Abstract :

T

hirty Aboudeleik ewes aged 3-5 years with an average body weight of 37.5±3.75 kg were used in the study at Ras Hederba Valley region (Shalateen Research Station, Desert Research Center). The present work was designed to evaluate the effects of organic and inorganic salt additives on some histological responses of skin and wool follicles and coat changes of Aboudeleik ewes. Sheep skin consists mainly of epidermis and dermis. The epidermis composed of stratified squamous keratinized epithelium. The dermis consists of connective tissue which is divided into an upper papillary layer and a lower reticular layer.The experimental results revealed that the addition of the two forms of salt additives to the sheep nutrition showed variable changes in the thickness of all skin layers of treated animals than the control group. The skin thickness and the papillare layer were thinner in sheep fed on organic salt additives while the reticular layer increased significantly by the two forms of salt additives. Values of all primary and secondary wool follicle dimensions increased by the use of the two forms of salt additives than the control group. The external and internal diameters of the primary follicles increased significantly in the treatment groups. In case of secondary follicles, the external diameter and the wall thickness were affected significantly in the inorganic group than those of the other two groups. The diameter of fibres produced from the primary follicles and the medulla thickness increased significantly by the two forms of salt additives than those of control group with no significant differences between them. Whereas organic salt additives affected significantly the diameter of the fibres produced by the secondary follicle. The coat fibres of Aboudeleik sheep were of bimodal structure usually consists of outer and under coats. Animals have supplemented diets with the two forms of salt additives recorded the highest percentage of fibres from type A and also the under coat percentage whereas inorganic group represented the highest percentage of type B. The greatest percentage of type C was found in the animals supplemented with organic salt additives. The fibres length and number of crimps/centimeter in Aboudeleik sheep was affected by the use of the two forms of salt additives. Sheep had inorganic salt additives recorded a significant increase in the length of type A than those of the other two groups and of type B only with the control group. It could be concluded that the supplementation of sheep diets with salt additives is a useful method in challenging the unbalanced salt conditions found in the rangeland of desert regions which affects the livestock development throughout the production and performance of animals. 

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Research :