Effect of a sepiolite product on pellet durability in pig diets differing in particle size and in broiler starter and finisher diets

Sepiolite is a hydrated magnesium silicate clay with binder properties. The effect of a sepiolite product on pellet durability of diets varying in particle or fat addition was studied in two experiments. In the first experiment, a 2 X 3 factorial arrangement with two particle sizes (3 and 6 mm) and three sepiolite product levels (0, 10 and 20 g kg(-1)) was designed. Four samples of feed pellets were obtained from each combination of factors in order to measure durability using the Pfost durability tester. Temperatures at two points of the pelleting process, pellet production (kg h(-1)), and percentage of fines in the cooler were measured. Durability of pellets varied between 81.5 and 91.0, Durability of pellets increased with the low particle size accounting for 79.3% of the total variability (P < 0.001). The sepiolite product improved durability, independently of particle size (P < 0.001) accounting for 20.5% of the total variability. The sepiolite product increased the temperature of pellets at the outlet of die (P < 0.01). In the second experiment the effect of sepiolite in starter and finisher chicken diets was investigated using three sepiolite product levels (0, 10 and 20 g kg(-1)). Four samples of feed pellets were obtained from each treatment in order to measure durability using the Pfost durability tester. Temperatures at two points of the pelleting process and percentage of fines in the cooler were measured. The sepiolite product improved the durability of pellets of starter chicken diets (P < 0.05) but not in the finisher diets (P > 0.05). The response in the starter diet was dose dependent. Temperature of pellets at the exit of die increased by the addition of the sepiolite product in the starter diets only (P < 0.10).