Comparative study of genetic influence on the susceptibility of exotic cockerels, pullets and broilers to infectious bursal disease virus

This study investigated comparatively the genetic influence on the susceptibility of exotic cockerels, pullets and broilers to natural infection with infectious bursal disease (IBD) virus in a flock of 150 seven-week-old exotic breed of chickens comprising of 50 Black Harco cockerels, 50 Black Harco pullets and 50 White Marshall broilers. Evaluation of possible genetic resistance was based on clinical signs, mortality and pathological changes in affected chicks. The virus was highly pathogenic for cockerels and pullets as clinical signs were evident on day 1 after the onset of the infection with hundred percent (100%) of the cockerels and pullets showing severe clinical disease on day 2 of the infection, while the broilers had the shortest timing as clinical signs were evident with 8% morbidity on day 2 of the infection only. The clinical signs were severe depression, diarrhoea, anorexia, prostration followed by death. Mortality was 92%, 78% and 6% for cockerels, pullets and broilers, respectively, within 3 days of the infection followed by recovery. Severe haemorrhages were present in the skeletal muscles, bursa, proventriculus-gizzard junction and caecal tonsils of dead cockerels and pullets only, while dead broilers showed only swollen bursae. Histologic lesions showed marked oedema, congestion of blood vessels, haemorrhages and necroses in the skeletal muscles, kidney, liver, and thymus of cockerels and pullets. Lymphocytic necrosis and depletion were marked in the spleen and caecal tonsils of the cockerels and pullets. Marked lymphoid depletion, oedema and heterophilic infiltrations were observed at day 2 of the infection in the bursae of cockerels, pullets and broilers. Assessing the clinical signs and lesions observed from affected chickens revealed that broiler is the least susceptible. It also revealed that within the Black Harco breed, cockerels are more susceptible to clinical IBD than the pullets. The low morbidity and mortality, and differential lesions observed in broilers indicated probable genetic resistance to clinical IBD.Keywords: Infectious bursal disease, chickens, breeds, susceptibility disease pattern, patholog

Leucogram, serum protein parameters and histopathology of broiler chickens (Gallus gallus domesticus) treated with cyclophosphamide and infected with velogenic Newcastle disease virus

The present study evaluated the changes in leucogram, serum protein parameters and histology of lymphoid organs associated with  cyclophosphamide–induced immunosuppression in broiler chickens infected with velogenic Newcastle disease virus. At four-week-old, one hundred broiler chickens were randomly assigned into four groups of 25 each viz: A/CYTI – cyclophosphamide treated and velogenic Newcastle disease virus infected, B/CYTU – cyclophosphamide– treated and uninfected, C/CYNTI – cyclophosphamide non-treated, infected and D/CYNTU– untreated uninfected. Groups A/CYTI and B/CYTU were injected with   cyclophosphamide at the dose of 75mg/kg body weight daily for 3 days while groups A/CYTI and C/CYTU were infected with velogenic Newcastle disease virus at six-week-old. Blood samples were collected from randomly selected chickens in each group for leucogram and serum protein assays, while tissue samples were collected for histopathology. Cyclophosphamide induced significantly (P < 0.05) lower levels of circulating total leucocytes, lymphocytes and heterophils on days 7 and 14 post-treatment. On day 14 post-treatment, the total serum protein values of groups A/CYTI and B/CYTU were significantly (P < 0.05) lower than those of groups C/CYNTI and D/CYNTU. Examination of the tissue sections showed severe diffused lymphocytic necrosis and depletion in the bursa, spleen and thymus. Newcastle disease virus infection induced significantly (P < 0.05) higher levels of circulating total leucocytes, lymphocytes and heterophils and significantly (P< 0.05) decreased serum proteins in cyclophosphamide treated chickens on day 3 PC. The results showed that severe decreased leucogram and serum proteins and lymphoid cell depletion in cyclophosphamide treated broiler chickens, which together with the increased leukogram observed following velogenic Newcastle disease virus infection could be used as indicators of exposure to immunosuppressants.Keywords: Broiler chickens, Cyclophosphamide, Leucogram, Serum proteins, Newcastle diseas

Haemagglutination inhibition antibody responses of pullet and broiler chickens (Gallus gallus domesticus) to Newcastle disease virus LaSota vaccination

