The content of insoluble fibre and crude protein value of the aboveground biomass of Amaranthus cruentus and A. hypochondriacus

Twenty samples of the aboveground biomass of Amaranthus cruentus (varieties Olpir, Amar 2 RR-R 150, and A 200 D) and A. hypochondriacus (variety No. 1008) were analysed to determine their nutritional value during the experimental period covering five growth stages from inflorescence emergence till full ripening of grain. During plant growth, from day 80 to day 120 of cultivation, the nutritional value decreased. This was demonstrated by an increase in insoluble fibre and a reduction in crude protein concentration. The concentration of neutral detergent fibre in the dry matter (DM) increased from 356 to 420 g/kg (P less than 0.01); acid detergent fibre from 238 to 286 g/kg (P less than 0.01); acid detergent lignin from 22.9 to 53.4 g/kg (P less than 0.01). The concentration of crude protein in DM decreased from 174 to 109 g/kg (P less than 0.01). The aboveground biomass of A. cruentus and A. hypochondriacus could be used as a good source of fibre and protein in animal diets when harvested in the period from day 80 to 90 of cultivation.