Evaluation of immunoglobulin concentrations in ovine colostrum by routinely capillary electrophoresis instrument

Introduction - The best approach to assess the quality of colostrum in flock management is still debated. Aim - The aim of this work was to evaluate the use of a routinely capillary electrophoresis instrument to assess the concentration of immunoglobulins (Igs) in sheep colostrum. Materials and methods - During the summer of 2014, the colostrum was sampled from 12 Sarda sheeps (6-7 lactations) immediately after lambing (T-0) and at 12 (T-12) and 24 (T-24) hours post partum. At the same time, the blood samples were collected from respective lambs. Whey colostrum and serum samples were analyzed by a capillary electrophoresis instrument (Minicap, Sebia France). The Ig peak was determined by addition of protein G Sepharose coniugate (Gammabind G Sepharose) to whey colostrum and subsequent comparison of electropherograms before and after Ig subtraction. Results and discussion - Protein G Sepharose addition caused a strong decrement of Ig peak by Ig type G sequestration, identifying the Ig position on the electropherogram. In sheep whey colostrum, total Igs mean concentration at T0, T12, and T-24 was 9.66 g/dL (+/- 4.57 g/dL), 5.87 g/dL (+/- 3.79 g/dL), and 3.19 g/dL (+/- 2.48 g/dL), respectively. According to other Authors, the comparison of Ig means at different time, showed a statistically significant decrease (T-0 vs T-12 p<0.05; T-0 vs T-24 p<0.001). In lamb serum, total Igs mean concentration at T-0, T-12, and T-24 was 0.05 g/dL (+/- 0.01 g/dL), 2.85 g/dL (+/- 1.63 g/dL), and 3.39 g/dL (+/- 1.69 g/dL), respectively. The lamb serum Igs concentration increase was statistically significant (T-0 vs T-12 and T-0 vs T-24 p<0.001). Conclusions - This is the first work that suggest the use a routinely capillary electrophoresis instrument in the evaluation of the quality of sheep colostrum. Moreover, we confirm the suitability of this instrument to measure the serum Igs concentration in suckling lambs to assess passive immune transfer. In our opinion, the proposed method is simple, rapid, reliable, and fit with a purpose of creating a quality colostrum bank in flock management.