Newcastle disease outbreaks still occur sporadically in commercial vaccinated flocks and remains a constant threat to poultry producers despite advances in vaccination against the disease. Another aspect that can be a complementary control strategies or that is well recognized but is often neglected is the differences in immune response due to genetic or breed/type variation. This study investigated the immune responses to LaSota vaccination in light weight type or breeds of chickens (pullets) and heavy weight type or breeds of chickens (broilers) used in commercial poultry production. Fifty seven-week-old White Marshall broilers (Br) and 50 Isa Brown pullets (Pu) of the same age were randomly divided into 4 groups viz: vaccinated broilers chickens (VaBr), unvaccinated broiler chickens (UBr), vaccinated pullet chickens (VaPu) and unvaccinated pullet chickens (UPu). Chickens in groups VaBr and VaPu were vaccinated with LaSota vaccine while groups UBr and UPu were not vaccinated. The chickens were observed for clinical signs and lesions. Serum samples were collected from the chickens in all the groups on days 0, 7, 14, 21, 28 post vaccination (PV), and assayed for haemagglutination inhibition (HI) antibodies. The geometrical mean antibody titres (GMT) of the pullets were 2 to 3 times higher than those of the broilers on days 7 to 28 PV. Vaccination produced neither clinical signs nor lesions. The above observations show that naturally pullets produce higher antibodies than broilers, and suggest breed-based variation on immune responses to Newcastle disease vaccination. The knowledge from the present study may lead to genetic approach to vaccine development and development of more effective vaccination strategies to be used in commercial poultry production.Keywords: Broilers, Haemagglutination inhibition antibody, LaSota vaccination, Pullet

Haematological changes in Isa-brown laying chickens (Gallus gallus domesticus) experimentally infected with velogenic Newcastle disease virus

This study investigated the haematological changes in vaccinated and unvaccinated laying chickens experimentally infected with a velogenic Newcastle disease virus. Two hundred and forty laying chickens were randomly assigned into four groups of 60 each: vaccinated with Newcastle disease vaccines and infected with velogenic Newcastle disease virus (VI), vaccinated uninfected (VU), unvaccinated infected (UI), unvaccinated uninfected (UU). At peak production, 32-weeks-old, groups VI & UI were each inoculated intramuscularly with 0.2 ml of velogenic Newcastle disease virus. The changes in the blood cells were assayed in the groups on the specified days. The total red blood cell count (RBC) was significantly (P < 0.05) lower in UI group on days 6 & 15 post infection (PI). The packed cell volume (PCV) and haemoglobin concentration (HbC) were significantly (P<0.05) lower in UI group on day 15 PI. There were no significant (P > 0.05) differences between the PCV, RBC and HbC in VI & VU groups from day 0 to 21 PI. The leukogram showed significant (P < 0.05) differences in leukocytosis on days 3 & 6 PI followed by significant (P < 0.05) leukopenia on days 10, 15 & 21 PI in UI group. However, significant leukocytosis on day 10 PI followed by leukopenia on day 15 PI were recorded in VI group. These findings suggest that leukocytosis in UI & VI and decreased haemogram in UI are features of Newcastle disease in laying chickens.Keywords: Experimental infection, Haematology, Laying chickens, Leukocytosis, Newcastle diseas

Vaccination indices and concomitant serological status of Newcastle disease in chickens in Aba and Umuahia of Abia State

The vaccination indices of Newcastle disease (ND) in chickens in Aba and Umuahia towns of Abia state were studied alongside their corresponding antibody status. A total of 296 sera samples were collected from 74 chicken farms. A Haemagglution inhibition (HI) test was conducted to determine the ND virus serum antibody levels. Open and closed-ended questionnaires were administered to staff on the farms selected randomly in the study areas. Information on vaccine types, origin, administering personnel, revaccination interval, and records of ND outbreaks was collected. Whereas 68.9% of the farm carried out vaccination on their own, 27.0% and 4.1% of the vaccination were done by veterinarians and animal health scientists Farms in Aba and Umuahia had average geometric mean titres (GMT) of 166.32 and 100.33, respectively. Approximately 87% of the farms had protective immunity (GMT >8 or log23) against ND. Chickens aged 1-3, 4-8, 9-16, 17 weeks and above had average GMTs of 64.00, 76.99, 283.7 and 197, respectively. Post-vaccination antibody titres were 128.92, 110.63, 52.07 and 43.65, after 1 week, 2-3 weeks, 4 weeks, and above 4 weeks, respectively. Indigenous ND vaccines had an average GMT of 182.55, while foreign ND vaccines had a GMT of 120.82. The Result showed that 77% of farmers used foreign vaccines whereas 23% used indigenous vaccines. On vaccination interval, 40.5% revaccinated for ND every three weeks, 21.6% monthly, 8.1% bi-monthly and 29.7% revaccinated when necessary. About 54% of farmers reported previous ND occurrence. This study identified high seroprevalence of ND antibodies in the flock studied and indicated a high level of awareness and adherence to NDV vaccination among the farmers in the study area. The local vaccines elicited better immunogenic responses than their foreign counterparts. We, therefore, recommend that usage of the local vaccines be adopted, and revaccination is done before a month interval

