Heterogeneity of ruminant pestiviruses: academic interest or important basis for the development of vaccines and diagnostics?

Pestiviruses cause economically important diseases of farm animals. Members of the Pestiviruses are bovine viral diarrhea virus 1 (BVDV-1), BVDV-2, classical swine fever virus (CSFV) and border disease virus (BDV). Phylogenetic analyses based on the entire nucleic acid sequence encoding the Npro allow a statistically significant segregation of established species and of subgroups within the species. BVDV-1 strains isolated in Germany can be associated with at least five different subgroups. In contrast all BVDV-2 isolates detected in Germany so far are closely related, belonging to one subgroup. A group of virus isolates from sheep and zoo animals is clearly different from established pestivirus species and can be designated as BDV-2. Antigenetic relatedness of pestiviruses was studied using defined virus isolates and antisera in cross-neutralization assays. Six antigenic groups were distinguished corresponding to the genetic clusters BVDV-1, BVDV-2, CSFV, BDV-1, BDV-2 and Giraffe-1. A significant antigenic difference was also observed between members of subgroups 1a and 1b of BVDV-1. Studies on the genetic and antigenic heterogeneity of pestiviruses are important for the development of new vaccines, diagnostic tests and for eradication programs.     

Does multiple oral vaccination of wild boar against classical swine fever (CSF) have a positive influence on the immunity?

We studied the efficacy of multiple vaccinations of wild boar against classical swine fever (CSF) using a C-strain vaccine. The study consisted of two experiments. In the first experiment, 7 to 8 months old animals were vaccinated either three or four times at an interval of 7 days or twice at an interval of 14 or 28 days. In the second experiment, the efficacy of oral immunisation in young boars (3 months old) was examined after fivefold vaccination at intervals of 14 or 28 days. Independently of the immunisation scheme all wild boar developed neutralising antibodies. An evaluation of the antibody titres 28 days after the initial vaccine application showed that single vaccination and triple immunisation at an interval of 7 days induced the highest antibody titres (X > or = 1/80). In multiple vaccinated young boars (vaccinated at intervals of 14 or 28 days) the third vaccination led to a slight reduction or to an only moderate increase of the antibody titre. In a challenge study after the fifth vaccination all wild boar were protected (no viraemia, no virus excretion, no post-mortem virus detection in organs). This was confirmed by the fact that sentinel animals were not affected. Although other immunisation schemes also were effective, booster vaccination at an interval of 28 days is recommended as basic procedure for eradication of CSF in wild boar. Triple vaccination might also be used at the beginning of the control measures.     

Importance of claw quality in cattle: Review and recommendations to achieve genetic improvement. Report of the E.A.A.P. working group on “claw quality in cattle”

The objective of this report is to review results of research and to discuss recommendations to achieve genetic improvement of claw quality. High claw quality is defined as a low susceptibility for claw disorders and a low need for footcare. The economic importance of claw problems is considerable, with about 25% of dairy cows treated per year. Direct effects are costs of trimming, veterinary costs and forced culling (2–3%). Indirect costs are decreased milk production or daily gain, lower fertility, decrease of herd life, and lower salvage value.Lameness problems are mainly localized in the claws and can have a traumatic, systemic or infectious origin. The claw quality is a product of claw shape, characteristics of the horn and anatomy of the inner structure of the claw. Environmental factors like housing systems, management and nutrition give considerable herd effects. Improvement of claw quality in the short term can be achieved by managemental procedures that will reduce foot and leg problems in confinement.Genetic improvement can give a contribution in the long term. Genetic variation in claw traits and claw disorders are recorded between and within breeds. Heritabilities and additive genetic variation for claw shape measurements (e.g. claw length, claw angle) are high enough to obtain genetic change in these traits. Claw measurements are partly symptoms but also predisposition factors for claw disorders like sole ulcers. Shorter and steeper hind leg claws are favourable predispositions.Veterinary records on claw and leg disorders after treatment yield very low heritabilities. Claw judgements should be replaced by more effective measurements because of low h² and low correlation to claw disorders.Implementation of genetic improvement based on measurements of claw shape (angle, length) may start with a progeny test of 30–50 daughters in first lactation of the most promising A.I. bulls in milk production. Relationships of claw characteristics of young bulls with those of their parents and daughters is recommended for further analysis.     

Technical note: A novel method for routine genotyping of the G allele of β-casein (CSN2) and T allele of κ-casein (CSN3) in a sheep population using LightCycler

The goal of this work was to develop a protocol for rapid genotyping of A and G variants at the CSN2 locus and genotyping of T and C variants at the CSN3 locus in sheep breeds (Sumava and Valachian) by means of PCR and LightCycler analysis. The LightCycler technique combines rapid and efficient in vitro amplification of DNA in glass capillaries with melting curve analysis based on fluorescence resonance energy transfer for the sensitive detection of point mutation. The A variant had a greater frequency (Sumava, 0.778; Valachian, 0.835) than did variant G (Sumava, 0.222; Valachian, 0.165) in both sheep breeds. The CSN3 locus was found to be monomorphic, with no polymorphism identified in either population.