Restricted feeding at 20 g/head/ day from GD 6 to 20 induced increased embryo-fetal lethality and decreases in fetal and placental weights, and restricted feeding at 60g/head/day during the same stage induced increased embryo-fetal lethality (Matsuzawa et al, 1981). With regard to increased embryofetal lethality, the present results largely coincided with those in previous literature.…”

“…1, the study was composed of 5 groups that consisted of 8 pregnant animals each. Referring to the previous study (Matsuzawa et al, 1981), dose levels of restricted feeding were set at 20 and 60 g/head/day. These groups were subjected to restricted feeding in the following ways: (B) 60 g per day from GD 6 to 18 (middle period), (C) 20 g per day from GD 6 to 18, (D) 20 g per day from GD 19 to 28 (post-middle period), and (E) 20 g per day from GD 6 to 28 (middle and post-middle periods).…”

“…Distinction between causes of anorexia, therefore, is indispensable for evaluation of results of studies. In previous major reports dealing with maternal effects of restricted feeding on embryo-fetal development in rabbits, the stage for restricted feeding was exclusively limited to the middle period such as gestational Days (GD) 6 to 18 (Clark et al, 1986;Petrere et al, 1993), GD 7 to 19 (Cappon et al, 2005) or GD 6 to 20 (Matsuzawa et al, 1981). However, the stage of administration in routine practice of reproductive toxicity studies using rabbits often extends to the post-middle period (GD 19 to 28) in addition to the middle period (GD 6 to 18).…”