Adoption and failure rates of vaccinations for disease prevention in chicken farms in Jos, Nigeria.

Vaccinations against diseases to prevent disease outbreaks are strategic to disease prevention, but vaccination failures may constitute a challenge in practice. This study was aimed at assessing the adoption and failure rates of vaccinations in 80 chicken farms in Jos, Nigeria. Data were obtained through a structured questionnaire validated by interviews and checking of farm and veterinary records. Vaccination score (0-1) from the vaccination checklist (5 for broilers and 12 for layers) and vaccination procedure score (0-1), based on scored adopted procedures, were calculated for each farm. Vaccine effectiveness was calculated for each vaccine using the odds ratio from the association of frequencies of disease outbreaks in vaccinated and unvaccinated flocks. Farmers used more of imported than local vaccines. Vaccination procedure and vaccination scores did not influence frequencies of disease outbreaks, but vaccination scores tended to non-robustly correlate (r = - 0.89, p > 0.05) with rates of disease outbreak. Vaccination rates were highest against Newcastle disease and infectious bursal disease, and their vaccinations also had the highest effectiveness. There was an association (p = 0.009) between composite vaccination rates and disease outbreaks with 2.1 odds of outbreaks in vaccinated than unvaccinated flocks. Vaccination failures occurred in the use of 11 out of 12 vaccines and the highest failure rate (47.9%) was in vaccination against coccidiosis. Therefore, vaccination failure is a critical factor in poultry vaccination practice within the locality. The adoption of poultry vaccinations needs to be strategised in the context of a national poultry vaccination policy in order to promote effective poultry disease prevention and control.

Appraisal of Chicken Production with Associated Biosecurity Practices in Commercial Poultry Farms Located in Jos, Nigeria.

A questionnaire-based study of chicken production system with on-farm biosecurity practices was carried out in commercial poultry farms located in Jos, Nigeria. Commercial and semicommercial farms had 75.3% and 24.5% of 95,393 birds on 80 farms, respectively. Farms using deep litter and battery cage systems were 69 (86.3%) and 10 (12.5%), respectively. In our biosecurity scoring system, a correct practice of each indicator of an event scored 1.00 and biosecurity score (BS) of each farm was the average of the scores of biosecurity indicators for the farm, giving BS of zero and 1.00 as absence of biosecurity and optimal biosecurity, respectively. Semicommercial farms had higher BS than commercial farms. The flock size did not significantly (p > 0.05) affect the mean BS. Disease outbreaks correlated (r = -0.97) with BS, showing a tendency of reduction of disease outbreaks with increasing BS. Outbreaks were significantly (p < 0.05) associated with deep litter system. In conclusion, the chicken production system requires increased drive for excellent biosecurity practices and weak points in the biosecurity could be ameliorated by extension of information to farmers in order to support expansion of chicken production with robust biosecurity measures that drastically reduce risk of disease outbreak.

Testicular and Related Size Evaluations in Nigerian Sahel Goats with Optimal Cauda Epididymal Sperm Reserve.

Testicular sizes of animals are important for identification of those with adequate sperm production. The aim of this study was to define the testicular and related size estimates that would be associated with optimal cauda epididymal sperm counts (ESC) in Sahel goats based on postmortem evaluations. A stratified quota sample population of 125 male goats inclusive of all testicular sizes was taken at a slaughterhouse in Maiduguri, Nigeria. The bucks were aged 18-30 months and weighed 17.04 ± 2.99 (12-25) kg. Body, testicular, and epididymal weights of each goat with other related size measurements were estimated. ESC was determined from homogenized tissue using a manual cytometer. At the cut-off ESC of >1.1 × 10(9) sperm heads, 66 (52.80%) of the goats had optimal ESC which was associated with testicular weight of 59.90 ± 16.10 (31.40-86.20) g, gonadosomatic index of 3.51 ± 0.69 (2.00-4.50) g/kg, and scrotal circumference of 19.07 ± 1.29 (17.00-21.80) cm. The size variables of the scrotum and testis correlated with one another and with the ESC. These findings provide data that may be used to anticipate adequate antemortem sperm reserve based on testicular size during preliminary selection of sires for breeding from a sexually mature Sahel buck population.

