12. Breeding

Question 1

what stages are in the estrous cycle?

Answer 1

proestrus
estrus
metestrus
diestrus
anestrus

Question 2

proestrus

Answer 2

follicles begin developing and growing

estrogen increases according

Question 3

estrus

Answer 3

period of female sexual receptivity =heat

Estrogen production peaks

Question 4

metestrus

Answer 4

Not all species have a
Metestrus

Period during which the corpus luteum (CL) develops

Progesterone produced by the CL temporarily inhibits
ovulation

Lining of the uterus prepared for implantation of a
fertilized ovum

Question 5

Diestrus

Answer 5

Corpus luteum at maximum size and exerting maximum effect by secreting progesterone

If fertilized ovum implants, CL is retained well into the pregnancy

If pregnancy does not occur, the uterus releases prostaglandin which causes the CL degenerate to at the end of diestrus (i.e. luteolysis).

Question 6

anestrus

Answer 6

not all species have an anestrus

period of temporary ovarian inactivity (ovaries temp. shut down)

Question 7

how long can the oocyte last being unfertilized before it begins to degrade?

Answer 7

12 hours

but sperm travels very fast :)

it takes several minutes to hours after breeding to reach the oviducts

Question 8

why should you never tell a cow a secret?

Answer 8

because it goes in one ear and out the UDDER

keep up the good work!

hit the 5 so this pops up least

Question 9

pregnancy

Answer 9

fertilized oocyte becomes a zygote

embryo moves to the uterus

implantation usually occurs between 14 and 40 days in farm animals but varies between species

Question 10

how do you identify proper breeding candidates?

Answer 10

records, analysis, and statistics

molecular testing

Question 11

genomics

Answer 11

Study of the function of genes and their relationships

Question 12

genome

Answer 12

The complete set of genes and associated regulatory DNA

Question 13

Genome Map

Answer 13

The known order for a set of genes or DNA markers at intervals along a chromosome

Question 14

Genome Mapping

Answer 14

Locating & identifying genes on chromosomes

Identifying gene effects & interactions

Question 15

Marker-assisted selection (MAS)

Answer 15

DNA Marker - a sequence of nucleotides with a known or unique location on a chromosome.

used to identify individuals that have favorable alleles at several loci

Question 16

Single Nucleotide Polymorphism

Answer 16

A site on a chromosome where animals in a

population have different nucleotides

Question 17

Heritability

Answer 17

Measure of the degree to which phenotypic differences for a trait are genetic

Reproductive traits tend to have low heritability
(< 0.20)
Growth traits tend to have moderate heritability
(0.20–0.40)
Carcass traits tend to have fairly high heritability
(> 0.40)

Question 18

breeding value

Answer 18

Value of the animal as a parent

Parents transmit a random sample of the their genetic
material to offspring

provides an estimate of the transmitting ability of the animal

Question 19

expected progeny difference

Answer 19

equal to half of the breeding value

provide a prediction of future progeny performance of one individual compared to another individual within a breed for a specific trait

Means of expressing the predicted difference in progeny of two or more animals (usually sires), when mated to similar animals (usually females), in similar production environments

Question 20

Sire summaries

Answer 20

include a sampling of the available genetic material in each breed.

Provide info on economically important traits:
expected birth wt, weaning wt, yearling wt, carcass wt, fat thickness, marbling score, etc