Table 1 Mean and standard deviation (SD) of estimated variance components (VC) of genetic (Gij), permanent environmental (Pij) and residual effects (Embedded Image) over 10 replicates from repeated individual measurements and group measurements based on different grouping and drop out scenarios1
IndividualGroup3×4Group6×2Group1×12
VC2SimulatedNo_DropDropranDroppheNo_DropDropranDroppheNo_DropDropranDroppheNo_DropDropranDropphe
G1163.4261.37 (2.15)61.18 (2.36)42.40 (1.95)58.72 (7.79)58.93 (7.15)45.66 (7.88)57.62 (3.62)58.24 (4.41)45.80 (3.34)60.15 (8.21)60.68 (8.85)41.85 (7.15)
G12−5.42−5.22 (0.78)−5.24 (0.78)−5.44 (0.84)−5.23 (1.55)−5.04 (1.71)−5.14 (1.76)−5.11 (1.60)−4.80 (1.70)−5.24 (1.24)−6.33 (3.05)−5.95 (2.95)−6.19 (3.10)
G226.856.63 (0.80)6.74 (0.78)5.70 (0.74)6.21 (1.78)6.61 (1.96)5.56 (2.04)6.30 (1.00)6.31 (0.92)5.29 (1.08)5.14 (1.78)5.80 (1.74)4.92 (1.57)
P1130.6131.15 (1.07)31.28 (1.10)28.15 (0.95)33.71 (5.62)33.56 (5.60)28.16 (5.59)35.73 (7.06)34.01 (6.47)28.28 (3.90)30.92 (4.71)31.38 (5.53)30.13 (4.80)
P124.284.26 (0.48)4.34 (0.59)2.77 (0.43)3.80 (2.80)3.52 (1.72)2.14 (2.87)3.84 (3.45)3.34 (3.23)2.41 (2.03)5.00 (2.71)5.13 (2.00)3.38 (2.97)
P2229.2529.36 (0.64)29.21 (0.63)25.92 (0.64)29.60 (2.38)29.45 (2.75)25.45 (2.04)29.27 (2.94)29.27 (3.49)25.38 (2.65)30.32 (2.61)29.95 (2.41)25.22 (1.85)
Embedded Image53.4553.47 (0.33)53.47 (0.33)50.92 (0.34)53.37 (1.03)53.30 (1.03)50.64 (0.99)53.42 (0.64)53.46 (0.67)50.53 (0.48)53.93 (0.77)53.81 (0.85)50.98 (0.88)
  • 1 Medium within and across pen genetic relationship (Group3×4): group was consisted of 4 different families with 3 pigs from each family; High within group relationship (Group6×2): all animals from 2 different litters were allocated to a group; Low within group relationship (Group1×12): all animals were from different litters. No_Drop: measurements without drop out animals; Dropran: drop out animals were randomly selected and the drop out time of each drop out animal was sampled from a vector of the integers from 1 to 6 representing the six testing time points; Dropphe: six time intervals were defined based on six testing time points, the number of drop out animals at each interval was sampled from a Poisson distribution with a mean equal to the total size of drop out animals divided by six. Animals were ranked based on their phenotypes at each testing time point, then dropped out based on the number sampled from the Poisson distribution.

  • 2 G(P)11: variance of intercept; G(P)12: covariance between intercept and slope; G(P)22: variance of slope.