Effect of prolonged oral administration of aqueous ficus sycomorus stem-bark extract on testicular size of growing albino rat / Efecto de la administración oral prolongada de extracto acuoso de la corteza de ficus sycomorus en el tamaño testicular de rata albina en crecimiento

Decoction of Ficus sycomorus stem bark is used to treat infertility involving low sperm counts, but the reproductive risk associated with its use is uncertain. The aqueous stem-bark extract was orally administered at 200-600 mg/kg for 30 days to post-pubertal growing albino rats. Within the period, the live body weights, scrotal diameters and testicular size parameters were estimated. The mean live body weight, scrotal diameter of the control and treated rats significantly (p<0.05) increased as the animals grew, but the treatment did not significantly (p>0.05) affect the parameters. There were no significant (p>0.05) variations in mean testicular size parameters in treated and control rats, and no dose-dependent nor time-dependent effects occurred. Sections of the testes of the treated animals showed active spermatogenesis in the seminiferous tubules with no apparent histological lesions. It is concluded that the use of the crude extract of the Ficus sycomorus within our dose range portends minimal male reproductive risk and underscores the need to study its pro-spermatic effect.

La decocción de la corteza del tallo de Ficus sycomorus se usa para tratar la infertilidad relacionada al bajo conteo de espermatozoides, pero es incierto el riesgo reproductivo asociado con su uso. El extracto acuoso de la corteza se administró, en ratas albinas, por vía oral, en una dosis de 200-600 mg/kg, durante 30 días post-crecimiento puberal. Durante el período, fueron controlados los siguientes parámetros: peso corporal in vivo, diámetro escrotal y tamaño testicular. El promedio de peso corporal in vivo y diámetro escrotal de las ratas control y tratadas, tuvieron un incremento significativo (p<0,05) en los animales, pero el tratamiento no afectó significativamente (p> 0,05) esos parámetros. No hubo variaciones significativas (p> 0,05) en la media de los parámetros tamaño testicular en las ratas tratadas y control, ni tampoco se produjeron efectos dependientes de la dosis, ni en función del tiempo. Las secciones de los testículos de los animales tratados mostraron una espermatogénesis activa a nivel de los túbulos seminíferos, sin lesiones histológicas aparentes. Se concluye, que el uso del extracto crudo de Ficus sycomorus, dentro de una dosis de 200-600 mg/kg, presenta mínimo riesgo en la reproducción masculina, sin embargo, se hace necesario estudiar su efecto pro-espermático.

Unilateral cryptorchidism in Nigerian sahel bucks / Criptorquidia unilateral en cabras sahel nigerianas

Out of 1608 Nigerian Sahel male goats (bucks) examined for cryptorchidism in an abattoir, 9 (0.6 percent) had right unilateral cryptorchidism. The coat colour-specific prevalence was highest among the brown bucks (2.1 percent); and was 0.8 percent, 0.6 percent, and 0.3 percent among black, white, back-and-white bucks, respectively. The condition was not found among bucks with brown-and-black, brown-and-white, and multiple coat colours. The right and left testes of normal bucks and the descended testes of cryptorchid bucks had comparable gross testicular measurements, but the retained cryptorchid testes were smaller in size. The estimates of the testicular measurements showed that testicular weights (with the entire epididymes), peripheral longitudinal lengths and mid-circumferences of the cryptorchids were reduced by 5.8-6.5, 1.8-1.9, and 1.7-1.8 folds, respectively, when compared with the normal values; an indication that reduction in weight was the most remarkable index of change in testicular size. In 2 cases (20 percent), cryptorchid testes were at a subcutaneous location, embedded in a subcutaneous fascia in the ventral perineal region, while in the other 8 cryptorchid cases (80 percent), the testes were in the abdomen. Histopathological changes in the cryptorchid testes included hypoplasia, degeneration, interstitial non-suppurative inflammation and fibroplasia. This is the first report of cryptorchidism in the Sahel goat and the first evidence that cryptorchid testis may be located subcutaneously in the goat.

