VGO 511: Veterinary Andrology and Reproductive Techniques (1+1)

PRECOPULATORY BEHAVIOUR

• Each stage of the reproductive behaviour becomes the stimulant for the next stage.

Searching of sexual partner

• The identification of sexual partner involves the various senses like olfactory, optic, auditory and tactile senses.
• The male animals will search its partner by seeking and identifying the estrual signs of the female animals.
• Secretions from the female reproductive tract serve as sexual attractants and sexually stimulate and attract the male to female.
• Pheromone is a volatile substance secreted or released outside the body and is perceived by the olfactory system of other individuals of the same species.

Males also produce sex pheromones that attract and stimulate females eg. Boars.

• Males also produce sex pheromones that attract and stimulate females eg. Boars.
• Boars produce 2 attractants – from preputial pouch and in saliva secreted from submaxillary salivary gland.
• The active components of the saliva are 3 alpha androstenol and 5 alpha androstenone. Both the compounds have musk like odour.
• The presence of the male will stimulate the females to intensify its sexual responses.

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• The searching behaviours in are as follows:

  Species	Male	Female
  Bovine	Approaching the female and testing for lordosis ,Chin resting	Bellowing, restlessness, increased locomotion, twitching and elevation of tail
  Equine	Visual search	Increased locomotion and flagging of tail
  Caprine & ovine	Neck outstretched and head held horizontally Sniffing and licking the ano-genital region, Nudging and exhibiting Flehmen’s reflex	Restlessness
  Canine	Roaming in its territory	Roaming
  Swine	Moving with sows to identify the receptive animal	Mild Restlessness
  Feline	Prowling	Vocalization
  Nudging – touching or pushing gently Prowling – move restlessly

Courtship/Sexual display The identification of the sexual partner leads to the initiation of courtship behaviour with sniffing of the vulva by the male, urination in the presence of male, flehmen reflex, chin resting, circling and increased phonation. The common courtship behaviours in different species are as follows Some pheromones are less volatile and need to be detected by the vomeronasal organ in the bull, ram, stallion and to some extent, the boar. The vomeronasal organ is an accessory olfactory organ and is connected to two small openings in the anterior roof of the mouth just behind the upper lip. Many species such as the bull, ram and bucks smell the genetalia as well as the urine and exhibit the flehmen response which is characterized by elevation of head and curling of the upper lip. Curling of the upper lip closes the nostrils and allows a suckling response to occur in the nasopalatine duct. Less volatile substances are aspirated into the nasopalatine organ where they are evaluated by sensory neurons. As in males, females also exhibit flehmen response to placenta, newborn animals and volatile substance. The Flehmen’s reflex is noticed in all animals except swines.

Species	Male	Female
Bovine	Flehmen, nuzzling and licking the perineal region	Increased grooming and mounting of other females
Equine	Flehmen and High degree of excitement	Urinating in the presence of stallion
Caprine & ovine	Flehmen, sniffing and licking of vulva, nudging the ewe	Urinating in the presence of ram
Canine	Sniffing and licking the vulva	Immobile stance
Swine	Nuzzling, grinding of teeth, foamy saliva	Immobile stance
Feline	Biting the queen at neck	Crouching, head rubbing and rolling

• Nuzzling – rub or push against with nose
• Sniffing - smelling
• Grooming - cleaning
• Crouching – bending the knee and brining the body forward and down

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Sexual arousal

• Among the all stimuli the visual stimuli is important for the sexual arousal.
• The courtship behaviours will end in lordosis/immobile stand/willingness to mate, which stimulates the significant sexual arousal in male animals.
• Once the male identified the female is displaying the lordosis, it is intensively stimulated.
• The following are the characteristics of sexual arousal in farm animals.

Species	Male	Female
Bovine	Penile protrusion with dribbling of seminal fluid with few spermatozoa, erection and attempted mounts	Homosexual mounting and standing to be mounted
Equine	Penile protrusion with no pre-ejaculatory expulsion of seminal fluid	Presents hind quarters to male, Clitoreal exposure by labial eversion (winking of clitoris), pulsatile contraction of labia
Ovine and caprine	Repeated dorsal elevation of scrotum, Penile protrusion with no dribbling of seminal fluid	Immobile stance
Boar	Penile protrusion, shallow pelvic thrusts, attempted mounting	Immobile stance

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Erection

• The penile erection requires a series of neural and vasomotor reactions.

Erection is characterized by the marked increase in rigidity of the penis.

• Erection is characterized by the marked increase in rigidity of the penis.
• The rigidity is due to elevated arterial blood flow, dilatation of corporal sinusoids, restricted venous outflow, elevated intra penile pressure and relaxation of the retractor penis muscle.
• The penis of the bull, ram and boar is fibroelastic in nature and is having sigmoid flexure. Therefore during erection in these species the diameter will not increase much.
• In stallions, the penis is vascular in nature and it is not having sigmoid flexure. So there is significant enlargement in size of the penis occurs in this species.
• The erection is predominantly under the control of parasympathetic nervous system.
• The reflex stimulation of the testis, urethra, prostate and glans penis cause erection.

Penile protrusion

• The erection will leads to the separation of the glans penis from the prepuce.
• During this period, the dribbling of the secretions of Cowper’s gland is noticed in bulls.
• The male will keep its chin on the receptive female and the female will stand quietly to allow the male to mount.

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