RESUMO
BACKGROUND: In any calf rearing system it is desirable to obtain healthy animals, and reduce morbidity, mortality, and economic losses. Bovine syndesmochorial placentation prevents the direct transfer of bovine immunoglobulins to the fetus, and calves are born hypogammaglobulinemic. These calves therefore require colostrum immediately after birth. Colostrum is rich in immunoglobulins (Ig) and its consumption results in the transfer of passive immunity to calves. The Ig absorption occurs within the first 12 h after birth. Immunoglobulin Y (IgY), derived from chicken egg yolk, has been used in the prevention and control of diseases affecting calves because it is very similar in structure and function to immunoglobulin G (IgG). In the current study, we sought to establish whether administration routes of colostrum supplemented with avian IgY affected passive immunity in calves. RESULTS: No significant differences were observed with respect to route of administration for colostrum. However, we did observe some differences in certain interactions between the various treatments. Calves fed colostrum containing egg yolk had higher levels of TP, ALB, and IgG, along with increased GGT activity. CONCLUSIONS: Our results suggest that supplementing colostrum with egg yolk has a beneficial effect when given to calves, regardless of administration route.
