No abstract

Fowl pox disease is a slow-spreading viral infection of wild and domesticated birds of both genders, all ages and breeds. The disease occurs in two distinct forms; the more common cutaneous or dry form and the less common diphtheritic form. Fowl poxvirus (FWPV) is a member of the Avipoxvirus (APV) and it is one of the greatest challenges facing the poultry industry, its incidence is higher in tropical and subtropical countries. It causes a significant level of morbidity and increased mortality, especially in the diphtheritic form which may reach to 50%. Avipoxvirus has been recorded in Egypt and Africa in the early of 1960, since then, it has been recorded in variable domesticated and wild bird species in different countries and Governorates. The free-living and wild birds represent a potential threat and source of infection for the domesticated poultry species. In the last ten years, the phylogenetic analysis of the partial genome sequences has gained insight into the evolutionary biology of APV in Africa. One of the main characters of APV is relative genetic stability, especially in fpv167 region of the genome. This area of the genome clustered the APV of chicken and turkey origin phylogenetically into fowl poxvirus subclade A1 together with other avipoxviruses (APVs) isolated from Galliformes worldwide. However, the pigeon poxviruses phylogenetically belong to subclade A2 with other APVs isolated from Columbiformes worldwide. The analysis of the fpv140 region provides a further comprehensive taxonomic classification based on the virus-host origin and distribution, especially in the case of the pigeon poxvirus (PGPV), which clustered separately into different subclades according to their geographical distribution. This review focus on the origin, distribution, classification and taxonomy of APVs circulating in Egypt mainly with a brief report on the situation of APVs in the other neighboring.

Chicken infectious anemia virus (CIAV) is among the naturally occurring viruses that cause immunosuppression in chickens. In the present study, the impact of CIAV infection on both NDV vaccination immune responses and bird performance were demonstrated. Post CIAV infection, the mean live body weights of the ND-vaccinated groups showed improvement compared with the non-NDV vaccinated groups. The immunosuppressive effects of CIAV infection was higher and more obvious on live ND vaccinated group compared with the other vaccinated groups. The vaccination with combination of live and inactivated vaccines showed better HI-NDV Ab responses especially when inactivated vaccine was administrated at 9 days (group II). In consistent, both the phagocytic Percent and Index were lower in case of vaccination with live NDV vaccine only and CIAV infection. Birds were vaccinated with both live and inactivated NDV vaccines at different time points showed superior protection rate (100%) compared with the other groups. Microscopically, CIAV infection led to severe deterioration in the lymphoid tissues (thymus, bursa, spleen and bone marrow) such as focal to diffuse depletion of lymphocytes and hematopoietic cells. This study highlights the negative impact of CIAV infection on both bird performance and immune status.

This study was aimed at determining the antibodies of IBDV in some poultry species in Maiduguri, Nigeria. A total of 944 serum samples were collected from village chickens, broilers, layers, ducks, turkeys and geese in Maiduguri and tested for IBDV antibodies using inzyme linked Immunosorbent assay (ELISA) and a seroprevalence of 46.6% was recorded. The species distribution showed that 33.4% of local chickens (134/401), 67.3% of layers (35/52), 50.8% of broilers (159/313), 60.6% of turkeys (77/127), 65.5% of ducks (19/29) and 72.7% of geese (16/22) sampled were positive for IBDV antibodies. Males showed a seroprevalence of 70% while females recorded 30%. IBDV seropositive sera showed that samples from broilers reacted with 31.5% middle OD values and turkeys with 9.4% middle OD values. Samples from other species reacted with lower OD values. Samples from other species reacted with lower OD values. Presence of IBDV antibodies in species other than chickens suggested that different bird species might have IBDV and could serve as reservoirs for IBDV transmission. Because of this threat to poultry industry, there is need for continuous surveillance of IBDV in all poultry species so as to institute effective preventive measures against the disease.

Whenever a cleaning process and removal of weeds from water channels is carried out, the weeds re-appear in a matter of weeks and sometimes days. This costs a lot of effort and money. Hence, there is an urgent need for harmonization between the presence of weeds of acceptable densities and to maintain water levels in the last reaches of the channels which are mainly infested by the weeds. The present paper aims to study experimentally the impact of the existence of submerged weeds on the flow characteristics in case of maintaining the water levels behind the infested areas. The data were collected using a laboratory flume of relatively large dimensions (60cm wide, 65 cm depth, and 20.8 m long) with fixed bed slope (0.0062). Flexible branched roughness elements were used with different intensities (0.0062, 0.0123, and 0.0246). The weeds intensities were tested with different discharges and different tail water depths. Dimensional analysis was used to correlate the flow characteristics to the other relevant parameters of the flow and weeds. Dimensionless general equations in terms of these parameters for computing both heading up, relative energy loss, Manning coefficient and relative shear velocity of the flow through the infested reach were developed and compared with the experimental data. The comparison proved a good reliability and high accuracy. The equation of Manning coefficient was reduced to the case of non-infested canals and verified with different irrigation canals (El-salam main canal and its branches Om El-Reesh , San El-hagar stage 2 and 3 and El-Sheikh Gaber canal).