For protein evaluation of feedstuffs for ruminants, the Streptomyces griseus protease test offers a purely enzymatic approach to estimate ruminal protein degradation. This study was conducted to determine the enzymatic crude protein (CP) degradability of alfalfa, sainfoin, and common vetch hays, which are commonly used in ruminant nutrition. To estimate CP degradation, fifteen samples from each type of hay were incubated in vitro with a commercial protease extracted from Streptomyces griseus. The incubation was carried out for 1, 4, 24, and 48 hours in a borate-phosphate buffer at pH 8. Significant differences in CP degradability values were found among all three types of hay across all incubation periods. For all incubation periods, sainfoin had the lowest CP degradability values (P < 0.05), due to its high content of cell wall components and condensed tannins (CTs). For incubation periods longer than 1 hour, common vetch had the highest CP degradability values, followed by alfalfa and sainfoin, respectively (P < 0.05). As a result, the use of the protease enzyme extracted from Streptomyces griseus was confirmed as an effective method for estimating the CP degradability of selected legume forages in the laboratory, eliminating the need for animal testing. However, since plant proteins are often embedded within carbohydrate complexes, it is recommended that future tests consider the combined use of protease and carbohydrase, particularly for sainfoin, which is rich in cell wall components and condensed tannins.

Sainfoin (Fabaceae) is one of the most critical animal forage crops. However, the tolerance of sainfoin is low against to salinity. This study aims to investigate biochemical responses of the shoot and root tissue of sainfoin seedlings to moderate salt stress under in vitro conditions. For this aim, the seed of sainfoin were sown MS medium containing 100 mM NaCl. Antioxidant enzymes (CAT, SOD, APX, and GR), proline and malondialdehyde (MDA) contents were measured in shoot and root tissue of 35-day-old seedlings of sainfoin. A significantly higher constitutive catalase (CAT) and superoxide dismutase (SOD) activity was observed in shoot tissues when compared to root tissues. Overall, salt stress caused significant more enhancement in the activity of antioxidant enzymes (CAT, SOD, APX, and GR) in shoot tissues than root tissue. On the other hand, among the antioxidant enzymes, SOD seems to be more active in both tissues of sainfoin. Interestingly, the activity of GR reduced in both tissue under salt stress. The content of proline and MDA has been increased under salt stress and this increase has been more in the root tissue. This study has revealed biochemical responses to salt stress in different organs of sainfoin.

The health and vitality of callus growth is one of the prerequisites for the success of further in vitro studies. This study investigated the efficiency of different percentage (0%, 10%, 20%, 30%, and 40%) of vermicompost tea as an organic substance on in vitro callus growth in sainfoin. Morpho-physiological responses of calli to vermicompost tea measured under in vitro conditions. As a result of this investigation, a combination of plant growth regulators (4 mg/l BAP and 0.5 mg/l NAA) with 20% of vermicompost tea causing significant callus initiation and growth in sainfoin stem explants. Under the light of these scientific findings, vermicompost tea might be used as an organic bio stimulant for efficient callus growth and complementary to commercial chemical hormones in sainfoin. This research is important due to it can contribute positively to the plant species that are difficult in terms of callus growth and plant regeneration in tissue culture.