Effects of Different Watering Options on Standardized Ileal Digestibility of Amino Acids and net Energy in Diets fed to Growing Pigs

Abstract Two experiments were conducted to test the hypothesis that different watering options affect the standardized ileal digestibility (SID) of amino acids (AA), apparent total tract digestibility (ATTD) of dry matter (DM) and gross energy (GE), and concentration of net energy (NE) by growing pigs. A corn-soybean meal-based diet was used in both experiments. There were 3 treatments: 1) dry feeder plus a water nipple located outside the feeder, 2) wet-dry feeder with the water nipple inside the feeder, and 3) combined system with a water nipple both inside the feeder and also an outside nipple. In Exp. 1, pigs (n = 6; initial weight = 27.53 kg) that were equipped with a T-cannula in the distal ileum were allotted to the 3 treatments using a replicated 3 × 3 Latin square design with 6 pigs and three 7-d periods. All pigs were fed an N-free diet for an additional period to determine basal endogenous losses of AA. Chromic oxide was added to all diets and ileal digesta were collected according to standard procedures. In Exp. 2, 24 pigs (initial weight = 50.23 kg) were allotted to the 3 treatments using a replicated 3 × 3 Latin square design with 6 chambers (i.e., 4 pigs per chamber) and three 15-d periods. Oxygen consumption and CO2 and CH4 productions were measured during fed and fasting states and fecal and urine samples were collected. In both experiments, pigs were allowed ad libitum access to feed and water. Results indicated that there were no differences among watering options for SID of AA, feed intake, total and fasting heat production, ATTD of DM and GE, or NE in diet. In conclusion, different watering options did not affect the digestibility of AA, DM, and GE and concentration of NE in a corn-soybean meal diet fed to growing pigs.