This Alpaca World magazine article is worth repeating at this time of year. Failure of passive transfer can be a killer and veterinarian Stephen R Purdey DVM has the answers.
Any new born cria that fails to suckle and therefore doesn’t get colostrum is in danger of failure of passive transfer of immunity. Unless this is addressed the newborn may be prey to potentially fatal infections. Veterinarian Stephen Purdy explains what colostrum consists of and what to do to keep at risk crias healthy.
Antibodies are produced by the immune system in response to antigenic (foreign molecule) exposure. They are protein molecules which complex with foreign substances such as bacteria and viruses within the body to help remove them. Neonatal camelids are thought not to be fully capable of creating antibodies until approximately eight weeks after birth. Preformed protective antibodies are transferred to the neonatal circulation across the intestinal tract from consumption of the dam’s colostrum, the first milk after birthing. This transfer occurs during the first 24 hours after birth only, with most of the transfer occurring within the first 12 hours. It is therefore important that the consumption of antibody rich colostrum occurs shortly after birth. These antibodies are what protect the cria from disease while its immune system is developing.
All immunoglobulins share a basic structure (figure 1) except camelids and a few other unrelated species (notably sharks). The antibodies of major importance in camelid colostrum are all of the IgG class (immunoglobulin G). Of three identified so far, IgG1 has the classical structure and IgG2 and IgG3 have the heavy chain antibody structure. IgG1 is the one present in the largest quantity (Daley, 2007).
Colostrum antibody levels depend on the immune system competence of the dam, as in does her immune system respond to foreign substances? The dam’s specific environmental challenges also determine what antibodies she produces. Colostrum is also an excellent source of nutrition for the neonate in addition to providing the cria with these preformed antibodies. Colostrum from other species (most commonly from goats or cows) may be used if the dam has no milk.