Factors influencing the quality of Karakul pelts, with emphasis on discrete characteristics

Author: J.R. Albertyn, S.J. Schoeman and H.T. Groeneveld
Year: 1993
Issue: 5
Volume: 23
Page: 183 - 186

The study was undertaken to assess the influence of various environmental effects, e.g. sex, age of dam, month of birth and mating types (black X black, black X grey, grey X black and grey X grey) on pelt traits of black Karakul lambs. Data of single-born lambs (5703) born between 1972 and 1983 were included in the analysis. Models were compiled through multiple regression and other models handling discrete data. From the study it was apparent that all pelt traits show a small, but significant (P < 0.05) deterioration with increasing ewe age. The decrease in hair quality and pattern scores were only 0.05 and 0.06 per yearly increase in dam age, respectively. The age of dam effect was more prominent in certain types than in others, which complicates adjustment for this effect. Black lambs born from black X grey, grey X black, and grey X grey matings were inferior to those from black X black matings for all traits, except for pattern score. Lambs born in summer were also inferior for excellence of pattern, but superior for hair quality and texture scores. The opposite was true during winter, when hair quality and texture scores were inferior to those from summer-born lambs. Sex of lamb was less important and affected pattern score only.

 

Keywords: Fixed effects, Karakul lambs, pelt traits
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