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Lecture 14: Sexual Behavior a. General Behavior Animal Science 434

Lecture 14: Sexual Behavior a. General Behavior

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Animal Science 434. Lecture 14: Sexual Behavior a. General Behavior. Reproductive Behavior. Very strong drive and can take precedence over other activities Purpose Promote copulation Assure sperm and oocyte meet Goal is to achieve pregnancy and parturition. Stages of Reproductive Behavior. - PowerPoint PPT Presentation

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Page 1: Lecture 14: Sexual Behavior a. General Behavior

Lecture 14: Sexual Behaviora. General Behavior

Animal Science 434Animal Science 434

Page 2: Lecture 14: Sexual Behavior a. General Behavior

Reproductive Behavior• Very strong drive and can take precedence

over other activities

• Purpose» Promote copulation» Assure sperm and oocyte meet

• Goal is to achieve pregnancy and parturition

Page 3: Lecture 14: Sexual Behavior a. General Behavior

Stages of Reproductive Behavior

• precopulatory

• copulatory

• post copulatory

Page 4: Lecture 14: Sexual Behavior a. General Behavior

Precopulatory Stage

• Search for sexual partner» in female, generally limited to estrus

• increased physical activity• In primates can occur at any time

» in male can occur at any time» involves all of the senses

• sight• smell• hearing• tactile

Page 5: Lecture 14: Sexual Behavior a. General Behavior

Search For Partner

Page 6: Lecture 14: Sexual Behavior a. General Behavior

Search for Partner

Page 7: Lecture 14: Sexual Behavior a. General Behavior

Search for Partner

Page 8: Lecture 14: Sexual Behavior a. General Behavior

Search for Partner

Page 9: Lecture 14: Sexual Behavior a. General Behavior

Precopulatory Stage (cont.)

• Courtship» species specific events» sniffing of the vulva by male» urination by the female» flemen lip curl» chin resting on female rump» increased phonation» male checks for female lordosis» human

• eye contact, touching, detection of pheremones

Page 10: Lecture 14: Sexual Behavior a. General Behavior

Urination

Page 11: Lecture 14: Sexual Behavior a. General Behavior

Lordosis

Page 12: Lecture 14: Sexual Behavior a. General Behavior

Winking of the Vulva

Winking of the Vulva

Page 13: Lecture 14: Sexual Behavior a. General Behavior

Sniffing the Vulva

Page 14: Lecture 14: Sexual Behavior a. General Behavior

Biting To Check For LordosisBiting To Check For Lordosis

Page 15: Lecture 14: Sexual Behavior a. General Behavior

Unresponsive MareUnresponsive Mare

Page 16: Lecture 14: Sexual Behavior a. General Behavior

Sniffing the VulvaSniffing the Vulva

Page 17: Lecture 14: Sexual Behavior a. General Behavior

Checking for LordosisChecking for Lordosis

Page 18: Lecture 14: Sexual Behavior a. General Behavior

Sniffing Vulva

Page 19: Lecture 14: Sexual Behavior a. General Behavior

Chin Rest

Page 20: Lecture 14: Sexual Behavior a. General Behavior

Lordosis and Mount

Page 21: Lecture 14: Sexual Behavior a. General Behavior

Phonation of Elk

Page 22: Lecture 14: Sexual Behavior a. General Behavior

Phonation of Elk

Page 23: Lecture 14: Sexual Behavior a. General Behavior

Human Courtship

Sight, eye contact, touch, pheremones

Page 24: Lecture 14: Sexual Behavior a. General Behavior

Precopulatory Stage (cont.)

• Search for sexual partner

• Courtship

• Sexual arousal» Female

• Lordosis• Presents hindquarters to male

» Male• Erection• Penile protrusion

Page 25: Lecture 14: Sexual Behavior a. General Behavior

Copulatory Behavior

• Mounting

• Intromission

• Ejaculation

Page 26: Lecture 14: Sexual Behavior a. General Behavior

Copulatory Behavior (cont.)

• Varies among species» short copulators (1 - 3 seconds)

• bull• ram

» sustained copulator (5 - 20 minutes)• boar

» intermediate (20 to 60 seconds)• stallion

Page 27: Lecture 14: Sexual Behavior a. General Behavior

Short CopulatorShort Copulator

Page 28: Lecture 14: Sexual Behavior a. General Behavior

Short CopulatorShort Copulator

Page 29: Lecture 14: Sexual Behavior a. General Behavior

Short CopulatorShort Copulator

Page 30: Lecture 14: Sexual Behavior a. General Behavior

Copulatory Behavior (cont.)

