Gross Morphometry of the Bovine Placentome during Gestation

Forty-seven pregnant uteri were collected from an abattoir at eight chronological stages of gestation. Assessments were made of placentome number, weight, length shape and ratio of foetal to maternal tissue by weight. The study showed that there was a great variation in number, size, weight and shape of placentomes. There was no significant change in the total number of placentomes during gestation. Both mean weight and length increased significantly during gestation, but there was a significant change in the relationship between the two as gestation progressed. There was no correlation between the number of placentomes and the mean weight or length of the placentomes. The development of the placenta in the non-pregnant horn was significantly different from that of the pregnant horn, with fewer, smaller, lighter placentomes. However, there was no evidence that placentome development in the non-pregnant horn was affected by placentome development in the pregnant horn. The proportion of the placentome that was maternal tissue increased during gestation, but there was no significant effect of placentome number, or individual placentome weight or length on this proportion. Two placentome shapes were identified, but no effect on foeto-maternal proportion or relationship between shape and total placentome number or weight was identified.     

Morphologic and cytochemical characteristics of blood cells from the desert tortoise (Gopherus agassizii).

Morphologic and cytochemical staining characteristics of erythrocytes, leukocytes, and thrombocytes of the desert tortoise (Gopherus agassizii) were evaluated, using blood smears prepared from 23 healthy tortoises of Kern County, Calif. Special emphasis was placed on differentiating features of the various leukocytes and thrombocytes. A variety of cytochemical stains, including benzidine peroxidase, Sudan black B, chloroacetate esterase, alpha-naphthyl butyrate esterase, acid phosphatase, leukocyte alkaline phosphatase, periodic acid-Schiff, and toluidine blue were used. Heterophils had a characteristic, large, focal area of positive staining with chloroacetate esterase, alpha-naphthyl butyrate esterase, and acid phosphatase. Eosinophils stained diffusely positive with benzidine peroxidase, allowing differentiation of this leukocyte from heterophils. Thrombocytes stained focally positive with periodic acid-Schiff, allowing differentiation of these cells from lymphocytes, which stained uniformly negative. An intracytoplasmic body, commonly observed within erythrocytes, was considered ultrastructurally to represent a degenerate organelle.     

Survey of internal parasites in Western Australian pig herds 2. Relationship to anthelmintic usage and parasite control practices

The housing, management and internal parasite control practices used in piggeries in Western Australia was surveyed by interviewing the owner/manager of 100 randomly selected piggeries. At the time of the interview 20 faecal samples were collected from pigs and examined for evidence of internal parasites. Most herds (80%) in which anthelmintics were used, had evidence of nematode infection. Some pig producers were using an anthelmintic that was ineffective against nematode species present while some herds had nematodes that should have been controlled by the anthelmintic being used. Prevalence of nematode infection was higher in pigs run in paddocks than in pigs housed intensively. Washing sows prior to farrowing was associated with a lower prevalence of nematode infection. The findings suggested that pig producers should ensure that the anthelmintic used is effective against the nematodes present in their pigs. It was concluded that administering anthelmintics as a single dose in the feed may not be the most effective method of deworming pigs.     

Phylogenetic characterisation of bluetongue viruses from naturally-infected insects, cattle and sheep in Australia

SUMMARY The polymerase chain reaction was used to detect the presence of blue-tongue virus (BTV) in a number of clinical and insect samples collected in the Northern Territory of Australia. Sequence analyses of the amplified BTV genes differentiated endemic Australian and exotic viruses. Two potential exotic BTV were detected as a result of PCR analyses of blood from sentinel animals and of the insect vector, Culicoides wadai. The detection of BTV in C wadai was the first direct demonstration of the presence of BTV in this potential vector. This new technology can significantly reduce the time taken for a diagnosis from a clinical sample and increase the amount of useful information obtained on a BTV isolate by using rapid sequencing techniques. Sequence data were used to differentiate between BTV20 isolated in 1975 and two isolates of the same serotype, isolated in 1992, and indicated that the latter were probably a recent incursion into Australia from Indonesia due to their greater VP3 sequence homology to the BTV9 (Java) than to Australian BTV isolates.     

Comparison of three enzyme-linked immunosorbant assays with the indirect immunofluorescent antibody test for the diagnosis of canine infection with Ehrlichia canis

The aim of this study was to compare three different enzyme-linked immunosorbant assays (recombinant major antigenic protein 2 (rMAP2)-ELISA, the Immunocomb (Biogal, Israel) and the Snap 3Dx assay (IDEXX Laboratories Inc., USA)) with the indirect immunofluorescent antibody test in detecting anti-Ehrlichia canis immunoglobulin-G (IgG) antibodies. Samples tested were collected from dogs suspected to be naturally infected with E. canis and from experimentally infected dogs.When qualitative results (positive/negative) were compared, there was an overall agreement of 81% (54/67) between the indirect immunofluorescence antibody (IFA) test and the rMAP2-ELISA. An overall agreement of 94% (63/67) was found between the IFA test and the Immunocomb, and an overall agreement of 91% (61/67) was found between the IFA test and the Snap 3Dx assay. In 50 of 67 (74.6%) samples tested, complete agreement in the qualitative results was found in all four tests. Sixteen of 17 samples with disagreement in the qualitative results were found to have IFA titers of 1:320 or less. The sensitivities and specificities of the tests were found to be 0.71 and 0.85 for the rMAP2-ELISA, 0.86 and 0.98 for the Immunocomb, and 0.71 and 1.00 for the Snap 3Dx assay.The tests performed in this study were found to be highly specific in detecting E. canis antibodies. Their sensitivity was found to be low with sera having IFA titers of < or =1:320, while high with sera having titers greater than 1:320. Repeating the serological tests 1-2 weeks after the first antibody assay may overcome the sensitivity problem with titers of < or =1:320.     

Effect of dietary protein and environmental temperature on growth performance and water consumption of male broiler chickens

1. Male broilers were reared in individual cages from 23 to 44 d of age. The effect of 2 temperatures (22° and 32°C) and 2 crude protein (CP) levels (160 and 200 g/kg) were studied. The low protein diet was supplemented with lysine, methionine, arginine, threonine and valine in order to meet requirements.

2. At 22°C, a reduced CP content did not affect growth rate and breast muscle but slightly increased adiposity and food to gain ratio (FCR). Water consumption was reduced.

3. High temperature reduced growth rate and absolute and proportional breast muscle weight, and increased adiposity and FCR. These effects were more pronounced with the low CP diet. Water consumption was also reduced.

4. It was concluded that reducing CP content did not seem a good way to help broilers to withstand hot conditions. This experiment suggests that amino acids other than lysine, methionine and cystine are probably involved in the detrimental effect of high temperature.     

Ultrathin films of a polyelectrolyte with layered architecture

Posttransfer modification of preformed Langmuir-Blodgett films of poly(tert-butyl methacrylate) and poly(tert-butyl acrylate) by gaseous hydrochloric acid yields films with layered architecture of poly(methacrylic acid) and poly(acrylic acid), respectively. X-ray reflectivity and infrared spectroscopy confirm monolayer by monolayer transfer of the source polymers and their transformation to acid multilayer assemblies with retention of low surface roughnesses. The incorporation of cross-linking groups into the system offers the possibility for further chemical modification to produce ultrathin films of model networks desirable for bioadsorption studies and as hydrophilic spacing layers for tethered membranes.