Effect of the DGAT1 K232A Mutation on Cows' Lactation Values for Milk Yield and Composition
| Trait | a± 2std.err. | d ± 2std.err. | α ± 2std.err. |
r
|
PvalueQTL |
r
|
r
|
| Milk yield (kgs) | −144 ± 60 | −42 ± 78 | −161 ± 66 | 0.03 | 1.05E − 8 | 0.54 | 0.43 |
| Fat yield (kgs) | 7.82 ± 2.6 | −0.89 ± 3.48 | 7.46 ± 2.96 | 0.09 | 1.77E − 20 | 0.46 | 0.45 |
| Protein yield (kgs) | −2.34 ± 1.9 | −0.76 ± 2.52 | −2.64 ± 2.14 | 0.01 | 4.35E − 2 | 0.37 | 0.42 |
| Fat (%) | 0.41 ± 0.054 | 0.03 ± 0.070 | 0.42 ± 0.06 | 0.31 | 2.5E − 108 | 0.49 | 0.20 |
| Protein (%) | 0.08 ± 0.028 | 0.03 ± 0.038 | 0.08 ± 0.032 | 0.04 | 1.60E − 20 | 0.72 | 0.24 |
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(i) a: half the difference between the genotypic values of the KK and AA genotypes (Falconer and Mackay 1996). (ii) d: dominance deviation (Falconer and Mackay 1996) deviation of the KA genotypic value from the midpoint between the AA and KK genotypic values, none of these proved to be significantly different from zero. (iii) α: average K to A substitution effect, computed as a + d(q −p) (Falconer and Mackay 1996), where q is the allelic frequency of K (=0.7) and p ofA (=0.3). (iv)r
: proportion of the trait variance explained by the DGAT1 K232Apolymorphism. (v) P valueQTL: statistical significance of the DGAT1 K232A effect (2 df). (vi)r
: proportion of the trait variance explained by the random, polygenic effect in the mixed model. (vii)r
: proportion of the trait variance unexplained by the model.
