The Chronology of Fetal Development

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.

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