Effect of dietary manipulation and vaccination of turkey breeder hens on immunoglobulin levels of yolk, yolk sac and neonate poults
Vaccination of breeders is a common management procedure to prevent diseases in a hatchery and a brooder house. Antibodies pass to eggs and thereby to chicks and mostly the maternal antibodies disappear from the chicks within 5–14 days of age (Grindstaff, Broadie, & Ellen, 2003; Grindstaff et al., 2006). In fact, maternal antibody transfer can be defined as the transfer of antibodies by a female to her offsprings either through the placenta, colostrum, milk, or through the egg (Grindstaff et al., 2003). Birds transmit maternal antibodies to their offspring by depositing antibodies in eggs (Brambell, 1970). There are three classes of antibodies in chickens, namely IgY (IgG), IgA, and IgM. In chickens, the transfer of IgY from dams to her offsprings takes place in a two‐step process. In the first step, IgY is taken up into egg yolks by IgY receptors in ovarian follicles from dam's blood (Cutting & Roth, 1973; Loeken & Roth, 1983). In the second step, IgY is transferred from egg yolks to offsprings via embryonic circulation.
There is a close nexus between nutrient requirements and the physiological state of birds. A redirection of nutrient flow to meet the metabolic requirements of an immune response or inflammatory reaction is referred to as homeorhesis (Bauman & Currie, 1980). This is in clear contrast to the homeostatic mechanism of maintaining metabolic equilibrium. In fact, it is the need of hour to study the impact of dietary manipulation on promoting disease resistance and immunity. Protective immune responses require a supply of nutrients at appropriate times and amounts (Humphrey, Koutsos, & Klasing, 2002). Hence, the study was undertaken to evaluate the effect of dietary manipulation and vaccination in turkey breeder hens on the immunoglobulin levels of yolk, yolk sac, neonate poults and also to determine the correlation between immunity of breeder hens and their progenies.