Bo Emikpe

Isolation and Preliminary Characterization of Chicken Anemia Virus from Chickens in Nigeria

Abstract Chicken anemia virus (CAV) was isolated for the first time from the Nigerian chicken population. The virus was recovered from necropsied birds from broiler and pullet flocks that suffered disease outbreaks tentatively diagnosed as infectious bursal disease. A sensitive polymerase chain reaction (PCR) assay detected CAV DNA in tissues of necropsied birds. Restriction endonuclease analysis performed with the 733-bp PCR product and the Cfo I enzyme indicated at least two different CAVs were circulating among the Nigerian chicken population. Four isolates were obtained from pooled liver and thymus tissues using the MDCC–MSB1 cell line. These isolates were found to be antigenically closely related to the Cuxhaven-1 (Cux-1) reference strain of CAV when reacted with four monoclonal antibodies prepared against the Cux-1 virus. One of the isolates (isolate A) induced thymus atrophy, bone marrow aplasia, and low hematocrit values when inoculated into 1-day-old specific-pathogen-free chickens. These findings not only demonstrate that CAV is present in Nigeria, but they also likely represent the first cell culture isolation of the virus in Africa.

Comparison Prior and Post Vaccination of Inactivated Recombinant Vaccine Against Mannheimiosis in Boer Goats Farm in Sabah

The study was conducted to evaluate the efficacy of inactivated recombinant vaccine of Mannheimia haemolytica (MH) against naturally occurring mannheimiosis in a breeding Boer goat farm in Sabah, Malaysia. From the inception of Rural Development Corporation (RDC) farm in year 2005, the farm suffered a high incidence of mannheimiosis, one of the major caprine respiratory diseases in Malaysia. In order to reduce the incidence of the disease, the efficacy of the laboratory tested inactivated recombinant vaccine for mannheimiosis (RVM) was carried out on the farm goats. Goats more than 6-months-old were given the vaccine intranasally, followed by a booster dose on day 14, and subsequently a second booster dose was administered at 6 month interval (for two years). The data of goats that died of mannheimiosis were collected based on gross pathology and subsequent bacterial isolation to confirm the diagnosis. The effect of vaccination was evaluated by review of mortality pattern attributable to mannheimiosis during the three year study that spanned between 2006 and 2008. There was significant reduction of incidence and nmortality attributable to mannheimiosis in RDC farm with a resultant drop in mortality rate from 10-22 death per month to 3-2 per month after vaccination also 3.71% in 2006 prior to the introduction of the vaccination regime to 0.08% after the introduction in 2008. This is clearly showed that the RVM is suitable to be use on the farm goats.

Effects of levamisole hydrochloride on cellular immune response and flock performance of commercial broilers

Levamisole hydrochloride (Lev.HCl) has been acclaimed to boost immune response particularly in immunocompromised state. Its routine use as an immunomodulator in poultry production is yet to be well embraced, thus its effects of on cellular immunity and flock performance of commercial broilers were evaluated. One hundred and fifty Anak broiler chicks were separated into two groups of 75 each. Broilers in group 1 were sensitized with 150µg of Staphylococcus aureus antigen each at 4 and 5 weeks, while those in group 2 were not sensitized. Each group was further divided into subgroups A, B, and C. Levamisole hydrochloride (40 mg/kg) was administered orally to 1A and 2A at 45 and 46 days of age and to 1B and 2B at 47 and 48 days of age, while 1C and 2C were not treated. At 47 days of age, 12 broilers from all subgroups were challenged with 75µg of S. aureus antigen each at the right wattle. Wattle thickness was measured till 72 hours post challenge (pc) and delayed wattle reaction (DWR) was determined. Tissues were harvested at 72 hours pc for histopathology. Morbidity, mortality and live weights at 8 weeks of age were recorded. DWR peaked at 4 hours pc in 1A (2.22 ± 0.21 mm) and 1B (2.96 ± 0.21 mm) and 24 hours pc in 1C (3.39 ± 0.34 mm), the difference being significant (p<0.05). Inflammatory lesions were observed in wattles of sensitized subgroups and were more severe in 1C. Mortality rates were 4.17% and 29.17% in 1A and 1C respectively. Mean live weights in A and B i.e. 1.57± 0.06 kg and 1.56 ± 0.06 kg respectively, were significantly higher (p<0.0) than 1.43 ± 0.08 kg in C. Levamisole enhanced DTH via an early response, improved broiler liveability, and its anti-inflammatory property was confirmed.

