magic104
Well-Known Member
Equine Fetal Development Milestones
Day Major Milestone
1 Zygote ( two cells formed) Now called an Embryo
4 Morula (16 cells plus formed)
8 Blastocyst, (embryonic mass) seen
9 Ectoderm (outer) and endoderm (inner) germ layers evident, beginnings of gut
11 Embryo looks like the well known bean and outline of skull top seen
12 Primitive gut evident
16 Formation of the amnion (sack foal is in) seen, first blood vessels evident
18 Main artery and vein identifiable, fetus begins to take on characteristic C shape
20 Allontois (inner foal sack) forming, chorionic vesicle oval shape, eye vesicle and ear present
21 Amnion (foal sack) complete
23All basic bodily structures evident, although in beginning/basic state
25First evident attachment of fetus
26Forelimb bud is seen, the eye becomes visible
30Genital tubercle present, eye lens seen
36Rudimentary three digits seen on hoof, eyes pigmented
40Ear forming, nostrils seen, eyelids seen, all limbs evident and elbow and stifle joint areas identifiable
42Ear triangle in shape, mammary buds seen along ridge
45External genitalia evident
49Mammary teats evident, Now called a fetus
55Eyelids closing
63Eyelids fused, fine eye development occurring, hoof, sole and frog areas seen
75Female genital present
80Male genital clearly seen
95Hoof appears yellow in color
112 Tactile hairs on lips growing
120 Fine hair on muzzle and chin and eyelashes beginning to grow, eye prominent
150 Eyelashes clearly seen, enlargement of mammary gland
180 Mane and tail evident
240 Hair of poll, ears, chin, muzzle and throat evident
270 Whole of body covered in fine hair, longer mane and tail hair clearly seen
320 Testes might drop from this time onward
320-340 Birth of fully developed fetus
Mo is between 240 & 270 days (259 days on Sunday)
Day Major Milestone
1 Zygote ( two cells formed) Now called an Embryo
4 Morula (16 cells plus formed)
8 Blastocyst, (embryonic mass) seen
9 Ectoderm (outer) and endoderm (inner) germ layers evident, beginnings of gut
11 Embryo looks like the well known bean and outline of skull top seen
12 Primitive gut evident
16 Formation of the amnion (sack foal is in) seen, first blood vessels evident
18 Main artery and vein identifiable, fetus begins to take on characteristic C shape
20 Allontois (inner foal sack) forming, chorionic vesicle oval shape, eye vesicle and ear present
21 Amnion (foal sack) complete
23All basic bodily structures evident, although in beginning/basic state
25First evident attachment of fetus
26Forelimb bud is seen, the eye becomes visible
30Genital tubercle present, eye lens seen
36Rudimentary three digits seen on hoof, eyes pigmented
40Ear forming, nostrils seen, eyelids seen, all limbs evident and elbow and stifle joint areas identifiable
42Ear triangle in shape, mammary buds seen along ridge
45External genitalia evident
49Mammary teats evident, Now called a fetus
55Eyelids closing
63Eyelids fused, fine eye development occurring, hoof, sole and frog areas seen
75Female genital present
80Male genital clearly seen
95Hoof appears yellow in color
112 Tactile hairs on lips growing
120 Fine hair on muzzle and chin and eyelashes beginning to grow, eye prominent
150 Eyelashes clearly seen, enlargement of mammary gland
180 Mane and tail evident
240 Hair of poll, ears, chin, muzzle and throat evident
270 Whole of body covered in fine hair, longer mane and tail hair clearly seen
320 Testes might drop from this time onward
320-340 Birth of fully developed fetus
Mo is between 240 & 270 days (259 days on Sunday)
