Estimation of genetic parameters in a Suffolk sheep group breeding scheme

1996 ◽  
Vol 1996 ◽  
pp. 113-113 ◽  
Author(s):  
M. Araghi ◽  
M.K. Curran ◽  
G.E. Pollott
Keyword(s):  
Genetic Parameters ◽  
Carcass Traits ◽  
Genotypic Correlation ◽  
The South ◽  
Breeding Scheme ◽  
Live Animal ◽  
Group Breeding ◽  
Initial Nucleus ◽  
Estimation Of Genetic Parameters ◽  
Wye College

In 1989, ten Suffolk breeders co-operated to establish a nucleus flock at Wye College. The group is known as the Wye Suffolk Improvement Group (WSIG). The members each contributed 5-10 pedigree ewes to use as the initial nucleus flock. Eighty-nine ewes were delivered to the College by the various participants. The objective of this study was to obtain estimates of the heritabilities of live animal traits, used to improve carcass traits, and phenotypic and genotypic correlation estimates between them in the Suffolk lambs in the south of England.

Estimation of genetic parameters in a Suffolk sheep group breeding scheme

1996 ◽  
Vol 1996 ◽  
pp. 113-113
Author(s):  
M. Araghi ◽  
M.K. Curran ◽  
G.E. Pollott
Keyword(s):  
Genetic Parameters ◽  
Carcass Traits ◽  
Genotypic Correlation ◽  
The South ◽  
Breeding Scheme ◽  
Live Animal ◽  
Group Breeding ◽  
Initial Nucleus ◽  
Estimation Of Genetic Parameters ◽  
Wye College

In 1989, ten Suffolk breeders co-operated to establish a nucleus flock at Wye College. The group is known as the Wye Suffolk Improvement Group (WSIG). The members each contributed 5-10 pedigree ewes to use as the initial nucleus flock. Eighty-nine ewes were delivered to the College by the various participants. The objective of this study was to obtain estimates of the heritabilities of live animal traits, used to improve carcass traits, and phenotypic and genotypic correlation estimates between them in the Suffolk lambs in the south of England.

The CAMDA sheep breeding scheme: I. Estimation of genetic parameters for 18-week weight

1999 ◽  
Vol 1999 ◽  
pp. 119-119 ◽  
Author(s):  
A. A. Aslaminejad ◽  
R. M. Lewis ◽  
J. A. Roden ◽  
V.R. Fowler
Keyword(s):  
Growth Rate ◽  
Genetic Parameters ◽  
Live Weight ◽  
Breeding Scheme ◽  
Sheep Breeding ◽  
Group Breeding ◽  
Incomplete Performance ◽  
Mature Size ◽  
Lamb Growth ◽  
Estimation Of Genetic Parameters

The CAMDA group breeding scheme was established in 1976. Its objective is to increase lamb growth rate, mature size and maternal ability of the Welsh Mountain sheep while retaining their hardiness and breed type. The opportunity to achieve this goal depends on the extent of genetic variation within the breed for these traits. The objective of this study was to estimate the amount of variation in 18-week live weight attributable to the lamb genotype (direct) and dam maternal ability, both genetic and environmental, in Welsh Mountain sheep within this scheme.A total of 12954 records of 18-week live weight of Welsh Mountain lambs collected between 1976 and 1995 from 4 flocks of the CAMDA scheme were considered. The data were edited for small contemporary groups and for incomplete performance or pedigree recording.

The CAMDA sheep breeding scheme: II. Genetic progress over twenty years

1999 ◽  
Vol 1999 ◽  
pp. 120-120
Author(s):  
A. A. Aslaminejad ◽  
R. M. Lewis ◽  
J. A. Roden ◽  
V.R. Fowler
Keyword(s):  
Genetic Parameters ◽  
Genetic Effect ◽  
Live Weight ◽  
Maximum Likelihood Algorithm ◽  
Breeding Scheme ◽  
Genetic Progress ◽  
Group Breeding ◽  
Selection Decisions ◽  
Derivative Free ◽  
Lamb Growth

Two aspects of the CAMDA group breeding scheme is to improve lamb growth rate and the mothering ability of Welsh Mountain sheep. Genetic variation for these traits is present (Aslaminejadet al., 1999) but the rate of genetic progress depends on the selection decisions made within the scheme. The objective of this study was to estimate the genetic gain achieved in the nucleus and members’ flocks over the 20 years since the scheme began.A total of 31887 records of 12 and 18-week live weight of Welsh Mountain lambs collected between 1976 and 1995 in 7 flocks of the CAMDA scheme were used in this study. Each flock was analysed separately fitting a univariate animal model with a direct and maternal random genetic effect. Genetic parameters were estimated using a derivative-free restricted maximum likelihood algorithm (DFREML; Meyer, 1993).

scholarly journals Use of robust multivariate linear mixed models for estimation of genetic parameters for carcass traits in beef cattle

2014 ◽  
Vol 131 (6) ◽  
pp. 504-512 ◽  
Author(s):  
S.O. Peters ◽  
K. Kizilkaya ◽  
D.J. Garrick ◽  
R.L. Fernando ◽  
E.J. Pollak ◽  
...  
Keyword(s):  
Beef Cattle ◽  
Mixed Models ◽  
Genetic Parameters ◽  
Linear Mixed Models ◽  
Carcass Traits ◽  
Estimation Of Genetic Parameters

Genetic parameters for carcass traits and their live animal indicators in Simmental cattle1

2003 ◽  
Vol 81 (6) ◽  
pp. 1427-1433 ◽  
Author(s):  
D. H. Crews ◽  
E. J. Pollak ◽  
R. L. Weaber ◽  
R. L. Quaas ◽  
R. J. Lipsey
Keyword(s):  
Genetic Parameters ◽  
Carcass Traits ◽  
Live Animal
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