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Haemagglutination Inhibition Antibodies, Rectal Temperature and Total Protein of Chickens Infected with a Local Nigerian Isolate of Velogenic Newcastle Disease Virus

Changes in values of haemagglutination inhibition (HI) antibody titre, rectal temperature (RT) and total protein (TP) were determined for Shaver Brown chickens infected with Newcastle disease virus (NDV) Kudu 113. The infected chickens came down with Newcastle disease by day 3 post infection (PI). The major clinical signs were depression, greenish diarrhoea, paralysis of legs and wings, opisthotonus and torticolis. Mortality and morbidity were 52% and 100%, respectively. There were haemorrhagic lesions in the wall of the intestine, proventricular mucosa and caecal tonsils. There were necrosis and mononuclear cell infiltration of the liver, kidney and spleen. There was a significant increase in daily mean HI antibody titres from days 3 to 9 PI. Similarly, significant rise in daily mean RTs were noticed in the infected chickens from days 1 to 13 PI. On the other hand, there was a decrease in daily mean TP concentrations of infected chickens, beginning from day 3 PI, and the lowest concentration of 2.60±0.15 g/dl was obtained by days 7 and 11 PI. The values of HI, RT and TP for the control chickens were relatively constant during the experiment. The correlation coefficient (r) between HI and RT was positive and highly significant (r = 0.725, p<0.001), while the relationship between HI and TP was negative but highly significant (r = –0.712, p<0.001). It was concluded that NDV Kudu 113 induced increases in values of HI and RT, which occurred concurrently with a decrease in TP concentrations of infected chickens.

Salmonella serovars and their distribution in Nigerian commercial chicken layer farms

Commercial poultry farms (n° 523), located in all the six regions of Nigeria were sampled with a view to generate baseline information about the distribution of Salmonella serovars in this country. Five different matrices (litter, dust, faeces, feed and water) were collected from each visited farm. Salmonella was isolated from at least one of the five matrices in 228 farms, with a farm prevalence of 43.6% (CI95[39.7–48.3%]). Altogether, 370 of 2615 samples collected (14.1%, CI95[12.8; 15.5%]) contained Salmonella. Considering the number of positive farms and the number of positive samples, it was evident that for the majority of the sampled farms, few samples were positive for Salmonella. With regard to the matrices, there was no difference in Salmonella prevalence among the five matrices considered. Of the 370 isolates serotyped, eighty-two different serotypes were identified and Salmonella Kentucky was identified as having the highest isolation rate in all the matrices sampled (16.2%), followed by S. Poona and S. Elisabethville. S. Kentucky was distributed across the country, whereas the other less frequent serovars had a more circumscribed diffusion. This is one of few comprehensive studies on the occurrence and distribution of Salmonella in commercial chicken layer farms from all the six regions of Nigeria. The relatively high prevalence rate documented in this study may be attributed to the generally poor infrastructure and low biosecurity measures in controlling stray animals, rodents and humans. Data collected could be valuable for instituting effective intervention strategies for Salmonella control in Nigeria and also in other developing countries with a similar poultry industry structure, with the final aim of reducing Salmonella spread in animals and ultimately in humans.

Investigation of potential risk factors associated with Salmonella presence in commercial laying hen farms in Nigeria

BACKGROUND In 2012/13, the Federal government of Nigeria approved the surveillance of salmonellae in commercial poultry farms with the aim of generating baseline data for the development of a control programme. That baseline provided an opportunity to investigate potential risk factors in commercial layer farms. METHODS Five hundred and twenty-three farms were evaluated for the presence of Salmonella. Each farmer was interviewed through a structured questionnaire. Univariate analysis identified 26 variables potentially associated with Salmonella presence on the farms, with different levels of significance. To simultaneously evaluate the effect of these variables, a multivariable logistic regression model was implemented. RESULTS Farmers that are member of the Poultry Association of Nigeria (PAN) emerged as a risk factor, as well as being farmer as exclusive occupation. The risk of Salmonella increased in farms with a combined housing system as compared to farms with a single housing system. Moreover, in terms of farm management the use of plastic egg crates had a higher risk of Salmonella presence compared to paper crates. Higher risk of contamination was also identified in farms having regular contact with animal health workers, since this could be indicative of animal health problems requiring continuous assistance. Farms with no previous outbreak of salmonellosis were associated with an increase risk, since most of the farms in this category were newly established. With regard to feeding, the use of coccidiostats and commercial feeds were associated with the spread of Salmonella. Unexpectedly, the presence of other farms at distances further than 1 km away was associated with an increase in Salmonella presence as compared to farms which were in closer proximity. Close proximity among farms could favour the application of stricter biosecurity measures. CONCLUSIONS The results of the survey can be considered a baseline for implementing effective measures aimed at reducing the Salmonella prevalence in Nigerian laying hen farms.

