Breeding the Mare and Choosing the Stallion

What are some things to look for when choosing a stallion?

Temperament, conformation, athletic ability, blood lines, fertility, health checks

The descendants of a person, animal; offspring

Progeny

Set of behavioral characteristics which are stable in time and in similar situations

Temperament

Personality of a horse

Temperament

Innate character + environment

Temperament

What are the 5 dimensions of temperament?

Emotivity, Herd instinct, locomotive activity, reactivity to humans, sensorial sensitivity

The tendency to react more or less strongly to sudden events (e.g. surprise) or new events (e.g walking over an alien surface)

Emotivity

Can the horse bear to be separated from the other horses?

Herd instinct

Does the horse move spontaneously or not at all?

Locomotive activity

Does the horse go easily towards an unfamiliar human being?

Reactivity to humans

Does the horse react more or less strongly to stimuli, specifically touch?

Sensorial sensitivity

The horse’s body should appear rectangular, length slightly greater than height and balanced proportions between forehand, barrel, and hindquarters

Balance

A well-defined jaw, a neck set high and vertical, connecting smoothly to prominent withers for good head carriage and collection

Head and Neck

Prominent, well angled shoulders, sloping shoulders (around 45 degrees) allow for freedom of movement, with the withers reaching behind the elbow

Shoulders and Withers

A proportionately short back (less than 50% of body length) connected to a deep, well sprung rib cage

Back and barrel

A strong, sloping croup (around 45 degrees) to the point of the buttock, leading to powerful engagement

Hindquarters

Adequate bone, straight from all angles, with well-angled pasterns (half to three-quarters cannon bone length) to absorb concussion

Legs

Power generated from the hindquarters, with a balanced, correct stride and good freedom in the front legs

Movement

What shape should the body of a horse look like?

Rectangular

At what angle should the shoulders slope?

45 degrees

Should the withers be in front of or behind the elbows?

Behind

What should the back be like?

Short (less than 50% of the body length)

What should the croup look like?

Strong and sloping (45 degrees)

What do you use for a fertility and health check?

Breeding soundness exam (BSE)

What does the breeding soundness exam analysis in the semen?

Volume, concentration, motility, morphology

What does the breeding soundness exam test for?

Venereal diseases (e.g., equine viral arteritis)

What is required to work a breeding soundness exam?

Veterinary certification

Mares are receptive; covered every other day (Bred naturally ever 48 hrs)

Natural cover

Insemination as soon as semen is collected

Fresh

Collected - processed - chilled - transported; 48hrs-72 hrs

Fresh, chilled

Collected - processed - frozen in liquid nitrogen - defrosted (6-12 hours)

Frozen

What are the four ways to supply semen?

Natural cover, fresh, fresh and chilled, frozen

Examination of which external genitalia in the pre-breeding assessment

Vulva, perinium, mammary tissue

What does the ultrasound exam in the pre-breeding exam?

Uterus, ovaries, cervix

What is the general clinical examination of the mare in the pre-breeding exam?

Lameness and orthopedic problems

During the pre-breeding assessment, swabs are taken to determine what?

Organisms that affect fertility

What are the three organisms that affect fertility that are determined through the swab test?

Taylorella equigenitalis, pseudomonas aeruginosa, Klebsiella pneumoniae

During the pre breeding exam blood is taken for look for what?

Disease

What are some diseases that are found in the blood pre breeding test?

Equine viral arteritis, equine infectious anemia, positive/negative strangles

Receptive to male

Heat

What are some signs that the mare is in heat?

Lifting her tail, tip pelvis, often urination, evert clitoris

How long is the estrous cycle?

21-22 days

How long is estrus?

4-7 days

When does ovulation occur?

1-2 days before the end of estrus

During estrus, what does the mares uterus look like?

Soft with edematous endometrial folds visible on ultrasound

What is the cervix like when in estrus?

Widening and relaxed

An injection of PGF lyses the corpus luteum, causing the mare to come into heat in 3-4 days and ovulate in 8-10 days

Prostaglandin

Prostaglandin

PGF

Administering Altrenogest (progestin) for 9-12 days and giving PGF on the last day induces heat within 2-5 days after stopping the progestin

Progestin + PGF

For mares with a large follicle, hCG or GnRH analogs can induce ovulation within 24-48 hours

GnRH analog/hCG

Exposing mares to 14-26 hours of intense artificial light daily for 8-10 weeks can stimulate earlier cyclicity

Artificial lighting

Drugs like domperidone increase prolactin, encouraging cycling in transitional mares, with about 60-80% responding

Dopamine Antagonists

A single injection of estradiol can induce estrus in silent heat mares

Estrogen

“Water” in the uterus

Edema

Split the semen dose to ½ prior to ovulation and ½ after ovulation

Fresh semen

Causes muscle contractions

Oxytocin

When is the first scan post ovulation?

14-16 days

When is the second scan that can sense the heartbeat?

28 days