exam 3 Flashcards
(198 cards)
1
Q
define selection
A
most efficient mean to influence the rate of genetic change and improvement
2
Q
what helps change the genotype
A
h^2, selection differential, population size, generation interval
3
Q
what does h^2 do
A
the higher it is, the faster the rate of change
4
Q
what is the equation for selection differential
A
mean of selected individual - the mean of the population
5
Q
what is population size
A
greater size means greater superiority
6
Q
what is the generation interval
A
the number of years for a population to turn over
7
Q
define sources of information
A
selecting animals to change a population
8
Q
what four things are sources of information
A
individual performance, pedigree, collateral relatives, progeny
9
Q
individual performance is ____________
A
measurable
10
Q
define pedigree
A
the performance of an individual’s ancestors
11
Q
define collateral relatives
A
performance of half sibs and full sibs to look at sex-limited traits
12
Q
define progeny
A
the best way to measure genetic worth
13
Q
define accuracy
A
an estimate of how accurately the genotype of an individual for a certain trait can be predicted from phenotypic average of its relatives
14
Q
define individual performance
A
a value highly related to h^2
15
Q
what are the disadvantages of individual performance
A
sex-limited traits
traits requiring time
carcass traits
how h^2 traits
16
Q
define estimated breeding value
A
a single trait
17
Q
what is the equation for EBV
A
h^2(x-mean of x)/2
18
Q
improvement is ____________
A
static
19
Q
define accuracy of individual performance
A
based on one record
20
Q
accuracy =
A
the sqrt of h^2
21
Q
define pedigree
A
based on ancestor performance or the degree of a relationship
22
Q
environmental correlation is between…
A
ancestors and individuals
23
Q
what are the advantages of pedigrees
A
cheap
valuable for sex-limited traits
valuable for traits expressed later in life
low h^2 traits
24
Q
how are traits measured accurately
A
by being measured in the same environment at the same age.
25
what are the disadvantages of a pedigree
inaccurate/no records
no comparative base for selection
can't see if ancestry is good for a trait
mistakes can happen
26
what make up collateral damage? describe them
full siblings- same parents
half siblings- one common parent
27
what are the values of collateral damage
sex-limited traits
traits that require slaughter to measure
accuracy is lower
28
what factors affect the accuracy of sibling tests
h^2 of a trait
relationship of sibs
number of sibs tested
29
what makes up the correlation of the phenotype
environmental correlation
maternal environment
30
full sibs are _______ related
half sibs are ________ related
half
1/4
31
what are sibs helpful for
showing the accuracy of how h^2
32
define progeny testing
evaluation of the genetic makeup of an individual by phenotype of its progeny
33
what does progeny testing look at
qualitative and quantitative traits
34
what does progeny testing do
help determine the likelihood that an individual is a carrier of a detrimental allele
35
what factors affect the success of progeny
genetic makeup
number of offspring produced
36
define test mating
the number of offspring required to determine the likelihood an animal is not a carrier
37
what is the advantage and disadvantage of sirexrecessive
A- fewer matings required
D- finding recessive animals
38
what is the advantage and disadvantage of sire x heterozygote
A- known carrier
D- ID animals and more mating
39
what is the advantage and disadvantage of sire x daughter
A- easy to obtain
D- inbreeding depression, many progeny required
40
what is the BV of offspring compared to its parents
1/2
41
what does increased progeny mean
there is an increased accuracy
42
what does it mean if accuracy equals 1.22
it is 22% more accurate than normal
43
as h^2 increases...
more progeny are required to equal the accuracy of individual performance
44
what does net value depend on
several traits
45
what are the three basic methods of selection
tandem
independent culling method
selection index
46
define tandem
individually selecting one trait, then another
47
what are problems with tandem
genetic relationship of traits
more traits means slower progress
long time
48
define independent culling method
if an animal has below the minimum level in any trait is culled
49
what's a problem with independent culling method
the animal may be outstanding in one trait, but below average in another trait, thus getting culled
50
define selection index
it places different degrees of emphasis on traits of interest
51
what does selection index determine?