Seroepidemiology and assessment of risk factors for the spread of avian influenza in birds in two Nigerian states

Abstract Despite modified stamping out eradication policy adopted in Nigeria, there was resurgence in 2015 of highly pathogenic avian influenza (HPAI) H5N1 with greater infectivity. A survey of the risk of spread of HPAI in two HPAI‐infected and ‐uninfected Nigerian states were studied. A cross‐sectional study to detect avian influenza (AI) H5 antibodies was conducted using haemagglutination inhibition (HI) test and enzyme‐linked immunosorbent assay (ELISA). A total of 950 birds’ sera were tested for AI H5 antibodies. Questionnaires were also administered to evaluate risks of AI spread in two states of Nigeria in 2013. AI H5 seroprevalence of 3% and 5% were obtained in Bauchi and Gombe states, respectively. Free flying and captive wild birds had 15% and 11% seroprevalence, respectively. Ninety‐two per cent AI awareness and 90% preparedness to report outbreaks of poultry diseases were recorded. Veterinary personnel, radio and television contributed 87% to HPAI awareness. Of the 10 risk categories evaluated, Gombe state had 3 moderate and 1 high risk of AI virus spread. Bauchi state recorded 5 moderate and 1 high risk of AI virus spread. Chi‐square analysis showed associations of altitude, temperature, rainfall and presence of live bird markets (LBMs) (P < 0.05) to AI seroprevalence. Odds ratio at 95% CI (1.313–6.333) indicated LBMs presence to be three times more likely to influence AI occurrence. HPAI H5N1 resurged in many states and occurred for the first time in Gombe state in 2015. Veterinary personnel, radio and television may be reliable in changing farmers’ attitudes to adopt good biosecurity practices.

A nine - year retrospective study of avian neoplastic diseases in Zaria, Kaduna state, Nigeria

Avian neoplastic diseases have been identified as one of the leading causes of mortality and production losses in commercial chickens in Nigeria. Although available reports described the trend of Marek’s disease in Zaria, Kaduna state, they did not take cognizance of other neoplastic diseases of poultry hence the need for this study. The clinic records of the Avian Clinic of the Veterinary Teaching Hospital (VTH), Ahmadu Bello University (ABU), Zaria, were examined for cases of all avian neoplastic diseases from 2002 to 2010. The overall prevalence of avian neoplastic diseases was 7.58% (234/3085). Marek’s disease (MD) and avian leukosis (AL) were the only avian neoplastic diseases of poultry reported during the period under review. Marek’s disease contributed 85.90% (201/234) of the total avian neoplastic diseases outbreaks while AL was responsible for only 14.10% (33/234) of the outbreaks. The overall prevalence of MD was 6.25% (201/3085) while that of AL was 1.07% (33/3085). Chicken (99.57%) and duck (0.43%) were the only species of birds affected by the diseases. The types of chickens that were affected include commercial layers (97.85%), exotic broilers (0.86%), exotic cockerels (0.86%) and Nigerian indigenous chicken (0.43%). The average age of poultry affected was 20.17 (SD=±2.6) weeks for MD and 41.43 (SD=±15.4) weeks for AL. Weight loss (55.98%), ruffled feathers (47.01%), diarrhea (39.79%) and leg paralysis (17.52%) were the most reported clinical signs. The most consistent gross lesions observed were hepatomegaly (76.50%), emaciated carcass (75.64%), renomegaly (52.56%) and splenomegaly (44.87%). Neoplastic growths were mostly observed on the liver (46.58%), kidney (28.2%) and heart (25.21%). The sciatic nerve (20.51%) and bursa of Fabricius (3.85%) were also affected. There is a remarkable increase in the cases of avian neoplastic diseases over the study period which underscores the importance of a National control program for these important diseases of poultry. Keywords: Avian neoplastic diseases, Avian leukosis, Clinico-pathological changes, Marek’s disease, Prevalence

