Krogh, U., Bruun, T. S., Amdi, C., Flummer, C., Poulsen, J. and Theil, P. K. 2015. Colostrum production in sows fed different sources of fiber and fat during late gestation. Can. J. Anim. Sci. 95: 211–223. The objective was to study yield and composition of colostrum and transient milk from 36 second-parity sows fed a standard lactation diet (CON) low in fiber or one of two high-fiber diets based on sugar beet pulp (SBP) or alfalfa meal (ALF), combined with one of three fat sources, palm fatty acid distillate (PFAD), soybean oil (SOYO) or trioctanoate (C8TG) from day 105 of gestation onward. Sows were milked at 0, 12, 24 and 36 h relative to onset of parturition. Jugular vein blood was collected on day 112 of gestation. Plasma acetate content was affected by dietary fiber and fat treatment (P<0.05), indicating altered intermediary metabolism. Colostrum yield, predicted from piglet birth weight, suckling duration and weight gain, was unaffected by dietary treatments (P>0.10). Colostral (24 h) and transient milk dry matter contents were greater in SOYO compared with PFAD and C8TG sows (P<0.05). Colostrum (12 and 24 h) and transient milk lactose contents were greatest in CON-fed sows compared with sows fed ALF or SBP diets (P<0.05). In conclusion, nutrition in late gestation affected the intermediary metabolism and colostrum composition, but did not affect colostrum yield of sows.