De las 1608 cabras Sahel Nigerianas macho examinadas para criptorquidismo en un matadero, 9 (0,6 por ciento) tuvieron criptorquidia unilateral derecha. La prevalencia en relación al color específico del pelaje fue mayor entre las cabras marrones (2,1 por ciento), y fue de 0,8 por ciento, 0,6 por ciento y 0,3 por ciento entre cabras de color negro, blanco, y blanco/negro respectivamente. La condición no fue encontrada entre las cabras con pelajes marrón y negro, marrón y blanco, y pelajes de múltiples colores. Los testículos derecho e izquierdo de las cabras normales y los testículos descendentes de las cabras con criptorquídia tuvieron mediciones testiculares comparables, pero los testículos retenidos por criptorquídia fueron de menor tamaño. Las estimaciones de las mediciones testiculares mostraron que los pesos testiculares (con todo el epidídimo), la longitud periférica y la circunferencia media de las criptorquídicas fueron reducidas por 5,8-6,5; 1,8-1,9 y 1,7-1,8 pliegues respectivamente, en comparación con el los valores normales; una indicación que la reducción de peso fue el índice de cambio más notable en el tamaño testicular. En 2 casos (20 por ciento), los testículos criptorquídicos se encontraron en una ubicación subcutánea, inmersos en una fascia subcutánea en la región perineal ventral, mientras que en los otros 8 casos criptorquídicos (80 por ciento), los testículos fueron encontrados en el abdomen. Cambios histopatológicos en los testículos criptorquídicos incluyeron hipoplasia, degeneración, inflamación intersticial no supurativa y fibroplasia. Este es el primer informe de criptorquidia en cabras Sahel y la primera evidencia de que los testículos criptorquídicos pueden ser localizados por vía subcutánea en la cabra.

Diminazene aceturate resistance on the virulence of Trypanosoma brucei for rats.

Four groups (A, B, C and D) of 10 naïve rats were used to compare the virulence of isolates of a strain of Trypanosoma brucei before and after the development of diminazene aceturate resistance. Group A rats were uninfected (controls). Group B rats were infected with a trypanosome isolate unexposed to the drug, while groups C and D rats were infected with two different drug-resistant isolates of the same strain. Rats in the three infected groups each received 10(6) trypanosomes intraperitoneally. Prepatent periods were longer (P<0.05) in groups C and D than in group B. The parasitaemic periods in groups B, C and D were similar, but group C and D rats differed from group B rats in surviving longer, and in showing lower degrees of parasitaemia, anaemia and hepatomegaly. No differences were noted between group C and D rats. Thus, diminazene aceturate resistance appeared to reduce the virulence of T. brucei.

The pathogenicity of diminazene aceturate-resistant Trypanosoma brucei in rats after treatment with the drug.

