Genetic study on pelt quality traits in the Gotland sheep breed

Abstract

Genetic parameters were estimated for pelt quality traits of the Gotland sheep breed using data from the Swedish Sheep Recording Scheme and multiple-trait animal models. Data on detailed pelt quality traits were available for 51,455 lambs born from 1991 to 2003. For 4,771 lambs there also was information about a subjectively measured overall score for pelt quality. Sex of lamb, age of ewe, litter size, age of lamb, and interactions between these had significant effects on pelt quality. Heritabilities were moderately high (0.20 to 0.48) and genetic correlations between the traits were low to highly positive (−0.18 to 0.95). Breeding for an increased overall score will in the short term improve score for quality of hair, score for curl, and score for nuance of colour. Size of curl and score for thickness of fleece may also increase and this is not always advantageous as these are traits with optimum values.

Keywords:

• Genetic correlations
• genetic evaluation
• hair quality
• heritabilities

Acknowledgments

Grants from the Swedish Farmers Foundation for Agricultural Research and from the Swedish Sheep Breeders Research Foundation are gratefully acknowledged. Sincere thanks are expressed to Nils-Åke Fag, Association of the Gotland sheep breed, and to Lotta Rydhmer and Freddy Fikse at the Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, for helpful criticism and valuable suggestions on the manuscript.