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This study was performed to evaluate hammermill tip speed, assistive airflow and screen hole diameter on hammermill throughput and characteristics of ground corn. Corn was ground using two Andritz hammermills (Model: 4330-6, Andritz Feed & Biofuel, Muncy,PA) measuring 1-m in diameter each equipped with 72 hammers and 300 HP motors. Treatments were arranged in a 3 × 3 × 3 factorial design with 3 tip speeds (3,774, 4,975, and 6,176 m/min), 3 screen hole diameters (2.3, 3.9 and 6.3 mm), and 3 air flow rates (1,062, 1,416, and 1,770 fan RPM). Corn was ground on 3 separate days to create 3 replications and treatments were randomized within day. Samples were collected and analyzed for moisture, particle size, and flowability characteristics. Data were analyzed using the GLIMMIX procedure of SAS 9.4 with grinding run serving as the experimental unit and day serving as the block. There was a 3-way interaction for standard deviation (Sgw), (linear screen hole diameter × linear hammer tip speed × linear air flow, P = 0.029). There was a screen hole diameter × hammer tip speed interaction (P < 0.001) for geometric mean particle size dgw (P < 0.001) and composite flow index (CFI) (P < 0.001). When tip speed increased from 3,774 to 6,176 m/min the rate of decrease in dgw was greater as screen hole diameter increased from 2.3 to 6.3 mm resulting in a 67, 111, and 254 μm decrease in dgw for corn ground using the 2.3, 3.9, and 6.3 mm screen hole diameter, respectively. For CFI, increasing tip speed decreased the CFI of ground corn when ground using the 3.9 and 6.3 mm screen. However, when grinding corn using the 2.3 mm screen, there was no evidence of difference in CFI when increasing tip speed. In conclusion, the air flow rate did not influence dgw of corn but hammer tip speed and screen size were altered and achieved a range of dgw from 304 to 617 μm. [ABSTRACT FROM AUTHOR]

The objective of this study was to determine effects of pelleting on the standardized ileal digestibility (SID) of amino acids (AA) in diets with or without increased concentrations of free AA and reducing sugars (RS). Eight individually housed, ileal cannulated barrows (initially 69.2 kg) were allotted to a replicated 8×8 Latin square with 8 diets and eight 7-d periods with ileal digesta collected on d 6 and 7. Treatments were arranged in a 2×2×2 factorial with main effects of diet form (mash vs. pellet), crystalline AA (low vs. high), or reducing sugars (low vs. high) provided by dried distillers grains with solubles and bakery meal. Diets were pelleted to achieve a hot pellet temperature of 85 to 88°C. Data were analyzed as a completely randomized Latin square using the GLIMMIX procedure of SAS. A feed form×RS interaction (P < 0.026) for SID of tryptophan was observed. Feeding pelleted low RS diets improved SID of tryptophan compared with mash high and low RS diets, and pelleted high RS diets. For main effects of feed form, the SID of total AA, CP, and indispensable AA increased (P < 0.042) in pigs fed pelleted diets compared with mash diets. For main effects of crystalline AA, pigs fed high crystalline AA had increased (P = 0.007) SID of tryptophan and decreased (P = 0.050) SID of histidine compared with those fed low crystalline AA diets. For main effects of RS diets, pigs fed high RS diets had decreased (P < 0.05) SID of total AA, CP and indispensable AA. In conclusion, pelleting diets with increased crystalline AA or RS did not affect the improvement in AA digestibility from pelleting. Pelleting diets improved AA digestibility. Diets formulated with high crystalline AA had increased SID of tryptophan. Formulating diets with high RS resulted in decreased AA digestibility compared with corn-soybean meal-based diets. [ABSTRACT FROM AUTHOR]