Serological Survey of Newcastle Disease in Free Ranging Local Chickens in the Federal Capital Territory, Abuja, Nigeria

A serological survey was carried out in four area councils (Abuja Municipal, Kuje, Gwagwalada, and Kwali) of the Federal Capital Territory (Abuja) to determine the prevalence of antibodies to Newcastle disease virus in local chickens using haemagglutination inhibition (HI) tests. In each area council, one hundred sera samples were collected from apparently healthy local chickens with no history of vaccination. Abuja Municipal, Kuje, Gwagwalada, and Kwali area councils had prevalence of 37, 44, 79, and 68%, respectively. The overall prevalence of antibody to Newcastle disease in the four area councils was 57%. This study shows that Newcastle disease virus is circulating in local chickens in the study area, and this may pose a serious threat to the commercial poultry industry within these four area councils of the Federal Capital Territory (Abuja) where this study was carried out.

Evaluation of Some Fowl Pox, Gumboro and Newcastle Disease Vaccines Marketed in Nigeria

Enzootic nasal adenocarcinoma (ENA), a contagious retroviral disease of sheep and goats, characterized by neoplastic growth of the ethmoidal mucosa in the nasal cavity is described in a West African Dwarf goat (WAD). A two-year old WAD goat, weighing approximately 20kg was observed in the Teaching and Research Farm of the University of Agriculture Abeokuta, Nigeria. The WAD goat was presented with a clinical history of 31/2 months seromucoid to mucopurulent nasal discharge, dyspnoea with audible rales, stertorous breathing with open mouth, coughing and sneezing. Cytological evaluation revealed anaplastic features such as hyperchromasia and binucleation with 2 or more nucleoli. Haematological profile revealed leukocytosis, due to lymphocytosis initially, which later changed to neutrophilia with left shift, however, the was absence of anaemia. Grossly, there was unilateral, left facial swelling, bilateral, separate and discrete nodular and papillary tumourous masses in each nasal cavity with concomitant inflammation, necrosis and distortion of the nasal bones, turbinates and the median septum. Microscopically, two forms of the tumour mass were observed, which include; polyploidy and papillary forms and characterized by well-differentiated tubulo-acinar and cystic glands with their content Periodic Acid Schiff positive for glycoprotein. This report, to the best of our knowledge, is the first reported case of ENA in WAD goats in Nigeria. Keywords : Enzootic nasal adenocarcinoma, West African Dwarf goat, Nigeria.The quality of live commercial fowl pox (FP), Gumboro disease (GD) and Newcastle disease (ND) vaccines manufactured by four laboratories and on sale in Nigeria were tested. One of the nine vaccines yielded Aspergillus sp ., two Salmonella sp . and three Escherichia coli when grown on culture media. All the four ND vaccines and one of the three FP vaccines tested contained the recommended virus titre. None of the two GD vaccines tested contained the recommended virus titre. Two of the three FP vaccines were able to protect 100% of vaccinated chicks challenged with a virulent FP virus. All chicks vaccinated orally (PO) or intramuscularly (IM) with Two of the three vaccines had pox lesions when challenged while only 17% of chicks had pox lesions following IM vaccination with one of the three FP vaccines. Two weeks post vaccination (PV) only 17% and 33% of the chicks vaccinated with two of the three GD vaccines had precipitin antibodies (PAb) in their sera while 100% of the chicks vaccinated with one of the three GD vaccines had PAb. All the three GD vaccines caused reduction in body weight gain and atrophy of the bursa of Fabricius when administered at one or 10 times the normal dose. The haemagglutination inhibition (HI) antibody titre of ND vaccinated chicks was highest two weeks PV and in chicks vaccinated intraocularly with 10 times the normal dose. Only 50%, 56% and 78% of chicks vaccinated with three ND vaccines were protected when challenged with a local virulent ND virus. Live viral