Bronchopneumonia and polyarthritis due to Mycoplasma bovis in a calf

This case report describes gross lesions and histopathological findings in a 3-months-old calf originating from a feedlot with approximately 400 cattle. In this animal and additional 14 cattle of similar age, which were kept together in the same stable, swollen joints had occurred suddenly. The examination of this calf showed that a severe polyarthritis induced by haematogenous spread of Mycoplasma bovis following bronchopenumonia was present, which was characterised by necrotising lesions of the joint capsules and severe cartilage erosions.     

The prevalence of itchmite, Psorergates ovis, among sheep flocks with a history of fleece derangement

An investigation of sheep flocks in the main sheep raising areas of New South Wales showed that the itchmite Psorergates ovis was frequently associated with fleece derangement. In 26 of the 41 flocks examined, P. ovis was the only ectoparasite detected. P. ovis and the sheep body louse Damalinia ovis, were found in 5 flocks. No external parasites were found on sheep examined from the 10 remaining flocks. The type of fleece derangement most frequently recorded was rubbing which in some cases was combined with areas of chewed fleece. Among flocks, there were positive relations between the prevalence of fleece derangement and prevalence of itchmite or scurf and between itchmite count and mean scurf score. Within flocks, itchmite infested sheep or sheep with scurf had higher prevalences of fleece derangement than sheep on which no mites or no scurf were found. Itchmite infested sheep had a higher prevalence of scurf than those with no detectable mite infestation. There were no significant differences in itchmite populations or fleece derangement between untreated flocks and flocks treated with synthetic pyrethroids, organophosphates or arsenic and rotenone.     

Effect of supplementation of mustard oil cake on intake,digestibility and microbial protein synthesis of cattle in a straw-based diet in Bangladesh

The objective of this study was to analyse the effects of different levels of rumen-degradable protein (RDP) on intake, digestibility and microbial protein synthesis by supplementing mustard oil cake (MOC) on rice straw-based diet of cattle (Bos indicus) in Bangladesh. A 4 × 4 Latin square design was applied. Four diets having constant energy (7.0 MJ/kg of dry matter (DM)) with varying levels of RDP (M ₀ = 4.1 g/MJ (control), M ₁ = 6.3 g/MJ, M ₂ = 8.3 g/MJ and M ₃ = 12.4 g/MJ of metabolizable energy (ME)) were received by each animal for a period of 28 days. A metabolism trial was conducted for 7 days. Results indicate that with increasing levels of RDP, crude protein (CP) and RDP intake increased significantly (P < 0.01). The significant (P < 0.01) increase in digestibility values are obtained for DM, organic matter, CP and digestible organic matter in the rumen. The digestibility of neutral detergent fibre and acid detergent fibre was also increased significantly (P < 0.05). The total nitrogen (N), ammonia-N and total volatile fatty acids increase significantly (P < 0.01) while the rumen pH increased from M ₀ to M ₂ and decreased thereafter. The efficiency microbial N intake increased significantly (P < 0.01) but showed a curvilinear response with higher RDP level (12.40 g/RDP/MJ ME). This study concludes that supplementation of RDP from MOC enhances the intake, digestibility and microbial protein synthesis which ultimately increases utilization of low-quality feed resources that can be used for developing cost-effective feeding systems on a straw-based diet in tropical regions.     

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.     

The diagnosis of listeria encephalitis in ruminants using cultural and immunohistologic methods. II. Immunohistologic studies in formalin-fixed paraffin sections]

The unlabelled peroxidase-antiperoxidase (PAP)-technique was compared with the avidin-biotin-peroxidase-complex (ABC)-technique in the identification of Listeria antigen in formalin-fixed paraffin sections of 58 ruminant brains, 44 of which showed histopathological lesions typical for listeric encephalitis. Rabbit hyperimmune serum, obtained by immunization with a Listeria monocytogenes strain of serotype 1/2 a, served as primary serum in the immunohistochemical investigations. The antiserum was tested for specificity using formalin-fixed smears of various bacterial species. Listeria antigen was demonstrated in 40 of the 44 brains with histopathological CNS alterations, as seen in listeriosis, using the ABC method, whereas their identification with the PAP method only succeeded in 34 of the brains. Despite the higher dilution of the primary antibody, the ABC method distinguished itself further, in comparison with the PAP method, through more intense immunohistochemical staining of Listeria antigen. Listeria spp, could be isolated from 46 of 52 brains, which were also examined bacteriologically. They could be isolated from 14 brains, which showed no histopathological lesions indicative of listeriosis. In contrast to this, Listeria antigen was only detected immunohistologically in brains with typical histological listeric CNS alterations. In three cases the presumptive histological diagnosis could not be confirmed immunohistologically.