Haematological changes associated with intranasal and parenteral routes of vaccination against Peste des petits ruminants in West African dwarf goats

The haematological indices of West African dwarf goats vaccinated against Peste des petits ruminants virus via the parenteral and the mucosal (intranasal) routes were studied and compared with an unvaccinated control. The post vaccination packed cell volume (PCV) and haemoglobin (Hb) concentrations of the vaccinated groups did not show any statistically significant difference (pu2009>u20090.05) from the unvaccinated control. However, a statistically significant difference was observed in the total white blood cell (WBC) counts between the vaccinated groups and the unvaccinated control, as well as between those vaccinated via the mucosal route and those vaccinated via the parenteral routes, though all within the normal reference values for West African dwarf goats. Differential WBC counts showed the significant difference to be due to increase in lymphocyte population, suggesting that PPR vaccine administered via the different routes was able to stimulate a cellular immune response which is mostly lymphoproliferative. Thus, it can be suggested that intranasal vaccination against Peste des petits ruminants as well as vaccination via the conventional route is safe.

Serological Detection of Newcastle Disease Virus Antibodies in Local Chickens and Guinea Fowls in the Area of Kumasi, Ghana

Newcastle Disease (ND) has been identified as a major constraint to local poultry production with its impact being felt more in rural poultry production which forms about 80% of Ghana poultry population. However documented evidence on ND virus activity in rural poultry in Ghana is still lacking. Hence, this study was conducted to evaluate the level of circulating antibodies against ND using the Haemagglutination Inhibition (HI) technique. Sera collected from unvaccinated 292 chickens and 153 guinea fowls randomly selected from households and a live bird market in Kumasi and its environs were evaluated for Newcastle disease virus antibodies. Results showed 81.8 % (239/292) of local chickens and 24.2 % (37/153) of guinea fowls tested positive for ND antibodies. Comparison was made between the seroprevalence of ND antibodies in household and live bird market as well as between sexes. Significantly higher prevalence rate (p<0.05) was observed with chickens sampled from households compared to those from the live bird market. Higher ranges of titers were also observed in chickens from households than those from live bird markets. The presence of ND antibodies in these unvaccinated local chickens and guinea fowls indicated the presence of the virus amongst the rural poultry population, hence aneed for improvement in vaccine campaignand delivery against ND for rural poultry especially with the use of thermostable and improved oral or feed-based vaccine delivery systems.

Haematological, serum biochemical and tissue pathological changes induced by γ-irradiated millet

The objective of this study was to evaluate the effect of γ-irradiation (2, 4 and 8xa0kGy) of millet on some haematological, serum biochemical and tissue pathological parameters of Wistar rats. Wistar rats in different groups were fed with non-irradiated and irradiated (2–8xa0kGy) millet on daily basis for 4xa0weeks. Packed cell volume (39–45xa0%), haemoglobin concentration (13.4–15.12xa0g/L), albumin (1.16–1.48xa0μL), platelets (12.0–13.4xa0g/dL), mean corpuscular volume (26.0–54.0xa0fl), mean corpuscular haemoglobin (8.0–17.56xa0pg), neutrophils (34.0–45.4u2009×u2009109xa0L), and monocytes (1.0u2009×u2009109–1.5u2009×u2009109xa0L) increased significantly (pu2009<u20090.05) during the 4-week feeding period. Packed cell volume and body weight gain increased in the group of rats fed with γ-irradiated millet. The increased lymphocytes, platelets, albumin and globulin values during the feeding period indicated that feeding of rats with pre-irradiated millet did not adversely affect the haematological and serum biochemical parameters. The liver, kidney, heart and lungs showed no visible gross lesions over this period, indicating that the feeding on irradiated millet by Wistar rats might not have posed toxic hazard.