Comparative in protein and amino acid digestibilities in growing pigs and sows

An experiment was conducted to compare apparent total tract protein digesti bilities and apparent ileal digestibilities pf protein and amino acids in g rowing pigs and adult pregnant and lactating sows. Twelve growing pigs and 12 sows were used and surgically fitted with simple T-cannulas at the dista l ileum. Six experimental diets based on corn, barley, wheat, soybean meal, canola meal, or meat and bone meal were formulated, and each diet was fed to growing pigs, gestating sows, and lactating sows for 7 d. Chromium oxide was included in all diets as an indigestible marker (.25%) for calculating nutrient digestibilities. Fecal material was collected on d 5 of each feed ing period by grab sampling, and ileal samples were collected for 12 h/d du ring the last 2 d of each feeding period. Apparent fecal protein digestibil ities for all feed ingredients were higher (P < .05) in gestating and lacta ting sows compared to growing pigs, but no differences between the two grou ps of sows were observed (P > .05). At the distal ileum, no differences (P > .05) in protein digestibilities were detected between sows and growing pi gs regardless of feed ingredient. For all feed ingredients tested, lactatin g sows had apparent ileal digestibilities of most amino acids that were two to six percentage units higher than those obtained in growing pigs, but no t all of the differences were significant. Gestating sows had digestibiliti es of most amino acids that were intermediate between those of growing pigs and lactating sows. The combined results from the six feed ingredients sho wed that lactating sows had higher(P < .05) digestibilities of all indispen sable amino acids except arginine, and gestating sows had higher (P < .05) digestibilities of five of the indispensable amino acids than did growing p igs. The results of this experiment indicate that apparent fecal protein an d apparent ileal amino acid digestibilities obtained in growing pigs are no t always representative of digestibilities in either gestating or lactating sows.