ADS Chp 10 Hormones

Testosterone

anabolic growth, sperm production, secondary sex characteristics

Melatonin

partial control of seasonal reproductuve patterns

Progesterone

maintains pregnancy, mammary development

Oxytocin

gamete transport, uterine contraction, milk let down

Estrogen

mating behavior, uterine growth, secondary sex characteristics

Prostaglandin F2g

regression of corpus luteum, uterine contraction, ovulation

Luteinizing hormone (LH)

ovulation, corpus luteum formation, progesterone production

Follicle-stimulating hormone (FSH)

development of follicle, estrogen synthesis, sperm production

The estrous cycle is…

a predictable pattern of events that allow for multiple opportunities for pregnancy

Polyestrous

consistent throughout year

Which livestock are known to be polyestrous?

cattle and swine

Seasonally polyestrous

consistent through specific seasons

These livestock are seasonally polyestrous…

sheep, goats, horses

Monoestrus

one or two cycles per year

This animal is monoestrus…

dog

What does the anterior pituitary do?

tells the Leydig cells in the testicles to produce testosterone

What does the hypothalamus do?

sends factors through the blood vessels that affects the anterior pituitary’s production of FSH and LH

What makes up the follicular phase?

proestrus and estrus

Proestrus follicles…

form and produce estrogen

Another word for estrus is…

ovulation

What makes up the luteal phase?

metestrus and diestrus

Does metestrus or diestrus last the longest?

diestrus

Metestrus

CL is formed and progesterone is secreted

Diestrus

sustained release of progesterone

What will the uterus release if pregnancy doesn’t occur?

PGF2a

Estrous Cycle Length of CATTLE

21

Estrous Cycle Length of SHEEP

17

Estrous Cycle Length of HORSE

22

Estrous Cycle Length of SWINE

21

Estrous Cycle Length of GOAT

21

Estrous Cycle Length of BISON

21

Sperm and oocyte uniting equals?

fertilization; conception

Placenta

an organ that creates the metabolic connection between embryo/fetus and dam

What else does the placenta do?

produces hormones that maintain pregnancy, prepare mammary system, and enhance growth of fetus

The different types of placentas is…

diffuse, cotyledonary, zonary, discoid

Diffuse placenta

sow and mare, have even distribution of chorionic villi

Cotyledonary placenta

cows, ewes, and does, have placentomes

What do placentomes look like?

balled shaped/meatballs

Zonary placenta

cats and dogs, have a distinct zone where all exchange occurs

Discoid placenta

primates and rats, have disc-like structure where all exchange occurs

Gestation Length of COW

285 days

Gestation Length of EWE

147 days

Gestation Length of MARE

336 days

Gestation Length of SOW

114 days

Gestation Length of DOE

150 days

What hormone initiates parturition?

cortisol

Parturition includes…

delivery of fetus and placenta

The “proper” birthing position is…

diving position