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Wool Arabi Sheep Fiber diameter Regression Maximum R2
This study was carried out at Private flock in Murtkah District - Erbil Governorate. Samples of wool were taken from mid-side of 72 Arabi ewes during May, 2017. to study the effect of ewes age and the sex of the lambs on the physical wool characteristics The overall means of raw fleece weight, clean fleece, fiber diameter, crimps, staple length and fiber length were 1653.75 g, 79.06%, 28.24 micron, 1.33 cm, 9.36 cm and 16.03 cm respectively. The percentages of the fibers of each of Fine, Coarse and Kemp were 52.42, 38.89 and 8.68% respectively. and S/P ratio 1.27. Age of ewe effects appeared to be significant on raw fleece weight and coarse fiber (p ≤ 0.05), also on fine fiber and (S/P) ratio (p ≤ 0.01) only, while the effects of sex of lamb were non-significant on all physical wool properties except the percentage of kemp fiber (p ≤ 0.05). Although the maximum R-square increased very little gradually in the equation to predict fleece weight depending on body weight and dimensions, the simplest equation includes body weight could be considered the most significant (P<0.01) and more reliable than others to predict fleece weight (The equation is: fleece weight = 353.41 + 31.84 (body weight). The multiple regression equations were calculated to predict clean wool percentage, staple length, fiber length, crimps, fine fiber percentage, coarse fiber percentage, and S/P ratio from fleece weight, body weight and dimensions and the maximum R-square for all characteristics were very small. Fiber diameter could be predicted using the formula of multiple regression includes body weight and length and chest depth according to the maximum R-square (P<0.01). While Kemp fiber percentage could be predicted using the formula includes body weight, fleece weight and Shoulder height. Only the simple regression equation of Fleece weight on body weight was significant (P<0.01) with R-square (0.19). The correlation coefficient was done among all studied characteristics and ranged between -0.69 (p<0.01) (between fine fiber and coarse fibers) and 0.94 (p<0.01) (between fine fiber and S/P ratio). It was concluded that wool properties of Arabi sheep were not at standard level especially in both fine and Kemp properties and need to be improved
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