Table 1. Effect of PIGR haplotype on milk composition traits.
| Genotype of Haplotype | ||||||||
| Phenotype | I/I | I/II | I/III | II/II | II/III | III/III | P-Value | |
| Colostrum, 2nd milking | IgA (mg/mL) | 1.91 (0.12) | 1.41 (0.15) | 1.79 (0.12) | 0.62 (0.33) | 1.48 (0.18) | 1.36 (0.29) | 0.0013 |
| IgG (mg/mL) | 7.5 (0.46) | 8.82 (0.58) | 8.31 (0.46) | 9.25 (1.31) | 9.24 (0.72) | 7.28 (1.17) | 0.2672 | |
| Milk Volume (L) | 8.33 (0.2) | 7.97 (0.26) | 8.15 (0.2) | 7.84 (0.58) | 7.88 (0.31) | 7.26 (0.51) | 0.4208 | |
| IgA Yield (mg) | 15.67 (0.95) | 10.56 (1.2) | 14.06 (0.96) | 4.48 (2.72) | 10.41 (1.48) | 10.09 (2.43) | 0.0001 | |
| Colostrum, 8th milking | IgA (mg/mL) | 0.51 (0.012) | 0.36 (0.015) | 0.47 (0.012) | 0.16 (0.034) | 0.34 (0.018) | 0.37 (0.03) | 4.51×10−28 |
| IgG (mg/mL) | 1.04 (0.04) | 1.19 (0.05) | 1.13 (0.04) | 1 (0.11) | 1.2 (0.06) | 1.01 (0.1) | 0.0552 | |
| Milk Volume (L) | 10.06 (0.2) | 9.4 (0.25) | 9.86 (0.2) | 9.88 (0.56) | 9.62 (0.31) | 10.49 (0.5) | 0.2787 | |
| IgA Yield (mg) | 5 (0.13) | 3.27 (0.16) | 4.49 (0.13) | 1.58 (0.36) | 3.24 (0.2) | 3.87 (0.32) | 1.63×10−26 | |
| Mid-Lactation | IgA (mg/mL) | 0.82 (0.024) | 0.55 (0.03) | 0.76 (0.024) | 0.32 (0.068) | 0.57 (0.037) | 0.65 (0.061) | 3.99×10−17 |
| IgM (mg/mL) | 0.14 (0.005) | 0.13 (0.006) | 0.14 (0.01) | 0.09 (0.01) | 0.13 (0.01) | 0.13 (0.01) | 0.0099 | |
| Secretory componenta (mg/mL) | 9.69 (1.77) | 3.51 (1.64) | 5.62 (0.76) | 3.79 (1.16) | 5.73 (1.22) | N/A | 0.1323 | |
| Protein (%) | 3.78 (0.02) | 3.82 (0.02) | 3.78 (0.02) | 3.78 (0.05) | 3.83 (0.03) | 3.86 (0.04) | 0.2571 | |
| Fat (%) | 5.29 (0.04) | 5.29 (0.05) | 5.31 (0.04) | 5.32 (0.11) | 5.29 (0.06) | 5.55 (0.1) | 0.2493 | |
| Milk volume (L) | 17.1 (0.18) | 16.7 (0.23) | 16.8 (0.18) | 17.3 (0.51) | 16.2 (0.28) | 16.2 (0.46) | 0.1036 | |
| Somatic cell count (×1000) | 148 (27) | 121 (34) | 111 (27.2) | 93 (76.9) | 131 (42) | 107 (68.7) | 0.9359 | |
a
n = 38 observations.
mean presented with standard error in brackets.