Copulatory Behaviour - Anatomy & Physiology

Mounting

Elevation of the front legs of the male to straddle the posterior region of the female.
Learned behaviour

The reflex expulsion of spermatozoa and seminal plasma from the male reproductive tract.
Sensory stimulation, primarily to the glans penis causes a series of coordinated muscular contractions.
Once intromission has been achieved, reflex impulses are initiated.
- Neural impulses derived mainly from sensory nerves in the glans penis.
Upon threshold stimulation, impulses are transmitted from the glans peinis by the internal pudendal nerve to the lumbosacral region of the spinal cord.
Sensory impulses result in firing of nerves in the spinal cord.
Forcing of semen into the urethra by nerves in the hypogastric plexus innervating target muscles.
- Urethralis muscle
- Ischiocavernosus muscle
- Bulbospongiosus muscle
Emission and ejaculation
- Emission is the movement of seminal fluids from the accessory sex glands into the pelvic urethra so that they can mix with spermatozoa.
- Emission occurs before and during ejaculation.

Species	Ram	Bull	Stallion	Boar
Duration of Copulation	1-2 seconds (1 Pelvic Thrust with Foreleg Clasp)	1-3 seconds (1 Pelvic Thrust with Foreleg Clasp)	20-60 seconds (Multiple Pelvic Thrusts,Flagging,Followed by Innactive Phase)	5-20 minutes (Rapid Pelvic Thrusting to Engage Penis in Cervix) When Penis is Engaged,Thrusting Stops and Ejaculation Commences
Volume of Ejaculate (ml)	0.8-1.0	3-5	75-120	200-250
Site of Semen Deposition	External Cervical Os	Fornix Vagina	External Cervical Os, but Semen Enters Uterus at High Pressure	Cervix and Uterus
Average Numbers of Ejaculations to Satiation	10	20	3	3
Maximum Number of Ejaculations to Exhaustion (Refractory Period)	30-40	60-80	20	8