Processing Grain Amaranth for Use in Broiler Diets

Two experiments were conducted in which grain amaranth (Amaranthus cruentus) was processed by autoclaving or extrusion and incorporated into broiler diets at 20 or 40%. In Experiment 1, grain was autoclaved for either 30, 60, or 90 min. Body weight gains and feed efficiencies were similar for the diet containing 20% grain amaranth autoclaved for 60 min and the corn-soybean meal control diet. At 40% inclusion, grain amaranth depressed growth significantly compared with the control diet regardless of autoclaving length. In Experiment 2, grain amaranth was processed by autoclaving and extruding. Only one of the feed efficiencies differed significantly from that of the control diet. Autoclaved amaranth, at 20% of the diet, produced body weight gains similar to the control diet regardless of processing length. When autoclaved amaranth was included into the diets at 40%, gains similar to those of chickens fed the control diet were obtained with processing lengths of either 30 or 45 min. Extruded amaranth, which was included only at 40%, produced body weight gains similar to those of chickens fed the control diet when extrusion was either “dry” or “normal”. These studies indicate that broilers can utilize up to 40% grain amaranth in their rations if the amaranth is properly processed by either autoclaving or by extrusion. At present, there is no sufficient assay to determine if the toxic or feed refusal factor(s) present in amaranth have been sufficiently processed without resorting to chick feeding trials. Further studies are needed to identify these factors in grain amaranth.