Experimental designs for Quantitative Trait Loci detection in
the New Zealand dairy industry
R. Spelman, N. Lopex-Villalobos and D. Garrick
Department of Animal Science, Massey University, Palmerston North
Proceedings of the New Zealand Society of Animal Production. 1998,
58: 6-9
Detection of loci that affect quantitative traits such as milk
production has been undertaken with daughter and granddaughter designs
in the N.Z. dairy industry. Two other experimental designs, selective
DNA pooling of trait extremes and the use of first cross
Holstein-Friesian-Jersey bulls, offer the opportunity to detect more
loci than the current two designs. Selective DNA pooling involves the
collective pooling of DNA from daughters at each extreme (high and low)
of the trait distribution. A sire family of 100,000 daughters with DNA
pools created from the top and bottom 1% of progeny pooled has the same
power (probability of detection) as approximately 5,000 progeny being
individually genotyped with less than 1% genotyping effort.
Crossbreeding in the New Zealand dairy industry opens up the opportunity
to identify QTL alleles that contribute to the genetic differences
between the two breeds. Identification of breed specific QTL alleles can
be achieved at a power of 90% based on some 600-1500 progeny from
matings of F1 Holstein-Friesian x Jersey bulls to F1 cows.
Keywords: NZSAPAB;
Quantitative trait loci; experimental design; dairy industry.
Last Updated 12-09-1998
