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.

Elevated rectal temperature, mucopurulent nasal discharge, mortalities and abortion of pregnant ewes were the main clinical abnormalities recorded in sheep flocks at Seedy Salem Village, Kafr Al-Sheikh Governorate, Egypt following their vaccination by the attenuated Rift Valley vaccine. Meanwhile, 45 of the farmers in the village showed variable findings suggestive for a RVF epidemic and 17 farmers died of haemorrhagic fever as reported by the World Health Organization, WHO (2003). Blood serum samples were collected from 78 humans and 86 sheep and tested for RVF antibodies. We found that, where 11 (12.94%) and 10 (19.30%) of sheep and human sera respectively were positive. The recent history of vaccination of such flocks using the attenuated RVF vaccine lead us to suggest that the used vaccine might be the source of such epidemic.

Survival of the neonate relies on the integrated expression of appropriate behaviours from both mother and young. In this study, the effect of birth difficulty on maternal and lamb behaviours and its influence on lamb survival was investigated in crossbred primiparous ewes (½ Finnish x ½ Rahmani). Assisted ewes spent significantly (P<0.05) less time licking (30.83±1.39 min/2 h) and nosing (24.25±1.79 time/2 hr) their lambs than unassisted mothers (38.52±2.96 min, 28.80±1.68 time/2 h) respectively. They were found to be more aggressive towards their lambs when attempt to suck (9.80±0.37, 12.90±0.84 and 10.50±0.50 time/2 h) when compared with unassisted one (8.00±0.40, 10.20±1.52 and 7.66±0.88 time/2h) respectively. Lamb behavioural development were found to be significantly (P<0.05) affected by birth difficulty with lambs that require assistance at birth even if they survive the birth process, they were slower to progress through the sequence of neonatal behaviours. These lambs were therefore at greater risk of not surviving to weaning (28.57% vs. 11.42). It could be concluded that ease ofdelivery was an important factor determining the subsequent behaviour of the lamb and ewe and hence lamb survival, thus manipulation of husbandry and breeding system to improve delivery will improve lamb survival

The objective of this study was to determine whether Bos taurus cattle differ form Bos indicus in their susceptibility to infection with the Muguga stabilate of Theileria parva and in their resistance to the resultant disease. Ten Friesians (B. taurus), ten improved Borans (B. indicus), ten unimproved Borans (B. indicus) and ten Zebus (B. indicus) born to dams from an East Coast fever (ECF) endemic area were inoculated with an infective dose50 dilution of T. parva Muguga stabilate 147. All the animals except one Friesian and one Zebu developed schizont parasitosis. All the improved Borans, nine of the Friesians, eight of the unimproved Borans and six of the Zebus developed a febrile response. Four of the improved Borans, four of the Friesians and three of the unimproved Borans died of theileriosis. No significant difference (P > 0.05) in the prepatent period occurred between the groups, but the Zebus had a significantly shorter duration of schizont parasitosis (P > 0.05) and took a significantly shorter time to recover (P > 0.05) than the other three groups. There was no significant difference in the two parameters between the other three groups. The study showed that three B. indicus breds and a B. taurus breed are equally susceptible to T. parva infection. However, Zebus born to dams from an ECF endemic area showed a better ability to control the course of disease than cattle from ECF free areas.

The pharmacokinetic profile of difloxacin was investigated in camels after single intravenous and intramuscular administration of 5 mg kg-1 b.wt. After i. v. injection, serum concentration time curve was best described as two compartment open model. The distribution and elimination half lives (t0.5 (') and t0.5())) were 0.513± 0.01 h and 6.3±0.15 h. respectively. Difloxacin was distributed extravascularly with a volume of distribution (Vdss) 1.10 ± 0.035 l kg-1., and total body clearance (CLB) of 0.141+ 0.031 l kg-1 h-1. following intramusclar injection, peak serum concentration (Cmax) 2.59 ± 0.19 ug ml-1 attained after Tmax 3.05 ± 0.035 h. The absorption and elimination half lives (t0.5 (ab) and t0.5 (el)) were 0.95 ± 0.003 and 5.86 ± 0.33 h., respectively. The systemic bioavailablility (F) and the plasma protein binding were 87.95 and 23 %, respectively.

