Livestock Reproduction

Question 1

What is the goal of reproduction?

Answer 1

delivery of live neonates

Question 2

What does poor reproductive efficiency lead to?

Answer 2

loss of money

Question 3

Why is it important to carefully choose livestock to breed?

Answer 3

because who you choose will pass genetics to future generations

Question 4

What are the methods of selection for breeding?

Answer 4

estimated progeny differences, estimated breeding values, pedigree, and confirmation

Question 5

What is estimated progeny differences?

Answer 5

predicts the characteristics of an offspring before they are born

Question 6

What are estimated breeding values?

Answer 6

determines the value of a breeding between 2 animals before breeding occurs

Question 7

What is inbreeding?

Answer 7

mating of two animals that are closely related

Question 8

What is linebreeding?

Answer 8

mating several generation of offspring to a particular animal or descendants (inbreeding at a distance)

Question 9

What is crossbreeding?

Answer 9

sire and dam of different breed (same species, different breeds)

Question 10

What is purebreeding?

Answer 10

mating two animals of the same breed

Question 11

What is autocrossing?

Answer 11

mating between families of the same breed

Question 12

What is grading up?

Answer 12

mating of purebred and a grade animal

Question 13

What are the stages of the estrous cycle?

Answer 13

proestrus, estrus, metaestrus, diestrus, anestrus

Question 14

What is proestrus?

Answer 14

begins with drop in progesterone due to surge of prostaglandin F2a (F2alpha) in diestrus

Question 15

What is estrus?

Answer 15

estrogen reaches a certain level that causes the releases of LH; this triggers ovulation

Question 16

What is metaestrus?

Answer 16

decreasing estrogen due to ruptured follicle

Question 17

What is diestrus?

Answer 17

sexual inactivity; if not pregnant, prostaglandin surge of PGF2a starts cycle over again

Question 18

What is anestrus?

Answer 18

break in the cycle that is seen in seasonally polyestrus species and in pregnant polyestrus species

Question 19

What is the goal of breeding soundness exams?

Answer 19

evaluation of the reproductive performance of an animal

Question 20

What are the primary methods of collecting sperm?

Answer 20

electroejaculation, natural stimulation, artificial vaginas

Question 21

How is semen prepared for artificial insemination?

Answer 21

frozen in hollow straws or ampules

Question 22

What are extenders?

Answer 22

combination of liquid and solid ingredients used to nourish the sperm and help them survive outside live animal

Question 23

What is rectal palpation?

Answer 23

feeling for ovary signs of follicle and/or carpus lutea

Question 24

Vaginal examination is most useful in _____________.

Answer 24

horses

Question 25

Diagnostic ultrasound per rectum is primarily used in ______.

Answer 25

mares

Question 26

What is the most reliable way of observing standing heat in remnants?

Answer 26

mounting behavior: cow being mounted is in heat

Question 27

What is the most reliable way observing standing heat in swine?

Answer 27

lordosis - characteristic stance seen in females when pressure is placed on their back

Question 28

How can estrus be synchronized?

Answer 28

use hormone treatments to synchronize estrus in females

Question 29

In what animals is artificial insemination common in?

Answer 29

cattle, horses, and swine (dairy cattle most common)

Question 30

How do you prep the perineum/vulva for reproductive procedures (AI)?

Answer 30

tail in wrapped, vulva, perineum, anus, and buttock are cleaned with mild soap and water

Question 31

What is a horse's gestation length?

Answer 31

305-365 days (~11 months in general)

Question 32

What is the gestation length of cattle?

Answer 32

283 days

Question 33

What is the gestation length of sheep/goats?

Answer 33

~150 days

Question 34

What is the gestation length of swine?

Answer 34

114 days

Question 35

What are the three stages of labor?

Answer 35

preparatory stage, expulsion of fetus, passage of placenta

Question 36

What is dystocia?

Answer 36

difficult birth

Question 37

What is the most common cause of dystocia?

Answer 37

abnormal fetal position

Question 38

What is normal fetal position?

Answer 38

extended forelimbs, head first

Question 39

What are some signs of dystocia?

Answer 39

visualization of head first out, one foot out

Question 40

What are the three primary methods of treating dystocia?

Answer 40

mutation and delivery by traction, c-section, and fetotomy (fetus/neonate dead)

Question 41

What is the most common way to treat dystocia?

Answer 41

mutation and delivery by traction

Question 42

What are calf jacks?

Answer 42

allow for additional leverage when pulling

Question 43

C-sections are common in __________.

Answer 43

ruminants

Question 44

What is a fetotomy?

Answer 44

involves cutting/amputating portions of fetus to allow easier removal by traction