Four groups (A, B, C and D) of 10 rats were used to determine the effect of comparatively high doses of diminazene aceturate on diminazene aceturate-resistant Trypanosoma brucei and the pathogenic effect of relapse infection. Group A rats were uninfected (controls) while group B, C and D rats were inoculated intraperitoneally with 0.5 x 10 (6) diminazene aceturate-resistant T. brucei and treated with diminazene aceturate at 14.0, 17.5 and 21.0mg/kg body weight, respectively, on day 14 post-infection (PI) as a single intraperitoneal injection. Prepatent periods and also levels of parasitaemia were comparable in groups B, C and D. Packed cell volume (PCV) decreased in the infected groups by day 14 PI and returned to pre-infection values by day 63 post-treatment (PT). Anaemia was comparable in groups B, C and D. Relapse parasitaemia occurred in six rats in group B on day 70 PT and in five rats in each of groups C and D on day 77 PT. The PCV of the rats with relapse infection decreased progressively up to day 105 PT, when the experiment was terminated, whereas the PCV of rats without relapse did not. The levels of anaemia and parasitaemia on day 14 post-relapse were significantly higher (P<0.05) than the levels obtained on day 14 PI in the same animals. Thus, comparatively high doses of diminazene aceturate failed to cure drug-resistant T. brucei infection in 50-60% of infected rats and relapse infections were more severe than the primary infections before treatment.

Effects of combined parenteral vitamins C and E administration on the severity of anaemia, hepatic and renal damage in Trypanosoma brucei brucei infected rabbits.

Rabbits infected with Trypanosoma brucei brucei (Basa isolate) were intraperitoneally administered with vitamins C and E at 100 mg/kg and 10 mg/kg body weight, respectively, from day 7 before infection to day 12 post-infection (p.i.). Another group of rabbits were similarly infected, but received no vitamin treatment. The uninfected (control) rabbits were either untreated or treated with vitamins like the infected group. Treatment of the infected animals did not affect the onset and level of parasitaemia. On day 12 p.i., the anaemia tended to be ameliorated, but insignificantly, by the treatment. The infection increased (p<0.05) serum urea and creatinine concentrations to similar levels in treated and untreated groups. However, the increase (p<0.05) in alanine and aspartate transaminases in the untreated infected animals was prevented in the treated infected ones. Therefore, it seemed that the treatment with antioxidant vitamins boosted their storage in hepatic cells, but not in erythrocytes and glomeruli, to annul any cellular injury due to infection. It is concluded that this may be an indirect evidence that the hepatic damage may be principally due to oxidative injury.

Fasting hyperglycaemia with oral glucose tolerance in acute Trypanosoma congolense infection of rats.

Intraperitoneal inoculation of rats with Trypanosoma congolense (Federe strain) produced a sustained parasitaemia from days 7 to 23 post-infection (pi). The fasting tail-blood glucose (FBG) concentrations in the infected animals increased (p<0.05) from 3.8+/-0.2 mmol/l on day 0 pi to 4.6+/-0.2, 4.9+/-0.2 and 5.8+/-0.3 mmol/l on days 7, 10 and 17 pi and decreased (p<0.05) to 3.1+/-0.8 and 2.9+/-0.7 mmol/l on days 20 and 23 pi, but the values in the uninfected controls varied between 3.8+/-0.3 mmol/l on day 0 pi and 3.9+/-0.2 mmol/l on day 23 pi. After oral glucose intake (1.0 g/kg) and determination of tail-blood glucose (BG) concentrations after 2 h, the percentage increase in BG from FBG was either comparable in infected and uninfected groups (days 7, 20, 23 pi) or lower (p<0.05) in the infected group (days 10, 17), suggesting the same rate of tissue glucose delivery in both groups or a faster rate in the infected group. Therefore, oral glucose tolerance in the infected rat was not impaired, but there was initial fasting hyperglycaemia followed by fasting hypoglycaemia in the later stage.

Increased severity of acute Trypanosoma brucei brucei infection in rats with alloxan-induced diabetes.

