Immunoglobulin-G status of camels during six months <em>post-natum</em>

Abstract

The immunoglobulin-G (IgG) status of camel calves from birth until six months of age was investigated in a natural herding situation on a livestock ranch in Kenya. Camel IgG was quantified post-natum (pn) up to six months of age by indirect antibody ELISA in serum of 68 camel calves. First colostrum intake was observed on average at 3.6 ± 3.0 h pn and the average precolostral serum IgG concentration was 0.26 ± 0.23 mg/ml (range 0-1.07 mg/ml). The average maximum IgG concentration (IgG peak) in calf serum was 21.1 ± 11.7 mg/ml. Most calves had IgG peaks between 18 and 30 h pn, but 19% of the calves had later peaks (30-66 h pn) with significantly lower concentrations. After the peak, serum IgG concentration declined, the half-life of maternally derived IgG in the newborn’s circulation being 16.3 ± 8.5 d. The average minimum IgG concentration was 8.1 ± 3.3 mg/ml (range of 1.6-15.1 mg/ml) and was observed on average at 27.6 ± 21.3 d pn. Following onset of own IgG synthesis, IgG concentration increased and reached a plateau on average of 24.5 ± 8.8 mg IgG/ml around 120 d pn, indicating that the immune system had matured. Two types of IgG profiles were observed, one with “immediate” concentration increase (above 10 mg/ml already at 30- 40 d pn), the other with “delayed” concentration increase (below 10 mg/ml until around 70 d pn). Calves with delayed increase attained significantly lower IgG plateau values (19.0 ± 6.5 vs. 29.6 ± 7.3 mg IgG/ml). There is a tendency where early colostrum intake results in earlier and higher IgG peaks, but substantial IgG transfer is possible well after 24 h pn if calves are fasting until first suckling. Low serum IgG concentrations should be expected between two weeks pn and two months pn. Considering these findings in health care programs will contribute to improved camel calf rearing.

Keywords

• Dromadaire
• Jeune animal
• Immunoglobuline
• Colostrum
• Kenya