• Cow welfare in grass based milk production systems

      Boyle, Laura; Olmos, G.; Llamas Moya, S.; Palmer, M.A.; Gleeson, David E; O'Brien, Bernadette; Horan, Brendan; Berry, Donagh; Arkins, S.; Alonso Gómez, M.; et al. (Teagasc, 2008-08-01)
      Under this project, aspects of pasture based milk production systems, namely different milking frequency and feeding strategies as well as genetic selection for improved fitness using the Irish Economic Breeding Index (EBI) were evaluated in terms of dairy cow behaviour, health, immune function and reproductive performance. Additionally, a typical Irish pasture based system was compared to one in which cows were kept indoors in cubicles and fed a total mixed ration for the duration of lactation in order to elucidate the perceived benefits of pasture based systems for dairy cow welfare.
    • Impact of three inactivated bovine viral diarrhoea virus vaccines on bulk milk p80 (NS3) ELISA test results in dairy herds

      Sayers, Riona; Sayers, Gearoid; Graham, David A.; Arkins, S.; Irish Dairy Levy Research Trust (Elsevier, 2015-03-25)
      Bovine viral diarrhoea virus (BVDV) is endemic in many countries and vaccines are used as a component of control and eradication strategies. Surveillance programmes to detect exposure to BVDV often incorporate the use of bulk milk (BM) testing for antibodies against BVDV p80 (NS3), but vaccination can interfere with these results. The aim of this study was to evaluate whether BVDV vaccines would confound BM testing for specific antibodies in a nationally representative group of commercial dairy farms in the Republic of Ireland. A total of 256 commercial dairy herds were included in the statistical analysis. Quarterly BM or serum samples from selected weanling heifers (unvaccinated homeborn youngstock) were assessed by ELISA for antibodies against the BVDV p80 subunit and whole virus. Wilcoxon ranksum and receiver operating characteristic (ROC) analyses were used to examine differences among groups vaccinated with one of three commercially available inactivated BVDV vaccines. Two of the three vaccines showed evidence of interference with ELISA testing of BM samples. ROC analysis highlighted that one vaccine did not reduce the discriminatory power of the BVDV p80 ELISA for identification of herds with evidence of recent BVDV circulation, when compared with unvaccinated herds; thus, administration of this vaccine would allow uncomplicated interpretation of BM ELISA test results in vaccinated seropositive herds. Seasonal differences in BM antibody results were identified, suggesting that the latter half of lactation is the most suitable time for sampling dairy herds containing predominantly spring calving cows. The results of the present study are likely to prove useful in countries allowing vaccination during or following BVDV eradication, where BM testing is required as part of the surveillance strategy.
    • Prevalence of exposure to bovine viral diarrhoea virus (BVDV) and bovine herpesvirus-1 (BoHV-1) in Irish dairy herds

      Sayers, Riona; Byrne, Nicky; O'Doherty, Eugene; Arkins, S.; Irish Dairy Levy Fund (Elsevier, 2015-03-05)
      Bovine viral diarrhoea virus (BVDV) and bovine herpesvirus 1 (BoHV-1) are contagious bovine viral agents. The objectives of this study were to use quarterly bulk milk and ‘spot’ testing of unvaccinated youngstock to establish the national prevalence of exposure to BVDV and/or BoHV-1 in Irish dairy herds. Seasonality of bulk milk ELISA results was also examined. From a geographically representative population of 305 dairy herds, 88% and 80% of herds yielded mean annual positive bulk milk readings for BVDV and BoHV-1, respectively. Of these, 61% were vaccinated against BVDV and 12% against BoHV-1. A total of 2171 serum samples from weanlings having a mean age of 291 days yielded 543 (25%) seropositive for BVDV, and 117 (5.4%) seropositive for BoHV-1. A significant seasonal trend in bulk milk antibody ELISA readings and herd status was recorded for BVDV, with more herds categorised as positive in the latter half of the year.