Evaluation of a Type Appraisal Program in Holsteins

T.E. Aitchison, A.E. Freeman, G.M. Thomson

Journal of Dairy Science · 1972 · 22 citations · 7 references

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Abstract

A total of 11,106 records collected by Midwest Breeders Cooperative from their Mating Appraisal for Profit (MAP) program in Iowa, Minnesota, Nebraska, and Wisconsin were used. Ratings were on 13 type traits. All type traits were scored from 1 to 5 with 1 most desirable. Dairy Herd Improvement records were acquired on 752 cows in Iowa and Nebraska. Significant differences in scoring existed among the five evaluators. They differed most in scoring body capacity, feet and legs, and mammary system. Least squares estimates were used to correct the data for evaluator differences. Total variation between herds of the type traits ranged from 5.0 to 10.6%. Heritability estimates by a paternal half-sister analysis of variance were .09 and .11 for the owner-evaluated traits of milking speed and disposition, about .25 for the udder traits, and .50 for basic form. Heritabilities for the other traits were between .25 and .40. Correlations within herds among type traits ranged from zero to .58. Correlations between milk production and type traits were between .06 and --.10, except one of --.14 between milk production and basic form.

References

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