Sixty thoroughbred mares were used to perform this work. Colostrum of each mare was taked just before and 12h after suckling to evaluate colostral color, viscosity, specific gravidity (SG) and immunoglobulin (Ig) concentration. This data were correlated with serum Ig of the newborn foals from 3h - 7 days after first suckling. Premature lactation (PL) was negatively correlated with colostral and serum Ig of the newborn foals being their serum levels direct correlated to the amount of colostral Ig ingested. SG determination using a colostrometer was a quick and precise method to verify colostral Ig levels. Colostri with SG> 1060 had levels of Ig above 9.0g/dl and serum Ig levels of the these foals suckling were in average over 800mg/dl. visual evaluation of color and viscosity were good indicators of colostral Ig concentration.
foal; immunodeficiency; immunoglobulin; colostrum
