This study was designed to investigate associations between transfer of passive immunity, selected illness-es (diarrhoea, pneumonia, and fatigue anorexia syndrome-FAS) and growth performance [body weight (BW) and aver-age daily gain (ADG)] in preweaned lambs. A total of 347 lambs were blood sampled at 24±1 h of age after birth and the serum IgG concentration for each lamb was measured after colostrum intake using a commercial ELISA kit. Lambs were weighed on a scale immediately after birth (before colostrum intake) and reweighed on day 28 (end of neonatal period) and day 84 (age of weaning). Lambs ADG was calculated from 0 to 28 d of life, from 29 to 84d of life, and from 0 to 84 d of life. Growth performance (BW and ADG) of lambs with diarrhoea and FAS in the neonatal period and with pneumonia in the postneonatal period was significantly lower than that of healthy lambs of the same period (P