Plant & Animal Genome VI Conference Plant & Animal Genome VI Conference
W60
USDA,ARS
A backcross population of Meishan by White composite pigs was produced to
identify QTL affecting growth, carcass composition and reproduction.
Forty-one F1 females were produced by reciprocally mating
Meishan and White composite pigs. F1 females were then mated to
either Meishan or White composite boars to produce 2 parities. A genomic
scan with markers at 20 cM intervals (n=156) was conducted across the
entire population. Five hundred forty pigs were slaughtered at
approximately 100 kg live weight and carcass measurements were recorded.
Five measurements were collected for subcutaneous fat deposition (fat over
the first, tenth and last ribs, over the last lumbar vertebra and average
backfat), hot carcass weight, carcass length, loineye area, leaf fat and
weight of untrimmed and trimmed wholesale products. Statistical analyses
implemented a least-squares regression approach utilizing genotypic data
for the entire chromosome. Each chromosome was analyzed separately. Fixed
effects included in the model were contemporary group, sex and breed of
sire. A covariate for hot carcass weight was fitted for analyses of all
composition traits. Four genomic regions located on chromosomes 1, 4, 7
and X affected carcass traits at the genome wide level of significance of
.05 (F-ratio > 9.3). Pleiotropic effects were detected for SSC1, 7 and X.
These data did not detect QTL at previously identified regions for fat
deposition on chromosomes 4 and 13 in a Wild boar by Large White
population. Further studies need to be implemented to refine the location
of the QTL and determine potential positional candidate genes.