Natural parvovirus infection in laboratory rabbits

Laboratory rabbits from various commercial and private sources were found to have high serum antibody titers specific for lapine parvovirus (LPV). By both immunofluorescence and hemagglutination inhibition assays, 75% of these sera were positive for LPV. This finding, together with the recovery of LPV from kidneys of neonatal rabbits, suggested that LPV infection is common in commercially available rabbits in the United States. It was concluded that use of infected rabbits could interfere with research in which rabbit cell cultures or in vitro immunologic assays are used.     

The effectiveness of the new morantel sustained-release trilaminate bolus against gastrointestinal nematode infections in cattle in their first grazing period

The efficacy of a recently developed Morantel-Sustained-Release-Trilaminate-Bolus (Paratect Flex Bolus [PFB]-Pfizer Inc.) against gastrointestinal nematode infections in cattle was assessed by monitoring faecal egg counts (EpG), herbage larval counts, serum pepsinogen levels and liveweight gains in first season calves. In two field trials (1987 and 1988), a PFB-Bolus was administered to two different groups of animals (1987: 15 calves; 1988:13 calves) at turnout (29 May 1987; 26 May 1988), control groups were included. In 1988, 13 calves received for comparison an Oxfendazole-Release-Bolus (Systamex Intervall Bolus [OXF]-Coopers Inc.). All groups were grazed on adjacent but separately fenced pastures throughout the season, until housing (27 October 1987; 15 October 1988). When compared with controls, the PFB-groups showed significantly lower EpG values and consequently, lower herbage larval counts throughout the season in both trials. From day 30 after turnout, the PFB-group had significantly lower serum pepsinogen levels, which reflects the low degree of abomasal damage in these animals. When compared to controls, the PFB-treated animals showed significantly higher weight performances. The mean weight-gain benefit of PFB-treated animals was +12.5 kg (p less than 0.05) and +21.1 kg (p less than 0.005) in 1987 and 1988, resp. No difference occurred between PFB-treated and OXF-treated calves, the latter outperformed the control animals by +21.6 kg (p less than 0.005).     

Phospholipid content of subcellular structures in skeletal muscles after halothane loading in Landrace swine in relation to mating variants and genotype

Membraneous phospholipids of subcellular structures were determined from the musculature of German Landrace pigs of the GDR, following exposure to halothane. Mating variants A (H+ male X H+ female), B (H+ male X H- female), and C (H- male X H+ female) were used for positive responders (MHS), while variants B, C, and D (H- male X H- female) were used for negative responders (MHN). Four phospholipid fractions were recorded from the muscle samples for mitochondria and microsomes (according to SR section). Differences between the MHS and MHN groups for the above fractions and without consideration of mating variants and genotype were not observed, although unambiguous responses were exhibited by all animals, either positive or negative to halothan. Significant differences with regard to the above phospholipid fractions were recordable only for variant A (MHS group) as compared to D (MHN), in other words, for the homozygous genotypes, once the above results had been rearranged within MHS and MHN along with different mating variants and genotypes. However, no unambiguous results were obtainable for the heterozygous genotypes of mating variants B and C. Possible underlying reasons are discussed in some detail. The results obtained from mating variants A and D are likely to confirm earlier findings and seem to suggest that the sarcoplasmic reticulum is the primary site of origin of susceptibility to halothane or malignant hyperthermia.     

Studies of infectious laryngotracheitis vaccines: immunity in layers

Ten-week-old layer chickens obtained from a commercial source were eye-drop vaccinated with chicken-embryo-origin (CEO) or tissue-culture-origin (TCO) vaccines for infectious laryngotracheitis (ILT). Controls were not vaccinated. Approximately one-third of the layers were challenged with virulent ILT virus at 21, 40, or 60 weeks of age. Serum samples taken from the layers before challenge were used in a virus neutralization (VN) test to determine vaccination titers at those three ages. Both vaccines induced low VN titers (geometric mean titer [GMT] less than 6). At 21 weeks of age, the titers produced by the two vaccines were not significantly different, but at 40 and 60 weeks of age the VN GMT of the CEO-vaccinated group was significantly greater than that of the TCO-vaccinated group. The VN GMTs did not drop over time in either group and actually rose between 21 and 60 weeks of age in the CEO group. Both vaccines protected layers against severe challenge with virulent ILT virus, neither being significantly better than the other under these experimental conditions. Unvaccinated sentinel chickens were maintained in contact with the vaccinated layers during three intervals between 1 day and 6 weeks post-vaccination. Diagnostic tests performed on the sentinels to detect lateral spread of vaccine virus from vaccinated to unvaccinated chickens showed scattered positive results.     

