PSI-24 The Effect of Formic Acid and Lignosulfonate on Pellet Quality

Abstract

The objective of this study was to determine the effect of formic acid and lignosulfonate (LignoTech USA) on pellet quality. The 5 treatments consisted of a control, or the control with 2 levels of formic acid (0.36% and 0.60%), or the control with formic acid with lignosulfonate (0.24% and 0.40%). Diets were steam conditioned (245 mm×1397 mm Wenger twin shaft pre-conditioner, Model 150) for approximately 30 sec and pelleted on 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 pellet durability index using the Holmen NHP 100 (TekPro Ltd, Norfolk, UK) and via both standard and modified tumble box methods. Pellet hardness was determined by evaluating the peak amount of force applied before the first signs of fracture. Pellets were crushed perpendicular to their longitudinal axis using a texture analyzer (Model TA-XT2, Stable Micro Systems). Voltage and Amperage data was collected via Supco DVCV Logger (Supco, New Jersey, US). Data were analyzed using the MIXED procedure in SAS 9.4, with pelleting run as the experimental unit. Increasing formic acid in the diet decreased (linear, P < 0.0001) pH. No evidence for differences were observed for pellet mill energy consumption, pellet durability regardless of testing method or pellet hardness when adding formic acid or lignosulfonate to the diet. In conclusion, pellet quality was not influenced by formic acid or lignosulfonate.