Table 6.

Results from a multivariate GLM¹ modeling 28-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 = 235)

Variable	Level	LSM Estimate,2 kg	P-value	90% CI3
				Lower	Upper
Treatment group4	CS	0.24	0.04	0.22	0.27
	PS	0.22	0.39	0.19	0.25
	UC	0.20	Reference	0.17	0.23
Serum IgG category5	FPT	0.15	<0.01	0.11	0.20
	PFPT	0.24	0.12	0.21	0.26
	APT	0.27	Reference	0.25	0.29
Weight category6	Low	0.27	<0.01	0.24	0.30
	Mid	0.23	<0.01	0.20	0.25
	High	0.16	Reference	0.13	0.20
Calf ranch	A	0.33	<0.01	0.31	0.36
	B	0.12	<0.01	0.10	0.16
	C	0.21	Reference	0.18	0.24

¹F-value = 16.16; df = 8; P < 0.0001; and R² = 0.36.

²Least squares mean estimate.

³CI = confidence interval.

⁴CS = 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.

⁵FPT = 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.

⁶Low: ≤38.5 kg; mid: between 38.6 and 45 kg; high: ≥45 kg.