Wool follicle characteristics in the Awassi fat-tailed sheep.

In Awassi sheep, the total number of wool follicles per square millimetre was affected significantly by age, sex, and type of birth. The density of the primary follicles was only significantly affected by age and type of birth. The secondary follicles to primary follicles (S/P) ratio values were 2.0 at birth, 4.0 at 2 months and 4.2 at 6 months of age, in Awassi sheep. The males exceeded the females, in most ages of the experiment. The single lambs surpassed the twins in the S/P ratio values. The effect of age and type of birth on the S/P ratio was highly significant. The external diameter of wool follicles increased with higher values at 2 months of age than afterwards, till 6 months of age. The contrary was the case in the internal diameters of wool follicles. The increase was higher in the primary than in the secondary follicles, during the period of the study. The males surpassed, in general, the females in the values of the external and internal diameters of the primary and secondary follicles. Single lambs showed higher values than twins in the external and internal diameters of primary and secondary follicles in most ages of the experiment. Age and type of birth affected significantly the diameters of follicles, while sex effect was only highly significant on the external diameter of the secondary follicles. The length of the primary and secondary follicles and the thickness of skin increased significantly, as the animals grew older. Sex showed no significant effect on the length of follicles, while it affected significantly the thickness of the skin. Single lambs showed higher significant values than twins, in length of follicles and skin thickness. The bulbs of each of the primary and secondary follicles increased significantly, as the animals grew older. Sex had no significant effect on the bulb diameters of the two types of follicles. The single lambs surpassed the twins in the values for follicle bulb diameter, in most ages of the experiment. The effect of the type of birth on the bulb diameter of the two types of follicles was highly significant.