Effect of Three Colostrum Diets on Passive Transfer of Immunity and Preweaning Health in Calves on a California Dairy following Colostrum Management Training

Table 2

Effect of treatment on 24-hour serum total protein and IgG concentrations, apparent efficiency of IgG absorption, and passive transfer status of Holstein and Jersey calves in a randomized field trial comparing the effect of feeding either first-milking pooled colostrum alone or first-milking pooled colostrum followed by either a colostrum-derived replacer or second-milking pooled colostrum.

Item	Treatment 1*	Treatment 2*	Treatment 3*	𝑃 value
	𝑁=58	𝑁=54	𝑁=54
24-hour serum total protein (g/dL):
mean (SE^†)	5.9^a (0.08)	5.2^b (0.07)	5.4^b (0.06)	<0.001^‡
24-hour serum IgG (g/L):
mean (SE)	24.6^a (1.06)	15.9^b (0.78)	18.3^b (0.66)	<0.001^‡
Apparent efficiency of IgG absorption (%):
mean (SE)	37.0^a (1.14)	26.3^b (1.01)	40.0^a (1.29)	<0.001^‡
Failure of passive transfer: % (95% CI)
IgG (<10 g/L)	0.0^a (—)	9.3^a (1.53, 16.99)	1.9^a (0, 5.45)	≥0.05§

∗Treatment 1: 4L 1st-milking pooled colostrum, treatment 2: 2L 1st-milking pooled colostrum followed by 2L colostrum-derived replacer, and treatment 3: 2L 1st-milking pooled colostrum followed by 2L 2nd-milking pooled colostrum.
^†SE: standard error.
^‡One-way ANOVA using the Tukey multiple comparison procedure with 5% level of significance. Means without a common superscript are significantly different.
§Column proportions were compared using a 𝑧-test with the alpha adjusted for multiple comparisons using the Bonferroni method.
Means without a common superscript are significantly different at the 5% level.