Histochemistry of complex carbohydrates in the horse duodenal gland

Complex carbohydrates were examined in glandular cells of the horse duodenal gland by using lectin histochemical techniques. In the horse, the duodenal gland was distributed in the area from the uppermost part of the small intestine to a point about 6m caudal to the pylorus. It consisted of two types of cells, mucous and serous cells. The former was found in glands distributed almost all over this part, but the latter was present in glands distributed restrictedly to the uppermost part of the small intestine at a point about 10 cm caudal to the pylorus. The cytoplasm of the mucous cell contained neutral glycoproteins with different saccharide residues as alpha-D-mannose, N-acetyl-beta (1----4)-D-glucosamine, galactose, alpha-galactose, alpha-N-acetylglucosamine, beta-D-Gal (1----3)-D-GalNAc, alpha-L-fucose and sialic acid. On the other hand, the serous cell contained neutral and acid glycoproteins with different residues such as alpha-D-mannose, alpha-D-glucose, beta-D-galactose(1----3)-D-N-acetylgalactose, alpha-L-fucose, N-acetyl-alpha-D-galactosamine, N-acetyl-beta (1----4)-D-glucosamine, galactose, alpha-galactose, alpha-N-acetylglucosamine and sialic acid. It is also elucidated in the present study that lipase, an enzyme for digestion, is contained in the serous cell of the equine duodenal gland.     

Seroprevalence of <Emphasis Type="Italic">Brucella</Emphasis> antibodies in camels in Katsina State,Nigeria

A cross-sectional study was carried out to determine the status of Brucella infection in one-humped (Dromedary) camels in the North and Central senatorial districts of Katsina State, Nigeria. Nine hundred and eighty serum samples from live and slaughtered camels were tested. Modified Rose Bengal plate test (RBPT) and serum agglutination test (SAT) with ethylenediaminetetraacetic acid, (EDTA) were used as screening and standard tests, respectively. The prevalence of Brucella antibodies were 110 (11.2%) and 103 (10.5%) for RBPT and SAT, respectively. Of the 472 and 508 serum samples tested from the herds and abattoirs, respectively, 63 (13.3%) and 47 (9.3%) were positive by RBPT while 62 (13.1%) and 41 (8.1%) were positive by SAT, respectively. Based on the results, it was concluded that Brucella antibodies were present in camels in the study area. Poor management practices and mixing of camels with other species of livestock as well as unrestricted movement of camels were proposed to be the reasons for the prevalence of the disease in the study area. In view of the public health importance of the disease, it is recommended that there is the need to develop a strategic plan to decrease spread of brucellosis in the study area.     

Comparison of the Value of Pulsed-field Gel Electrophoresis,Random Amplified Polymorphic DNA and Amplified rDNA Restriction Analysis for Subtyping Taylorella equigenitalis

Eight strains of Taylorella equigenitalis were identified by a polymerase chain reaction using a primer pair specific to the 16S rDNA of T equigenitalis. These eight strains were chosen because they had previously been shown to represent eight distinct genotypes by pulsed-field gel electrophoresis analysis after separate digestion of the genomic DNA with ApaI or NotI. The eight strains could be classified into six or seven types by random amplified polymorphic DNA analysis using different kinds of primers. Amplified rDNA restriction analysis after separate digestion with five restriction enzymes, including AluI and MboI, of the 1,500 bp fragments of rDNA amplified by polymerase chain reaction did not discriminate the genomic variations among the eight strains of T equigenitalis. Thus, pulsed-field gel electrophoresis was shown to discriminate these eight organisms better than random amplified polymorphic DNA analysis, while amplified rDNA restriction analysis was found to be unsuitable for subtyping T equigenitalis.