Given the recent increases in feed cost, the demand for rice straw has been increasing on dairy farms because it is cheaper than expensive imported forages. Therefore, it is necessary to study the effect of rice straw feeding on the growth and productivity of dairy heifers. This study compared how feeding tall fescue and rice straw affects the growth, age at first calving, and feed cost of heifers. we compared the growth, age at first calving, and feed cost for each group during the breeding period. Body height was higher in the tall fescue-fed group than in the rice straw-fed group (p<0.05). The length of the growing stage was significantly shorter in the tall fescue group than in the rice straw group (p<0.001) and the age at calving also showed a significant reduction in the tall fescue group compared to the rice straw group (p<0.001). However, the feed cost was lower in the rice straw group because of the difference in the unit price of forage (p<0.001). Based on these results, during the growing period, the rice straw group had delays in growth and the age at first calving compared to the tall fescue group, but also had reduced feed costs in the short term.

Ⅰ. 서론
Ⅱ. 재료 및 방법
    1. 농가 선정 및 분석기간
    2. 기초자료 수집
    3. 분석모형
Ⅲ. 결과 및 고찰
    1. 육성기 월령별 체고
    2. 초산 분만 월령
    3. 육성기 사료비 계산
Ⅳ. 요약
Ⅴ. 사사
Ⅵ. REFERENCES

• 이성실(경상국립대학교 농업생명과학연구원(중점연구소), 경상국립대학교 응용생명과학부(BK21)) | Sung Sill Lee (University-Centered Labs, Institute of Agriculture and Life Science, Gyeongsang National University, Gyeongsangnam-do, Jinju-si 52828, Republic of Korea, Division of Applied Life Science (BK21), Gyeongsang National University, Gyeongsangnam-do, Jinju-si 52828, Republic of Korea) Corresponding author
• 김현진(서울대학교 농업생명과학대학 농업생명과학부) | Hyun Jin Kim (Department of Africultural biotechnoloty College of Agricuture and Life Sciences, Seoul National University 599 Gwanak-ro, Gwanak-gu, Seoul, 08826, Korea)
• 이신자(경상국립대학교 농업생명과학연구원(중점연구소)) | Shin Ja Lee (University-Centered Labs, Institute of Agriculture and Life Science, Gyeongsang National University, Gyeongsangnam-do, Jinju-si 52828, Republic of Korea)
• 유진수(경상국립대학교 응용생명과학부) | Jin Su Ryu (Division of Applied Life Science, Gyeongsang National University, Gyeongsangnam-do, Jinju-si 52828, Republic of Korea)