Twenty rats were made diabetic by treatment with alloxan monohydrate (10% solution, 100 mg/kg body weight). Ten diabetic and ten non-diabetic rats were intraperitoneally infected with the same infective doses of Trypanosoma brucei brucei (Lafia strain). The uninfected controls were ten diabetic and ten non-diabetic rats. The prepatent period was shorter in the diabetics (3.5 +/- 0.5 days) than the non-diabetics (4.2 +/- 0.4 days). Although the infected diabetic and non-diabetic rats had comparable levels of peak parasitaemia, the diabetics had significantly (P < 0.05) higher parasitaemia before this peak. The survival time was shorter (P < 0.05) for the infected diabetics (12.1 +/- 3.2 days) than for the infected non-diabetics (14.8 +/- 1.7 days). The infection did not affect the level of diabetic hyperglycaemia, but caused a more severe anaemia in the diabetics than the non-diabetics, with the percentage decreases in packed cell volume in the diabetics being higher (P < 0.05) from days 3 to 12 post-infection. In conclusion, the pathogenic effects of trypanosome infection may be more severe in rats having alloxan-induced diabetes.

Effects of acute bovine trypanosomosis (Trypanosoma vivax) on plasma kinetics of intravenously administered lactose.

Four calves infected with Trypanosoma vivax and four uninfected control calves were each injected intravenously with repeated doses of 0.5 g lactose kg-1 body weight, thrice daily at intervals of 4 h. Plasma samples were collected at specified time intervals and analysed for lactose. Pharmacokinetic parameters were calculated from the data. T. vivax infection delayed excretion of lactose from the body, thus leading to significantly (P < 0.001) increased biological half life (t1/2) and a significantly (P < 0.001) reduced elimination rate constant for lactose in the body. The apparent volume of distribution and total clearance of lactose were not affected by the infection. T. vivax infection also appeared to cause accumulation of lactose in the plasma after repeated intravenous administration.

Fasting hyperglycaemia and impaired oral glucose tolerance in acute Trypanosoma brucei infection of rats.

Trypanosoma brucei (Federe strain) produced all acute infection in rats given 10(6) parasites intraperitoneally. Parasitaemia, which first appeared at 2 days post-infection (pi), was heavy from day 5 until death at 8 to 12 days pi. The fasting tail-blood glucose (FBG) concentrations in the infected rats increased significantly (P<0.05) from 2.73+/-0.14 mmol/l on day 0 pi to 6.21+/-0.16 mmol/l and 5.93+/-0.33 mmol/l on days 5 and 8, respectively. However, the values had decreased in most of the rats on day 11 pi, at which time 4 out of 12 had less than 0.5 mmol/l. The mean FBG showed a quadratic relationship with the duration of infection and the fitted curve had a high goodness of fit (r2=0.98). Oral glucose tolerance was impaired in the infected rats on days 5, 8 and 11 pi. Tail-blood glucose concentration was determined 2 h after the intake of glucose (1.0 g/kg). The mean percentage increases in blood glucose from the FBG concentrations were significantly (P<0.05) higher in the infected than in uninfected rats. There was a positive correlation (r=1.0) between the mean percentage increases and the duration of infection. It seems probable, therefore, that the delivery of glucose into the tissues was reduced, with other metabolic implications likely to affect the pathogenesis of the disease.

Lack of correlation of anaemia with splenomegaly and hepatomegaly in Trypanosoma brucei and Trypanosoma congolense infections of rats.

Isolates of Trypanosoma brucei and Trypanosoma congolense from the blood of cattle were used to infect growing rats. Despite the use of similar infective doses, T. brucei parasitaemia appeared earlier than T. congolense parasitaemia. After the same period of parasitaemia, the degrees of anaemia, splenomegaly and hepatomegaly were similar in both infections. The percentage decrease in packed cell volume was not correlated with splenic and hepatic weights. Neither infection significantly affected the weight gain of the rats. It was concluded that both organisms caused diseases of comparable severity and that the mere enlargement of the spleen and liver made no significant contribution to the development of the anaemia.

Effect of acute Trypanosoma vivax infection on cattle erythrocyte glutathione and susceptibility to in vitro peroxidation.

