Two fish pathogens, namely Listonella anguillarum (Vibrio anguillarum) and Vibrio vulnificus, which were beta-haemolytic, hemagglutinating with 1% D-mannose and hydroxamate siderophore producer were used in this study. The extracellular products (ECPs) of both species were of high enzymatic and haemolytic activities. SDS-PAGE analysis of ECPs of L. anguillarumand V. vulnificus revealed 4 band (20.7 to 47.5kDa) and 2 bands (30.1 to 46kDa) respectively. The cumulative mortalities in O. niloticus produced by crude ECPs of L. anguillarum (0.2ml/fish; 2.4mg protein /ml) and V. vulnificus (0.2ml/fish; 1.6mg protein /ml) were 90% and 80%. Heat treatment of ECPs of L. anguillarum and V. vulnificus at 56°C for 30 min reduced the mortalities to 30% and 20%, respectively. LD50 values in O. niloticus using crude and heat treated ECPs of L. anguillarum were 1.7 and 3.9 ^g protein/g fish; while those of V. vulnificus were 1.34 and 2.8 ^g protein /g fish, respectively. Injection of levamisole at a dose of 5mg/Kg fish, concurrently with ECPs of L. anguillarum and V. vulnificus resulted in subsidence of the mortality percentages from 90 to 40 and from 80 to 30, respectively. Ten laying hens were immunized with ECPs of L. anguillarum for preparation of specific egg immunoglobulins. The total protein content of IgY preparations collected from eggs of hens immunized with ECPs of L. anguillarum reached its peak 2 weeks post 3rd booster dose (3.820 ± 0.0700 g/dl). The molecular weight of separated protein bands of IgY preparations ranged from 183-191kDa. Fish injected (I/P) with specific anti ECPs IgY of L. anguillarum (4 mg/ fish) followed by I/P injection of ECPs of L. anguillarum (0.2 ml/fish; 2.4 mg protein /ml) showed a 10% mortality rate, while those challenged after receiving specific anti ECPs (100 mg/ kg B.W. orally) showed no mortalities.

Merthiolate (Thiomersal) is known to be used as antimicrobial agent in inactivated vaccines without affecting vaccine potency. The present work investigated the effect of thiomersal contents in ND, AI and IBD inactivated vaccines on liver and kidney functions of vaccinated birds. The histopathological effect and the withdrawal time of such mercurial product from vaccinated chicken muscles were also investigated. Results revealed that residual thiomersal contents in ND, AI and IBD were 0.03; 0.02 and 0.03mg/ml respectively. Liver and kidney function parameters showed significant increases in serum activities of alanine aminotransferase (ALT) and serum aspartate aminotransferase (AST) up to the 4th week post vaccination. Serum urea was significantly decreased on the 3rd week in vaccinated birds compared to control ones. Significant increase in serum creatinine in vaccinated chickens was recorded on the 5th week post vaccination. Liver and kidney functions’ parameters remain high allover the experimental period (8 weeks). The histopathological examination of liver specimens revealed degeneration of hepatic cells and congestion of the central vein with inflammatory cell infiltration and congestion of blood vessels as well as coagulative necrosis. The spleen of vaccinated chickens showed depletion of lymphocytes while lungs showed thickening of the alveolar. Mercury contents in muscle were 0.72, 0.52; 0.046 and 0.00 mg/kg on the 1st, 2nd, 3rd and 4th week post last vaccination that considered safe to the consumer. It is recommended that vaccinated poultry with inactivated vaccines containing thiomersal should not be slaughtered before at least 4 weeks and it is preferable to use combined inactivated vaccines to reduce the thiomersal contents as possible.

Our field studies had been carried out after in vitro antibiogram of E. coli to compare the effect of pulmotil (macroloide), enerofloxacin (fluoroquinolones) and doxycycline (tetracycline) in controlling mycoplasma and E. coli as a cause of CRD in broilers. The drugs were used in single or in combination. Two doses at the 3rd and 23rd day of age on performance of commercial broiler Ross derived from mycoplasma SPA-test positive breeders and E. coli positive isolation at the 1st day of age. The prevalence of marked air sac gross lesions in non treated control group indicated the development of CRD and severity of lesions increased with age. The used drugs played a role in controlling infection as treated groups showed milder lesions while more sever lesions were in doxycycline treated group. Protection against mortality was less in the treated pins than untreated ones. Cumulative culls % was low (1.1) in pen treated with enrofloxacin, (1.5) in pulmotil + enrofloxacin, (1.6) in doxycycline, and (1.7) in pulmotil + enrofloxacin; while pulmotil and control were the same (2.2%). Losses expressed as total mortality and culls % were the lowest in pulmotil + enrofloxacin and enrofloxacin (3.2 and 3.6), other treated pins showed the same values (4.2), while the highest was in non treated ones (5.8%). Average Body wt. in pulmotil + enrofloxacin, pulmotil, and enrofloxacin treated pens were higher (1934, 1924 and 1819 gm) than doxycycline (1802 gm), Pulmotil + Doxycycline (1705 gm) and non treated control (1708 gm). CFCR in pulmotil or enrofloxacin and in combination medicated pens were higher than other treatments and non medicated pen. Average day/ week/ gain in control non treated was equal to that of pulmotil or enrofloxacin (65g), slight lower value was in their combination (63g) followed by 58 g in doxycycline. The lowest ADG /w/g value was in pulmotil + doxycycline (52 g). Calculated EEF of treated and non medicated pens were higher than > 280. The medicated pens with either pulmotil or/ enrofloxacin and there compilation were superior (333, 313 and 330; respectively) and close to the farm stander (346). This study pointed out that E. coli, and Mycoplasma with life ND vaccine reduced broiler performance and the used drugs were of values in control such infections. The in vitro antibiotics sensitivity testing of E. coli is important to obtain good results and drug combinations must be carefully performed.

