Reproductive Behavior

What is the purpose of reproductive behaviors?

To promote opportunities for copulation and increase the probability of fertilization

What are the functions of female reproductive behavior?

• Attractivity - behaviors that attract males

  • Postures, vocalizations, chemical cues (pheremones), increased activity

• Proceptivity - behaviors that ncourage male to copulate

• Receptivity - copulatory behaviors of female

  • Immobility/standing response, tail deviation, backing up towards male

The short peroid of receptivity in females limits the time during which precopulatory behavior occurs in most females

• Males gnerally capable of initiating any time after puberty

What is the first stage of the male reproductive behavior?

Precopulatory behavior:

• Search for sexual partner; looking for female signals

• Courtship behavior

  • Initiated after identifying a partner; generally under influence of female

  • Sniffing, vulva, and phonation: female urinates in presence of male

  • Flehmen response

• Sexual arousal

  • Triggered by lodosis (mating posture) by the females

• Erection and penile protrusion

What is the second step of the male reproductive behavior?

Copulatory behavior

• Mounting

  • Requires lordosis in female and elevation of male’s front legs to straddle caudal region of female

• Intromission - entrance of penis into vagina

• Emission - movement of seminal fluid, sperm into pelvic urethra

• Ejaculation - expulsion of semen from penis into female tract

What is the third stage of male reproductive behavior?

Postcopulatory behavior

• Dismount

• Refractory period -period in which a second copulation will not take place

• Memory

  • Positive experiences promote reproductive behavior

  • Negative experiences inhibit reproductive behavior

Describe the role of estradiol and the CNS in controlling reproductive behavior

Reproductive behavior is initated by cues:

• Olfactory

• Visual

• Auditory

• Tactile

Hypothalamus must be sensitized

• Male - constant supply of estradiol

• Female - only prior to estrus

What are the two types of tissue in the penis?

Corpora cavernosa (cavernous tissue)

• Spongy erectile tissue in shaft of penis

• Majority of penile interior

• Allows for influx of blood during erection

Corpus spngiosum:

• Spongy erectile tissue surrounding penile urethra

What does penile erection require?

• Elevated arterial blood flow into penis

• Dilation of coporal sinusoids (copora cavernosa)

• Restricted venous outflow

• Elevated intrapenile pressure

• Relaxation of retractor penis muscle

Describe the difference between erecton in Fibroelastic penis and vascular penis

Fibroelastic penis (bull, boar, ram)

• Limited erectile tissue; no significant increase in diameter

• Sigmoid flexure straightens; penis protrudes from sheath

Vascular penis (stallion, dog)

• Significant increase in diameter

• A lot of erectile/vascularized tissue; engorgement with blood is essential

What is ejaculation? What is it caused by?

Ejaculation is the reflex expulsion of spermatozoa and seminal plasma from the male tract

• Caused by a simple neural reflexed caused by

  • Intromission

  • Stimulation of the gland penis

  • Forceful muscular contractions

What is the difference between satiation and exaustion?

• Satiation: Further stimuli will not cause immediate responsiveness or motivation (refractory period)

• Exhaustion: No further sexual behavior can be induced (even with sufficient stimulation)

Depends on

• Degree of sexual rest before copulation

• Age and species of male

• Degree of femal novelty

• Number of previous ejaculations

What are the two fundamental ways to collect semen?

Artificial vagina - a device that stimulates the vaginal conditions of a female in estrus

Electroejaculation - electrical stimulation of the accessory sex glands and the pelvic urethra

What should the design of an AI vagina accomplish

• A suitable environment for stimulation of the glans penis

• An environment that prevents damage to the penis

• An environment that maximizes sperm recovery and minimizes sperm insult