TABLE 2.

J5-specific antibody OD values for sera of J5 vaccinates and controls^a

Antibodyb	J5 vaccinate serum OD (SD)	Control serum OD (SD)
Dryoff IgM	0.53 (0.16)	0.50 (0.17)
Dryoff IgG1	0.65 (0.24)*	0.51 (0.23)*
Dryoff IgG2	0.28 (0.13)	0.26 (0.09)
Dryoff IgG1:IgG2 ratio	2.52 (1.09)	2.11 (1.00)
Postcalving IgM	0.63 (0.27)	0.53 (0.25)
Postcalving IgG1	0.71 (0.25)***	0.47 (0.29)***
Postcalving IgG2	0.43 (0.16)**	0.34 (0.14)**
Postcalving IgG1:IgG2 ratio	1.76 (0.60)	1.41 (0.74)
Postmastitic IgM	0.56 (0.15)	0.52 (0.25)
Postmastitic IgG1	0.86 (0.27)	0.75 (0.27)
Postmastitic IgG2	0.39 (0.12)	0.36 (0.71)
Postmastitic IgG1:IgG2 ratio	2.29 (0.79)	2.20 (0.71)

^aJ5 vaccinates, n =27; controls, n = 24. *, significantly different at P = 0.05, ANOVA; **, significantly different at P < 0.05, ANOVA; ***, significantly different at P < 0.01, ANOVA. SD, standard deviation.

^bDryoff, blood collected at the time of drying off, before the first J5 vaccination. Postcalving, blood collected 1 to 7 days postcalving, approximately 21 to 35 days after the second and last J5 immunization. Postmastitic, blood collected 17 to 77 days after the end of treatment for clinical mastitis.