Evaluation of the effectiveness of two infectious bronchitis virus vaccine programs for preventing disease caused by a California IBV field isolate

Infectious bronchitis virus CA99 serotype was isolated from several broiler flocks in Northern California. The virus caused late-onset respiratory disease and increased airsacculitis condemnation in affected flocks despite the use of an established infectious bronchitis virus vaccination program. An experimental study compared Holland/Arkansas and Massachusetts/Arkansas vaccination protocols to determine the efficacy of commercial infectious bronchitis virus vaccines in reducing respiratory disease and airsacculitis lesions found at processing that were associated with a CA99 field isolate. All vaccination groups were given Massachusetts/Connecticut strains of infectious bronchitis virus vaccines at age 1 day followed by vaccination with either Holland/ Arkansas or Massachusetts/Arkansas vaccine strains at 18 days of age. Birds were challenged at age 31 days with a CA99 field isolate. Gross pathology, histopathology, and virus isolation were evaluated. Chickens vaccinated with Holland/Arkansas had marginally better protection against CA99 challenge than chickens vaccinated with Massachusetts/Arkansas, although differences were not statistically significant.     

Feline leucocyte antigen class II polymorphism and susceptibility to feline infectious peritonitis

There are four outcomes to feline coronavirus (FCoV) infection: the development of feline infectious peritonitis (FIP, which is immune-mediated), subclinical infection, development of healthy lifelong carriers and a small minority of cats who resist infection (Addie and Jarrett, Veterinary Record 148 (2001) 649). Examination of the FCoV genome has shown that the same strain of virus can produce different clinical manifestations, suggesting that host genetic factors may also play a role in the outcome of infection. FIP is most prevalent amongst pedigree cats, although how much of this is due to them living in large groups (leading to higher virus challenge and stress which predisposes to FIP) and how much is due to genetic susceptibility is not known. If host genetics could be shown to play a role in disease, it may allow the detection of cats with a susceptibility to FIP and the development of increased population resistance through selective breeding. The feline leucocyte antigen (FLA) complex contains many genes that are central to the control of the immune response. In this preliminary study, we used clonal sequence analysis or reference strand conformational analysis (RSCA) to analyse the class II FLA-DRB of 25 cats for which the outcome of FCoV exposure was known. Individual cats were shown to have between two and six FLA-DRB alleles. There was no statistically significant association between the number of alleles and the outcome of FCoV infection. No particular allele appeared to be associated with either the development of FIP, resistance to FCoV, or the carrier status. However, the analysis was complicated by apparent breed variation in FLA-DRB and the small number of individuals in this study.     

Evaluation of the Lime-Cooking and Tortilla Making Properties of Quality Protein Maize Hybrids Grown in Mexico

Eleven experimental and three commercial white quality protein maize (QPM) hybrids and two regular endosperm controls were planted at Celaya, Guanajuato, Mexico with the aim of comparing grain physical characteristics, protein quality, lime-cooking and tortilla making properties. All genotypes were planted under irrigation using a density of 80,000 plants/ha and fertilized with 250 kg N-60 P-60 K per hectare. When compared with the controls these QPM genotypes had lower test (77.4 vs. 76.5 kg/hL) and 1,000 kernel weights (327 vs. 307 g), softer endosperm texture (2.5 vs. 1.8 where 1 = soft, 2 intermediate and 3 hard endosperm), lower protein (10.0 vs. 8.0%), higher nixtamal water uptake after 30 min lime-cooking (50.0 vs. 53.1% moisture) and lower pericarp removal scores. The lower thousand-kernel weight and softer endosperm texture observed in the QPM genotypes lowered the optimum lime-cooking time as estimated with regression equations. Most QPM genotypes had higher amounts of lysine, tryptophan and albumins/globulins when compared with the controls. QPMs HEC 424973, HEC 774986 and HEC 734286 had the best grain traits for nixtamalization and therefore the best potential for industrial utilization. The commercial use of these QPM hybrids should benefit Mexicans who depend on tortillas as the main staple.     

Biosorption kinetics of Cu (II) ions removal from aqueous solution using bacteria

The present study highlights the effective removal of Cu (II) ions from synthetic solution using bacteria such as B. subtilis, P. aeruginosa and E. cloacae. Batch biosorption studies show that the biosorption of B. subtilis is effective when the concentration ranges from 25-200 mg L(-1). Biomass dosage, pH and the initial metal ion concentration have a profound effect on the biosorption process and this is reported in this study. In order to understand the nature of the biosorption process, Langmuir and Freundlich isotherm models were applied. Pseudo first and second order models were used to study the biosorption kinetics. The results show that these bacterial strains are very much suitable for the removal of Cu (II) ions. Being cost effective and efficient in toxic metal ion removal, these bacteria can be used on a large scale.     

