To investigate the effect of cold exposure on absorption of colostral immunoglobulins, 56 piglets were weaned at birth and placed in either a thermoneutral (35 C) or cold (21 C) environmental chamber. Thermoneutral piglets had a survival rate of 62% at 48 h, but survival among cold-exposed piglets was only 36% (P less than .10). Cold aid reduced (P less than .01) rectal temperature by more than 6 C after 24 h of exposure. A constant amount of bovine colostrum was administered orally at 4 h after initiation of thermal treatments. Bovine immunoglobulin G1 (IgG1) was readily absorbed and reached a serum level of 17 mg/ml after 24 h. Bovine IgM also was absorbed and increased to approximately 2 mg/ml at 24 h. However, absorption of colostral IgG1 and IgM was not affected by cold exposure. Cold air increased (P less than .05) incidence of diarrhea by over five fold after 72 h, and severity of diarrhea was nearly doubled (P less than .01). Hematocrit was also higher (P less than .05) in cold-exposed piglets. These data demonstrate that a cold stressor sufficient to induce hypothermia does not impair absorption of colostral macromolecules in piglets. However, cold exposure was related to increase incidence and severity of diarrhea.