• Varies among species» short copulators (1 - 3 seconds)

• bull• ram

» sustained copulator (5 - 20 minutes)• boar

» intermediate (20 to 60 seconds)• stallion

Page 31: Lecture 14: Sexual Behavior a. General Behavior

Sustained CopulatorSustained Copulator

Page 32: Lecture 14: Sexual Behavior a. General Behavior

Sustained CopulatorSustained Copulator

Page 33: Lecture 14: Sexual Behavior a. General Behavior

Copulatory Behavior (cont.)

• Varies among species» short copulators (1 - 3 seconds)

• bull• ram

» sustained copulator (5 - 20 minutes)• boar

» intermediate (20 to 60 seconds)• stallion

Page 34: Lecture 14: Sexual Behavior a. General Behavior

Intermediate CopulatorIntermediate Copulator

Page 35: Lecture 14: Sexual Behavior a. General Behavior

Postcopulatory Behavior• Male

» Dismounting» Refractory period - all males have this

• time when copulation will not occur• Dependent on:

– Species dependent– sexual rest prior to copulation– age of male– degree of female novelty– number of previous ejaculates

• for semen collection try to minimize» Memory

• a bad experience will carry over

• Female - will often mate again immediately

Page 36: Lecture 14: Sexual Behavior a. General Behavior

Endocrine Effects on Sexual Behavior

• Prenatal steroid exposure» Feminization» Masculinization (defeminization)

• Postnatal Behavior» castrated female

• no steroids - no estrus behavior• plus estradiol - estrus behavior• plus progesterone and estradiol - maximum estrus

behavior• plus testosterone - male-like behavior

Page 37: Lecture 14: Sexual Behavior a. General Behavior

Sexual Behavior (cont.)

• Postnatal Behavior» castrated male

• no steroids - decreased sexual behavior• plus testosterone - sex behavior restored• plus dihydrotestosterone - decreased sex behavior• plus estradiol - sex behavior restored

Page 38: Lecture 14: Sexual Behavior a. General Behavior

Aromatization

Testosterone

Dihydrotestosterone

Estradiolaromatase

Page 39: Lecture 14: Sexual Behavior a. General Behavior

Sexual Behavior (cont.)

• both male and female sexual behavior is dependent on estradiol receptors in brain

Page 40: Lecture 14: Sexual Behavior a. General Behavior

Control of Reproductive Behavior• Sensory systems

» Olfactory, visual, auditory, tactile

• Hypothalamus» Estradiol receptors, increase response to sensory

neurons

• Midbrain» Signals from hypothalamus

» Speeds up nerve impulses

• Medulla» Coordinates lordosis and mounting

• Spinal Chord» Sends signals to specific muscles

Page 41: Lecture 14: Sexual Behavior a. General Behavior

Sensory Inputs for Reproductive Behavior

• specific importance varies with species

• olfaction» pheromone

• volatile substance which elicit specific behavior in the recipient

• males produce– boars

– humans

• females produce during estrus– dogs and rats can sense cow pheromones

• flehmen response

Page 42: Lecture 14: Sexual Behavior a. General Behavior

VomeronasalOrgan

Vomeronasal Organ

Nasopalatine DuctFluids

Fluids

Page 43: Lecture 14: Sexual Behavior a. General Behavior
Page 44: Lecture 14: Sexual Behavior a. General Behavior
Page 45: Lecture 14: Sexual Behavior a. General Behavior

Sensory Inputs for Reproductive Behavior (cont.)

• Auditory» cows bellow» sows grunt» good for long-range signaling

• Visual» posturing» males observing other males or females mounting» valuable for close encounters

Page 46: Lecture 14: Sexual Behavior a. General Behavior

Sensory Inputs for Reproductive Behavior (cont.)

• Tactile» biting on neck or whithers of mare» chin resting on cow» boar nudging of sow flank» final stimulus before copulation» leads to erection

Page 47: Lecture 14: Sexual Behavior a. General Behavior

Erection, Emission and Ejaculation

• Erection» Vasodilatation, inhibit vasoconstriction, relax

retractor penis muscle

• Emission» Contraction of cauda epididymis and vas deferens• Oxytocin from posterior pituitary• Sympathetic neurons

» Release of accessory gland fluid• Sympathetic neurons

• Ejaculation» Contraction of smooth and striated muscles

Page 48: Lecture 14: Sexual Behavior a. General Behavior

Homosexual Behavior

• common in farm animals

• useful to detect when females in heat» selection by man may have enhanced this

• can collect bulls off of other bulls as mounts

Page 49: Lecture 14: Sexual Behavior a. General Behavior