Equine - Stallion Reproduction Flashcards
How is puberty described in a stallion?
-Able to produce an ejaculate consisting of 50 million spermatozoa and at least 10% progressive motility
OR
- Histologic evidence of mature spermatogenesis
OR
- Produce an ejaculate ‘capable’ of sustaining a pregnancy
When does puberty happen in the stallion?
Average 20-21 months, however it can happen anywhere between 12-24 months of age- very breed dependent (Warmbloods typically reach it sooner)
When are stallions typically sexually mature? Reach peak performance?
Mature by 3 years of age with peak performance at 4-5 years of age
When does testicular dissension begin? When is it completed?
It begins during the last month of gestation and is completed somewhere around 10-14 days post foaling
When do stallion produce semen?
year-round
When is a stallion’s peak semen production?
during the spring and summer
What changes happens in a stallion during long days?
Increased testicular size and weight, more sperm output, increased libido, and increased plasma concentrations
How is the equine testis oriented?
Horizontally - cranial (head of epididymis) to caudal (tail of epididymis) orientation
What accessory sex glands does the male horse have?
prostate, seminal vesicles, bulbourethral glands, and ampulla
What is the ampulla?
a dilation of the ductus deferens
What type of penis does the stallion have?
musculocavernous penis
How is an erection in the stallion achieved?
by venous vasoconstriction and arterial vasodilation to cause engorgement of the penile erectile tissue (corpus cavernosum and corpus spongiosum)
How would you describe the prepuce of the stallion penis?
It is a telescoping prepuce - it basically folds within itself when there is no erection
What are the components of the glans penis?
the urethral sinus and diverticulum, and fossa glandis
What is frequently accumulated in the glans penis? What management methods are done to this prior to semen collection?
smegma aka ‘bean’
It is washed prior to semen collection
Where are samples taken from for culture for CEM and other potential reproductive pathogens?
the glans penis
What should you wear when working with stallions and/or mares during collection and/or breeing procedures?
a helmet
What are the reasons for performing a stallion BSE?
Estimation of reproductive potential
Evaluation at the beginning of the breeding season
Determination of cause of poor reproductive performance
What are the objectives for performing a stallion BSE?
Determine physical and reproductive fitness
Quality and quantity of semen
Libido testing
Identification of reproductive pathology and/or reproductive disease
What is missing from the standard BSE?
fertility testing
What all occurs during breeding soundness examinations?
Getting a thorough history (type of insemination, book size, frequency of collection, reproductive disease screening), general physical examination, observation of libido, collection of semen, evaluation of semen
What are the components of a reproductive examination?
scrotal and testicular palpation, palpation of the spermatic cord, and examination of the penis upon obtainment of erection
What is measured when you do scrotal and testicular testes?
Size, symmetry, and consistency
The total testicular width - it is measured with an ultrasound
What should the total testicular width be in a fertile male?
greater than or equal to 80mm
What is the daily sperm output?
The daily amount of cells ejaculated = cells produced per day
How is daily sperm output measured?
Either collecting daily for 5 to 7 days for an accurate number or estimating it by collecting from the stallion twice approximately one hour apart