Lecture 8: Lacation Flashcards
what is puerperium
Period following parturition where the reproductive tract turns back to its non-pregnant state
During puerperium, myometrial contractions occur to do what?
Shrink the uterus (involution) and expel Lochia (blood, uterine lining, discharge)
What is the economic benefit of shortening the puerperium period in livestock
Increase frequency of breeding, increased pregnancy in dairy cows increases lifetime milk yield
What is the time required for uterine involution in a beef cow
30 days
What is the time required for resumption of ovarian activity in a beef cow
50-60 days
What is the time required for uterine involution in the bitch
90 days
What is the time required for resumption of ovarian activity in the bitch
150 days
What is the time required for uterine involution in the dairy cow
45-50 days
What is the time required for resumption of ovarian activity in the dairy cow
18-25 days
What is the time required for uterine involution in the mare
21-28 days
What is the time required for resumption of ovarian activity in the mare
5-12 days
What is the time required for uterine involution in the queen
30 days
What is the time required for resumption of ovarian activity in the queen
30 days
In dairy cows, calves are often removed within 24 hours, why?
Fewer oxytocin episodes that extend puerperium, avoids delayed involution that may delay reproduction
Is energy balance negative or positive in cows after parturition
Negative
To maximize milk production cows are usually bred at least every __ days
365 days
The first ovulation post partum occurs without any visible signs of estrus why?
Silent ovulations because have yet to produce progesterone and estrogen that will induce behavioral estrus
In some cows nursing may delay estrus, why?
Suckling feedback loop suppresses GnRH and LH therefore can’t induce estrus or ovulation
Describe changes from silent ovulation to first behavioral estrus
- After anestrus or pregnancy the ovary follicle develops without behavioral estrus (silent)
- CL produced from the ovulation follicle from silent ovulation secretes progesterone that “primes” the brain, no behavioral estrus
- Priming of the brain by progesterone enables estradiol secretion by next ovulatory follicle to elicit behavioral estrus
Mammary glands are ___glands
Sweat
What are mammary ridges
Occur as two lines of tissue that run centrally from the axial region to the inguinal region
What are primary mammary buds
Result of thickened epidermal tissue that penetrates into the dermis
What are secondary mammary buds
Occur as branching that further invades the dermis
What is canalization
Occurs when the duct system dorms with cells that have excretory capacity and myoepithelial cells that have contractile capability