|
PRINT: ISSN 2221-1896
ONLINE : ISSN 2223-0343
|
|
|
Potential benefits of genomic pre-selection of
candidate bulls for genetic superiority and inbreeding rate of dairy
cows in a progeny testing program: a simulation study
|
Abbas Moazen1, Saeed Khalajzadeh*1
and Jafar Yadi2 |
1Department of Animal Sciences, College of
Agriculture, Saveh Branch, Islamic Azad University, Saveh, Iran; 2Department
of Veterinary, College of Agriculture, Saveh Branch, Islamic Azad
University, Saveh, Iran
|
|
Abstract |
This study was performed
to investigate the effect of pre-selection programme of young bull on
genetic progress and inbreeding rate of dairy cows in a progeny test
program. Dairy cattle population, consisted of 10,000 dairy cows across
5 parities, was simulated. Two scenarios including conventional progeny
testing program (Con-PT) and genomic pre-selection of young bulls
(Gen-PT) were compared. Genetic superiority and inbreeding were studied
during 20 years of selection in four distinct paths of selection.
Genetic superiorities of 62.5, 37.9, 27.3, and 89.5% were observed for
active sires, young bulls, bull dams, and milking cows in Gen-PT
relative to Con-PT scenario respectively. The result showed the large
amounts of genetic gain are obtained via genomic pre-selection of young
bulls in all paths of selection. Means of inbreeding were obtained
2.34±0.44 and 3.36±0.63% for Con-PT and Gen-PT scenarios respectively
(P<0.001). The average annual rate of inbreeding increased at a constant
rate from 11th to 25th year at annual rate of
0.38±0.01 and 0.54±0.004% in Con-PT and Gen-PT scenarios respectively.
According to different generation intervals in scenarios (5 years in
Con-PT versus 3 years in Gen-PT), inbreeding rates per generation were
1.9 and 1.62% respectively, indicating less inbreeding rate per
generation in Gen-PT in comparison to Con-PT. In general, use of genomic
values for pre-selection of young bulls can be applied as an effective
tool to enhance genetic merit of cows in dairy cattle breeding schemes.
|
Keywords:
Genetic gain;
pre-selection; progeny test; genomic; dairy cow |
|
To cite this article:
Moazen A, S Khalajzadeh and J Yadi, 2014.
Potential benefits of genomic pre-selection of
candidate bulls for genetic superiority and inbreeding rate of dairy
cows in a progeny testing program: a simulation study.
Res.
Opin. Anim. Vet. Sci., 4(9): 496-499. |
|
|