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

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?
Yu
m

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

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

11. 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

12. 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…

13. Freemartins
• An “androgenized”
heifer born twin to a
bull
• Result when fetal
blood mixes
• Sterile females are
unwanted in livestock
production

14. 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

15. Another question is raised . . .
• Why is the incidence of freemartins so
much higher in cattle than in sheep?
Yu
m