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Abstract Background Mycoplasmas are present worldwide in a large number of animal hosts. Due to their small genome and parasitic lifestyle, Mycoplasma spp. require complex isolation media. Nevertheless, already over 100 different species have been identified and characterized and their number increases as more hosts are sampled. We studied the applicability of amplified rDNA restriction analysis (ARDRA) for the identification of all 116 acknowledged Mycoplasma species and subspecies. Methods Based upon available 16S rDNA sequences, we calculated and compared theoretical ARDRA profiles. To check the validity of these theoretically calculated profiles, we performed ARDRA on 60 strains of 27 different species and subspecies of the genus Mycoplasma. Results In silico digestion with the restriction endonuclease AluI (AG^CT) was found to be most discriminative and generated from 3 to 13 fragments depending on the Mycoplasma species. Although 73 Mycoplasma species could be differentiated using AluI, other species gave undistinguishable patterns. For these, an additional restriction digestion, typically with BfaI (C^TAG) or HpyF10VI (GCNNNNN^NNGC), was needed for a final identification. All in vitro obtained restriction profiles were in accordance with the calculated fragments based on only one 16S rDNA sequence, except for two isolates of M. columbinum and two isolates of the M. mycoides cluster, for which correct ARDRA profiles were only obtained if the sequences of both rrn operons were taken into account. Conclusion Theoretically, restriction digestion of the amplified rDNA was found to enable differentiation of all described Mycoplasma species and this could be confirmed by application of ARDRA on a total of 27 species and subspecies.

Fodder beets (Beta vulgaris L.) are especially respected for their high feeding value and high netto-energy yield per hectare. The price per nutritive value is lowest as compared to other forages. Preservation of fodders beets demands thorough cleaning without damaging and regularly occurs as a whole in well closed piles. In addition, feeding them to the animals is labour demanding. These disadvantages enforce the research towards other preservation methods which may be able to valorise this valuable type of roughage. The preservation of fodder beets in silages using silo bags, either separately or in combination with maize was investigated. Fodder beets were harvested and ensilaged at the ideal moment of maize harvest (October) or fodder beets were harvested at the ideal moment for fodder beet harvest (November) and consequently ensilaged with previously ensilaged maize. Highest energy yields of the silages were recorded at optimal harvest time for fodder beets. Ensilaging fodder beets separately resulted in large energy losses due to effluent and dry matter losses. Using lab scale silage, possible solutions for these large losses were investigated. Addition of 10% maize did reduce the effluent losses but dry matter losses remained at a high level. Addition of 4,5 1 propionic acid per ton beets reduced effluent and dry matter losses sufficiently. Ensilaging foliage was another point of interest. This appeared to result in a lowered energy yield at organic and dry matter basis, an increased amount of ashes and doubling of the iron (Fe) concentration. [ABSTRACT FROM AUTHOR]

Small ruminant lentivirus (SRLV) control programs are mainly based on diagnostic tests performed on blood samples collected from sheep and goats. Since blood sampling is costly and stressful for the animals, we evaluated whether milk could be used as an inexpensive and easily collectable matrix for SRLV detection. We therefore compared SRLV detection via two commercial enzyme-linked immunosorbent assays (ELISAs) and quantitative polymerase chain reaction (qPCR) in blood and corresponding milk samples from 321 goats originating from eight different SRLV-infected farms in Flanders (Belgium). The IDscreen® ELISA had a better relative sensitivity (97% vs 93%) and specificity (100% and 97%) than the Elitest® ELISA for SRLV-specific antibody detection in milk compared to serum. The higher sensitivity correlates with a 10-fold higher analytical sensitivity of the IDscreen® test. In contrast to the overall good ELISA results, qPCR on milk cell pellets lacked sensitivity (81%) and specificity (88%), compared to molecular detection in blood leucocyte pellets. Our results show that serology is more suitable than qPCR for SRLV diagnosis, and that milk may represent an interesting matrix for a preliminary evaluation of a herd's infection status. Serum remains however the sample of choice for control programs where it is important to identify positive animals with the highest sensitivity. [ABSTRACT FROM AUTHOR]

Skin lesions due to infection with the parasitic Psoroptes mite is a common problem in Belgian Blue Beef and causes substantial growth reduction. Skin lesions due to fungi such as Trychophyton verrucosum are considered to have little economic implications. We studied weekly growth over 11 weeks in 36 growing animals of both sexes. Twelve were infested with Psoroptes mites and developed lesions by week 11. 19 animals spontaneously obtained a Trychophyton infection. First skin lesions were observed in week four. Behaviour was scored daily from week 1 till week 6, and from week 10 till week 11. Animals without lesions, with lesions due to Psoroptes and with lesions due to Trychophyton did not show a significant difference in weight gain. There was however an effect of surface of lesions (of any kind) on the growth (p<0,02): larger lesions related to less growth. Lesion surface also related to reduced rumination quality. Animals with Psoroptes lesions showed more itching behaviours (licking, tail switching; scratching rubbing) in relation to lesion surface from week 5 on. We confirm that are welfare implications and economic implications in animals with skin lesions due to Psoroptes or Trychophyton. [ABSTRACT FROM AUTHOR]