Evaluation of amitraz against ticks and mites infestation in cattle and sheep in comparison with diazinon and deltamethrin was performed. Amitraz showed over 95 % inhibition of oviposition and hatching of laid eggs at dilution of 1:500 while diazinon and deltamethrin produced around 90 % inhibition of oviposition at the same dilution. Fed ticks were more susceptible for all tested acaricides than the unfed ticks, where amitraz reached its full effectiveness (100 % kill of fed and unfed) 2 weeks after application while diazinon and deltamethrin produced over 90 % at the same dilution. Spraying application of amitraz 12.5 % resulted in 100 % tick control by day 5 and the effect was maintained for further 28 days whereas diazinon and deltamethrin were fully effective by days 9 and 13, respectively and their efficacy were maintained for 16 and 20 days, respectively. Spraying application of amitraz 12.5 % produced 100 % efficacy as no live mites were found on day 17 and maintained in full effectiveness till day 33 where respraying was needed. In conclusion, amitraz produced rapid detachment of ticks from animals; its residual effect was long and protected animals from re-infestation for 29 days and was able to eradicate psoroptes mite infestation in sheep.

The development of thyroid glands of New-Zeland rabbits was studied in 28 fetuses (10-30 days) and 28 rabbits (3 days-5 years). The thyroid premordia appeared at the 12th day of gestation as 2 masses of cords and clumps of cells. The gland assumed the bilobed form with a narrow isthmus in between at the 18th day. Small primitive follicles with narrow empty lumina appeared in 14-day-old fetuses. True follicles were recorded in 20-22 days old fetuses while colloid was seen in the lumina of the central follicles at the 24th day. Light (C- or Parafollicular) cells were seen for the first time at the 12th day. With development of the follicles, C-cells appeared between the follicular cells and some of them come in contact with colloid. The ultimobranchial body (UBB) was observed in 20 days old fetuses close to the thyroid anlage and entered into its tissue at the 22nd day. Later on, it gave thyroid-like follicles or ultimobranchial cysts. With the electron microscope (EM) follicular cells of earlydeveloping fetuses were not yet differentiated. They contained few ill-developed rough endoplasmic reticulum (rER) and mitochondria. The organelles became well developed and the cells started to secrete colloid in full term fetuses. The maximum rate of secretory activity was achieved in the glands of adult rabbits. Changes in the thyroid glands during the postnatal life up to 5 years of age (age of senility) were followed up and described.

In this study, two methods for determination of formalin amount were applied on samples of inactivated vaccines representing local or foreign companies. The first method; matching method was conducted by using phenyl hydrazine while in the other method is; spectrophotometry phloroglucinol was used. Spectrophotometrical method was found more sensitive and more accurate than the matching one. At the same time, the spectrophotometry method could be used for determination of formalin in all inactivated vaccines either bacterial or viral vaccines.

The present study was designed in a trial to use serum replacement instead of the newborn calf serum in propagation of BHK-21 cell cultures with subsequent reducing the cost of foot and mouth disease (FMD) vaccine production. Two batches of BHK-21 cell culture were prepared where the medium of the first batch was supplemented with newborn calf serum while the medium of the second batch was supplemented with serum replacement. FMD virus was propagated 7 passages using BHK-21 cell culture. Both virus titration and complement fixation titer (CF) revealed that propagation of FMD virus in cell cultures supplemented with newborn calf serum yields a titre higher than that in case of cells supplemented with serum replacement. Also two batches of FMD inactivated vaccine were prepared from the virus propagated in the two-mentioned cell culture batches. Two groups of susceptible calves were vaccinated with these vaccines. Both of virus neutralization test (VNT) and enzyme linked immunosorbent assay (ELISA) revealed that higher antibody levels were induced in calves vaccinated with the vaccine prepared from cells supplemented with calf serum than those vaccinated with vaccine prepared from cells grown with serum replacement. BHK-21 cell culture supplement with newborn calf serum is most susceptible for FMD virus propagation yielding higher titer of the virus. Moreover, the growth pattern of the used cell culture was much better when the newborn calf serum was used.

