AMARANTH GRAIN FOR ANIMAL FEEDING: A HIGH-QUALITY WHOLESOME CROP

The present research aims to explore the agronomic traits, proximate composition and oil and fatty acid content of five amaranth species, namely Amaranthus cruentus, A. hypochondriacus, A. hybridus, A. caudatus and A. tricolor, grown in a semiarid Mediterranean area, with the purpose of increasing the knowledge of these plants, as a source of nutrients and essential fatty acids, for animal feeding. A. cruentus resulted the most productive species (382 g/m2) even though not differentiated from A. hypochondriacus and A. hybridus (273 and 256 g/m2, respectively). The highest thousand seed weight was recorded in A. hypochondriacus and A. cruentus (0.84 and 0.71 g, respectively). The crude protein showed the significant highest value in A. tricolor (18.5%) while the significant highest starch content was ascertained in A. cruentus (60%) and A. caudatus (59.9%). A. hybridus showed the highest oil content (7.06%) and the highest crude fibre content (17.2%). Among the fatty acids of nutritional interest, A. hypochondriacus and A. cruentus emerged as the best healthy ingredient for animal feeding. A. hypochondriacus seeds showed a high content of polyunsaturated fatty acid of the n6 (linoleic acid) and n3 (linolenic acid) series, while, A. cruentus showed a high content of monounsaturated fatty acid of the n9 series (oleic acid). As regards the nutritional indices, results showed significant differences for atherogenic and thrombogenic indices, and hypocholaesterolemic and hypercholaesterolemic ratio among the species, giving the best values for A. hypochondriacus, while A. hybridus and A. caudatus showed the lowest peroxidation index and therefore the highest stability. According to present findings, grain amaranth can be recommended as a promising non-conventional source for animal healthy diets provided that further studies will ascertain the best species for Mediterranean environmental conditions and animal species, and sustainability of the cultivation phase.