This study demonstrated that inlet moisture content is a critical factor influencing drying efficiency, production rate prediction accuracy, and feed value changes of Italian ryegrass (IRG) in a multi-stage conveyor-type hot-air forage dryer. The experiment was conducted by uniformly loading IRG at a fixed drying height of approximately 25 cm with four different inlet moisture contents (30, 40, 50, and 60%). Drying time increased exponentially with increasing inlet moisture content, and a strong linear relationship was observed between inlet moisture content and the time required to reach 15% moisture, enabling the development of a reliable drying time prediction model. The proposed model showed high applicability and prediction accuracy at inlet moisture contents of 30–40%, where predicted and measured production rates were in close agreement. However, at inlet moisture contents of 60% or higher, the model substantially overestimated production rates, indicating limitations under high-moisture conditions. This behavior was attributed to reduced airflow penetration and diminished heat and mass transfer efficiency caused by increased material thickness and particle mass at high moisture levels. Feed value analysis revealed that crude protein content decreased by 12–20% following hot-air drying compared with fresh material, while ether extract, crude ash, and fiber components were not significantly affected. No significant differences in crude protein loss were observed among treatments with inlet moisture contents of 60% or lower. In conclusion, the multi-stage conveyor-type hot-air dryer and the proposed prediction model are suitable for drying Italian ryegrass at inlet moisture contents of 40% or lower and can be effectively applied under practical operating conditions. However, at inlet moisture contents of 60% or higher, improvements in airflow distribution within the dryer or the incorporation of moisture-dependent correction factors are required to enhance drying performance and prediction accuracy.

ABSTRACT
Ⅰ. 서론
Ⅱ. 재료 및 방법
    1. 조사료 열풍 건조 생산시스템 구성
    2. 건조 조건별 수분변화 조사 방법
    3. 건조 조건별 수분변화 조사 방법
    4. 다단컨베이어형 열풍건조기 생산성 평가
    5. 사료가치분석
    6. 통계분석
Ⅲ. 결과 및 고찰
    1. IRG 투입 수분에 따른 열풍 건조시간별 수분변화
    2. IRG 투입 수분에 따른 열풍 건조시간 예측
    3. 다단컨베이어 조사료 열풍건조기를 활용한 이탈리안 라이그라스 건조성능 평가
    4. 다단컨베이어 조사료 열풍건조기를 활용한 이탈리안 라이그라스 사료가치 변화
Ⅳ. 요약
Ⅴ. 사사
Ⅵ. REFERENCES

• 정진우(국립축산과학원 조사료생산시스템과) | Jin Woo Jeong (Forages Production Systems Division, National Institute of Animal Science, Cheonan 31000, Republic of Korea)
• 박형수(국립축산과학원 조사료생산시스템과) | Hyung Soo Park (Forages Production Systems Division, National Institute of Animal Science, Cheonan 31000, Republic of Korea)
• 우제훈(국립축산과학원 조사료생산시스템과) | Jae Hoon Woo (Forages Production Systems Division, National Institute of Animal Science, Cheonan 31000, Republic of Korea)
• 양승학(국립축산과학원 조사료생산시스템과) | Seung Hak Yang (Forages Production Systems Division, National Institute of Animal Science, Cheonan 31000, Republic of Korea)
• 고하늘(국립축산과학원 조사료생산시스템과) | Ha Neul Ko (Forages Production Systems Division, National Institute of Animal Science, Cheonan 31000, Republic of Korea)
• 정승민(국립축산과학원 조사료생산시스템과) | Seung Min Jeong (Forages Production Systems Division, National Institute of Animal Science, Cheonan 31000, Republic of Korea)
• 최기춘(국립축산과학원 조사료생산시스템과) | Ki Choon Choi (Forages Production Systems Division, National Institute of Animal Science, Cheonan 31000, Republic of Korea)
• 정종성(국립축산과학원 조사료생산시스템과) | Jeong Sung Jung (Forages Production Systems Division, National Institute of Animal Science, Cheonan 31000, Republic of Korea) Corresponding author