In this study field application of RB51 vaccine combined with the policy of test and slaughter as well as application of hygienic measures for control of bovine brucellosis were carried out and evaluated in a dairy herd of cattle for two years. Serological examination of 1280 cattle using tube agglutination, buffered acidified plate antigen, Rose Bengal plate antigen and Rivanol tests revealed 240 (18.75%) positive animals with a previous history of abortion of 12 cows. Brucella melitensis biovar 3 could be isolated from tissue specimens of slaughtered cows. Animals that tested negative in the first examination were vaccinated with RB 51 vaccine with periodical examination every three weeks and slaughtering of positive cases. New positive cows continued to develop up to the 5th examination then three successive sero-negative tests were obtained with release of the farm from quarantine. Examination of animals 6,12,18 and 24 months post release of quarantine revealed 2, 3, 0 and one positive cases respectively the matter which clarified that the control of the outbreak using RB51 vaccine associated with policy of test and slaughter and application of hygienic measures showed some limitations.

In the present study, the humoral immune response developed following vaccination with the live-attenuated (Smithburn) Rift Valley fever (RVF) vaccine in sheep, goats, cattle, buffaloes and camels was investigated. Results showed that, serum neutralizing antibody titers of RVF virus started to appear in the sera of all vaccinated animals with live-attenuated Rift valley fever vaccine after the first week post-vaccination and reached its peak after the third month of vaccination. It persisted to be higher than the acceptable limit of protection (>40) in the sera of sheep and goats in more than 6 months post-vaccination while it declined in the sera of cattle, buffaloes and camels to become lower than the acceptable limit of protection (<40) after the sixth month post-vaccination. On the other hand, the serum neutralizing antibody titers remained negative in the sera of non-vaccinated (control) animals throughout the study. It could be concluded that, the neutralizing antibodies following vaccination of cattle, buffaloes and camels with live attenuated RVF (Smithburn) vaccine was low and of a short duration compared with those in sheep and goats. Hence, it is important to prepare a new vaccine which is safe and gives a high immune response for long period in cattle, buffaloes and camels instead of live attenuated (Smithburn) RVF vaccine to protect these animals species against this disease.

The eggs of femares of .4.s'c'ari.s' I.zunhric'r)iclc.s‘ which collected from the patients after given the hendazol (200mg) and then performed artificially hatching and maturation of these eggs to obtain the third larvae stage. The results appeared Prothromhin and thrombin clotting time when added the extract of the third larvae _‘ stage was prolonged when compare to the control. This study is the first time because dose not any information regarding the antithrombotic activity ofthe larvae

Liza aim fish were exposed to different concentrations of the Diazinon pesticide (Organophosphate pestieide)'(diethyl 2—isopropyI -6- methyl -4- pyriinidiny'l phosphoro ~thionate) in the acute exposure (96) hour and chronic exposure (I4) days , l'llSlDptlI.l]0l0glCE1l examination showed the hyperplasia of tl1c gill tissue, some engorgement with blood of the secondary larnellae, epithelial separation . necrosis . clubbing of epithelial cells and fusion of adjacent secondary lamcllae. These changes different according to the pesticide concentration and it's exposure time

The present study investigated the toxicologic histopathologie effect ofallatoxin Hi, 60 broiler chicks ol&rsquo; one-day aged devided randomly and equally into three groups. for dietary study, using one group as untreated control, while the other groups were given aflatoxin B. mixed with diet in concentration of 0.5 and 1.5 ppm respectively, for 30 days, the study showed fatty degeneration of liver associated with bile duct prolilicration, accompanied by infiltration of monenuclcar cells and lymphocytes. Also there was degeneration in proximal convoluted tubules mostly as hyaline degeneration especially at 0.5 ppm dose level. Those at 1.5 ppm dose level, there was focal liver cell necrosis associated with fibrosis and enlarged proliferated bile ducts. sever vacuolation and necrosis of epithelial of renal proximal convoluted tubules with thickening of the glomerular basement membrane