HERITABILlTY AND REPEAT ABILlTY OF SOME TYPE --APPRAISAL TRAITS*

Abstract

Data from 208 Holstein cows sired by 5i bulls with 634 type classification records in the North Platte and Scotts Bluff Agricultural Experiment Stations were analyzed. No corrections were made for age of cow, season, or herd. Scoring was made according to the following scale: i O, excellent; 9, very good; 8, lowvery good; 7, good plus; 6, law good plus; 5, good; 4, löw good; 3, fair; z, law fair; and i, poor. Avarage scores for some type components of three year-ol.d cows were: rump 5. 25, barrel 6.48, front udder 5. 09, rear udder 4. 93, and final rating 55.05. Heritabilities were o: 55 for rump, o. 32 for barrel, 0.59 for front udder, 0.26 for rear udder, and 0.36 for final rating. The North Platte herd had h~gher heritability values than did the Scotts Bluff herd. Average first classification scores for rump, barrel, front udder, rear udder, and final rating were 5. 42, 6.76, 4.88, 4.86, and 55.54, respectively. Second and subsequent classifications averaged as rump 5.54, barrel 6.86, front udder 4.98, rear udder 4. 95, and final rating 56.12. Second and subsequent average s were slightly but not significantly higher than first classification averages. Repeatabilities were estimated to be as follows: 0.58 for rump, 0.26 for barrel, 0.48 for front udder, 0.52 for rear udder, and 0.53, for final rating.

Keywords

• Herıtabılıty
• appraısal traıts
• Repeat

References

1. Ankara Üniversitesi- Ankara Üniversitesi Veterinerlik Fakültesi Dergisi