the genetic worth of an animal
52
what does selection index do
gives an animal a total score by adding all the values
53
I=
b1x1 + b2x2 + bnxn
54
what does I, b, and x stand for in the equation
index value
weight vector
single item of phenotypic information
55
define BLUP
best linear of selection index
extension of selection index
56
where does performance data come from with BLUP
contemporary groups
57
what are contemporary groups
age
herd
etc
58
what are the three keys for selection? describe them
1. genetic relationship among traits
how strong a relationship is
2. number of traits being selected for
more traits means slower process
3. h2 of traits
correlated response (strength of movement of traits)
59
what is the most important trait in dairy cows
milk production
60
what are common dairy breeds
holstein, jersey, gurnsey, brown Swiss, Ayrshire, shorthorn
61
what traits are selected for in dairy cattle
milk production
fertility
% fat
temperament
calving ease
62
define total fat
increases with volume
63
define % fat
increases by unit
64
what are linear traits in dairy
stature
strength
body depth
dairy form
rump angle
foot angle
65
what is the h2 of milk production
0.35
66
what is the fat yield in cows
+0.75
67
what is % fat in cattle
-0.4
68
true or false: crossbreeding is constantly used in dairy cattle
false
69
which breed is best for the pound of milk produced
holstein
70
what cow has the best % fat
Jersey
71
what are the two sources of genetic improvement in dairy? describe them
sire- most genetic progress because they produce more
dam- little genetic process
72
what is dairy selection
the number of progeny vs. dam
73
what does AI allow for
large progeny
74
what is selection based on
closeness of females relatives and progeny testing of offspring
75
what does the DHIA do
create a system of records
76
what do DHIA records include
performance records of many sources of variation in performance and private cooperative operated through NCSU
77
what percentage of diary producers participate in DHIA
45%
78
what are sires selected on
PTA
79
what are the three keys in DHIA selection
1. record systems are based on comparisons of contemporaries on a similar basis
help select the best animal
2. limited number of traits are selected for
3. adoption of technology
80
what type of technology do dairy breeders use
AI
environmental control
81
define environmental control. give examples.
modifying the environment for animals to produce more
health programs
nutrition
facilities
equipment
82
define bST
a naturally occurring hormone in cows that regulate milk production
83
what is IGF-1
insulin-like growth factor 1
84
what does increased IGF-1 cause
increased milk
85
what does bST cause
mastitis
86
what does large scale use of information allow for
knowledge of differences in DNA sequencing in individual cattle
87
describe cervical vertebral malfunction
year
bull
diagnosis
gene that is mutated
1999
Carlin M Ivanhoe Bell
genetic testing
SLC35A3
88
describe bovine brachyspina
year
name
type of disease
symptoms
70s-80s
Sweet Haven Tradition
autosomal recessive
shortening of spine
reduced body weight
uneven teeth
malformed organs
89
how many genes are deleted in bovine brachyspina
3.3 Kb
90
describe the bovine leukocyte adhesion deficiency
year
bull
symptoms
affected gene
50s-60s
Osborndale Ivanhoe
fever
low appetite
chronic pneumonia
diarrhea
ulcers
stunted growth
impaired wound healing
gene affected is #383 on CD18 gene
91
bovine leukocyte adhesion deficiency is an ____________ recessive and infects the _________ ___________
autosomal
soft tissue
92
what amino acid is changed in BLAD
glycine replaces aspartic acid
93
describer syndactlyl
phenotype
symptoms
mutation
autosomal al recessive with variable penetrance
digits are fused (commonly on front leg)
superior fat and milk
2 mutations on LRP4 gene
94
describe bovine progressive degenerative myeloencephalophathy
autosome
affected genes
bos taurus autosome 4
affects 46 to 56 million base pairs
PNPLAS
CTTNBP2
95
define synonymous
does not change amino acid being produced
96
define non-synonymous
changes amino acids being coded for
97
in beef selection, what is modified?
