Respiratory infections in Norwegian dairy calves

Abstract

The aims of this study were to estimate the seroprevalence of respiratory agents in Norwegian dairy calves and to identify risk factors for respiratory disease. The participating 135 herds were randomly selected from those in The Norwegian Dairy Herd Recording System with at least 15 cow years. Each herd was followed for 1 yr. Blood samples from calves of >150 d of age (n = 1,348) were analyzed for antibodies against parainfluenza virus 3, bovine coronavirus (BCoV), bovine respiratory syncytial virus (BRSV), and Mycoplasma bovis. Calves reported to have been on pasture (n = 139) were tested for antibodies against Dictyocaulus viviparus. Seroprevalences for parainfluenza virus 3, BCoV, BRSV, and D. viviparus at the calf level were 50.2, 39.3, 31.2, and 4.3%, respectively. No calves were antibody positive for M. bovis. Calves in herds with BCoV-seropositive calves had an increased risk of respiratory disease compared with herds in which BCoV antibodies were not detected [hazard ratio (HR) = 3.9], as had calves in herds in which the majority (>54%) of the sampled calves were seropositive for BRSV (HR = 2.7). Other factors found to increase the risk of respiratory disease in calves were shared housing with cows during the first week of life compared with separate housing (HR = 16.7), a larger herd size (>50 cow years) compared with smaller herds (HR = 8.2), more than an 8-wk age difference between calves housed together in the same group pen compared with having pen mates of a more similar age (HR = 3.9), previous recordings of diarrhea compared with no recorded diarrhea (HR = 3.9), and leaving calves with dams for >24 h after birth compared with earlier separation (HR = 3.5).

Scientific Opinion on the welfare of cattle kept for beef production and the welfare in intensive calf farming systems

“…Housing calves with a difference in age of more than 8 weeks together in the same group increased the risk of respiratory disease compared with having pen mates of a more similar age (Gulliksen et al, 2009b At the same time, however, group housing of calves, especially young animals, is generally identified as a risk factor for enteric and respiratory infectious diseases (Gulliksen et al, 2009a;Marcé et al, 2010;Lorenz et al, 2011;Brscic et al, 2012). Thus, it is usually advised to house calves in individual pens for several weeks after birth before moving them to collective pens (e.g.…”

“…Keeping calves in stable groups, as opposed to dynamic groups, where new calves are continuously introduced or removed, and grouping animals of similar age lowers the risk both for diarrhoea and respiratory disease (Gulliksen et al, 2009b ;Pedersen et al, 2009). If calves from different farms are put into the same building without a means of preventing pathogen spread, the risk of disease will be high for all the calves.…”

Detecção molecular e análise filogenética de vírus respiratório sincicial bovino (BRSV) em swabs e tecido pulmonar de bovinos adultos

“…As manifestações clínicas da infecção pelo BRSV podem estar relacionadas a diferentes fatores relacionados ao agente, ao animal e ao ambiente: a virulência das cepas pode ser variável (Schrijver et al 1998); a ocorrência de coinfecções bacterianas ou parasitárias (Ellis et al 2009, Gulliksen et al 2009, Brodersen et al 2010. A susceptibilidade dos bovinos também pode variar, especialmente quanto ao seu arcabouço genético relacionado à imunidade celular (Antonis et al 2006).…”

Seroprevalence of bovine viral diarrhoea virus in Hungary — situation before launching an eradication campaign

“…For countries that have implemented systematic control, Tables 1 and 2 include surveys performed before or at the beginning of the schemes (Greiser-Wilke et al, 2003;Vilcek et al, 2003;Hagglund et al, 2006;Gulliksen et al, 2009;Ridpath, 2010). …”