Breeding horses

Question 1

From what age can mares be bred from? What is the optimum age?

Answer 1

2 years old

5-6 is optimum

Question 2

The integrity of which 3 anatomical seals is essential?

Answer 2

Vulva
Vestibule
Cervix

Question 3

Describe the light regime and its role

Answer 3

• extend light to 16 hours per day
• tricks the mare into thinking the days are longer
• switch light on 30 mins before sunset

Question 4

How long does it take for the lighting regime to have an effect?

Answer 4

60-90 days

Start before the 15th of December for Feb-March breeding

Question 5

What type of breeders are horses?

Answer 5

Seasonal polyoestrus - long day breeder

Question 6

Describe the horses normal cycle, include length, oestrus, and ovulation

Answer 6

• Mean 21 days
• Oestrus for 3-7 days
• Ovulate 24-48 before the end of oestrus

Question 7

Where does a mare ovulate from?

Answer 7

From an ovulation fossa on the ovary

Question 8

What size will a follicle be when it ovulates?

Answer 8

35mm

Question 9

How do gestation lengths vary?

Answer 9

Full term = 320+ days

Avg thoroughbred = 341 days

Question 10

What is the limit of viability for a foal?

Answer 10

300 days - any days born before this have practically 0 chance of survival

Question 11

From what day is it called a foetus rather than an embryo?

Answer 11

Day 40

Question 12

What % of ovulations are twins?

Of twin conceptions what % are unicornual?

Answer 12

20%

70%

Question 13

Is a mare more likely to abort both in a unicornual or bicornual pregnancy?

Answer 13

72% in Bicornual

12% in Unicornual

Question 14

Embryo death of one is more likely to occur in unicornual or bicornual? what are the consequences of this?

Answer 14

75% in unicornual
10% in bicornual

• 78% chance of having a single live offspring id embryo death of one embryo occurs in a unicornual pregnancy

Question 15

What are some cost factors that need to be considered when breeding a mare?

Answer 15

• Transport to stud
• Stud fee
• Groom and ‘in foal’ fee
• Veterinary fees
• Livery at stud

Question 16

Mares need to be certified free of what before arriving at the stud?

Answer 16

Transmissible venereal disease

Question 17

Describe the natural service procedures of a mare and stallion

Answer 17

• Vulva and penis of the breeding pair are washed immediately before covering
• Mare should be adequately restrained
• Breeding rolls to limit penetration
• Gonadotrophin and GnRH used to induce ovulation

Question 18

From what age are stallions used?

Answer 18

3-5 years old

Question 19

What 5 feature are required for a good stallion?

Answer 19

• Libido
• Mount and serve
• Semen quality and quantity
• Free from disease
• Longevity

Question 20

What are expected stallion behaviours?

Answer 20

• Immediate interest in mare
• Erection within 2 mins of contact with mare
• Ready to mount 5-10 seconds after erection
• Ejectulation after 5-6 pelvic thrusts

Question 21

What are some signs that a mare is getting close to parturition?

Answer 21

• Isolation from group
• Nesting
• Restlessness
• Raising tail
• Teats fill: 7-10 days
• Vulva swells and relaxes
• Drop in body temp

Question 22

What timings should a foal meet post-partum to show it has vigour?

Answer 22

Sternal: 1-2 mins
Suckling reflex: 20 mins
Standing: 15-120 mins
Nurse < 4hours