Azomite, a dacitic (rhyolitic) tuff breccia, included at 0.25% in feed manufactured with 32, 38, and 45 mm pellet die thicknesses increased pellet production rate by 5.0, 7.9, and 11.8%, respectively

Abstract

SUMMARY: Azomite (AZM) has been shown to increase pellet production rate (PPR) when included in corn and soybean meal-based diets containing dicalcium phosphate and dried distillers’ grains with solubles. It is presumed that these increases in PPR are due to the scouring and lubrication properties associated with AZM. The objective of this study was to determine the effect of AZM (0.25% diet inclusion) on PPR, pellet durability index (PDI), and hot pellet temperature (HPT), while utilizing 3 different pellet die thicknesses (PDT, 32 mm, 38 mm, and 45 mm). Feed was manufactured in a 2 (AZM) × 3 (PDT) factorial in a Latin square design, utilizing a California Pellet Mill conditioner and pellet mill, with 653 kg experimental unit batches. The inclusion of AZM increased overall PPR by 7.9% (P < 0.001) and decreased PDI by 1.6 percentage points (P < 0.001). As PDT increased (32 mm to 38 mm/45 mm), PPR decreased by 28.5% (P < 0.001), and PDI increased by 10.1 percentage points (P < 0.001). The interaction of AZM and PDT influenced HPT (P = 0.007), with AZM reducing HPT for the 32 mm and 38 mm PDTs; however, no difference was observed for the 45 mm PDT. Linear contrast analysis showed that PPR increased by 5.0, 7.9, and 11.8% when comparing AZM treatments to their respective PDT controls (all PDT; P < 0.001). In conclusion, AZM increased pellet production rate across pellet die thickness and decreased pellet durability index, albeit to the extent that would likely not affect broiler performance.

Keywords

• Azomite
• pellet die thickness
• pellet production rate
• pellet durability