the animal, not the environment
98
what are the 6 steps of beef infrastructure
purebred
cow/calf
stocker
feedlot
packer
consumer
99
define purebred in the beef industry
provide genetics of cattle
100
define cow/calf
produce one calf/cow/year
looking for calving ease and fertility traits
101
define stocker
provide pasture for calves
102
define feedlot
increase growth rate and IMF through feed
103
define packer
slaughter and package meat
104
define consumer
buy and consume products
105
what are the three steps in beef selection
1. producer goals and objectives
2. different environments and available natural resources
3. more traits of economic importance
106
what are the goals/objectives of beef
calf production and increasing weight
107
what does it mean if there are more traits being selected for in beef
the progress is slower
108
define vertical integration
a main company
109
true or false: the beef industry has vertical integration
false, it does NOT have vertical integration
110
what is an example of vertical integration
tyson
111
give examples of fertility traits
calving ease
heifer pregnancy
rebreeding rate
days open
daughter pregnancy rate
112
give examples of growth traits
birth weight
weaning weight
yearling weight
ADG
feed efficiency
113
give examples of carcass trait
IMF
fat thickness
ribeye area
114
how does beef differ from dairy
performance records and technology usage
115
what do beef cattle have in place of record systems
a sire summary for each breed
116
what percentage of AI is used in beef
13%
117
what can alter performance of beef cattle
GxE interactions
118
why do beef have a slower adaption to technology
because herds are small and ranchers are part time
119
what does crossbreeding take advantage of
heterosis
120
what is the most useful tool for commercial beef producers
EPD
121
what does EPD allow for
the best selection
122
what does EPD do in rotational crossbreeding? in terminal?
uniformity
divergence
123
why is the Angus at 0?
because it is the base for beef cattle because the bloodline is seen in most breeds
124
what helps determine against deleterious recessive allele
genetic testing
125
describe curly calf syndrome
year
breed
genotype
symptoms
1680
Angus
recessive
curved spine
extended and contracted limbs
126
describe developmental duplication
the latest genetic disorder in Australia where calves are born with extra limbs
127
define genetic testing
used to test for carriers of a trait
128
what is MAS
marker assisted selection
129
what are the 3 good points of beef selection? describe them
1. economic traits have hight H2 and are not sex limited
easier to select and offspring look like parents
2. traits are easy to measure
3. consolidation of packing industry
cattle must be a particular weight and changes should be consistent
130
what are the five keys to success for beef selection? describe them
1. value of performance records and EBVs
allows faster genetic increasing
2. recognition and identification of breeds that excel in certain characteristics
no one breed can be the best or perfectly fitted to the environment
3. selection
avoid fads
determine herd objectives
based on performance
4. adjusted weaning weight
possible sources of variation
cow/calf
age of calf
breed
age of dam
sex of calf
5. MPPA
accounts for cows with different records
131
define genetic standpoint
adjusted weights eliminate some variation
132
what is the equation for genetic standpoint
(actual wt-birth wt)/age (x+birth wt)
133
define repeatability
estimates probability of repeating
134
what is the h2 of weaning wt? r?
moderate
0.4
135
what does each portion stand for in HA+NR/H(n-1)r(CA-HA)
N- number of records/individuals
R- repeatability estimate for one record
HA- herd average
CA- cow average
136
what are the best animals
ones with the highest number
137
what are the three genres for sheep in the US
purebred
commercial
dairy
138
describe purebred sheep
seed stock for commercial producers
show sheep or club lambs
139
describe commercial sheep
used for meat (majority of income)
and wool, which is a secondary income
140
describe dairy sheep
for cheese production, growing in the Great Lake region
141
what are the three traits for economic importance
meat production
wool production
milk
142
describe meat production
the number of lambs born and weaned
growth rate
143
describe wool produciton
fiber diameter
fleece weight
144
describe milk production
production/lactation
145
determine the h2 for:
1. growth traits
2. carcass traits
3. reproductive traits
4. fleece traits
1. low-mod
2. low-high
3. very low
4. mod-high
146
define prolificacy
production
147
dressing %=
dressing wt/live wt x 100
148
how many sheep breeds are there worldwide? in the US?
over 425
about 47
149
in sheep, when is crossbreeding used? inbreeding?
commercial production
purebreds and breeds with small numbers
150
are sheep EPDs common?
