Infectious bursal disease: seroprevalence and associated risk factors in major poultry rearing areas of Ethiopia

The study was conducted in eight districts of Ethiopia with the objectives of determining the seroprevalence and associated risk factors of infectious bursal disease (IBD). From the total of 2,597 chicken serum samples examined using ELISA, 83.1 % were found positive. The highest seroprevalence was found at Mekele (90.3 %) while the lowest was recorded at Gondar district (69.8 %). These differences among the study areas were statistically significant (p?<?0.05). Highest seroprevalence was found in crossbreed of chicken (91.4 %) while the lowest was recorded in indigenous breed of chicken (81.4 %). This difference was statistically significant (p?<?0.05) among the three breeds of chickens, but sex was not statistically significant (p?>?0.05). The seroprevalence of the disease was found high in young (≤8 weeks) age group (86.6 %) while the lowest prevalence was recorded in adults (>8 weeks) (72 %). This is also statistically significant (p?<?0.05) between young and adult age groups. The prevalence of IBD in different production system indicated that higher seroprevalence was recorded in intensive production system (85.9 %) while the lowest was recorded in extensive production system (81.6 %). This difference is also statistically significant (p?<?0.05).     

First confirmation of foot and mouth disease virus serotype SAT-1 in cattle and small ruminants in Ethiopia in 2007/08

The study was conducted in three regional states of Ethiopia: Amhara, Oromia, and the Southern Nations Nationalities and people regional state from August 2007 to April 2008 with the objective of identifying the foot and mouth disease virus (FMDV) serotypes circulating in the region. Two serotypes were recorded from epithelial tissue and oesophageal–pharyngeal (OP) fluid that were taken from outbreaks in study regions of Ethiopia. Serotype O FMDV was identified in Girar Jarso, Yabello, and Ankesha Guagusa districts while SAT-1 was isolated in Surma and Maji districts from tissue samples and this was the first report of the FMDV serotype in Ethiopia. Similarly, the OP fluid samples were found positive for SAT-1 FMDV in Maji and Surma districts.     

Outbreak investigations and genetic characterization of foot-and-mouth disease virus in Ethiopia in 2008/2009

The study was conducted in three regional states of Ethiopia: Amhara, Oromia, and Addis Ababa from August 2008 to April 2009 with the objectives of identifying the genetic diversity of serotypes and topotypes in Ethiopia, and determining the attack rate and associations of potential risk factors with foot-and-mouth disease (FMD) seropositivity. A total of 496 cattle were clinically and serologically examined for presence of specific lesions and nonstructural protein for FMD, respectively. Of which, 140 (28.2%) manifested clinical signs and lesions suggestive of FMD, and 219 (44.2%) were seropositive. From a total of 7,781 animals observed and recorded on a designed format in six districts, 1,409 (19.6%) were infected, and 15 (0.12%) died during outbreaks of FMD. Epidemiological investigations revealed that the morbidity rate of the disease was 21.1% in Akaki-kality sub-city, but the mortality rate was <2% in all districts. Furthermore, the mortality and case fatality rates were relatively higher, 1.6% and 8.9% in calves than the other age groups, respectively. From a total of 33 bovine epithelial tissue-cultured samples, 19 (57.6%) showed CPE for FMD virus, in which 16 samples had serotype O and EA-3 topotype, while three samples had found serotype A, Africa topotype, and G-VII strain. Various strains of FMD viruses were isolated in Ethiopia in this study, and therefore, further detailed studies on the evaluation of available vaccines and the development of a vaccine which contains cocktails of antigens of FMD virus strains in the country should be encouraged.     

