The effect of adjuvants on active and passive immunity in pregnant deer and their offspring.

Experiments were carried out to determine the effects of a range of adjuvants on immunoglobulin M (IgM) and immunoglobulin G (IgG) serum concentrations to a protein antigen administered subcutaneously to farmed female deer following mating. The antibody responses of animals immunised with keyhole limpet hemocyanin (KLH) in Freund's Incomplete Adjuvant (FIA), diethylaminoethyl dextran (DEAE-dextran) and aluminium hydroxide (alum) were compared with the response to antigen administered in the absence of adjuvants. Animals were subsequently challenged with a subcutaneous immunisation of the antigen in saline. Following parturition, the concentration of passively transferred antigen-specific antibody was measured in the serum of the offspring. The polyionic adjuvant, DEAE-dextran, produced the greatest enhancement of both primary and secondary IgG responses to KLH. Offspring suckling from mothers immunised with antigen in DEAE-dextran consequently had higher concentrations of specific antibodies in their serum than other fawns in the experiment. The adjuvants FIA and alum were approximately 20-fold less effective in enhancing antigen-specific IgG than DEAE-dextran but induced greater amounts of antigen-specific IgM. From the results presented in this paper, there is evidence that immunisation of deer during pregnancy may be an effective way of reducing morbidity in both mothers and offspring.     

The prevalence of feline A/B blood types in the Sydney region

OBJECTIVE: To determine the distribution of A/B blood types in pedigree and crossbred cats in the Sydney region, and to estimate the associated risk of administering incompatible blood in an unmatched random transfusion. DESIGN: A prospective/retrospective study of blood specimens collected from both sick and healthy cats. MATERIALS AND METHODS: Blood was collected from 355 cats from the Sydney region over a 12-year period from 1992 to 2003. Specimens were obtained from 187 domestic crossbred cats (short and long-haired) and 168 pedigree cats. The blood type of each cat was determined by one of three different laboratories using standard methods that varied over the duration of the survey. RESULTS: The distributions of blood types obtained by the three laboratories were not significantly different. The prevalence of type-A, type-B and type-AB blood types in crossbred cats was 62%, 36% and 1.6%, respectively. This is the highest percentage of type-B cats so far reported for an outbred population of domestic cats, and is significantly higher than the 26% reported previously for cats in the Brisbane region. The calculated frequency for the type-B allele assuming Hardy-Weinberg equilibrium for this feline population is 0.60; the corresponding frequency of the type-A allele is thus approximately 0.40. The calculated proportion of random transfusions from this population giving rise to an incompatible blood transfusion is 46%, with half of these being life-threatening events. The calculated proportion of random matings from this population at risk for developing neonatal isoerythrolysis is 23%. The distribution of A and B blood types for pedigree cats was in general agreement with data reported previously for cats in North America and Europe, suggesting that the distribution of blood types in these purebred populations is relatively consistent throughout the world. CONCLUSIONS: The prevalence of type B cats in the owned domestic and pedigree cat population is so high that blood typing or cross matching prior to transfusion should be mandatory, except in Siamese/Oriental cats.     

Factors associated with the presence of Escherichia coli O157 in feedlot-cattle water and feed in the Midwestern USA

Our objective was to generate hypotheses about associations between management, climate, and the presence of Escherichia coli O157 in feedlot–cattle water tanks and in feedlot–cattle feed. Water samples from 710 tanks on 73 feedlots, and feed-samples from a subset of 504 pens on 54 feedlots, in four US states were tested for E. coli O157. Management and climate factors were ascertained by survey and observation. Escherichia coli O157 were isolated from 13% of the water tanks and at least one water tank was positive on 60% of the feedlots. The factors significantly associated with E. coli O157 in water were greater percentage of cattle shedding E. coli O157 in faeces within the same pen, higher concentration of total E. coli in the water, lack of the clarity of the water, the use of fly traps, the reported frequency of rodent sightings in the pen or alley area, and the weather at the time of sampling. Escherichia coli O157 were isolated from 14.9% of the feed samples obtained from the feedbunks. Factors positively associated with E. coli O157 in feed were higher heat index at the time of sampling, the presence of cottonseed meal in the ration, and the feedlot location (state). Coliform counts in feed, presence of E. coli O157 in water tanks and faecal prevalence of E. coli O157 were not associated with the presence of E. coli O157 in feed.     

Food intake of normal and internal layers: a question of energy balance

1. Normal adult laying hens, which produced 41 g egg/hen d, ate 30 g/hen d more of a pelleted diet than did hens of the same age which were induced to lay eggs internally by surgical treatment of their oviducts. This implied that 0.336 MJ metabolised energy was required to produce 0.251 MJ egg, or 75% efficiency of utilisation of ME. 2. This may not have represented the true cost of egg production because both normal and internal layers gained weight during testing, at slightly different rates, suggesting that they did not regulate energy balance precisely. 3. The internal layers were less active and also saved energy by resorbing egg material. Their greater body weight was due to unresorbed eggs and to heavier fat deposits, which were accompanied by higher concentrations of lipid in the blood. 4. It was estimated that internal layers ate 4 to 5% more per day than was required to maintain the same lipid status as normal layers; these data provide further evidence that poultry do not regulate their food intake precisely by energostatic or lipostatic means.     

