THE EFFECT OF COLOSTRAL IMMUNOGLOBULIN SUPPLEMENT ON THE PASSIVE-IMMUNITY, GROWTH AND HEALTH OF NEONATAL CALVES

Neonatal dairy calves were randomly allotted to three colostrum feedin g regimens with increasing intakes of immunoglobulins (Ig) on the firs t day of life. The control group was fed one litre of pooled colostrum (Ig intake 19.5 g). In two experimental groups, the pooled colostrum was supplemented with 0.5 or 1.5 litres of commercial Ig-concentrate, giving a total Ig intake of 52.7 and 119.0 g, respectively. Serum IgG, IgM and IgA levels increased linearly (p < 0.001) on day 2 post partu m with the increasing Ig intake. The calculated mean Ig-absorption rat e was 61% and decreased linearly for IgM (p = 0.051) and IgG (p = 0.07 8) with increasing Ig intake. At the highest Ig intake, serum IgG rema ined above 10 g/l during 30 days post partum. In the experimental grou ps, serum IgM and IgA decreased sharply during the first week of life and were relatively constant thereafter. In the control group, however , there was an increase in serum IgM after one week post partum, perha ps due to the in situ production of Ig. With the increasing Ig intake there was a small and non-significant tendency for better live weight gain (p = 0.286) and a lower incidence of diarrhoea (p = 0.421) during the first four weeks of life. It is concluded that the Ig-product tes ted is well absorbed during 24 hours post partum and it can be used ei ther as a supplement to maternal colostrum when its quality is poor, o r as a substitute when colostrum is not available.