genetics quiz

Question 1

define breed

Answer 1

animals that, through selective breeding, closely resemble one another and pass traits down

Question 2

what traits should be selected for

Answer 2

economically relevant traits

Question 3

what are economically relevant traits

Answer 3

growth traits
milk production
weaning weight
reproductive traits
carcass traits
temperament
feed efficiency

Question 4

how many cattle breeds are there

Answer 4

250+ worldwide
80+ in USA

Question 5

describe British breeds

Answer 5

originated in the British Isles
small in size but good flesh and marbling

Question 6

what are the British breeds

Answer 6

Angus (black and red)
hereford
shorthorn
galloway
red poll
scotch highland
welsh black

Question 7

describe Angus

Answer 7

black or red and polled
Calving ease
good meat quality
imported 1873

Question 8

describe Hereford

Answer 8

red body
white face
horned or polled
introduced 1817
range cattle

Question 9

describe Shorthorn

Answer 9

red, white or roan
horned or polled
imported 1783

Question 10

describe Continental Breeds

Answer 10

originated in Europe
good weight gain and curability
large, lean, and muscular

Question 11

name the continental breeds

Answer 11

charolais
simmental
limousin
gelbvieh
chianina
Piedmontese
salers

Question 12

describe charolais

Answer 12

white
muscular
horned or polled
imported after WW1
oldest French breed

Question 13

describe Simmental

Answer 13

yellow or red and white, or black
polled or horned
swiss
imported 1967

Question 14

describe limousin

Answer 14

golden red or black
muscled
polled or horned
dual purpose
imported 1969

Question 15

describe gelbvieh

Answer 15

golden, red, or black
horned or polled
dual purpose
imported 1971

Question 16

describe the Bos indicus

Answer 16

good heat tolerance, pest resistance, and disease resistance
tougher meat

Question 17

name Bos indicus breeds

Answer 17

brahman
beefmaster
brangus
santa Gertrudis
Braford
brahmousin

Question 18

describe brahman

Answer 18

light grey, red, or back
developed from Indian cattle
imported 1849

Question 19

describe beefmaster

Answer 19

various color
horned or polled
brahman (1/2), hereford (1/4) and shorthorn (1/4)

Question 20

describe brangus

Answer 20

black
polled
3/8 brahman
5/8 Angus

Question 21

describe santa Gertrudis

Answer 21

deep red
polled, scurred or horned
5/8 shorthorn, 3/8 brahman

Question 22

what does MARC do

Answer 22

characterize breeds for rate and efficiency

Question 23

what is performance testing

Answer 23

records individual performance of a certain trait
depends on accurate measurements, adjustments for environmental effects, and contemporary groups

Question 24

what is adjusted weaning weight equation

Answer 24

(weaning wt-birth wt/age of weaning)x205days+birth wt

Question 25

where does testing take place

Answer 25

on the farm or central testing center

Question 26

what is bull testing

Answer 26

records abilities of bulls sound scientific basis

Question 27

what is heifer development

Answer 27

developed to replace breeding stock uniform development of heifers

Question 28

what is feedlot evaluation

Answer 28

allows producers to obtain feedlot carcass performance information allows smaller producers to retain ownership

Question 29

describe cross breeding

Answer 29

typically used by commercial producers increases breed complementary and heterosis

Question 30

describe 2 breed rotational crossbreeding systems

Answer 30

keeps some females must have enough pastures for each group each group should have 30 cows

Question 31

describe 3 breed rotational crossbreeding systems

Answer 31

more heterosis, less uniformity

Question 32

describe terminal sire crossbreeding

Answer 32

2 main groups, 3 group is sold

Question 33

describe rota-terminal crossbreeding system

Answer 33

use young females as replacements, then move into breeding group rotated about every 4 years

Question 34

define composite

Answer 34

crossbreed with set percentages of breeds

Question 35

define F1

Answer 35

crossbred cattle

Question 36

what are big problems with crossbreeding failures

Answer 36

certain breeds and traits are overused mating systems are too complex seedstock producers fail in creating a crossbreeding system poor quality bulls are used environmental difficulties

Question 37

what is selection

Answer 37

determines the parents of the next generation natural or artificial

Question 38

what are goals of selection

Answer 38

genetic improvement for desired change

Question 39

define tandem

Answer 39

one trait is selected at a time least effective method

Question 40

define independent culling level

Answer 40

minimum culling level for each trait disadvantage: might be excellent in all traits but one

Question 41

define selection index

Answer 41

most effective, but difficult to construct

Question 42

define pedigree

Answer 42

useful when no progeny is available used for longevity and sex-limited traits

Question 43

deine individual performance

Answer 43

widely used for highly heritable traits permits rapid generational turnover

Question 44

define progeny testing

Answer 44

accurate for lowly heritable traits limited, longer interval

Question 45

define expected progeny differences

Answer 45

compares animals across herds or breeds pedigrees estimate without data based on progeny, pedigree, and performance

Question 46

what are marker assisted selection

Answer 46

selection for specific alleles includes EPDs and genetic test results