Comparison of growth and quality of hydroponic grass from different barley varieties (Lines)

With the continuous increase in the scale of animal husbandry, the conflict between humans and livestock for food has become increasingly prominent. Hydroponic barley grass does not occupy arable land, has a short growth cycle, and features tender and juicy stems and leaves, a fragrant aroma, good palatability, easy digestion, and high protein and functional component content. It can be used as a new type of forage for livestock feeding. To identify germplasm resources suitable for the cultivation of hydroponic barley (H vulgare) grass, this study selected 25 barley varieties (lines) and conducted a comprehensive evaluation of their growth status, functional components, and nutritional quality. The grey correlation degree method and entropy weight method were used to evaluate the overall quality of hydroponic barley grass. The results showed that, in terms of growth status, the varieties with the highest fresh grass yield were ‘Gankensi 115’, ‘Gankenpi 119’, and ‘Gankenpi 118,’ which reached yields of 18.09, 17.14, and 15.34 kg/m², respectively, and exhibited relatively good plant height and germination rates. Regarding functional components, ‘Gankensi 515’, ‘Gankensi 223’, and ‘Gansimai No. 1’ ranked higher in γ-aminobutyric acid (GABA), with concentrations of 14.93, 13.33, and 7.78 mg/kg, respectively. ‘Gankenpi 611’, ‘Gankenpi 146’, and ‘Gankensi 151’ showed higher total phenolic content (TPC), with values of 107.68, 96.05, and 87.66 mg/kg, respectively. In terms of nutritional quality, ‘Gankensi 223’, ‘Gankenpi 611’, and ‘Gankenpi 42’ ranked higher in crude protein (CP), with percentages of 20.87%, 20.55%, and 19.90%, while exhibiting relatively low levels of acid detergent fiber (ADF) and neutral detergent fiber (NDF). The top three strains in the comprehensive evaluation of the grey correlation degree were ‘Gankenpi 611’, ‘Gankenpi 51’, and ‘Gankensi 115’, which demonstrated good overall production performance and could serve as valuable germplasm resources, providing a theoretical basis for the development of hydroponic barley grass.