Table 2 Results of the univariable model showing variables associated with the log₁₀ transformed TL (P < 0.15).

Calf

 Season of conception

Spring

Ref.

0.074

Summer

− 0.842

Fall

− 7.069

Winter

− 7.218

 Month of conception

0.018

 Season of birth

Spring

Ref.

0.070

Summer

− 6.816

Fall

− 7.490

Winter

− 0.895

 Month of birth

0.002

 Calf age at sampling

− 1.233

0.013

 Calf heart girth

− 0.708

0.038

Dam

 Dam parity (continuous)

− 1.457

0.062

 Dam parity (categorical)

1

Ref.

0.133

2

− 0.618

≥3

− 4.755

 Dam age at calving (months)

− 0.122

0.045

 MilkBot^® scale

− 0.200

0.121

 MilkBot^® milk at peak

− 0.276

0.129

 MilkBot^® milk at 60 DIM

− 0.005

0.121

THI

 Mean THI first trimester

0.455

< 0.001

 Days THI > 65 first trimester

0.137

0.002

 Days THI > 70 first trimester

0.221

0.004

 Mean THI third trimester

− 0.414

0.002

 Days THI > 65 third trimester

− 0.133

0.002

 Days THI > 70 third trimester

− 0.112

0.003

 Median weekly THI

− 0.436

0.054

 Median weekly THI first trimester

0.451

< 0.0017

 Median weekly THI third trimester

− 0.388

0.003

 Weekly THI’s week 25 until week 38^b

Between <0.001 and 0.071

 Days THI > 70 (whole gestation)

− 0.126

0.020