Evaluating alternate models to estimate genetic parameters of calving traits in United Kingdom Holstein-Friesian dairy cattle

Table 5 Variances and genetic parameters for calving ease, stillbirth and gestation length from first parity univariate models

Trait¹Model²	Variance components and genetic parameters³
Trait¹Model²	σ _P ²	σ _Ad ²	σ _Am ²	σ _TBV ²	σ _e ²	h _d ²	h _m ²	r _dm
CE¹
S-MGS²	0.464 (0.01)	0.050 (0.01)	0.024 (0.01)	0.048 (0.01)	0.443 (0.01)	0.108 (0.02)	0.051 (0.02)	−0.373 (0.15)
A1²	0.464 (0.01)	0.055 (0.01)	0.022 (0.01)	0.041 (0.01)	0.404 (0.01)	0.119 (0.02)	0.048 (0.01)	−0.523 (0.13)
A2²	0.462 (0.01)	0.054 (0.01)	0.022 (0.01)	0.046 (0.01)	0.401 (0.01)	0.117 (0.02)	0.033 (0.01)	−0.444 (0.13)
SB¹
S-MGS²	0.096 (0.001)	0.002 (0.001)	0.002 (0.001)	0.006 (0.001)	0.094 (0.001)	0.016 (0.01)	0.024 (0.01)	0.567 (0.47)
A1²	0.097 (0.001)	0.002 (0.001)	0.002 (0.001)	0.006 (0.002)	0.092 (0.001)	0.017 (0.01)	0.018 (0.01)	0.704 (0.75)
A2²	0.095 (0.001)	0.002 (0.001)	0.002 (0.001)	0.006 (0.002)	0.090 (0.001)	0.019 (0.01)	0.022 (0.01)	0.623 (0.62)
GL ¹
S-MGS²	24.30 (0.51)	12.06 (1.31)	1.99 (0.50)	12.35 (1.25)	18.95 (0.20)	0.496 (0.05)	0.081 (0.02)	−0.172 (0.12)
A1²	23.50 (0.42)	13.22 (1.41)	1.65 (0.45)	12.85 (1.19)	9.64 (0.85)	0.563 (0.05)	0.070 (0.02)	−0.216 (0.11)
A2²	23.32 (0.37)	11.66 (1.20)	1.67 (0.41)	11.86 (0.96)	10.73 (0.71)	0.499 (0.05)	0.072 (0.02)	−0.166 (0.11)

¹CE = calving ease, SB = stillbirth, GL = gestation length; ² S-MGS = sire-maternal grandsire model, A1 = animal model 1 excludes animals recorded at both birth and calving, A2 = animal model includes all records; ³σ_P² = phenotypic, σ_Ad² = additive genetic direct; σ_Am² = additive genetic maternal; σ_TBV²= total breeding value; σ_e² = environmental; h_d² = direct; h_m²= maternal heritability; r_dm = genetic direct-maternal correlation; standard errors are indicated in brackets.

ISSN: 1297-9686