Egg yolk as immunoglobulin G preservative in goat colostrum

Abstract

Colostrum is quite important for its nutrients, especially immune components, playing a key role in the transfer of passive immunity in goat kids. Its high level of immune components, especially immunoglobulin G (IgG), is necessary in the first hours of life for goats to obtain an efficient transfer of passive immunity. However, colostrum heat treatment may affect immunoglobulins loss by losing their structure and functionality. The present study aims to evaluate the effect of adding immunoglobulin Y (IgY) extracted from chicken egg yolk, on the protection of IgG during colostrum (56 °C during 60 min). In this study, ten goat colostrum samples were used. In these samples, IgY was added at two different doses (i.e., 4 mg/mL and 0.8 mg/mL). In addition, bovine serum albumin (BSA) proteins were used in equal quantities as a positive control and a negative control group was also included without addition of either IgY or BSA. A sample without heat treatment and without addition of either IgY or BSA was also included in the experimental design. Then, all samples were heat-treated, except for one sample which remained as non-heat-treated and the final IgG concentration was measured using ELISA. The results showed that despite IgY is known to resist heat treatment, adding this immunoglobulin to colostrum did not prevent IgG loss in heat-treated samples. Despite, in those sample slight numerical differences were observed among groups, there were not significant. In conclusion, adding IgY does not seem to prevent IgG degradation in heattreated colostrum. It is likely that heat treatment may affect colostrum differently depending on the concentration of other components. samples somewhat variably, possibly due to differences in the composition of the different colostrum exam