Table 2.

Final model of the associations between calf characteristics and serum IgG concentrations for calves sampled between 2 and 8 d of age (n = 601)

			95% Confidence interval
Predictor		Effect estimate (g/L)	Lower	Upper	P
Born to a heifer	Yes	−4.2	−1.3	−7.0	0.004
	No	Reference category
Twin	Yes	−6.1	−10.3	−1.9	0.004
	No	Reference category
Assistance at birth	Yes	−4.1	−7.6	−0.6	0.02
	No	Reference category
Calf age (d)		−1.5	−2.1	−0.9	< 0.0001