Abstract
The effect of the stage of parturition on plasma cortisol levels and absorption of immuno globulin G (IgG) was investigated in 37 newborn calves. Ten calves were born spontaneously, 19 by caesarean section and 8 after traction assistance. The vitality of the calves was assessed using a modified APGAR score. A defined volume of pooled colostrums was fed at specified time points. Blood samples for analysis of plasma cortisol and IgG were collected from the calves immediately after birth and at 1, 6, 12, 24, 36 and 48 hours thereafter. Plasma cortisol levels were analysed by RIA and IgG concentrations by ELISA. The APGAR scoring indicated that 18 calves were clinically depressed. The majority (7/10) of spontaneously born calves were vital whereas the proportion of calves delivered by assisted traction or caesarean section which had reduced vitality was greater, 4/8 and 8119, respectively. In the first 12 hours after birth plasma cortisol levels were highest in calves delivered after assisted traction. The greatest IgG concentrations were observed in calves delivered by caesarean section and lowest IgG concentrations were recorded in spontaneously born calves. The results indicate that assisted traction produces increased plasma cortisol levels in newborn calves. No evidence was found that IgG absorption is correlated with post natal plasma cortisol levels.
Riedl, J