A study on Cow s Conception Rate with Risk Factors

• 발행기관: 한국자료분석학회
• 저자명: 정대현(Daehyun Chung)
• 간행물 정보: 『Journal of The Korean Data Analysis Society (JKDAS)』Vol.8 No.5, 1687~1698쪽, 전체 12쪽
• 주제분류: 자연과학 > 통계학
• 파일형태: PDF
• 발행일자: 2006.10.30

영문 초록

This paper examines the effect of the risk factors on cow s conception rate after calving. The risk factors dealt here are farm, repeated animal, parity, calving season, calving condition, retained placenta, metabolic disorders, metritis and ovarian cysts. The preliminary analysis was performed to obtain the estimates of the probability that a cow conceive and the conditional conception rate at given times without considering the risk factors. To assess the effects of the risk factors on the conception rate, we used the Cox s regression model. We concluded that metritis and ovarian cysts showed to be negative from the analysis. But the factors of repeated animal and season associated positively with the conception rate. We also found the model to be adequate by testing the proportional hazards assumption and investing the outliers by martingale and deviance residuals.

목차

1. Introduction

2. Definition of Variables

3. Description of the Data

4. Cox s Regression Model

5. Conclusion

References

키워드

Cox s regression model proportion hazard Kolmogorov-type Supremum test martingale residual