Farm animals have a high economic importance because of their important products such as meat, milk, hair as well as skin, not only in our country but also all over the world. These animals can be infected by serious pathogens, external and internal parasites causing severe damage, which result in losses of animal production. Accordingly, the study of external parasites with light microscope and scanning electron microscope were recorded, to clarify the exact composition of species. Also, differences in the morphological characteristics between the two Myiasis species: Oestrus ovis (Linnaeus, 1758) and Cephalopina titillator (Clark 1797), were investigated.

Ultrastructure study revealed two types of fly larvae Pizhevalskiana silenus (Brauer,1858) and Cochliomyia hominivorax (Coquerel, 1858) that causes myasis in Goats in Saudi Arabia, The study recorded that the exact composition of these two genus showed differences in morphological characteristics, which cannot be identified using an optical microscope. All previous studies recorded on the same region never before carried out ultrastracture studied.

Among 20 bacterial isolates isolated from the soil of El-hawia, El-hada, El-kaym and Karwa in Taif governorate in Saudi Arabia,two isolates had high efficacy in producing cellulase enzyme. They belonged to genus Bacillus (Bacillus 8 and 17). Some factors such as carbon source and wheat bran as a raw material, nitrogen source, pH and. incubation temperature were investigated. Results indicated that CMC and cellulose were the most effective as they enhanced cellulases production .Sodium nitrate and ammonium chloride were the best nitrogen sources for cellulases production. Initial pH 7.0 was found to be optimal for growth and cellulase production. Incubation temperatures at 25 - 40°C achieved high cellulases production by the two isolates.

Among 17 fungal isolates isolated from soil of El-hawia, El-hada, El-kaym and Karwa in Taif governorate in Saudi Arabia, two isolates showed high efficacy in producing cellulases enzymes. They were identified to be Altemaria altemata and Aspergillus wentii. Some factors such as carbon and wheat bran as a raw material, nitrogen, pH and incubation temperature were investigated. Results indicated that glucose and cellulose were the most effective as a carbon source while, urea was the best nitrogen source for cellulases production. Initial pH 5.0 and incubation temperatures at 25 or 35°C achieved high cellulases production.

This study presents the Mallophaga and Anoplura lice which affects farm animals (camels sheep and goats), a local area east of the Saudi Arabia of different ages, races, classes. Study the classification of lice was recorded as using the optical microscope and electronic scanning. The study shows scanning electron microscopy micro-structure of the species: Bovicola (Damalinia) ovis, Linognathus africanus and the study showed the installation of a portfolio of head lice, and the distribution of filament head, chest and abdomen, as shown over the centuries, the difference in the form of remote sensing and Swallows in thesexuallice, the first study in this area.