Estrous cycle and anestrus Flashcards
Estrous cycles:
Time period between periods of estrus (sexually receptive to male), physiological events occurring between successive periods of estrus
Average estrous cycle length in cow (include range):
Average length: 21 days
Range: 17-24 days
Average estrous cycle length in ewe (include range):
Average length: 17 days
Range: 13-19 days
Average estrous cycle length in sow (include range):
Average length: 21 days
Range: 17-25 days
Average estrous cycle length in mare (include range):
Average length: 21 days
Range: 15-26 days
Reproductive cyclicity importance:
Provides the female with repeated opportunities to become pregnant.
Estrous cycles begin and end with:
estrus
Menstrual cycle:
Predictable reproductive events beginning and ending with menses
Estrus is commonly referred to as:
heat
Estrus is a ______.
Estrous is an _______.
Estrual is an ________.
noun
adjective
adjective used to identify a condition related to estrous
Different types of reproductive cyclicity:
Polyestrus, seasonally polyestrus, monoestrus
Estrus causes a dramatic increase in:
estradiol
Domestic canids have about ____ estrous cycles every two years. Estrus lasts _______.
three
several days
The four periods of the estrous cycle:
Estrus, metestrus, diestrus, proestrus
Estrus
Period of sexual receptivity and mating
Estrus length:
12-18 hours in cow
Dominant hormone in estrus and its function:
Estradiol
Behavior changes (receptive rather than disinterested), changes in reproductive tract
Metestrus
Period between ovulation and formation of a functional corpus luteum
Events of metestrus:
Ovulation occurs 27-30 hours after start of estrus or 12-18 hours after end of estrus. CH to CL formation. Progesterone rises. Metestrus bleeding
Metestrus bleeding:
Noticed 35-45 hours after estrus. Capillary breakage causes blood in mucus. Occurs in 90% of heifers and 45% of cows. If seen, you have missed the window for breeding.
Diestrus
Period for preparing the uterus for pregnancy