A retrospective study including reproductive and productive data of 1587 primiparous Holstein cows covering a period of eight years. The reproductive data ( interval to 1st service, service period, days open, number of inseminations per conception and calving interval ) and the productive data ( total milk yield, average daily milk yield and 305 day milk yield) were studied as a function of age at first calving and postpartum disorders. Furthermore, other data including life span longevity, number of parities, the cumulative productive days and the average calving interval were also studied as a function of age at first calving. Cows were classified according to the age at first calving into young age calvers (< 24 months), mid age calvers (> 24-28 months) and old age calvers (> 28 months). The obtained data were statistically analyzed, tabulated and discussed. The overall mean age at first calving was 26.68 months in Holstein cows under Egyptian circumstances. Most of first calving (90%) were recorded in cows less than 30 month of age. The results indicated that, the young age calvers tend to have prolonged interval to 1st service, days open and calving interval and the reverse was correct in old age calvers. The postpartum disorders had significantly detrimental effects on the reproductive performance among the different age groups. Young age calvers had a higher incidence of postpartum disorders than those of mid - age calvers and much higher than had the old age group. The postpartum disorders were associated with high milk production specially in mid and old age calvers which may indicate the high predisposition of superior producer cows to postpartum disorders. Life span, longevity, number of parities and the cumulative production days were found to be increased as a function of age at first calving. Meanwhile, the average calving interval of the young age calvers was longer than the other two age groups. Finally, it was recommended to avoid insemination of maiden Holstein heifers less than 17 month of age specially those having superior productive traits.

Edwardsiella tarda was recovered from cultured freshwater catfish (Claries gariepinus) with a prevalence rate of 0.42% in summer season. Experimental infectivity studies of E. tarda in Catfish and Tilapia nilotica were done using the intraperitoneal (I/P) and intramuscular (I/M) routes. Experimentally infected Catfish with a dose of 0.3 ml from E. tarda bacterial suspension of 108 CFU/ml manifested pathognomonic clinical signs and postmortem lesions than the experimentally infected Tilapia nilotica. Application of PCR technique for rapid detection of E. tarda infection in the experimentally infected fishes gave positive reaction in 4th day post infection in catfish and the 7th day post infection in Tilapia nilotica.

Biological hazards associated with oxidative stress resulted in defective in vitro embryo production “IVEP”. Reactive oxygen species “ROS” may originate from embryo metabolism and/or embryo surroundings. In an attempt to overcome such challenge, the present study correlates between the influence of 3 antioxidants and buffalo oocyte development up to morula and blastocyst stages. It was found that taurine addition (either alone or concomitant with ascorbic acid “AA” or mannitol) to media during in vitro maturation “IVM” has the potency to enhance IVEP in buffaloes. On the other side, AA and mannitol either alone or in combination are invalid to improve developmental rate of mature buffalo oocytes to reach morula and blastocyst stages. In a second experiment, the best treatment (taurine and AA) was added to both in vitro fertilization “IVF” and culture “IVC” media. This treatment resulted in significant elevation of the cleavage rate and morula development without influencing blastocyst rate as compared with their corresponding values following the addition to IVM medium alone. Thus, it could be concluded that addition of taurine with AA into both IVM and IVF media enhances maturation of buffalo oocytes and activates the cells to undergo cleavage and morula development.

