Effects of Different Drying Agents on the Quality of Avena sativa L. Hay

Purpose To study the effects of different chemical drying agents on the nutritional quality of oat (Avena sativa L.), providing a theoretical basis for selecting the optimal method of preparing oat hay.

Methods Using ‘Morton’ oats at the waxy maturity stage as the research object, three different mass fractions of drying agents: NaHCO₃ solution (0.5%, 1.0%, 1.5%), CaCO₃ solution (1.5%, 2.0%, 2.5%) and Na₂CO₃ solution (1.0%, 1.5%, 2.0%) were used to treat it, and natural air-drying was used as the control (CK). The drying time, nutritional quality and other related indicators of different treatments of oat hay were measured, and the comprehensive analysis was carried out by grey correlation degree.

Results The shortest drying time of 137.33 hours was observed with the 1.0% NaHCO₃ treatment. Oat hay treated with 1.5% CaCO₃, 2.0% Na₂CO₃, and 0.5% NaHCO₃ had significantly higher crude protein (CP) content compared with CK. Oat hay treated with 1.5% and 2.0% CaCO₃, 1.0% Na₂CO₃, and 1.0% NaHCO₃ exhibited significantly higher crude fat (CF) content compared with CK. Neutral detergent fiber (NDF) and acid detergent fiber content in oat hay treated with 1.5% Na₂CO₃ were significantly lower than those in CK. Oat hay treated with 1.5% NaHCO₃ and Na₂CO₃ (1.0%, 1.5%, 2.0%) showed significantly higher relative feeding value than CK. Correlation analysis showed that: NDF, crude ash, and dry matter intake were significantly positively correlated with drying time, while CP, CF, and dry matter digestibility showed significant negative correlations with drying time. The comprehensive analysis of grey correlation degree showed that: the equal weighting correlation of nutritional quality of oat hay, which was treated by 1.5% Na₂CO₃, was 0.8558, with ranking the 1st.

Conclusion The nutritional quality of oat hay treated with 1.5% Na₂CO₃ solution spraying is the best, which is the most suitable drying agent treatment for preparing oat hay in Yunnan area.