A total of 360 pigs (DNA 200×400; initially 11.3 kg) were used in an 18-d study to determine the effect of pelleting diets with or without increased concentrations of free amino acids (AA) and reducing sugars (RS) on pig growth performance. There were 9 replications/treatment and 5 pigs/pen. Treatments were arranged in a 2×2×2 factorial with main effects of diet form (mash vs. pellet), crystalline AA (low vs. high), and RS (low vs. high) provided by dried distillers grain with solubles and bakery meal included at 20% and 15%, respectively. Diets were pelleted to achieve a conditioning temperature of 86.7°C using a 22.4 kW pellet mill equipped with a 4.7 x 34.9-mm die. Data were analyzed as a CRD using the GLIMMIX procedure of SAS. There were no 3-way interactions observed. For the main effect of feed form, ADFI decreased (P=0.001) and G:F and caloric efficiency improved (P=0.001) in pigs fed pelleted diets compared to mash diets. For the main effect of crystalline AA, pigs fed diets with high crystalline AA had increased (P< 0.024) ADFI compared to those fed diets with low crystalline AA. For the main effect of RS, pigs fed high RS diets had decreased (P< 0.041) ADG, ADFI, G:F, and caloric efficiency compared to those fed low RS. In conclusion, there was no evidence of interactions between treatments, indicating that increasing amounts of crystalline AA and RS did not influence the response to pelleted diets. Pigs fed the high RS diets had reduced feed intake which resulted in reduced gain and improved feed and caloric efficiency. [ABSTRACT FROM AUTHOR]

A total of 720 barrows (initially 5.9 kg; Line 200 × 400; DNA, Columbus, NE) were used in a 42-d growth trial to test the effects of spray-dried Lactococcus-based fermentation products on nursery pig performance. There were 24 replications per treatment with pen randomly allotted to 1 of 6 dietary treatments. The positive control (PC) diet included zinc oxide (ZnO; phase 1), ZnO + chlortetracycline (CTC; phase 2) while the negative control (NC) diet did not include ZnO or CTC. Treatment diets included the negative control + 1 of 4 fermentation products (C, D, E, or F) added at 5% of the diet. Phase 3 diets contained a common control diet fed to all pigs plus treatment diets with fermentation products. Data were analyzed with pen as the experimental unit and barn within group as the blocking factor using PROC-GLIMMIX in SAS. From d 0 to 20, there was an overall treatment effect (P = 0.001) where pigs fed PC had increased (P < 0.05) d 20 BW, ADG, ADFI, and improved G:F compared to those fed the NC and NC + fermentation product. Overall, there was a treatment effect (P = 0.03) for pigs fed the PC having improved (P < 0.05) ADG and G:F compared to the NC and NC + fermentation product. In addition, pigs fed the NC had improved (P < 0.05) G:F compared to those fed additive D, E, and F. In conclusion, pigs fed the PC (zinc + CTC) diet had improved performance compared to pigs fed the NC with or without fermentation product. Adding fermentation products to the NC diet did not improve nursery pig performance. [ABSTRACT FROM AUTHOR]

The objective of this experiment was to determine the effect of conditioning temperature on pellet durability index (PDI) and pellet hardness. A nursery pig diet was formulated to contain 25% spray-dried whey. Treatments consisted of three different conditioning temperatures: 54, 63, and 71°C. Diets were steam conditioned (245 mm × 1397 mm Wenger twin staff pre-conditioner, Model 150) for approximately 30 sec and pelleted using a 1-ton 30-horsepower pellet mill (1012-2 HD Master Model, California Pellet Mill) with a 4.8 mm × 31.8 mm pellet die (L:D 6.7). The production rate was set at 900 kg/h. Treatments were pelleted at 3 separate time points to provide 3 replicates per treatment. Samples were collected directly after discharging from the pellet mill and cooled in an experimental counterflow cooler. Samples were analyzed for PDI using the Holmen NHP 100 for 60 sec (TekPro Ltd, Norfolk, UK). Pellet hardness was determined by evaluating the peak amount of force applied before the first signs of fracture. Although conditioning temperature was increased in a linear fashion, a quadratic increase (P < 0.002) in hot pellet temperature (HPT) was observed. The HPT were 68, 72, and 74°C for diets conditioned to 54, 63 and 71°C, respectively. Increasing conditioning temperature resulted in increased (linear, P < 0.045) PDI and pellet hardness. As conditioning temperature increased from 54, to 71°C PDI increased from 87% to 92% and the force required to crush pellets increased from 13.5 to 15.9 kg. There was a tendency for a correlation (P < 0.076, r = 0.618, r2 = 0.382) between pellet hardness and PDI. Overall, increasing the conditioning temperature increased pellet hardness and pellet durability. [ABSTRACT FROM AUTHOR]