Term
Which of the following is true about accuracy of selection?
A) it is the same for prediction of 1/2 breeding value (ex. EPD) as for full breeding value
B) it can be negative
C) it must always be greater in selection of males than of females
D) it is found by taking the square root of the coefficient of variation |
|
Definition
A) it is the same for prediction of 1/2 breeding value (ex. EPD) as for full breeding value |
|
|
Term
Mature size for half sibs is correlated as compared to unrelated pairs of animals. This correlation is caused by genetic and possible environmental likeness within half-sib families. The amount fo the correlation due to the genetic likeness is: A) 2 times heritability B) 4 times heritability C) .25 times heritability D) .50 times heritability |
|
Definition
C) .25 times heritability |
|
|
Term
When predicting breeding value based on the phenotypic performance of full-sibs, the presence of environmental likeness (c2) that increases the correlation between phenotypes of full-sibs will: A) hinder the accuracy possible for selection decisions B) enhance the accuracy possible for selection decisions C) cause accuracy to go to 1.0 as numbers of sibs increases D) have no effect on accuracy of selection decisions |
|
Definition
A) hinder the accuracy possible for selection decisions |
|
|
Term
Prediction of breeding value from progeny data for sire can approach perfect accuracy. A condition that would not enhance attainment of high accuracy is: A) having a very large number of progeny B) having no environmental likeness contributing to the correlation between progeny C) having all the progeny from different dams D) having all the progeny from the same dam
|
|
Definition
D) having all the progeny from the same dam |
|
|
Term
One of the major strengths of a selection index is: A) we can have greater intensity of selection for males B) it incorporates multiple ovulation of females C) it will rank animals on our best prediction of overall net merit breeding value, and this overall breeding value uses relative economic values for the component breeding values. D) it makes intensity of female selection as great as for male selection
|
|
Definition
C) it will rank animals on our best prediction of overall net merit breeding value, and this overall breeding value uses relative economic values for the component breeding values |
|
|
Term
Which of the following indexes will not rank animals the same as the others? A) I = 210 + 1.2 x Milk - 5.4 x Feed B) I = 2.4 x Milk - 10.8 x Feed C) I = 100 + 2.4 x (Milk-Milk average) - 10.8 x (Feed-Feed average) D) I = 100+3.6 x Milk - 6.8 x Feed |
|
Definition
D) I = 100+3.6 x Milk - 6.8 x Feed |
|
|
Term
In problem set 14, we calulated an index value for several pigs based on I = -100 EPDBF - EPDDAYS + 100 EPDNBA + 3 EPDLWT. The values used as multipliers of the EPD (1/2 breeding value) values for the various traits were: A) the standard deviations for the specific traits B) the variances for the specific traits C) the relative economic values for the specific traits D) the effective fractions selected for the specific traits |
|
Definition
C) the relative economic values for the specific traits |
|
|
Term
Multiple ovulation and embryo transfer in a species like cattle could have all the following effects on a selection program except which? A) reduce the generation interval for females B) increase the genetic variation available for selection C) increase intensity of female selection D) increase accuracy of selection
|
|
Definition
B) increase the genetic variation available for selection |
|
|
Term
In totally sustaining beef crossing systems, when a terminal crossing program is employed with natural reproduction, about 40% of the matings are for terminal crossing with all male and female offspring sent to slaughter, and about 60% of the matings are to sustain the production of replacement females. With the ability to control sex of calves, we would expect to change these proportions to: A) 20% of the matings are for terminal crosses and 80% are for replacement females B) 80% of the matings are for terminal crosses and 20% are for replacement females C) 30% of the matings are for terminal crosses and 70% are for replacement females D) 70% of the matings are for terminal crosses and 30% are for replacement females |
|
Definition
D) 70% of the matings are for terminal crosses and 30% are for replacement females |
|
|
Term
Prediction of breeding value when incorporating exact knowledge of the genotypes at specific quantitative trait loci will: A) reduce accuracy of selection decisions B) increase accuracy of selection decisions C) have no effect on accuracy of selection decisions D) reduce intensity of selection
|
|
Definition
B) increase accuracy of selection decisions |
|
|
Term
The terminal index that the American International Charolais Association has for its bulls is a what to rank sires for: A) reproduction B) maternal milking C) carcass and growth D) draft ability
|
|
Definition
|
|
Term
In class, we learned about research work with a lysozyme transgene in which species? A) horses B) cattle C) turkeys D) goats
|
|
Definition
|
|
Term
For milk yield in a dairy population, h2= 0.20 and re= 0.35. Accuracy when predicting breeding value for a "clone family" using 10 animal records in the clone family is: A) [(10)(0.20)(1)(1)]/[1+(9 x 0.20)]0.5 = 0.85 B) [(10)(0.20)(1)(1)]/[1+(9 x 0.35)]0.5 = 0.69 C) [4 x 0.20]0.5 = 0.89 D) [(10)(0.20)(0.20)]0.5 = 0.63
|
|
Definition
A) [(10)(0.20)(1)(1)]/[1+(9 x 0.20)]0.5 = 0.85 |
|
|
Term
Using complete sentences, give the two definitions of heritability (one as a fraction of phenotypic variance explained and the other as a regression coefficient).
|
|
Definition
Heritability is the fraction of the variance in phenotypic values that is explained (or is caused by) variance in breeding values Heritability is the regression of breeding value on phenotypic value |
|
|
