The Chronology of Fetal
Development
Maxine Kinne
Age (weeks) | Stage of Development |
End of embryo stage | Abdominal wall closed Genital "bump" in females; penile sheath in males Top of brain visible through soft, membranous skull roof Limb segments apparent Differentiation of mouth, nostrils, digits and dew claws |
6-7 |
Mammary buds in females; empty scrotal sac in males Jugular vein barely visible through the pink skin |
7-8 |
Eyelids close and ear canal opens Membranous soft center in the top of the head |
8-9 |
Jugular vein, facial vein and scrotal vessels all visible Nostrils open |
10-11 |
Hairs appear on eyelids |
11-12 |
Ear vein prominent Hairs on eyelids and muzzle |
12-13 |
Hairs on forehead Pigmentation around horn pits Testes palpable in scrotum |
13-14 |
Skin whitish and thicker Jugular, facial and scrotal veins no longer visible Ear vein visible Hairs along top of the neck Top of the head has hardened |
14-15 |
Hairs on chest Eyelids separated Temporary teeth buds just appear |
16-17 |
Body sparsely covered with hair, except limbs |
17-20 |
Dense hairs cover body and limbs Teeth buds prominent |
20 |
1-3 incisors barely erupted in females at birth Incisors at gum line in males at birth |
Adapted from "Foetal Age Estimation in Sheep & Goats," M.N. Sivchelvan, M. Ghali Ali, G.A. Chibuzo, Small Ruminant Research, The Journal of the International Goat Association, Volume 19/1 (1996), Elsevier Science. |
© Copyright 1994
Updated 2000
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