We conducted this study to investigate the impact of various seed ratios on the growth rate, performance, nutritive value, and digestibility of fodder grown in a hydroponic system. Seeds were applied at 1000 g for high seed density treatment (HSD: 4.761 kg m–2) and 750 g for low seed density treatment in each tray (LSD: 3.571 kg m–2). Three harvest times (8th, 9th, and 10th day of germination) were evaluated to measure the shoot height, root length, and fodder yield. Nutritive value and in vitro digestibility were determined at 10 days of harvesting. The HSD treatment had higher fresh weight and root length but lower shoot height throughout the harvest time. A higher green fodder yield, dry matter content, dry matter yield, crude protein yield, and lower contents of dry matter and crude protein loss were observed in HSD treatment. The fodder of LSD treatment had a higher content of ether extract, crude ash, crude fibre, and a higher digestibility rate but a lower content of neutral detergent fibre and acid detergent fibre compared to those in the HSD fodder. Taking performance factors into account, the more efficient fodder seems to be barley green fodder with high-density sowing, but considering parameters regarding the nutritive value and feed digestibility such as NDF, ADF, and IVDMD, the more efficient fodder appears to be barley fodder with low-density sowing.