Randomized controlled clinical trial on the effect of oral immunoglobulin supplementation on neonatal dairy calves with diarrhea

Chung, James J.; Rayburn, Maire C.; Chigerwe, Munashe

Median (95% CI) time to resolution of diarrhea for the TRXT, PLCB, and CONT groups were 10.5 (7, 13), 6.5 (3, 9) , and 8 (5, 10) days, respectively. Time to resolution of diarrhea was shorter (P = .008) in the PLCB group than in the TRXT group. There was no difference in the time to resolution of diarrhea between the PLCB and CONT (P = .89) or TRXT and CONT groups (P = .08). Kaplan-Meier curves for the 3 groups are depicted in Figure 1 . Age at enrollment (P = .36), serum IgG concentration (P = .49), fecal score at enrollment (P = .11), daily milk consumption (P = .23), F I G U R E 1 Kaplan-Meier curves depicting time to resolution of diarrhea in 3 groups of Jersey calves (N = 102). Median (95% confidence interval) time to resolution of diarrhea for the TRXT, PLCB, and CONT groups were 10.5 (7, 13), 6.5 (3, 9) , and 8.0 (5, 10) days, respectively. CONT, control; PLCB, placebo; TRXT, treatment Several reasons might explain the lack of effect on diarrhea after addition of immunoglobulins in milk in our study. We added 20 g of immunoglobulins per feeding (40 g per day) based on a previous study in calves which reported a reduction in frequency of occurrence of diarrheal disease in nonsick calves when 10 g of IgG was added twice daily to milk replacer. 12 Considering that calves in our study had diarrhea, we estimated that supplementing with twice as much immunoglobulins compared to previous studies 12 Calves in the TRXT group were supplemented with immunoglobulin derived from bovine serum. Serum derived immunoglobulin supplements contain higher IgG 2 concentrations than IgG 1 because bovine serum contains higher IgG 2 concentrations. 35 In contrast, bovine colostrum-derived immunoglobulin supplements contain higher IgG 1 concentrations than IgG 2 because IgG 1 is selectively secreted from the cow's circulation into colostrum. 36 Although IgG 1 is considered the principal immunoglobulin for passive immunization (requiring absorption from the gut), our study assessed local immunity by the immunoglobulins. Although previous reviews indicated that only IgG 1 activates complement, 35 other studies indicated that both bovine IgG 1 and IgG 2 activate complement and mediate phagocytosis. 36 Potentially, response of calves with diarrhea to supplementation with bovine serum-derived immunoglobulin might differ from bovine colostrum-derived immunoglobulin.