A study of some of the factors affecting the transfer of immunoglobulins from cows to calves : a thesis presented in partial fulfilment of the requirement for the degree of Master of Agricultural Science in Animal Science at Massey University
The immunological importance of passive transfer of colostral immunoglobulins to the young has been well recognised in cattle and other farm animals including pigs, horses, goats and sheep (Brambell,1958; Gay, 1965; Butler, 1969; and Simpson - Morgan and Smeaton, 1972). All these animals lack prepartum maternofoetal transfer of immunoglobulins probably due to the epitheliochorial (pigs and horses) or syndesmochorial placentation (cows, goats and sheep) (Sterz] and Silverstein, 1967), which are impermeable to macromolecules such as immunoglobulins, antitoxin (Mason_et al, 1930) and even to smaller molecules such as growth hormone (Alexander _et al, 1973). In the calves, this lack of prenatal transfer, coupled with the apparent inability of the newborn calves to actively produce antibodies in sufficient quantities during the immediate prenatal and postnatal period, means that the newborn are ill-equipped to resist pathogens. Their early ability to obtain and absorb adequate maternal colostral antibodies is therefore of paramount importance to ensure survival against most neonatal diseases. In order to fully understand the need for antibody transfer in newborn calves, some knowledge of the physiology of the bovine immune system is required. For this reason part of the present thesis will include a brief review of some of these aspects, particularly the characteristics of the immunoglobulins and the inherent factors which lead to the necessity for passive acquisition of immunity, and factors affecting this transfer in newborn calves.