The objective of this study was to determine the concentration of total immunoglobulins (Ig) in colostrum produced by dairy cows and establish the effect that breed and parity can have on Ig concentration. The data presented correspond to determinations of concentration of total Ig determined by a colostrometer in 537 colostrum samples obtained between the year 2010 and 2012, during the months of August to November in 50 dairy farms in the provinces of San José, Alajuela, Heredia and Cartago. Cow breeds were classified into Holstein, Jersey, HolsteinxJersey and other. Farm size ranged from 10 to 300 milking cows. For the purposes of this study, good quality colostrum was considered when Ig concentration was ≥ 50 mg/ml. Immunoglobulin concentration ranged from 10 to 140 with an average of 85 mg/ml. Of all the samples analyzed, 13.2% had an inadequate concentration of Ig. When considering breed effect on Ig concentration, no significant differences were found. Parity number significantly influenced Ig concentration and it was found that Ig concentration increases linearly with parity number. The information collected in this study indicates that Ig concentration in colostrum is good and that failure of passive transfer of immunity could be due to other factors such as the volume of colostrum consumed and the time between birth and the first feeding of colostrum.
Keywords: calves, dairy cattle, animal health, passive immunity