no, they're only used in a few breeds
151
what does the national sheep improvement program do?
calculates cross-flock EPDs for sheep
152
define the central ram test
measures moderate to high h2 in a young ram
153
describe spider syndrome
lethality
breeds
genotype
cause
semi-lethal to lethal
suffolk, Hampshire, southdown, Oxford
recessive
fibroblast growth factor receptors
154
what is scrapie
a CNS disease
155
how often is scrapie seen
1/500 mature ewes
156
what are the losses due to scrapie
$20-25 million lost per year
157
what does spider syndrome cause
lost export opportunities
increased offal disposal cost
reduced productivity
158
what are some symptoms of scrapie
scraping off wool and hair
itching and rubbing
wool pulling
bunny hopping of rear legs
high stepping gait of forelimbs
159
how does one diagnose scrapie
in a dead animal, examine the brain and lymph nodes for abnormal prions
in a live animal, examine the third eyelid
160
what is the treatment for scrapie
there is none
161
what causes scrapie
prion protein
162
what codons are tested for scrapie
136, 154, 171
163
what are important traits for sheep
booroola and callipyge
164
describe boorcola
discovered in merino in australia
increases ovulation rate
mapped to 6 chromosomes
higher liter size, but poor survival rate and growth
165
describe callipyge
mapped to chromosome 18
high dressing percentage and larger loin eye
creates tough meat
polar over dominance
decreases fat measure
improved feed efficiency and dressing %
166
why are horses the least studied livestock
recreational use
long GI
long gestation
age to puberty
offspring/yr
lack of accurate records
167
what is the main problem for determining h2 in horses
variation
168
what are examples of variation in horses
racing
surface
condition
age
level of training
nutrition
169
what is the largest variation in horses
environment
170
what is data bias
choosing and selecting animals that perform well without giving others a chance
171
what are traits for economic importance in horses
fertility and performance
172
what is live foal crop? its %?
the amount of foals that survive
50-70%
173
horses have a ______ performance compared to other livestock
lower
174
how long is a horses estrus
5-7 days
175
what is the artificial birth date of horses
Jan 1st
176
define hand mating and pasture mating
hand- selecting which individuals mate
pasture- letting animals mate freely
177
what are some examples of performance in horses
stride length
frequency of stride
muscle fiber types (1 or 2)
178
what is muscle fiber type one good for
endurance
179
what are horse sales based on
pedigree
180
what is used to measure h2 in horses
speed index
lifetime earnings
average earnings
181
what is the h2 for performance in horses
moderate
182
trotters are ________ and pacers are _________
dominant; recessive
183
what is the h2 of trotters and pacers
low
184
what are the divisions of cattle work? describe them
1. ranch work
working livestock and rough terrain
2. roping
close contact with animals and high agility
3. cutting
highly athletic and response to calf movement outside the herd
185
define cow sense
horse's interest in a cow
186
what is the h2 of cow sense
very low
187
define barrel racing
speed and agility
188
what is the h2 of:
1. free jump
2. with rider
3. winner over course
4. style
1. mod-low
2. low
3. low
4. high
189
why are colored breeds not purebred
they don't breed true
190
what are mating systems used in equine
line breeding
positive assertive mating
inbreeding
crossbreeding
191
describe equine line breeding
common
concentrates one individuals genes
192
describe equine positive assertive mating
breeding the best to the best
193
describe equine inbreeding
rare
used for creating new breeds or increasing small herds
194
describe equine crossbreeding
used somewhat for breed development
195
describe CID (combined immunodeficiency)
DNA PKCS
Arabian horses
recessive
affects immune system
196
describe bleeders
exercised induced pulmonary hemorrhage
blood vessels burst in lungs due to respiratory infection
pounding hooves cause trauma in the lungs
adversely affect performance
recessive
causes diuretic
197
describe wobblers syndrome
cervical vertebrae malformation
5, 6, and 7
ataxia
recessive
in TB and QH
198
describe HYPP
a line of QH from Impressive
defective sodium voltage gate ion in muscle cells cause high K in the blood
dominant
