Table 7.

Results from a multivariate GLM¹ modeling 60-d ADG in 3 field trials (ranches A, B, and C) evaluating the efficacy of feeding a colostrum supplement in milk replacer for 14 d to preweaned calves (n = 176)²

Variable	Level	LSM estimate,3 kg	P-value	90% CI4
				Lower	Upper
Treatment group5	CS	0.48	0.44	0.44	0.51
	PS	0.44	0.63	0.41	0.48
	UC	0.45	Reference	0.42	0.49
Serum IgG category6	FPT	0.39	<0.01	0.33	0.44
	PFPT	0.48	0.24	0.45	0.51
	APT	0.51	Reference	0.48	0.54
Weight category7	Low	0.46	0.62	0.42	0.50
	Mid	0.47	0.38	0.44	0.50
	High	0.44	Reference	0.41	0.48
Calf ranch	A	0.63	<0.01	0.60	0.66
	B	0.43	<0.01	0.40	0.46
	C	0.31	Reference	0.26	0.37

¹F-value = 16.49; df = 8; P < 0.0001; and R² = 0.44.

²Calves were lost to follow-up in the routine movement of calves within the calf ranches and because of a management change on ranch C that resulted in calves returning to the source farm at 1 mo of age.

³Least squares mean estimate.

⁴CI = confidence interval.

⁵CS = colostrum supplement (70 g of dried colostrum powder) added to milk replacer; PS = placebo supplement (70 g of nutritionally matched supplement without IgG) added to milk replacer; UC = unsupplemented control.

⁶FPT = failure of passive transfer: IgG ≤350 mg/dL; PFPT = partial failure of passive transfer: IgG between (and including) 351 and 999 mg/dL; and APT = adequate passive transfer: IgG ≥1,000 mg/dL.

⁷Low: ≤38.5 kg; mid: between 38.6 and 45 kg; high: ≥45 kg.