Gastroprotective effects of polyphenol rich extract of Anacardium occidentale L. leaf

The leaves of Anacardium occidentale are used in folkloric medicine for the management of gastrointestinal disorders. This study evaluated the gastroprotective properties of methanol extract of A. occidentale leaf against ethanol- and indomethacin-induced gastric ulcers. Cold maceration method was used in the preparation of methanol extract of A. occidentale leaf. The extract was concentrated under reduced pressure using a rotary evaporator. The gastroprotective effects of the methanol extract of A. occidentale was tested at 100, 200 and 400 mg/kg against ethanol and indomethacin-induced gastric ulcer. Omeprazole and misoprostol were used as the positive controls for the ethanol and indomethacin-induced gastric ulcer models respectively while distilled water was used as the negative control. The effects of the extract on histamine receptor were also evaluated on isolated rabbit jejunum. The extract significantly (p < 0.05) reduced ulcer index in the treated rats relative to the negative control. The effects of the extract were comparable with the effects of the reference drugs. The extract relaxed spontaneously contracting rabbit jejunum and inhibited histamine induced contraction of rabbit jejunum. This study suggests a pharmacological basis for the folkloric use of Anacardium occidentale in the management of gastric ulcer.Keywords: Anacardium occidentale; ulcer; ethanol; indomethacin; misoprotol; omeprazol

Accessibility of resources and delivery methods as correlates of information literacy competence of undergraduates in southern Nigerian Universities

Information literacy (IL) connotes ability to use information resources from various sources for making decisions and solving problems. The IL competence enables individuals to identify their information needs, locate, retrieve, critically evaluate, synthesise and use information resources ethically, and communicate the results. However, research reports revealed that undergraduate students in Southern Nigerian universities have poor IL competence. This study, therefore, sets out to determine the factors responsible for poor IL competence of the students, by adopting survey research design of correlational type. Multistage sampling was used to select a sample size of 1,967 from a population of 39, 338 final year undergraduate students in nine universities in Southern Nigeria.  Researcher-designed questionnaire and IL competence test were used for the data gathering. After validation by experts, the instruments were subjected to test-retest reliability with two weeks interval, and the overall coefficient yielded r = 0.87. The findings reveal that resources with high accessibility were: conducive library environment (75.5%), Internet (60.7%) and IL educators (60.4%). Instructional videos (35.5%) and web 2.0 (31.7%) had poor accessibility; face-to-face lectures in classrooms (78.5%) dominated IL instructions, whereas ICT laboratories (39.8%), power-point presentations (30.8%) and web 2.0/web-based tutorials (16.7%) were hardly used; students’ IL competence level was found to be very poor, with overall mean of 30 %. Strong positive and significant relationships were found among resources accessibility, delivery methods and IL competence, rs(1541)=.919,p<0.05 and rs(1541)=.919,p<0.05, respectively. The study concluded that resources and delivery methods were the factors affecting students’ level of IL competence, and recommended adequate provision of requisite resources, adoption and use of web-based IL instructional methods, sensitisation of the students on the essence of IL and development of IL competence framework for IL programmes in Southern Nigerian universities.Keywords: Information Literacy Competence, Resources, Delivery Methods, Students, Universitie

The Pathology of Vaccination of Chickens with Varying Doses of Lentogenic LaSota Strain of Newcastle Disease Virus

