PSIII-11 - Interaction of phytase and diet on water usage and growth performance of grow-finish pigs

Abstract: Phytase and distillers dried grains with solubles (DDGS) are valuable in swine diets for improving nutrient availability and reducing feed costs. Phytase increases phosphorus absorption, supporting growth, while DDGS may provide a cost-effective source of protein and energy. The objective of this study was to evaluate the impact of dietary phytase and DDGS on water usage and performance in grow-finish pigs. A total of 1,116 grow-finish pigs (initial body weight (BW) 27.4±0.4 kg) were assigned to one of four dietary treatments in a 2x2 factorial arrangement: 1) Control (corn-soybean meal diet), 2) Control with phytase, 3) Control with DDGS without phytase, and 4) Control with both DDGS and phytase. Pigs were housed in 44 pens each with two cup drinkers (26 pigs per pen) and managed following standard protocols. Pens were assigned to one of the four dietary treatments within 11 total blocks based on barn location. Water usage was recorded weekly using water meters and growth performance measures were measured on day 21 and 48 of the trial. Average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency (G:F) were calculated for the periods and throughout the trial. On Day 21, ADG improved without phytase (675 vs 579 g/d; P < 0.01) also ADFI improved without phytase (1381 vs 1232 g/d; P < 0.01). Moreover, ADG was improved on day 48 with no DDGS inclusion (1137 vs 1089 g/d; P < 0.01). At the same time, ADFI was improved without DDGS (2491 vs 2343 g/d; P< 0.01) or without enzyme inclusion (2475 vs. 2358 g/d; P=0.02) and feed efficiency was improved without phytase inclusion (0.45 vs. 0.47; P = 0.02). Overall, ADG was improved during the trial without inclusion of phytase (933 vs 883 g/d; P < 0.01) and ADFI was improved throughout the trial with no phytase (2012 vs. 1884 g/d; P = 0.02) nor DDGS inclusion (2000 vs. 1897 g/d; P < 0.01). Additionally, both phytase (5.9 vs. 4.6 L/d; P < 0.01) and DDGS (5.8 vs. 4.7 L/d; P < 0.01) inclusion increased cumulative water usage. These results indicate that water usage and growth performance should be considered in diet formulation strategy with respect to phytase and DDGS inclusion.