Decreasing corn particle size increases energy and nitrogen digestibility in gestating sows

Results of previous research has demonstrated that reducing the particle size of corn improved metabolizable energy (ME) utilization in many phases of swine production. One phase that has limited research thus far is gestation sows. The objective of this experiment was to determine the effects of corn particle size on the digestibility of protein (CP), and digestible energy (DE), ME, and nitrogen adjusted metabolizable energy (AMEn) in gestating sow diets. A total of 27 sows during the second phase of gestation (day 40 to 74) were fed a common diet with one of 3 target geometric mean diameter (dgw) of corn ground to either 400, 800, or 1200 µm. Corn was ground using a 3 high roller mill (RMS model 924). Titanium dioxide (0.25%) was included in the diet as an indigestible marker for index digestibility calculations. Sows were fed experimental diets for 7 days to allow for diet adaptation before a 2-day collection period. Apparent total tract digestibility (ATTD) of crude protein (CP), and DE, ME, and AMEn increased (linear, P <0.001) as corn particle size was reduced from 1200 to 400 µm. The ME and AMEn (88.5% DM) of the diet increased by 178 and 172 kcal/kg, respectively, which resulted in a 22.3 and 21.5 kcal/kg, respectively, improvement for every 100 μm decrease in particle size.