Perfil eletroforético do colostro de ovelhas suplementadas com propileno glicol e cobalto associado à vitamina B12 no final da gestação

Abstract

This study aimed to evaluate the proteinogram of the colostrum of ewes submitted to administration of propylene glycol and cobalt associated with vitamin B12 in late pregnancy. Eighteen pregnant Santa Inês ewes 18 months to 5 years old were distributed by probabilistic sampling into three experimental groups, about 30 days before the expected delivery date. In group 1 (G1/n=6), daily oral doses of 30ml propylene glycol PA were administered; Group 2 (G2/n=2) received a daily oral dosage of 1mg cobalt chloride in 1% solution and 2mg of vitamin B12 intramuscularly once a week, and Group 3 (G3/n=6) was the control group. Soon after delivery 30mL of colostrum was harvested from each ewe, which were stored in appropriate containers and sent to the laboratory. After homogenization, we added to each 1000μL of colostrum 75μL solution of rennin, which was kept in a water bath at 37°C for about 20 minutes and centrifuged at 21.000G for 10 minutes in a refrigerated centrifuge. Later, the intermediate fraction, corresponding to colostrum whey, was aliquoted and kept in a -80oC ultrafreezer for subsequent determination of proteins. The determination of the total colostral protein whey was performed using a commercial reagent, observing the linearity test for colostrum. The separation of proteins was performed using the technique of electrophoresis on polyacrylamide gel containing sodium dodecyl sulfate (SDS-PAGE). Lactoferrin, IgA, albumin, IgG heavy chain (IgGCP), β-casein, IgG light chain (IgGCL), β-lactoglobulin and α-lactalbumin proteins were identified. There was no influence of the administration of supplements during late pregnancy on the concentration of proteins identified in the colostrum of the ewes.