Recently, it was demonstrated under laboratory conditions that increased doses of LaSota vaccine increased ND antibody response significantly in chickens. In this study, we have used the same model to investigate whether vaccination with increased doses of  lentogenic LaSota strain of Newcastle disease virus are associated with pathological changes in chickens. Four-week-old broiler chickens (n=100) were randomly assigned into four groups of 25 each: ZD, each drenched with phosphate-buffered saline, SD, DD and TD broilers were each drenched with single, double and triple dose of LaSota vaccine, respectively. The chickens were observed for clinical signs and lesions. Serum samples were collected from the chickens in all the groups at weekly intervals post inoculation (PV) and assayed for haemagglutination inhibition (HI) antibodies. The vaccinated broilers showed no morbidity and mortality. Only the bursa of all the vaccinated groups appeared slightly reduced in size on day 10 PV. The histopathological changes were lymphoid  hyperplasia and formation of germinal centres in the spleen and caecal tonsils from days 3 to 6 PV and mild depletion of bursal lymphocytes on day 10 PV. Generally, the integrity of the lymphoid organs was intact. Groups DD and TD antibody titres were  significantly (P < 0.05) higher than that of the SD on day 21 PV. This suggests that increased doses of LaSota vaccine does not cause  pathologic impairment and may be considered in improving the performance of the vaccine in the control of velogenic ND. Key words: Newcastle disease, LaSota vaccine, pathology, broiler chicken

An Investigation of the Awareness and Use of Open Access Initiative at the Federal Polytechnic, Offa, Kwara State, Nigeria

This study investigated the information environment of lecturers in Federal Polytechnic, Offa, Kwara State, Nigeria, in relation to their information seeking behavior, extent of use of the polytechnic library, perceptions of the resources and services of the library, level of awareness and extent of use of the open access model of scholarly communications, as well as the challenges of accessing and using information resources. It adopted the survey research method, using a questionnaire for data collection, while the descriptive statistics method was used to analyse the data, using tabular presentation and simple percentages. From a population of 280 lecturers for the study, a purposive sample of 164 was drawn. The findings showed that the lecturers' information needs are focused on online use; they hardly use the polytechnic library due to their perceptions of the resources and services of the library. They are, to a greater extent, aware of open access initiatives, but do not publish in open access outlets, while various challenges affect their access and use of information resources for teaching and research. A recommendation was made, among others, that the polytechnic management should pay more critical attention to the library especially in the areas of adequate, current and comprehensive collections on all the programmes of the institution, as well as the provision of wireless internet services on the campus through a public-private partnership arrangement

Evaluation of pathological changes of natural infectious bursal disease virus infection in the lymphoid organs of Black Harco pullets

This study examined the sequential pathological changes in the lymphoid organs (bursa of Fabricius, thymus, spleen and caecal tonsils) of 7-week-old Harco pullet chicks that showed severe clinical disease and lesions during a natural infection with a virulent infectious bursal disease virus. Clinical signs were sleepiness, droopy appearance, greenish-whitish diarrhoea, anorexia and prostration followed by death. Mortality rate was 78% within 3 days of the infection followed by recovery. Gross lesions were marked haemorrhages in the pectoral and thigh muscles, mucosa of the proventriculus and gizzard junction, and caecal tonsils. Bursa of Fabricius, thymus, spleen and kidneys were initially enlarged; however, bursa of Fabricius and thymus were later atrophic. Histologic lesions showed marked oedema, infiltration of heterophils, hyperaemia, and lymphoid depletion and hyperplastic corticomedullary layer in the bursa of Fabricius, lymphoid necrosis in thymus, spleen, and caecal tonsils. Lymphocytic depletion was marked in the bursa of Fabricius as early as day 1 of the infection, and in the spleen, thymus and caecal tonsils on day 2 of the infection. However, there were fibroplasias in the bursa of Fabricius and thymus but repopulation of lymphocytes in the spleen and caecal tonsils of birds sacrificed on day 6 of the infection. Confirmation of IBD was carried out using agar gel immunodiffusion test. The above observations showed that marked depletion of lymphocytes in the lymphoid organs correlated with marked clinical IBD while repopulation of lymphocytes in the spleen and caecal tonsils correlated with the recovery phase in pullet chicks. The description of the pathological changes in lymphoid organs caused by the IBDV currently circulating in Nigeria will be useful in assessing the time and recognition of early diagnostic features of the disease.Keywords: Infectious bursal disease, Lymphoid organs, Pathology, Pullet