This study reviewed previous research on livestock manure application in forage crop fields, with a focus on forage productivity, forage quality, and Hanwoo carrying capacity per unit area. This work was conducted as a narrative review, not as a systematic review or meta-analysis. Studies published between 2000 and 2025 were collected from the Research Information Sharing Service (RISS), the Korean Citation Index (KCI), DBpia, and Google Scholar. Many studies reported that manure application increased dry matter yield and improved forage nutritional components such as crude protein and total digestible nutrients. However, the size of these effects differed depending on crop type, soil condition, weather, and application rate. In several cases, nutrient use efficiency was lower under high rainfall or unstable temperature conditions, especially when liquid manure was applied. Carrying capacity was estimated using assumed animal body weight and forage contribution. When different assumptions were applied, the calculated values changed. This shows that carrying capacity is not a fixed number but a relative measure, and the results should not be used directly without considering farm management conditions. Livestock manure application increased forage production and helped nutrient movement in crop–livestock systems. However, similar results cannot be expected in all environments. Future studies should consider soil characteristics, forage productivity, forage use, and livestock performance together.

ABSTRACT
Ⅰ. INTRODUCTION
Ⅱ. LITERATURE SEARCH ANDSELECTION METHOD
    1. Search strategy
    2. Inclusion scope
    3. Review process
    4. Data extraction and summary
Ⅲ. EFFECTS OF LIVESTOCK MANUREAPPLICATION ON FORAGE CROPPRODUCTIVITY AND FORAGE VALUE
    1. Changes in productivity (Dry matter yield)
    2. Changes in forage value
    3. Effects of crop type, soil, and weather conditions
    4. Differences by manure type and application method
Ⅳ. LIVESTOCK MANURE APPLICATIONAND EVALUATION OF HANWOOCARRYING CAPACITY PER UNIT AREA
Ⅴ. LIMITATIONS AND FUTURE RESEARCHDIRECTIONS
Ⅵ. CONCLUSIONS
Ⅶ. REFERENCES

• Soon Hwangbo(Department of Companion Animal Industry, Daegu University, Gyeongsan 38453, Republic of Korea) Corresponding author