The purpose of this study was to investigate the egg freshness and eggshell characteristics of old laying hens by adding sea urchin shell powder to the feed of such hens to achieve the objectives continuously pursued by environmental management, such as business profitability and waste resource utilization. A total of 90 Hy-Line Brown layers (66 weeks of age) were randomly divided into 2 treatments with 3 replicates, each of which consisted of 15 older layers, for 4 weeks. These treatments included a control (i.e., 0%) and 2% sea urchin shell powder. The 2% supplementation of sea urchin shell powder increased the Haugh unit (HU) at 2 and 4 weeks and eggshell strength at 4 wks compared to the controls (p<0.05). The HU at 0 weeks, eggshell thickness from 0 through 3 weeks, and eggshell strength at 0 and 2 weeks were not different between treatments (p>0.05). These results suggest that the addition of 2% sea urchin powder to the feed of laying hens improves egg freshness and eggshell strength in old laying hens.

Abstract
1. 서 론
2. 연구방법
3. 결과 및 고찰
4. 결 론
REFERENCES

• 장우환(경북대학교 농경제학과) | Woo-Whan Jang (Department of Agricultural Economics, Kyungpook National University)
• 최인학(중부대학교 애완동물자원학과) | In Hag Choi (Department of Companion Animals and Animal Resources Science, Joongbu University) Corresponding author