Page 128 - Calculating Agriculture Cover 20191124 STUDENT - A

11-20 Large Animal: Beef, Swine and Sheep CH 11]

Homework #11-1
Name: ____________________________

ALWAYS SHOW YOUR WORK

Refer to page 11-3
1. A ewe has an average grease fleece weight of 20 pounds and comes from a herd which has an
average fleece weight of 15 pounds. What would be her Probable Genetic Value for grease fleece
weight? Refer to Table 11.1 Heritability estimates
Solution:
Probable Genetic Value = flock average + [(ewe’s value − flock average) x heritability estimate]
= 15 + [(20 − 15) x 40%]
Change % to Decimal = 15 + [(20 – 15) x 0.40]
= 15 + [ 5 x 0.40]
= 15 + 2
= 17

2. A heifer with an adjusted weaning weight of 520 pounds from a herd having an average weaning
weight of 485 pounds, what would be the genetic value? Table 11.1 Heritability estimates
Solution:
Probable Genetic Value = herd Average + [(heifers value − herd average) x heritability estimate]
= 485 + [(520 − 485) x 28%]
= 485 + [(520 – 485) x 0.28]
= 485 + [ 35 x 0.28]
= 485 + 9.8
= 494.8

3. If a boar with 1.0 inch backfat is selected from a herd having an average backfat of 1.5 inches,
what would his Probable Genetic Value be for backfat? Refer to Table 11.1 Heritability estimates
Solution:
Probable Genetic Value = herd average + [(boar value − herd average) x heritability estimate]
= 1.5 + [(1 − 1.5) x 50%]
Change % to Decimal = 1.5 + [(1 – 1.5) x 0.50]
= 1.5 + [ − 0.5 x 0.50]
= 1.5 + − 0.25
= 1.25

4. If a Holstein-Friesian cow produces an average butterfat percent of 4.0 and the herd average is 3.60,
what is her Probable Genetic Value? Refer to Table 11.1 Heritability estimates.
Solution:
Probable Genetic Value = herd average + [(heifers value − herd average) x heritability estimate]
= 3.60 + [(4.0 – 3.6) x 50%]
Change % to Decimal = 3.60 + [(4.0 – 3.6) x 0.50]
= 3.60 + [ 0.4 x 0.50]
= 3.60 + 0.20
= 3.80

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