Reproduction- Physiology Flashcards
Puberty
Animal becomes capable of reproduction
Sexual maturity
Reproduce at optimal level
Sexual maturity for heifers
15 months
Sexual maturity for bulls
2-3 months after puberty
Stages of reproduction(5)
Parturition
Gestation
Lactation
Rebreeding
Hormonal control
True or False: lactation prevents estrus with pigs
True
Estrous cycle definition
Period of time btwn one heat and the next
About 3 weeks
Anestrus definition
Interval if sexual inactivity
Which animals are polyestrous
Cow
Goats
Pigs
Which animal is seasonally polyestrous
Sheep
What happens during proestrus
Follicle enlarges
Estrogen increases
Vascularity increases
FSH and LH increase
What surges during estrus followed by what
LH followed by ovulation
What is 80% of the estrous cycle
Luteal phase
What takes places during diestrus
Longest phase
Progesterone is high(P4)
FSH low
Ends with luteolysis
What is luteolysis
Degradation of corpus luteum
What happens to corpus luteum if female isn’t pregnant
Regresses
Uterus releases PF2€
If offspring is present in a sow what happens dealing with anestrus period
Completely suppresses estrus
If offspring is present in a cow what happens dealing with anestrus period
Suppresses estrus up to 60 days
If offspring is present in a mare what happens dealing with anestrus period
Returns to estrus 9-11 days after foaling
What animals experience a photoperiod
Mare
Ewe
Flushing purpose food wise
Increase ovulation by increasing feed intake prior to estrus
What is seasonal anestrus controlled by
Photoperiod and temperature
With ewes what must be present before estrogen for behavioral estrus
Progesterone(p4)
How long does it take for luteolysis to occur
1-3 days
What increases uterine PGF2€
Oxytocin
True or False: a mare is less sensitive to PGF2€
False they’re more sensitive
What prevents polyspermy
Zone Pellucida
Vitelline membrane
Characteristic of Morula
Division of fertilized egg
Totipotent
Blastocyst characteristics
Trophoblast cells
ICM
Eutherian definition
Animals with placenta
What does ICM turn into
Embryo
How can cows recognize pregnancy
Interferon Tau is released
Inhibits PGF2€ at day 13
What day does implantation occur in cows
Day 12
How can a mare tell when pregnant
Physical presence
eCG
How many pregnancies will sows not exceed
4
Layers of placenta
Amnion
Chorion
Allantois
Amnion function
Closely covers embryo
Temp respiratory organs
Chorion function
Surrounds amniotic sac
Outermost layer
Includes trophoblast
Temp respiratory organs
Allantois function
Waste management and gas exchange
What happens hormonally in the first stage of parturition
Fetal adrenal cortisol releases in response to stress
Increase estrogen
Decrease progesterone
PGF2€ increases contractions
Cervical pressure induces oxytocin
FSH function
Hyperovulation to signal more
Initiates a new follicular wave
FSH origin and structure
Anterior pituitary
Glycoprotein
LH function
Treatment for cystic females
Used in estrous sync
Initiates ovulation
LH origin and structure
Anterior pituitary
Glycoprotein
GnRH function
Signals release of FSH and LH
GnRH origin and structure
Hypothalamus
Peptide
Estrogen function
Responsible for behavioral signs of estrus
Suppresses FSH
Estrogen origin and structure
Ovary
Steroid
Progesterone function
Maintains pregnancy
Progesterone origin and structure
Uterus
Eicosanoid
Adrenal Cortisol function
Released from fetus as part of stage 1 of parturition
Adrenal cortisol origin
Fetal adrenal glands
Oxytocin function
Uterine contractions
Milk let down
Oxytocin origins and structure
Hypothalamus
Peptide
Placentome definition
How body interacts with fetus when released after calving