The effects of pellet quality and pellet die thickness on growth performance of finishing pigs.

Two experiments were conducted to determine the effects of percentage pellet fines and pellet die thickness on finishing pig growth performance. In Exp. 1, 350 finishing pigs (600 × 241; DNA, Columbus, NE) were used over time across three separate weight ranges. In each of the three studies, there were 10 pigs per pen and seven pens per treatment. The three weight ranges were 44 to 68, 81 to 106, and 118 to 144 kg. Treatments consisted of a meal control diet and pelleted diets with 9 to 16, 41 to 47, 60 to 68, and 84 to 91% fines measured at the feeder. From 44 to 68 kg pigs, meal as percentage fines at the feeder increased, ADFI increased (linear, P = 0.006) and G: F decreased (linear, P = 0.002). Pigs fed the diet averaging 13% fines had increased (P < 0.05) G: F compared to those fed the meal diet. For 81 to 106 kg pigs, ADFI increased (linear, P = 0.016) and G: F decreased (linear, P < 0.001) as percentage fines at the feeder increased. Pigs fed pellets with an average of 13% fines had increased (P < 0.05) G: F compared to pigs fed the meal diet. From 118 to 144 kg pigs, ADFI increased (linear, P = 0.006) and G: F increased (linear, P = 0.002) as percentage fines at the feeder increased. Pigs fed pellets with up to 42% fines had improved (P < 0.05) G: F compared to pigs fed meal feed. In Exp. 2, 314 pigs (initially 52 kg) were used in a 76-day study to evaluate the effects of pellet die thickness on pig growth performance. Treatments consisted of a meal control diet or pelleted diets from a thick die effective length: diameter (L: D) ratio of 8.7 fed as-is, pellets from a thin die (L: D 5.5) fed as-is, screened thin die pellets (L: D 5.5), and screened pelleted fines fed as a meal. There were nine pigs per pen and seven pens per treatment. Overall, pigs fed thick die pellets (L: D 8.75, 28% fines) had increased (P < 0.05) ADG compared to those fed either meal, thin die pellets (L: D 5.5, 42% fines), or pellet fines. Pigs fed L: D 8.75 pellets had increased (P < 0.05) G: F compared to pigs fed the meal treatment. In conclusion, minimizing the amount of pellet fines present at the feeder increased G: F. Increasing pellet die thickness which reduced the amount of pellet fines at the feeder also led to an improvement in ADG and G: F compared to pigs fed meal diets, diets pelleted using the L: D 5.5, or pellet fines.