Document Type : Research Paper
Authors
Abstract
A total of 47672 greasy fleece weight records belonging to 13,758 Baluchi sheep (progenies of 491 sires and 8109 dams) collected during 28 years (1983-2010); and also 926 wool samples from 13 half sib families and their dams from two flocks of Abbas-Abad breeding centre were used in analysis. The effects of sex, year and season of shearing, litter size (single, twin and multiple) and herds (two class include one and two) on fleece weight and wool fibre characterstics were evaluated. Birth year had significant effect on most of wool traits except for the percent of true wool, medullated, hetero-type fibers and percent of fibers between 40 to 50 microns. Greasy fleece weight and staple length was higher in males compared with females. Year and season of shearing had significant effect on greasy fleece weight. The average fiber diameter was different between two flock of Baluchi sheep. Animal repeated model and animal model were used for genetic analysis of greasy fleece weight and quality traits of fleece, respectively. Heritability and repeatability of greasy fleece weight were 0.13 and 0.27, respectively. Heritability of wool quality traits i.e. staple length, wool yield, average fibers diameter, coefficient of variation of fibers diameter in sample and the percent of true, medullated and hetero-type wool were 0.48, 0.23, 0.32, 0.24, 0.65, 0.20 and 0.16, respectively. The average breeding values from base year (1983) to the final year (2010) was increased by 93.2 gram per year. The results showed that selection for increasing body weight over 28 years has led to an increase in greasy fleece weight, but had no effect on quality traits. Therefore, the use of quality traits in breeding programs will lead to an improved fiber quality
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