Risk factors associated with porcine cysticercosis in selected districts of Eastern and Southern provinces of Zambia

To determine the risk factors associated with Taenia solium transmission in humans and pigs in the rural areas of Eastern and Southern provinces of Zambia, a questionnaire was administered in 788 households from 155 villages. Pigs were examined from 800 households. Tongue examination and enzyme-linked immunosorbent assay (Ag-ELISA) for the detection of circulating antigens of T. solium cysticerci were used to measure infection in pigs. A snowballing technique was utilised to select households with pigs. Prevalence of households with pigs infected with T. solium on tongue examination by district ranged from 12.7% to 32.1% with Ag-ELISA having a range of 30.0-51.7%. Of the total number of households visited, 18.8% and 37.6% had at least one pig positive for porcine cysticercosis on tongue examination and Ag-ELISA, respectively. Risk factors associated with T. solium infection were lack of pork inspection at slaughter (96.7%), consumption of pork with cysts (20.1%), selling of pork infected with T. solium cysticerci (18.3%), free-range husbandry system (83.2%) and absence of latrines (58.0). Free-range husbandry system (OR=1.68; 95% CI=1.36-2.07) was a significant risk factor for porcine cysticercosis in the surveyed areas. The result that pigs were mostly kept on free-range and semi-intensive husbandry systems may have permitted them to have access to eating human faeces that could be contaminated with tapeworm eggs. This study has shown that T. solium infection poses a high public health risk in the study areas and urban areas as well. We recommend that a human survey be conducted to verify the human exposure to taeniasis and/or cysticercosis in Zambia.     

Normal ranges and temporal variation in plasma concentrations of L-lactate and free amino acids in adult sheep

To determine baseline variation in blood plasma concentrations of free amino acids and l-lactate, samples were collected at a single time point from nine flocks of different breeds of ewes at a common physiological stage and monthly from one flock of crossbred mule ewes over a 12 month period. Significant differences were detected between time points in the concentrations of all plasma metabolites. With few exceptions prion protein genotype had no significant effect on the plasma metabolite concentrations measured.     

Idiopathic granulomatous pneumonia in seven horses

The history, clinical signs and pathological findings in seven adult horses with histologically confirmed idiopathic granulomatous disease, primarily of the lungs, are reviewed. They ranged in age from eight to 21 years, five were geldings and two were females, they belonged to five breeds and there were no seasonal or geographical associations. The primary clinical signs were chronic weight loss, exercise intolerance and respiratory distress which did not respond to conventional treatment. The most consistent physical findings were depression, anorexia, tachycardia, tachypnoea and adventitious lung sounds. Thoracic radiographs revealed a diffuse, structured, nodular, interstitial pulmonary pattern in each horse. Haematological measurements suggested a chronic inflammatory process and the cytology of transtracheal washes was consistent with a mild suppurative inflammation. Idiopathic granulomatous pneumonia was confirmed histologically in each of the horses, either postmortem or by a lung biopsy. The horses responded poorly to medical treatment and only one of three treated horses is still alive.     

Effects of training on potassium homeostasis during exercise and skeletal muscle Na+,K(+)-ATPase concentration in young adult and middle-aged Dutch Warmblood horses

OBJECTIVE: To investigate the effects of moderate short-term training on K+ regulation in plasma and erythrocytes during exercise and on skeletal muscle Na+,K(+)-ATPase concentration in young adult and middle-aged horses. ANIMALS: Four 4- to 6-year-old and four 10- to 16-year-old Dutch Warmblood horses. PROCEDURE: The horses underwent a 6-minute exercise trial before and after 12 days of training. Skeletal muscle Na+,K(+)-ATPase concentration was analyzed in gluteus medius and semitendinosus muscle specimens before and after the 12-day training period. Blood samples were collected before and immediately after the trials and at 3, 5, 7, and 10 minutes after cessation of exercise for assessment of several hematologic variables and analysis of plasma and whole-blood K+ concentrations. RESULTS: After training, Na+,K(+)-ATPase concentration in the gluteus medius, but not semitendinosus, muscle of middle-aged horses increased (32%), compared with pretraining values; this did not affect the degree of hyperkalemia that developed during exercise. The development of hyperkalemia during exercise in young adult horses was blunted (albeit not significantly) without any change in the concentration of Na+,K(+)-ATPase in either of the muscles. After training, the erythrocyte K+ concentration increased (7% to 10%) significantly in both groups of horses but did not change during the exercise trials. CONCLUSIONS AND CLINICAL RELEVANCE: In horses, the activation of skeletal muscle Na+,K(+)-ATPase during exercise is likely to decrease with age. Training appears to result in an increase in Na+,K(+)-ATPase activity in skeletal muscle with subsequent upregulation of Na+,K(+)-ATPase concentration if the existing Na+,K(+)-ATPase capacity cannot meet requirements.     

Control of landing flight by laying hens: implications for the design of extensive housing systems

(1) Ten domestic hens (Lohmann Brown) were video-recorded while moving between perches at a horizontal distance of 0.6, 0.8 or 1.15 m apart. The take-off perch was either 0.2 m above or below the landing perch. (2) Weight and wing area of the hens were measured at the end of the experiment. The same measures where taken from 10 jungle fowls. (3) Clumsy or missed landings were observed on some downward flights over 0.8 and 1.15 m. (4) Hens' trajectories on take-off were closely related to the position of the target perch, and variation in take-off trajectory decreased as the distance between perches increased. (5) The standard deviation of the horizontal distance between head and perch, at the point when the feet first contacted the perch, did not vary with flight distance, suggesting that timing of foot extension was equally accurate at all distances. (6) The standard deviation of the vertical distance between head and perch, at the point when the feet first contacted the perch, did increase with distance, suggesting increasing difficulty in controlling the height of the flight trajectory above the landing perch. (7) Wing loading of the hens (mean 213 N/m2) was approximately twice that of the jungle fowl (mean 111 N/m2). (8) Loss of accuracy in hens' landings at greater distances can be attributed specifically to the effects of high wing loading on the ability to generate and control lift.