Livestock Reproduction Flashcards
What is the goal of reproduction?
delivery of live neonates
What does poor reproductive efficiency lead to?
loss of money
Why is it important to carefully choose livestock to breed?
because who you choose will pass genetics to future generations
What are the methods of selection for breeding?
estimated progeny differences, estimated breeding values, pedigree, and confirmation
What is estimated progeny differences?
predicts the characteristics of an offspring before they are born
What are estimated breeding values?
determines the value of a breeding between 2 animals before breeding occurs
What is inbreeding?
mating of two animals that are closely related
What is linebreeding?
mating several generation of offspring to a particular animal or descendants (inbreeding at a distance)
What is crossbreeding?
sire and dam of different breed (same species, different breeds)
What is purebreeding?
mating two animals of the same breed
What is autocrossing?
mating between families of the same breed
What is grading up?
mating of purebred and a grade animal
What are the stages of the estrous cycle?
proestrus, estrus, metaestrus, diestrus, anestrus
What is proestrus?
begins with drop in progesterone due to surge of prostaglandin F2a (F2alpha) in diestrus
What is estrus?
estrogen reaches a certain level that causes the releases of LH; this triggers ovulation
What is metaestrus?
decreasing estrogen due to ruptured follicle
What is diestrus?
sexual inactivity; if not pregnant, prostaglandin surge of PGF2a starts cycle over again
What is anestrus?
break in the cycle that is seen in seasonally polyestrus species and in pregnant polyestrus species
What is the goal of breeding soundness exams?
evaluation of the reproductive performance of an animal
What are the primary methods of collecting sperm?
electroejaculation, natural stimulation, artificial vaginas
How is semen prepared for artificial insemination?
frozen in hollow straws or ampules
What are extenders?
combination of liquid and solid ingredients used to nourish the sperm and help them survive outside live animal
What is rectal palpation?
feeling for ovary signs of follicle and/or carpus lutea
Vaginal examination is most useful in _____________.
horses
Diagnostic ultrasound per rectum is primarily used in ______.
mares
What is the most reliable way of observing standing heat in remnants?
mounting behavior: cow being mounted is in heat
What is the most reliable way observing standing heat in swine?
lordosis - characteristic stance seen in females when pressure is placed on their back
How can estrus be synchronized?
use hormone treatments to synchronize estrus in females
In what animals is artificial insemination common in?
cattle, horses, and swine (dairy cattle most common)
How do you prep the perineum/vulva for reproductive procedures (AI)?
tail in wrapped, vulva, perineum, anus, and buttock are cleaned with mild soap and water
What is a horse’s gestation length?
305-365 days (~11 months in general)
What is the gestation length of cattle?
283 days
What is the gestation length of sheep/goats?
~150 days
What is the gestation length of swine?
114 days
What are the three stages of labor?
preparatory stage, expulsion of fetus, passage of placenta
What is dystocia?
difficult birth
What is the most common cause of dystocia?
abnormal fetal position
What is normal fetal position?
extended forelimbs, head first
What are some signs of dystocia?
visualization of head first out, one foot out
What are the three primary methods of treating dystocia?
mutation and delivery by traction, c-section, and fetotomy (fetus/neonate dead)
What is the most common way to treat dystocia?
mutation and delivery by traction
What are calf jacks?
allow for additional leverage when pulling
C-sections are common in __________.
ruminants
What is a fetotomy?
involves cutting/amputating portions of fetus to allow easier removal by traction