During acute Trypanosoma vivax infection of calves, produced by intravenous inoculation, the mean packed cell volume and red blood cell counts of the infected animals decreased significantly (P < 0.05) between Days 6 and 13 post-infection (pi). The moderately severe normocytic anaemia started to develop during the first wave of parasitaemia which occurred from Day 2 pi and peaked between Days 4 and 5 pi. The mean erythrocyte glutathione (GSH) concentration of the infected calves decreased significantly (P < 0.05) from 58.4 +/- 11.4 mg 100ml-1 red blood cells (RBC) on Day 0 pi to 44.5 +/- 12.8 mg 100ml-1 RBC on Day 5 pi. As the GSH values recovered on Day 6 pi and increased thereafter, another slight decrease (P > 0.05) in GSH concentration occurred on Day 12 pi at the second peak of parasitaemia followed by a significant (P < 0.05) increase to 79.1 +/- 14.6 mg 100ml-1 RBC on Day 13 pi. In the uninfected calves, the mean GSH values ranged from 47.7 +/- 7.0 to 60.8 +/- 6.8 mg 100ml-1 RBC. When washed, erythrocytes of the infected and uninfected calves were separately challenged with hydrogen peroxide. They produced comparable amounts of thiobarbituric acid reactive substances as a measure of by-products of lipid peroxidation. This suggested that the ability of the erythrocytes to prevent peroxidative injury was not reduced, because GSH regeneration was probably enhanced and the antioxidant capacity of the erythrocytes was maintained.

Outbreak of infectious bursal disease associated with acute septicaemic colibacillosis in adult prelayer hens.

An outbreak of infectious bursal disease (IBD) occurred concurrently with acute septicaemic colibacillosis in 15 week old prelayer hens. The septicaemia was preceded by a subclinical IBD. Mortality in the outbreak began with lesions of septicaemia and Escherichia coli was isolated from the heart blood of the birds. After antibiotic treatment of the bacteraemia, mortality continued, spiked, declined and then ceased. IBD was confirmed by bursal lesions characterized by severe lymphocytolysis and cystic degeneration of the lymphoid follicles. Out of 253 birds, 42 (16.60%) died within eight days. The circumstances of the outbreak suggested that lack of IBD booster vaccination favoured the establishment of subclinical IBD, which suppressed immunity to predispose the birds to colisepticaemia.

Increased susceptibility of erythrocytes to in vitro peroxidation in acute Trypanosoma brucei infection of mice.

Trypanosoma brucei, Wamba strain, produced an acute infection in mice, and mortality was observed 2 days after the onset of parasitaemia which occurred 3-5 days postinfection. Anaemia was observed in the tail blood of the survivors. When washed erythrocytes from the heart blood were incubated in physiological saline containing 1.5% hydrogen peroxide, the erythrocytes of the infected mice produced significantly greater amounts of by-products of lipid peroxidation (measured as thiobarbituric acid reactive substances) than the erythrocytes of the control mice. This observation suggested that the infected mice may have a reduced ability in the prevention of free radical mediated lipid peroxidation in the erythrocyte membrane. It is concluded that peroxidative injury to the erythrocytes may contribute to the pathogenesis of anaemia in trypanosomosis.

Some plasma biochemical changes in experimental Trypanosoma brucei infection of Sokoto Red goats.

Plasma biochemical changes were studied for 8 consecutive weeks in Sokoto Red goats experimentally infected by intravenous route injection of 1.6 x 10(7) Trypanosoma brucei. The strain 8/18 was highly infective. The mean packed cell volume significantly decreased from 1 to 8 weeks post-infection (PI) at P < 0.05. During this period, the mean plasma total bilirubin concentrations significantly increased (P < 0.05). The mean plasma direct and indirect bilirubin concentrations significantly increased from 2 to 8 weeks PI (P < 0.05). The mean plasma albumin concentrations did not vary significantly (P > 0.05), but the mean total plasma proteins and mean plasma globulin concentrations significantly increased between 5 and 8 weeks post infection (P < 0.05). There were no significant changes in the mean plasma bicarbonate, creatinine and cholesterol concentration (P > 0.05).