Genetic analysis of fleece characteristics of Baluchi and Iran-black sheep

Quality of wool has a major impact on its consumption and ultimate use and therefore, evaluation and genetic analysis of wool characteristics is one of the most important research fields for native sheep. Considering that Iran-black sheep is a result of Baluchi and Chios crossbreeding, the present study was conducted to compare and genetic analysis of fleece characteristics of Baluchi and Iran-black sheep.

In this study, wool samples were collected from 176 Baluchi and 105 Iran-black sheep in Abbas-Abad sheep breeding center located near to Mashhad, Khorasan-Razavi province, in October 2017. Fleece characteristics, including greasy fleece weight, average fiber diameter, average staple length, hetero-type fibers (%), modulated fibers (%), and true wool fibers (%) were measured. To determine the fixed effects (breed, year of birth, type of birth and sex) affecting wool characteristics of the breeds, the GLM procedure of SAS software was used. Least square means comparisons of different fixed effects subclasses was carried out by Tukey-Kramer test at 5 percent probability levels. The components of (co) variances and genetic parameters of the studied traits were estimated using the multi-trait animal model and restricted maximum likelihood using WOMBAT software.

Results showed that the differences between the breeds were significant for average fiber diameter, hetero-type fiber percentage and true wool percentage. None of the studied traits were affected by sex of lamb except for hetero-type and true fiber percentages (P<0.05). Year and type of birth could only affect the greasy fleece weigh (P<0.05). Coefficient of variation for greasy fleece weigh (26.28 percent), hetero-type fiber (76.77 percent) and modulated fiber (99.59 percent) showed that considerable variations are there for these traits in the two studied breeds. Average fiber diameter in Baluchi (26.28 micron) was significantly lower than Iran-black breed (29.26 micron) (P<0.05). True wool percent in Baluchi (94.81 percent) was significantly higher than Iran-black breed (92.65 percent) (P<0.05). Heritability of wool traits in Baluchi breed ranged from 0.26 (modulated fiber percent) to 0.45 (hetero-type percent) and in Iran-black breed ranged from 0.28 (modulated fiber percent) to 0.34 (true fiber percent).

In general, Baluchi breed had finer wool than Iran-black and Iran-black fleece characteristics were worse than the native Baluchi parent. Moreover, moderate heritability for the studied traits in both of the breeds indicated that selection programs for improving these traits in these populations would be effective.Keywords: Baluchi Sheep, Crossbreeding, Wool, Genetic parameters