Avalia？？o da qualidade do colostro e transferência de imunidade passiva em animais mesti？os Holandês Zebu

the objective of this paper was to evaluate crossbred holstein zebu cows colostrum quality and passive immunity transfer to their calves. parity, calf sex, season of the year and cow genetic group effects in both responses were analyzed. quality (immunoglobulin - ig - concentration) was measured in colostrum samples of 186 crossbred cows from four different genetic groups with a colostrometer. calf’s blood samples were collected on the third day of life. serum total protein concentration (pt) was measured through refractometry and spectrophotometry. colostrum samples were classified as high quality and showed mean ig concentrations of 78.5mg/ml. passive immunity transfer was successful, since 88.3% of calves had pt higher than 5.5g/dl. there was no effect of parity, calf sex, season of the year or cow genetic group in colostrum quality or serum total protein concentration (p>0.05). crossbred holstein zebu cows produced high quality colostrums. there was success in passive immunity transfer to the calves.