Table 3.

Effect of ABCG2(2) on the breeding values of the daughters of the heterozygous sires and QTL effects derived from the animal model analyses

			Quantitative traits
Analysis	Genotypea	Number of cows	Kg milk	Kg fat	Kg protein	% Fat	% Protein
Class effectsb	-/-	78	0	0	0	0	0
	+/-	328	-185	0.4	1.2	0.059	0.065
	+/+	264	-432****	4.2**	3.3**	0.169****	0.145****
% Dominancec			14.3	80.9	27.3	30.2*	17.2*
Regressiond		670	-226****	2.6**	1.8**	0.093****	0.076****
Animal modeld			-597	2.2	1.3	0.225	0.193

Significance: ^*, p < 0.05; ^**, p < 0.01; ^***, p < 0.001; ^****, p < 0.0001.

^a581S was denoted the “-” QTL allele; Y581 was denoted the “+” QTL allele

^bSignificance of the class effect is indicated in the +/+ row. Effects are computed relative to the -/- homozygote

^cRelative to the -/- homozygote

^dAllele substitution effects assuming additivity