Module IV Applied Animal Breeding and Selection
Homework questions assigned August 1
To be returned by September 16, 2008
(Email to: larry.cundiff@ars.usda.gov)
In an experiment involving production of straightbred and reciprocal cross calves
among the Hereford (H), Angus (A) and Shorthorns, breed group means for 200 day
weaning weight were as tabulated.
Breed of dam
Hereford
Angus
Shorthorn
Hereford
419
455
457
Breed of Sire
Angus
427
419
433
Shorthorn
426
428
416
1) What is the effect of specific individual heterosis for Hereford-Angus (Hiah)
crosses in these data for weaning weight in this experiment (show work)? 2) What is
the effect of specific individual heterosis for Hereford-Shorthorn (Hihs) crosses in
these data for weaning weight in this experiment (show work)? 3) What is the
effect of individual heterosis averaged over all crosses (Hi) in this experiment (show
work)? 4) What is the effect of maternal heterosis in these data?
In the next generation of matings involving production of two-way and three-way
crossbred calves produced by straightbred and crossbred dams breed group means
for 200-day weaning weight were as tabulated:
Breed of dam
AA
AS
SA
SS
HH
HS
SH
SS
HH
HA
AH
AA
Hereford
Breed of sire
Angus
Shorthorn
452
466
459
454
425
455
456
429
416
428
456
431
5) What is the effect of specific maternal heterosis for Hereford-Angus (HMah)
crosses in these data for weaning weight in this experiment (show work)? 6) What is
the effect of specific maternal heterosis for Hereford-Shorthorn (Hmhs) crosses in
these data for weaning weight in this experiment? 3) What is the effect of maternal
heterosis averaged over all crosses (Hm) in this experiment (show work)?