Gross and histopathological studies on pulmonary lesions of camel (Camelus dromedarius) slaughtered at Addis Ababa abattoir,Ethiopia

This study was carried out with the aim of identifying types of gross and histopathological lesions in lungs of camels slaughtered between October 2009 and April 2010 at Addis Ababa abattoir enterprise, Ethiopia. All camels were originated from Borana and Kereyu areas. A total of 387 slaughtered camel lungs were inspected during the study period. Of which, one or more gross lesions were encountered on 300 lungs. Lesions were further subjected for detail gross and histopathological examinations. The occurrence of pulmonary lesions was 77.5%. The gross and histopathological examination of these lesions had revealed 60.2% emphysema, 21.2% hydatidosis, 18.6% pneumonia, 10.6% atelectasis, 4.9% aspiration of blood, 3.9% pneumoconiosis, 2.6% pulmonary edema and congestion, 1.6% abscess, 1% pleurisy, and 0.8% granulomatous pneumonia. Most camels had one or more pulmonary lesions on postmortem examination, but they were apparently healthy during antemortem inspection. Therefore, the prevailing stressful environmental condition coupled with the existing poor level of veterinary service in camel-rearing areas of the country might reverse these hidden inactive lesions and thereby contributed for the higher occurrence of respiratory diseases in camels.     

Assessment on major factors that cause skin rejection at Modjo export tannery,Ethiopia

A study was conducted from November 2009 to March 2010 with the objective of identifying the major causes of skin rejection on fresh, pickled, and wet blue skins at Modjo Mesaco Global tannery. A total of 401 fresh and 1,873 pickled and wet blue skins from the routine production system of the tannery were used. Overall, high prevalence of sheep ked (100%) followed by biting louse (64.4%), tick (50%), and sucking louse (45.8%) were observed on fresh sheep pelts, while, on fresh goat pelts, a high prevalence of sucking louse (54.5%), followed by tick (50%), and biting louse (35.5%) were observed. From the total of 90 rejected pickled and wet blue skins of sheep and goats, 98.8% were “ekek” and scratch, 85.6% sheep and goat pox, 74% poor substance, 73.3% heat, 72.2% scar, and 52.2% knife cut-in skins. Large number of skins rejections was recorded in large-sized skins (29.8%), and the lowest observed was in medium-sized skins (11.1%). There were highly statistically significant association (p < 0.05) between size and grades of shoat skins. Ekek and scratches together with sheep and goat pox were the common skin defects that hamper skin quality. However, there was no significant association (p > 0.05) between sheep and goat skins. Ekek and scratch caused high rejection of skin and entailed serious economic loss in terms of foreign exchange earning to Ethiopia. Therefore, the main causes of skin rejection and factors that cause downgrading of skin should be controlled.     

Ultrasonographic studies on ovarian dynamics and associated estrus manifestations of jennies under controlled management, Ethiopia

A serial ultrasonographic study was conducted on nine jennies aged 5–15 years from January to April 2008 with the objective of studying ovarian follicular dynamics and estrus manifestations under controlled management. Ovarian follicular activity was determined from the number and size distribution of follicles, length of interovulatory interval (IOI), growth rate of preovulatory follicles, diameter of follicles at the onset of estrus, and incidence of ovulation. Estrus manifestations were characterized using length of estrus and estrous cycle. The mean (±SD) number of follicle detected per ovary was 5.45?±?2.3 (range, 1–16) with sizes ranging from 2.9 to 44 mm. The mean (±SD) size of follicle encountered at the onset of estrus was 25.9?±?3.7 mm (range, 20.9–34.4) while that of the preovulatory follicles at ?1 day before ovulation was 36.81?±?3.78 mm. The mean (±SD) IOI, estrus, and estrous cycle length were 25.4?±?3.6, 7.9?±?2.9, and 24.2?±?7.4 days, respectively. The mean (±SD) growth rate of the preovulatory follicle after the day of divergence was 1.9?±?0.3 mm/day. Serum progesterone profile followed the same patterns of ovarian dynamics with maximum values being detected during midluteal phase. Serum progesterone assay revealed blood progesterone profiles of <1.0 ng/ml during estrus and up to 11 ng/ml during midluteal phase with a pattern following follicular dynamics. Body condition of the study jennies steadily increased and was positively correlated (r?=?0.52, p?<?0.001) with the diameter of the preovulatory follicle. In conclusion, the ultrasonic evaluation has revealed that follicular dynamics of jennies were generally related with body condition which might have been influenced by the type of management.