vaccines are therefore possible sources of bacterial and fungal infections for poultry in Nigeria. Some commercial vaccines contain low virus titres, are poorly immunogenic or pathogenic even at recommended dose therefore are unable to protect all vaccinated chicks when exposed to virulent viruses. The aforementioned factors are some of the likely causes of outbreaks of FP, GD and ND in vaccinated flocks in Nigeria. There is the need to routinely reassess the quality of all commercial poultry vaccines and maintain their quality by proper handling, transportation and storage. Vaccines should also to be properly administered by poultry farmers. Keywords : Safety, Poultry vaccines, Potency.In Nigeria infectious bursal disease (IBD) outbreaks have persisted despite routine vaccination. In a quest to determine some of the causes of the vaccination failures, the type of vaccines, vaccination schedules and seromonitoring for antibodies in breeder and commercial farms were investigated using structured questionnaires. The presences and level of maternally derived antibodies in broiler and layer day old chicks from four and six breeders respectively was determined using enzyme linked immunosorbent assay (ELISA) test. Based on the level of antibodies in day old chicks the central vaccination times and vaccination days were calculated using the Deventer formula. Not all breeder farms monitor for antibodies in breeders or chicks and only one of the 17 commercial farms sampled monitor for antibodies in chicks. The type of vaccines used and schedules vary with breeder farm. All broiler and layer commercial farms vaccinate with intermediate vaccine at 5 or 12 and 17 or 22 days of age. The mean IBD maternally derived antibodies (MDA) ELISA titre of day old broilers ranged from 1,564+873 to 2,472+962 while the titre was 2,015+1133 to 3,415+1958 for layers depending on breeder farm. Only the coefficient of variation of the MDA titre of day old chicks from two layer breeders was uniform (less than 30%). The calculated vaccination days using intermediate IBD vaccine for broilers was 14 and 20 days and 26 and 32 days for layers. About 2% to 24% of day old broilers and 2% to 16% layers had IBD MDA ELISA titre below 1,000. Based on the IBD MDA ELISA titre and %CV there is a need to harmonized and improve the vaccination strategies in breeder and commercial farms but breeders and day old chicks should meanwhile each should be seromonitored to determine the best time to vaccinate. In the absence of seromonotoring it is recommended that commercial farmers vaccinate broilers with intermediate at 14 and 20 days of age and layers with intermediate-plus IBD vaccine at 14 and 20 days of age in addition to instituting effective biosecurity to reduce the chances of exposure to IBDV early in life with resultant immunosuppression. Keywords : Farms, infectious bursal disease, maternal antibodies, vaccinationEight Uda weighing between 34-39kg, and aged 2-3years were used for this study. They were fed with 2kg of concentrate supplement (per day) divided into two parts (morning and evening). The weight all the ewes were taken before the commencement of feed supplementation, and for 14 weeks after at 2 weeks interval. Blood samples were collected for haematology and serum chemistry before the commencement of feeding. A significant increase (P<0.05) in weight of the Uda ewe was observed after the commencement of feed supplementation. A microcytic hypochromic anaemia which is believed to be nutritionally induced was observed. Certain nutrients needed for haemopoesis in a large sheep breed were believed to be inadequate. Furthermore reduction of Blood glucose, Blood Urea Nitrogen (BUN) and Total Protein following supplementation corroborates the inadequacies in the constituents of the ration used. It was concluded that this ration may only be beneficial to support physiological functions in a large breed of sheep like the Uda breed provided extensive mineral supplementation as well as crude protein and energy level are increased. Keywords : Primiparous Uda Ewe, Concentrate Supplement, Heamatology, Serum Chemistry.