EQST405 Breeding Soundness Exam (BSE)

estimate future reproductive potential, pre-purchase exam, determine cause of poor reproductive performance

3 goals of a BSE

Identification, reproductive history, physical exam, external & internal genital exam, libido and mating ability, semen eval, test cool, & test freeze

List 8 possible BSE procedures

microchip

Best form of identification for horses

nuccal ligament on left side (at base of crest)

Where is a microchip placed?

Equine Viral Arteritis (ERA)

What disease are we most concerned about vx history in a breeding Stallion?

venereal disease causes abortion outbreaks

Why are we concerned about EVA in breeding?

conception rates (per cycle or seasonality), pregnancy rates, & foaling rates

3 rates measured from a breeding stallions history

foaling rates

Best ratio for possible fertility & breeding success of a Stallion

young breeding stock

Indication for EVA vx

penis, prepuce, testes, epididymis, testicular measurements

5 parts of an external genital exam in a BSE

daily sperm production (DSP)

We can use testicular measurements to estimate what important number in a BSE?

scrotal calipers

used to get total scrotal width (TSW) measurement

10.8 cm

Normal avg. TSW of Stallions

total scrotal width (TSW), testicular volume

2 types of testicular measurements that can be taken during a BSE

3

How many TSW measurements are taken to average out?

breed & age

What 2 things is TSW dependent on?

widest point across scrotum

Where is the TSW measured?

testicular volume

What testicular measurement is most accurate?

length X width X height X 0.5233

testicular volume (cm³) equation

after collection of semen

When should testes be palpated on a breeding stallion?

(0.024 X total testicular volume) - 1.26

expected daily sperm production (DSP) equation (billions/day)

compare DSO with calculated DSP

How is spermatogenic effeciency calculated?

collect semen daily for 5-7 days to deplete reserves

How do you obtain DSO?

4-6 billion/day

Normal fertile DSO for stallion

1) min 60% progressively motile, 60% morphologically normal sperm

2) min of 1 billion progressively motile, morphologically normal sperm in 2nd of 2 ejaculates collected 1 hour apart after sexual rest of 1 week

2 accepted values for a semen analysis in a BSE

1 billion sperm

“ship” dose of semen contains how much sperm minimum?

500 million (0.5 billion) sperm

“on-farm” dose of semen contains how much sperm minimum?

conception & foaling rates in mares bred

2 final criteria of fertility in stallions