Seasonal Effect, Sexual Behavior

Question 1

Affect of Season

Daylight hours

Answer 1

many wildlife and some domestic species are seasonal breeders at temperate latitudes

Horse and Sheep

Mare foals in the spring: approximately 10.5-12 mo gestation, conceive in spring

Ewe lambs in spring: approximately 21 week gestation, conceive in fall

Question 2

Seasonal Breeders

Answer 2

Show seaonal pattern of prolactin secretion. Peak concentrations in spring summer (long days), nadir in autumn or winter (short days)

If light is detected during a specific tiem period, the day is preceived as long

Melatonin is secreted by pineal gland at night

The exact method of influence on the Hyppthalamic-pituitary- gonad axis is not known

Question 3

Equine

during anestrus

Answer 3

GnRH concentration in hypothalamus is low

LH and FSH secretion by the antuitary pituitary are reduced

Ovaries are inactive

Steroid production is low

Same result in males

Question 4

Equine

Spring transition

Answer 4

GnRH concentrations begin to increase shortly after winter solstice

FSH levels rise as GnRH increase

Numner and size of ovarian follicles increses

FIrst few large follicles do not ovulate

First ovulatory follicle is accompanied by and estradiol surge and LH surge - leading to ovulation

Transition takes 6-12 weeks

Breeding during this time is unsuccessful

Question 5

Equine

Breeding mares early

Answer 5

Many breed associateion observe January 1 as the official birth date of foals

Therefore - advantage to competition borses born near January 1

Increasing day length with artificial lights will return seasonally anestrous mares to reproducitve competence

Light therapy doesn’t shorten the transtion phase - it just moves ti early in theyear

Strategy - add artificial light during evening hours starting in Nov and Dec

Question 6

Ovine

Answer 6

the pattern of light formt he summer solstice to the autumnal equinox is most critical

Follicular waves continue during anestrus - follicles reach ovulatory size, but do not ovulate

Estrogen production is low during anestrus

The first LH surge of the season is not followed by ovulation - but progesterone form luteninized follicles rises

The second LH surge of the season is accompanied by ovulation and estrus

Question 7

Ovine

Breeding sheep out of season

Answer 7

Sheep gestation and length and speed of lamb growth should allow for two pregnancies per year

Some breeds are easier to “trick” into breeding during shorter days

Block exposure to morning or evening light by housing in light-tight barns

Expose to addtional artiicial light for 8-12 weeks, followed by 8-12 weeks of short days

Or melatonin implants for 4+ weeks

Rams need to be exposed to light treatment also

Withhold contact with rams until ready to breed

Treat with CIDR P4 sponge for CIDR for 12 days with eCG injection at P4 removal

Question 8

Sexual Behavior

Male sexua behavior

Answer 8

Courtship

Copulation

Both are under the control of testosterone

The brain undergoes sexual differentiation during a short period of time near puberty - necessary for normal sexual behavior

Question 9

Sexual Behavior

Primary Stimulated by visual cues

Answer 9

bovine, equine

Question 10

Sexual behavior

Primarily stimulated by olfactory cues

Males -effect on females

Answer 10

Procine, Ovine, Equine

male rodents, swine, sheep, and other species can stimulate earlier puberty, induce ovulation, and increase the speed of sperm transport in the female tract

Question 11

Sexual behavior

Primarily stimulated by olfactory cues

Female-effect on males

Answer 11

Identification ont he presence of females in estrus

Question 12

Pheromones

Answer 12

air-borne chemicals released by urine or feces or secreted by cutaneous glands tha elicit a response

Question 13

Flehmen response

Answer 13

is a particular type of curllng of the lips in ungulates, felids, and amny other mammals

THe pose, which is adopted when examining scents left by other animals of the same species, helps expose the vomeronasal organ and draws senct molecules back toward it

Question 14

Sexual Behavior

Female Sexual behavior

Estrogens

Answer 14

necessary for mating behavior

high around the time when a follicle is mature and able to ovulate a viable egg

Question 15

Sexual behavior

Female sexual behavior

Progestogens

Answer 15

inhibit mating behavior

high during pregnancy and during stages of the estrous cycle without fertilization egg

Question 16

Bovine Behavior

Bull

Answer 16

Libido isthe desire to mate

mating ability is the ability to successfully mate

both appear to be influenced by genetics

Bulls housed in groups will establish dominance heirarchy very quickly

Question 17

Bovine Behavior

Cow/Heifer

Answer 17

Females play the major role in soliciting sexual partners

Form sexually acitve group that stays in visual contact with bulls

Question 18

Bovine Behavoir

Mating activity

Answer 18

Bulls will “sham mount” a female to test her willingness to “stand” to be mated

The greatest stimulus to a bull is a female (or any large, similarly-shaped object) that is immoble

Question 19

Equine Behvior

Stallion

Answer 19

Vocalization, olfactory and tactile investigation, and the flehmen response

when brought toa mare - stallions will begin sexual behaviors within 2 minutes

stallions can have phychological breeding issues

Almost all stallions respond more vigorously when provided with more than one stimulus mare

Question 20

Equine Behavior

Mare

Answer 20

Estrus in a pasture setting - will approach stallion and exhibit sexual behavior: urination, deviation of tail, standing still

Diestrus in pasture setting - will avoid approaching stallion and exhibit aggression if he persists

will allow close contact with stallion during diestrus for non-sexual social behaviors

Mares will occasionally exhibit estrous behaviors during the anovulatory protions of the year

Question 21

Porcine behavior

Boar

Answer 21

When placed near females - boars will “chant”, salivate profusely, nuzzle the flank and head-rest on the back

When breeding for the first time - the experience needs to be very pleasant (calm, quite, good footing)

Confidence - intimidation by a group of gilts or being beat-up by a larger sow can ruin a young boar for future mating

Young boars should be exposed to one gilt of similar size that is in strong standing heat

do NOT hurry the first mating

Question 22

Porcine Behavior

Sow/Gilt

Answer 22

Male presence is necessary for females to show obvious estrus behavior

Take the female to the male - she assumes the major role in searching for the male

Even when in heat - the female may run away fromt he boar and he will follow her

Mating stance - sows/gults will adopt a “mating stance” (standing immobile with back arched and ears erect)

Question 23

Canine Behavior

Dog

Answer 23

mating should be done int he male’s territory

The dog will be attracted to any female in proestrus, estrus, or diestrus - approach and investigate the anal-genital area

Penile erection occurs after penetration

Question 24

Canine Behavior

Bitch

Answer 24

if not receptive tot he male (proestrus/diestrus)

bitch will sit down when approached

If receptive - will “flag” her tail and assume the mating stance

Question 25

Canine Behavior

The “tie”

Answer 25

After ejaculation - the dog dismounts bt the penis is “locked” in the vaginal vault by the swollen bulbus glandis and the mascular vulva

The dog and bitch position themselves posterior-to-posterior

THe “tie” lasts from a few minutes to over an hour