Bovine respiratory syncytial virus outbreak reduced bulls’ weight gain and feed conversion for eight months in a Norwegian beef herd

摘要: Cost-benefit evaluation of measures against respiratory disease in cattle requires accounting with the associated production losses. Investigations naturally occurring infections a herd setting are an opportunity for accurate estimates consequences. This article presents based on individual monitoring weight and concentrate intake several hundred bulls previous to, during after infection outbreak bovine syncytial virus (BRSV) as main pathogen. The aim study was to analyse association between exposure BRSV, gain feed conversion rate, quantify any change these parameters, estimate duration production. A comparison growth curves that were present revealed severe clinical signs had clear consistent trend poorer rate than those milder or no signs. weight/age-ratio 0.04–0.10 lower severely affected bulls, evident throughout period 8 months. rates apparently healthy being comparable group exactly 1 year later (n = 377) showed reduced 111 g/day first group. difference amounted 23 extra days needed reach reference weight. Feed also by 79 g gain/kilogram consumed year. indicates significant negative effects performance animals develop acute stage, is negatively many months apparent recovery. In addition, exposed affected. this decrease recovery, have not shown at all, has previously been documented. These losses will easily be underestimated, but contribute significantly costs producer. findings emphasize importance BRSV profitability animal welfare husbandry. illustrates utilising intra-herd health parameters productive approach consequences outbreak.