The present study was designed to investigate trypanosomiasis among one of native freshwater fish breed in Egypt namely catfish (Clarias gariepenus). Fifty fish were collected during summer season from the river Nile at Giza markets. The fish were examined for the presence of trypanosoma in the blood. Trypanosoma were detected in 10 (20%) of the collected fish. The main clinical signs of infected fish with trypanosoma were emaciation, dullness, respiratory distress, loss of escape reflex, mild ascitis and paleness of the gills. Post-mortem examination of infected fish revealed paleness of the internal organs (liver and kidneys) and slight congestion of spleen. Haematological examination of infected fish revealed significant decrease in erythrocytic count, haemoglobin and packed cell volume but significant increase in total leucocytic count accompanied with neutrophilia and eosinophilia. Serum biochemical analysis demonstrated a significant decrease in urea, total protein and albumin while a significant increase in AST, ALT, ALP, creatinine, glucose and 1- globulin were recorded. Microscopic examination of organ histopathological sections revealed cloudy swelling of hepatocytes with activation of kupffer cells, depletion of lymphocytes with thickening of tile trabeculae in spleen. While in kidney, necrobiotic changes of epithelial lining of renal tubules with vacuolation of glomeruli as well as hemorrhages were recorded.

The present investigation succeeded in following up the life cycle of Philophthalamus species cercaria emerged from Cleopatra bulimoides snail till production of adult worm Philophthalamus species. This adult worm was extracted from the nictitating membrane of the eyes after 35 days post oral infection of one-day old ducks by metacercaria of Philophthalamus species. The worm Philophthalamus species have a mean length of 4.365mm. The most interesting result of the present study is the success in obtaining Philophthalamus species adult worm. Moreover Philophthalamus cercaria was described for the first time from snails collected from Beni-Suef Governorate, Egypt

In this study a total of 120 diarrheic buffalo calves were examined clinically and bacteriologically was investigated. The role of E. coli in diarrheic buffalo calves. E. coli, could be isolated from 31 (25.80%) calves. K99 antigen could be detected in (12.90%) isolates. Studying some virulence factors of E. coli isolates revealed that 28 (90.30) isolates showed congored binding, 29 (93.50%) isolates were able to survive in serum and 23 (74.19%) were able to grow in calf serum, 25 (80.64 %) isolates could be proved as enterotoxin producers and caused accumulation of fluids in the intestinal tract of the inoculated mice. In addition, 28 (90.30 %) were able to produce verotoxins. The present study demonstrated the correlation between the presence of different virulence factors in E. coli isolates and its pathogenicity to newborn calves and its role in diarrheic calves

Two hundred, five-week old chickens were divided into six equal groups (30 chicks/group) and vaccinated with different live NDV vaccines in Nigella sativa oil. The vaccinated birds were bled at one-week interval post-vaccination over six weeks and the collected sera were tested by the HI test. Half of each group was challenged 21-days post-vaccination by intramuscular route of inoculation with 2X105EID50 of the velogenic viscerotropic Newcastle disease virus (VVNDV). Birds were observed for 15 days post-challenge for any clinical signs of Newcastle disease. Deaths within this period were subjected to post mortem examination. The remaining birds in each group were observed after challenge till 42-days post-vaccination.

Serum samples from 474 domestic pigs (Sus scrofa) from Zimbabwe were tested for anti-Toxoplasma gondii IgG antibodies using the indirect fluorescent antibody test. The results showed that T. gondii infection is widespread in Zimbabwean pigs. Seroprevalence was lowest in fattening pigs from large and small-scale commercial farms that practise good hygiene (19.75 % of 238) and highest in backyard scavenging pigs (35.71 % of 70). Only 11.7 % (11) of the 127 positive samples had titres of > 1:400 and nine (81.82 %) of these 11 originated from pigs reared under poor hygienic conditions. A prevalence of 3.51 % was found in the same group of fattening pigs using an indirect IgG enzyme-linked immunosorbent assay at the single serum dilution of 1:400. The serosurvey shows the importance of modern intensive husbandry systems in reducing the prevalences of T. gondii infection in domestic pigs.