Data of Holstein dairy cows in a private farm (TEC-DAP) in Al-Fayum Governorate comprising 5815 calving events (80 for twins and 5735 for singles) in the period from January 1997 to April 2008 were used to determine if there was any significant difference between twin and single calving cows in gestation length, reproductive performance, incidence of dystocia, perinatal calf survival and mortality rates and culling rate. Cows giving twins had shorter (p < 0.0001) gestation and more (p < 0.005) days to first heat, first service and days open than cows giving singles. Incidence of dystocia was higher in cows with twins (22.5%) than those with singletons (7.22%). Survival rate of singles was 12.9% greater than that of twins at birth, whereas perinatal mortality rate was 16.25 % (9.37% stillborn & 6.88% dead after birth) for twins and 3.33% (2.06% stillborn & 1.27% dead after birth) for singles. Culling rate was greater in cows producing twins (61.53%) than those with singles (30.73%). Twinning in cattle shortens the length of gestation, impairs subsequent reproductive performance by prolonging postpartum breeding intervals, increases the incidence of dystocia and perinatal calf mortality and increases number of cows to be culled during subsequent lactation. Thus, twinning in dairy cattle is undesirable due to its detrimental effect on cow fertility and health and calf survival. However, these adverse effects can be minimized by preparturient diagnosis of twin pregnancy and timely administration of obstetrical assistance which aids in management of dystocia to facilitate delivery of twin calves and to increase their neonatal survival.

The present study was conducted to determine the effect of salinomycin at a concentration 60 and 120 ppm alone and with vitamin E or selenium on haematological and biochemical parameters and histopathological changes of the treated chicken. Salinomycin (120 ppm) induced decrease in body weight, feed consumption and feed conversion efficiency. In addition, when salinomycin (120 ppm) given with vitamin E, the body performance improved significantly, but when sodium selenite used, body performance significantly decreased. Salinomycin at concentration 120 ppm induced decrease in blood parameters (RBCs count, TLC count, Hb content and PCV %). Concurrent use of vitamin E with salinomycin leads to improvement of these parameters. Salinomycin at 120 ppm induced significant increase in enzymes activities (ALT and AST). The uses of vitamin E with slinomycin (120 ppm) caused significant decrease in these activities. In contrast to selenium, which reduce the activity of AST enzyme only. Salinomycin at 120 ppm decreased the total protein concentration and increased the level of creatinine and uric acid. Concurrent administrations of vitamin E or selenium with salinomycin have no effect on these parameters. At 120 ppm salinomycin, selenium increased the creatinine concentration in blood serum. The drug at 60 or 120 ppm induced various pathological changes in certain tissues (liver, heart, kidney and skeletal muscle) ranged from degeneration to necrosis of these tissues. Concurrent administration of salinomycin with vitamin E or selenium revealed that vitamin E decreased the pathological changes of studied tissues.

The dynamics of some serum mineral concentrations during the first weeks of life of native and crossbred newborn calves in Assiut governorate were investigated. Blood samples of 25 Balady and 25 crossbred (Friesian x native) male calves were investigated. Blood was drawn from calves at 1, 7, 14 and 21 days after parturition. Serum levels of calcium (Ca), phosphorous (P), magnesium (Mg), sodium (Na), chloride (Cl), potassium (K), iron (Fe), Copper (Cu) and zinc (Zn) were monitored. Levels of Ca, P, Fe, Cu and Zn increased (P < 0.05) in relation to age of Balady and crossbred calves when compared by the day 1 of age. In contrast, decreased in concentrations of Na and Cl (P < 0.05) in relation to age of Balady and crossbred calves when compared by the day 1 of age were detected whereas Mg and K values remained unchanged. Native calves had higher (P < 0.05) Ca, P and Fe in the 7th day than crossbred calves whereas Na and Cl were higher (P < 0.05) in native calves than crossbred calves at the first day after birth. Results from this study suggested that breed and age may play an important role in mineral homeostasis during the first weeks of life in the newly borne bovine calves.

Contagious bovine pleuropneumonia (CBPP) or lung sickness, is an insidious pneumonic disease of cattle caused by Mycoplasma mycoides subspecies mycoides small colony variant (MmmSC) and it is one of the major diseases affecting cattle in Africa. With the imminent eradication of rinderpest from Africa (Somali ecosystem) CBPP has become the disease of prime concern in terms of epizootics that affect cattle on the continent. The control and/or eradication of the disease have suffered from unsustained control actions due to lack of operational funds to support such actions and deterioration in the quality of veterinary services in many countries affected by the disease. Stamping out procedures which were adopted by Botswana to control the disease (1995-1997) cannot be carried out by many countries currently affected by CBPP due to the high financial cost, the widespread nature of disease, animal welfare considerations and the potential loss of a valuable genetic resource base. The current scenario of CBPP disease epidemiology in sub-Saharan Africa requires that proactive measures are taken to safeguard countries in southern Africa which are currently free from CBPP from being contaminated by the disease thus affecting the beef industry and people's livelihoods; and to progressively control the disease in endemic zones of Western and Central Africa. This presentation discusses the epidemiology of CBPP in Africa, diagnosis of the disease, regional strategies that could be deployed to prevent and control the spread of the disease on the continent and research thrusts on CBPP.