DOI QR코드

DOI QR Code

The Development of Adjustment Coefficients for Linear Classifications in the Korean Holstein Dairy Cattle

국내 홀스타인젖소의 선형심사에 대한 보정계수 개발

  • Song, C.E. (Dept. of Dairy Science Chungnam National University) ;
  • Sang, B.C. (Dept. of Dairy Science Chungnam National University) ;
  • Do, C.H. (Korea Animal Improvement Association)
  • Published : 2002.02.28

Abstract

The environmental effects were studied to estimate age and lactation stage adjustment coefficients in the primary linear traits of Holstein dairy cattle in Korea. Calving year month, classifier, age-month at classification and lactation stage were the environmental factors which significantly affected the most of linear traits at the level of 0.01. F values of Stature, strength, body depth, thurl with and rear leg side view were relatively higher in the effects of age-month, and dairy form, rear udder height, rear udder width, and udder cleft had relatively higher F values in the effects of lactation stage. Udder depth were affected highly by both age-month and lactation stage. Through the least square means of traits and the interpolation and smoothing obtained by the regression analysis of log and exponential transformed adjustment coefficients, age-month and lactation stage coefficients were estimated, and applied to real data to check the variation in the age-month and lactation stage effects. The estimated mean squares showed that the variation in all the linear traits significantly were decreased for the adjusted factors without the significant changes of variation in calving year month and classifier. That udder depth adjusted for both the age-month and lactation stage resulted in the decreases of variation in the both effects.

Keywords

Adjustment coefficient;Lactation stage;Linear classification

References

  1. Do, C. H. 1992. Improvement in accuracy using records lacking sire information in the animal model. Ph.D. Thesis. Virginia Polytechnic Institute and State University. Blacksburg. VA.
  2. Holstein Association Linear Classification Program. 1985. Holstein-Fresian Association of America.
  3. Vinson, W. E., R. E. Pearson and L. P. Johnson. 1982. Relationships between linear descriptive type traits and body measurements. J. Dairy Sci. 65:995
  4. White, J. M. 1974. Genetic parameters of conformation and management traits. J. Dairy traits. J. Dairy Sci. 57:1267
  5. 이정구. 1985. 국내 홀스타인종 유우의 유량에 대한 연령보정계수 추정. Korean J. Anim. Sci. 27(2):67-73.