Reproductive behaviour Flashcards
Reproductive behaviour is…
obligatory component in repro
one of strongest drives in animal kingdom
Ultimate aim of reproductive behaviour?
To increase probability of sperm & egg union via copulation
3 goals of reproductive behaviour…?
Pregnancy
successful embryogenesis
parturition
Stages of sexual behaviour in male…?
precopulatory stage
copulatory stage
postcopulatory stage
Stages of sexual behaviour in female…?
attractivity
proceptivity
receptivity
Outline precopulatory behaviour (males)…
search for partner -> courtship -> sexual arousal -> erection -> penile protrusion
Outline copulatory behaviour (males)…
mounting -> intromission -> ejaculation
Outline postcopulatory behaviour (males)…
dismount -> refractory period -> memory
Difference in sexual behaviour between males vs females?
female sexual activity confined to oestrus (heat)
males are ready any time!
Typical search/courtship/consummation behaviour in bovines (male/female)…
Bull: approach sexual females & test for lordosis, flehmen/nuzzling, licking perineal region, testing for lordosis/penile protrusion & dribbling seminal fluid, erection, attempted mounts
Cow: ++locomotion & vocalisation, elevation of tail/ ++grooming & attempted mounting with other females/ homosexual mounting & standing to be mounted
Typical search/courtship/consummation behaviour in equines (male/female)…
Stallion: visual search & flehmen/++excitement/ penile protrusion NO EXPULSION OF SEMINAL FLUID
Mare: ++ locomotion & tail raised/ urination in presence of stallion/presents hindquarters to male, clitoral exposure (labial eversion), pulsatile contractions of labia
Typical search/courtship/consummation behaviour in ovines (male/female)…
Ram: sniffing & licking genital region, nudging ewe, flehmen/ neck outstretched head horizontal/repeated dorsal elevation of scrotum, penile protrusion NO EXPULSION OF SEMINAL FLUID
Ewe: short period of restlessness (ram seeking)/urination in presence of ram/ immobile stance
Short copulators?
bull, ram, tom
Inermediate copulators?
stallion
Sustained copulators?
boar, dog, camelids
Define emission
movement of seminal fluid from accessory sex glands -> pelvic urethra
Volume of ejaculate in ram/bull/stallion…?
0.8-1ml/3-5ml/75-120ml
describe copulation in dogs (out loud)
slide 17
What is refractivity? dependent on…?
sexual satiation dependent on:
- sexual rest prior to cop.
- age of male
- spp of male
- degree of female novelty
- no. of past ejaculations
What is recovery?
restimulation after refractivity
Reproductive behaviour is programmed when?
during prenatal development
Neural pathways eliciting reproductive behaviour…
- SENSORY (visual, olfactory, auditory, tactile) -> 2. HYPOTHALAMUS reacts to sensory signals & sex hormones (E2) & neurons produce behaviour specific peptides -> 3. MIDBRAIN receives peptides & speeds up impulses -> 4. MEDULLA intergrates postural adaptation for lordosis & mounting -> 5. SPINAL CORD generates signals to specific muscles for lordosis & mounting
Mechanism of penile erection…
- erotogenic stimuli causes sensory nerves to fire -> 2. stimulate repro. behavior center in hypo. -> 3. stim. of parasymp. nerves innervate penis -> 4. parasymp. nerve terminals release NO -> 5. NO initiates biochemical cascade -> ERECTION
Penile erection requirements…
\++ arterial blood flow dilation of corporal sinusoids restricted venous outflow \++ intrapenile pressure relaxation of retractor penis muscle
In a flaccid penis…
NANC (NO) pathway inhibited
Adrenergic neurons uninhibited
In erect penis…
NANC (NO) pathway uninhibited
Adrenergic neurons inhibited
Nerve pathways resulting in emission & ejaculation…
- intromission -> 2. sensory stimulation of glans penis (temp/pressure) -> afferent -> spinal cord -> efferent (motor) neurons -> 3. powerful contractions of urethralis, bulbospongiosus & ischiocavernosus muscles -> 4. expulsion of semen
List 2 ways of manipulating repro. behaviour…
- introduce novel stimulus (Coolidge effect)
2. change stimulus settings
Explain ways to maximise sperm output per ejaculate…
- manual deviation of penis to prevent intromission (false mounting)
- prevent mounting (restraint) 2-3 minutes
combine both for max output
In dairy bulls max sperm output how?
1 false mount, 2 mins restraint, 2 false mounts -> ejaculate
In beef bulls max sperm output how?
3 false mounts but no restraint -> ejaculate