58 Effects of Pellet Quality on Growth Performances of Pigs When Fed Diets During Varying Weight Ranges

Abstract

Abstract The objective of these experiments was to determine if the importance of pellet quality was dependent on pig weight ranges. Therefore, a total of 350 grow-finish pigs (line 600 × 241; DNA) were used in 3 separate experiments. Each experiment was conducted as a randomized complete block design. Pigs were weighed before the onset of each experiment and split into 7 blocks based on average body weight, resulting in 7 replications per treatment. For Exp. 1, 2, and 3, pigs were fed treatments for 20 days from 43 to 68 kg, 21 days from 81 to 107 kg, and 20 days from 118 to 144 kg, respectively. Pelleted diets for Exp. 1, 2, and 3 were steam conditioned at approximately 83, 77, and 67°C, respectively and subsequently pelleted with a 30-horsepower pellet mill (1012-2 HD Master Model, California Pellet Mill, Crawfordsville, IN). For Exp. 1 and 2 diets were pelleted with a 4.8 × 31.8 mm (L:D 6.7) die while a 4.8 × 57.2 mm (L:D 12) die was used for Exp. 3. Treatments consisted of a mash diet and pellets with fines inclusion rates of 9-16, 41-47, 60-68, and 84-91%. For Exp.1, pigs fed pellets with 12.5% fines had improved (P < 0.05) G:F when compared with those fed the mash diet. Pig ADFI increased (linear, P = 0.006) as percent fines at the feeder increased. Pig G:F decreased (linear, P = 0.002) as percent fines increased at the feeder. For Exp. 2, pigs fed pellets with 15.5% fines had improved (P < 0.05) G:F compared with those fed the mash diet. Pig ADFI increased (linear, P = 0.016) when fed pellets with increasing percent fines at the feeder. Pig G:F decreased (linear, P = < 0.001) as fines percentage increased at the feeder. For Exp. 3, pigs fed pellets with 9.6 and 41.8% fines had increased (P < 0.05) G:F when compared with those fed mash diets. Pig G:F decreased (linear, P = 0.005) as pellet fines percentage increased at the feeder. In conclusion, feeding pigs 12.5, 15.5, and 9.6% fines in Exp. 1, 2, and 3 improved G:F by 3.9, 5.4, and 9.1%, respectively, compared with pigs fed mashed diets. Increasing the percent fines from 12.5 to 90.4%, 15.5 to 86.0%, and 9.6 to 83.6% reduced G:F of pigs by 5.7, 7.7, and 5.6% for Exp. 1, 2, and 3, respectively.