Why do we want twins or triplets in sheep, but not in cows or horses

1
(No Transcript)
2
Why do we want twins or triplets in sheep, but
not in cows or horses?
3
Horses

• Twinning causes . . .
• high frequency of abortions
• birthing complications
• Uterus is too small to support growth of two
  fetuses together
• In rare cases, both fetuses survive

4
Cows

• Twinning can result in . . .
• retained placentae
• decrease in reproductive efficiency
• decrease in milk production
• Smaller calves with lower growth rates

50 of all double ovulations in cattle result
in bull/heifer combinations and 92 of these will
result in a freemartin
5
Freemartins

• An androgenized heifer born twin to a bull
• Result when fetal blood mixes

• Sterile females are unwanted in livestock
  production

6
Sheep

• Twinning is a good way to get more for your money
  

• Capable of giving birth to healthy twins
• Insignificant occurrence of freemartins in sheep

7
Another question is raised . . .

• Why is the incidence of freemartins so much
  higher in cattle than in sheep?

Yum

• ?

8
(No Transcript)