Feed Quality of Harvest Residues from Soybean (Glycine max L.) Varieties at the Grain Maturity Stage

Abstract

This study aims to determine the roughage quality of field residues (stems and straws) remaining after the grain harvest of different soybean varieties. In the dry plant samples, crude protein (CP), acid detergent fiber (ADF), neutral detergent fiber (NDF), potassium (K), phosphorus (P), calcium (Ca), magnesium (Mg), condensed tannin (CT), total phenolics (TP), total flavonoid (TF), and radical scavenging activity (DPPH) contents were determined. The highest CP content was found in the Kocatürk variety (8.74%), while the lowest was in the Yemsoy variety (6.98%). The K, P, Ca, and Mg contents of the soybean varieties ranged from 1.35-1.42%, 0.35-0.44%, 0.78-0.86%, and 0.25-0.32%, respectively. The highest CT content was found in the Göksoy (0.27%), Mitchel (0.24%), and Yemsoy (0.23%) varieties, while the lowest was in the Ataem-7 variety (0.17%). The TP, TF, and DPPH contents of the soybean varieties ranged from 17.95–27.68 mg GA g⁻¹, 0.67–1.20 mg QE g⁻¹, and 47.88–67.62%, respectively. As a result, the Kocatürk variety stood out among the different soybean varieties in terms of quality characteristics. This situation is important in terms of investigating the possibilities of evaluating the harvest residue of the mentionedvariety as animal feed. On the other hand, the quality characteristics of the straws of the soybean varieties used in the research were at a sufficient level in terms of animal health, quality, and yield.