Date of this Version
Forty pigs were used in a 14-week, 4-phase regime study conducted to evaluate the feeding value of diets with varying concentrations of DDGS for growing-fi nishing pig formulated on a standardized ileal digestibility (SID) lysine (lys) basis, DDGS withdrawal at the last feeding phase, and ractopamine (RAC)supplementation four weeks prior harvesting. Treatments consisted in 0, 15 or 40% dietary DDGS inclusion supplemented or not with RAC (4.5 ppm) four weeks prior harvesting. Increased dietary DDGS inclusion resulted in a linear reduction in average daily gain (ADG) during the Grower 1 period (P = 0.002). There were no treatment effects (P > 0.05) of increasing dietary DDGS inclusion for any of the variables examined during the Grower 2 feeding period. No differences among treatments were detected throughout the feeding phase Finisher 1 for ADG, average daily feed intake (ADFI), longissimus muscle area (LMA) and gain:feed (G:F) (P > 0.05). During the Finisher 2 feeding phase, there were no differences among treatments due to dietary DDGS inclusion on any of the variables studied. The inclusion of RAC four weeks prior harvesting did not affect growth performance (ADG, ADFI, and G:F; P = 0.436, 0.217, 0.880 respectively); however, there was a numerical increase in ADG due to RAC inclusion. The examination of 98-day BF and LMA data did not show differences due to RAC inclusion (P = 0.319 and 0.728 respectively). There were no changes in growth performance or ultrasound measurements due to withdrawal of DDGS (P > 0.05). Overall, growth performance was maintained as dietary DDGS inclusion increased from 0 to 40%.