The relationship of calfhood morbidity with survival after calving in 25 New York Holstein herds

The association of owner-diagnosed calfhood diseases with the length of herd life after calving was evaluated using data collected prospectively over a ten-year period in 25 New York Holstein dairy herds. Herds selected for the study were milking between 35 and 200 Holstein cows, used dairy herd improvement records, bred cows by artificial insemination unless they needed three or more services, and had regularly-scheduled herd health visits by clinicians from the Cornell University College of Veterinary Medicine. Owners recorded occurrences of dullness, respiratory disease, and scours from birth through 90 days of age for all heifer calves that lived at least 24 h and were to be kept as replacements. Milking herd life was measured as the difference between the age at first calving and the age at death or sale. Data on cows sold when the herd went out of business or still in the herd at the end of the study were censored observations. Cox's proportional hazards model was used for statistical analysis of the data. Controlling for age at first calving, study month of birth, and sire predicted difference for milk, there was no statistically significant association of calfhood morbidity with length of herd life. The estimated hazard rate ratios for leaving the milking herd and 95% confidence intervals for dullness, respiratory disease, and scours within 90 days of birth were 1.3 (0.9, 1.9), 0.9 (0.6, 1.3), and 1.0 (0.8, 1.3), respectively. Dullness was the only disease category with an estimated hazard rate ratio greater than 1, and although it was not statistically significant, may warrant evaluation in future studies of long term effects of calfhood morbidity.     

The ACVD task force on canine atopic dermatitis (I): incidence and prevalence.

There is an increasing incidence of atopic diseases (asthma, allergic rhinitis and atopic dermatitis) in humans, especially in developed countries. Although there is a genetic predisposition to the development of these diseases, the rapid rise in incidence is suspected to be caused by environmental rather than genetic factors. Neither the incidence nor the prevalence of atopic dermatitis in the general canine population has been studied. As many of the environmental factors associated with the increasing incidence of atopic dermatitis in humans are consistently found in the environment of dogs, it would seem likely that a similar increase in the incidence of this disease would be occurring also in dogs. Epidemiological studies of canine atopic dermatitis are needed to characterize the incidence and prevalence of atopic dermatitis, and to further study the factors that contribute to the development of this disease.     

Bacillus piliformis infection in an adult dog

Bacillus piliformis infection (Tyzzer's disease) was diagnosed in a 7-year-old spayed dog that had icterus, hepatosplenomegaly, and polyuria. Hematology revealed regenerative anemia, leukocytosis, lymphopenia, and thrombocytopenia. Serum chemical analyses indicated hypocalcemia, high alkaline phosphatase activity, hypoalbuminemia, and hyperglobulinemia. At necropsy, the liver was stippled with gray-white focal lesions. Microscopically, the liver lesions were necrotic and inflammatory. Warthin-Starry-stained sections revealed rod-shaped bacteria in crisscrossing patterns characteristic of B piliformis. This dog was considerably older than dogs previously reported to have Tyzzer's disease and had a concurrent systemic hyphomycosis, suggesting it had been immunocompromised.     

Development of a method for the identification, using the polymerase chain reaction, of Aspergillus fumigatus isolated from ostriches

Objective To develop a method for identifying DNA of Aspergillus fumigatus from ostriches, using the polymerase chain reaction (PCR). A fumigatus is the principal causative agent of avian aspergillosis.
Design A biochemical trial.
Sample population Twelve Aspergillus fumigatus isolates and three other Aspergillus species.
Procedure PCR primers that were based on the sequence of the alkaline protease gene from human isolates of A fumigatus were used.
Results We successfully tested the method on ostrich isolates from five states and showed that the test is specific for A fumigatus.
Conclusions In most cases the DNA sequence of A fumigatus isolates from ostriches is similar to that of human isolates. DNA sequences vary significantly among A fumigatus isolates, including those from affected ostriches in the same flock. The genetic variation may be used to trace aspergillus infections in ostrich flocks and determine if the disease is transmitted by contact with infected birds.     

Economic Evaluation of Different Stocking Densities for Various Sized in Texas

There has been a trend toward intensification of shrimp farming in the U.S. FiCteen simulated farms were used to evaluate economies of scale and to compare three Penaeus vannclmei commercial production strategies: semi-intensive, intensive, and very-intensive. Large economies of scale were associated with each production strategy. Over the range of farm sizes considered, investment cost per hectare decreased approximately 50% and production cost decreased approximately 25%. Farms' returns were measured with Internal Rate of Return (IRR). When investment was greater than $0.75 million, the intensive strategy provided slightly better returns to the investor than semi-intensive or very-intensive strategies. At investment levels less than $0.75 million, the semi-intensive strategy provided the highest IRR.