Intro Flashcards
describe the repro tract of a cow
bicornuate, 2 ovaries, 2 oviducts, 2 horns
describe the exocrine function of the ovary
ovum production
describe the endocrine function of the ovary
hormones
list the 2 main hormones produced by the ovary
- estrogen (E2)
2. progesterone (P4
describe the function of estrogen
comes from the follicle, creates environment for possible fertilization
describe the behavioral result of estrogen
estrus
describe the physiological function of estrogen
sperm transport
what secretes progesterone?
the corpus luteum
what is the function of progesterone?
creates environment possible for fetal development
list the 3 functions of the uterus
- sperm transport: dead and alive
- site of gestation: development; placental attachment
- endocrine
what is the function of the cervix?
portection of the uterus
when the cervix is closed, what is its function?
physical barrier
when the cervix is open, what is its function?
is response to E2, mucus production to flush out any bad things
what is the function of the cervix during parturition?
birth
what is the function of the vagina?
site of semen deposition (natural mating)
where is semen deposited in AI?
uterus
what is the estrous cycle?
all physiological and behavioral changes that occur from one ovulation to the next
how long is the estrous cycle for cattle?
21 days
what is estrus?
behavioral receptivity to be bred
how long is estrus for cattle?
12 hours
what is an ovum?
an unfertilized female gamete follicle
when does ovulation occur in cattle?
12 hours after estrus
how long is gestation for cattle?
285 days
what are the 2 phases of the estrous cycle?
the follicular phase and the luteal phase
describe the follicular phase of the estrous cycle
max growth of ovum and follicle, produces E2, induces estrus, follicle ruptures during ovulation
describe the luteal phase of the estrous cycle
corpus luteum formed, secretes P4, PGF2a causes regression of CL, cycle starts again
what event marks day 1 of the estrous cycle?
ovulation
what phase of the estrous cycle follows ovulation?
the luteal phase
what structure releases what hormone in the luteal phase?
the corpus luteum produces progesterone (P4)
are E2 levels high or low during the luteal phase?
LOW
what event triggers the end of the luteal phase and the beginning of the follicular phase?
luteolysis
what hormone is hugh during the follicular phase?
estrogen (E2)
what hormone stimulates follicle growth and, in conjunction with LH, E2 production?
FSH
what is the role of PGF2a?
regression of corpus luteum if animal not pregnant
what is the role of P4?
prepares repro tract for gestation
what is the role of E2?
prepares repro tract for fertilization
what is the role of LH? (3)
- ovulation
- maintains CL when P4 is high
- E2 production (with FSH)
what is the role of FSH? (2)
- follicle growth
2. E2 production (with LH)
what behavioral characteristics take place 6-10 hours before standing estrus? (6)
- animal will not stand to be ridden
- vocal
- nervous and restless
- smells other cows
- attempts to ride other cows
- vulva moist, red, and slightly swollen
what behavioral characteristics occur during standing estrus?
- stands to be ridden
- congregates
- rides other cows in standing estrus
- vulva moist, red, and slightly swollen
- clear mucous discharge
how long does standing estrus last? what is the average?
6-24 hours, average is 12 hours
what behavioral characteristics occur up to 10 hours after standing estrus? (2)
- animal will not stand to be ridden
2. clear mucous discharge
what behavioral characteristics occur 1-3 days after standing estrus? (2)
- animal will not stand to be ridden
2. bloody mucous discharge
in terms of estrus synchronization protocols, what is a CSU and how long does it last?
full estrous synchronization protocol, 5 day estrus detection
with 24hour/day monitoring, what percentage of estrus can be detected with CSU?
95%
with twice a day for 30 minutes each time monitoring, what percentage of estrus can be detected?
55%
where is PSU estrus detection found?
dairies
with PSU detection, what percentage of estrus is detected? what percentage is misidentified as being in estrus?
less than 50% estrus detected, and 30% false positive
what is the conception rate of breeding?
70% chance of conception/breeding
what is the percentage of embryonic mortality in breeding?
15-20%
what is the percentage of failure in sperm transport/fertilization?
10-15%
list 5 types of estrus detection aids
- records
- temp
- pedometers
- tail head
- progesterone assays
how much will body temperature change when an animal is in standing estrus?
as little as one-tenth of a degree
is temperature a good estrus detection aid? why or why not?
varies so little, need extremely accurate thermometer and timing
how does a pedometer aid in estrus detection?
detects increased movement as an animal comes into estrus
list and describe the 4 types of estrus detection aids involving the tail head
- hair: disturbed from others mounting
- chalk: if smudged, she was mounted
- patches: pressure sensors to detect mounting
- electronics: more pressure sensors
describe the role of progesterone assays in estrus detection aid
reduces misidentification, reveals accuracy of estru detection by showing when an animal is NOT is estrus
list and describe 6 other things that play a role in estrus detection efficiency
- frequency: more often= more accurate
- time of day: animals busier at dawn and dusk and when it’s not too hot
- environment temperature: too hot=upset cows due to rumen heat = less activity
- milking: don’t check as much when milking, as cows are worried about other things
- location-footing: slippery= cows move less
- novelty- animal and/or location: mixing animals = everyone excited