Breeding horses

When do mares reach puberty

1-2 years old

When can mares be bred

From 2 years old

What is the optimum age to breed mares

5-6 years old

When does mare fertility decrease

After 15 years old

What is the optimal body condition for mares at conception

3 out of 5

What are the three seals essential for reproductive integrity

• Vulva

• Vestibule

• Cervix

What should the cranio-caudal vulva slope be

Less than 10^o off verticle

How much of the vulva should be ventral to the dorsal ischial limit

Atleast 80%

What characterises oestrus activity in the horse

Seasonal poly-oestrus

What should the lighting regime be

• Extend light to 16 hours a day

• Switch on 30 mins before sunset

• Constant between days

• 200 W bulb for 12×12 box

What happens to oestrus cycle in spring transition

• Irregular oestrus behaviour

• Multipke anovulatory follicles

What is the normal oestrus cycle

• 21 days

• Oestrus 3-7 days

• Ovulation 24-48 hours before end of oestrus

• Ovulation fossa

What is the fertilisation rate of healthy young mares

90%

What is the pregnancy rate per cycle

60%

What are the foaling rates per breeding season

• Feral horses 23-85%

• Domestic horses 50-80%

What is the significance of pregnancy rates

• High value of breeding animals

• Owner expectation for foal

• Can’t rebreed that season if pregnancy is lost after 35 days

• If infectious it impacts future fertility

• Reputation loss for stud

What is the significance of foaling rates

• Economic viability of commercial studs

• Breeding horses maintained for longer

Why can’t you rebreed a horse if they abort after 35 days

Because of the formation of endometrial cups

How many ovulations are twins

20%

How many twin conception are unicornual and what does this mean

• 70%

• Both embryos implant in the same uterine horn

How do you diagnose pregnancy

• Ultrasound - day 11

• Manual palpation - day 20

• Blood endocrinology - day 40

What are the costs of breeding

• Transport to stud

• Stud fee

• Groom and in-foal fee

• Veterinary feed

• Livery at stud

What is in the HBLB code of practice

• Mares certified free of transmissible venereal diseases before arriving at stud

• Stud may repeat swabs on arrival or during subsequent oestrus

• Additional precautions if mare deemed high risk

• Culture by an approved lab

• Report on an official laboratory certificate

What are the stud procedures

• Leutolysis

• Monitor for oestrus

• Order semen and induce ovulation

• Remove shoes

• Service

• Post service check

• Pregnancy diagnosis

How do you monitor for oestrus

• Scan ovaries and uterus

• Teasing

• Cervical changes

What happens during natural service

• Vulva and penis of the breeding pair are washed immediately before covering

• The mare should be adequately restrained and protected

• Breeding rolls to limit penetration

When do stallions reach puberty

12-24 months

When are stallions typically used

3-5 years old

What are the functions of stallions

• Libido

• Mount and serve

• Semen quality and quantity

• Free from disease

• Longevity

How much nutrition do stallions require

• 2-3% of BW a day

• 50% should be from roughage

• 10% crude protein

• Vitamin A

How should semen be collected

1. Tease

2. Wash

3. Mount dummy

4. Collect into artificial vagina

What is expected stallion behaviour

• Immediate interest in mare

• Erection before 2 minutes of contact with mare

• Ready to mount 5-10 seconds after erection

• Ejaculation after 5-6 pelvic thrusts

What is the semen lifespan of mare

• Fresh - 72 hours

• Chilled - 36 hours

• Frozen - 12 hours

What are the preparation signs of foaling

• Restlessness

• Nesting

• Seperating

What are the post partum procedures on mares

• Expulsion of placenta

• Check udders

What are the post partum procedures of foals

• Check vigor

• Check navel

• Consume colostrum

When should foals show different behaviours

• Sternal after 1-2 minutes

• Suckle reflex after 20 minutes

• Standing from 15-120 minutes

• Nurse before 4 hours