Risk factors associated with subclinical mastitis in dairy cows on Swiss organic and conventional production system farms

Abstract

Epidemiological studies comparing risk factors for subclinical mastitis (SM) in organic (OP) and conventional dairy production systems (CP) are lacking. In 60 OP and 60 CP farms, 970 cows were used to study risk factors for SM at 31 days postpartum. Cows showing a positive (≥ 1+) California Mastitis Test (CMT) in at least one quarter, but without clinical symptoms, were classified SM-positive. For OP cows increased (<I>P</I> < 0.05) odds ratios (OR) for SM were found for other than Simmental and Simmental × Red Holstein breeds, for increasing number (> 27) of cattle on the farm, for the use of mineral feed supplements, for irregular milking intervals (< 12 and > 12 h/day), and for milk urea concentrations of 210.1–270 mg/dl, whereas decreased OR for SM were recorded for cows kept in barns on beddings other than on rubber mats or concrete, for farms with rinsing water temperatures of milking systems between 54.75 and 60°C, for milk lactose > 50.5 g/l, and for blood albumin levels of ł 38.5 g/l. For cows on CP farms, increased (<I>P</I> < 0.05) OR for SM were found for other than Simmental ´ Red Holstein and Simmental breeds, for a bedding area width of > 117 cm, and for antibiotic mastitis treatment since the last dry period, whereas reduced (<I>P</I> < 0.05) OR for SM were found for farms with a moderate (in contrast to good) hygiene status and for routine application of antibiotics during the dry period. Observed differences between OP and CP were assumed to be partially related to system-specific management, such as antibiotic dry cow therapy, nutrition and milking routine.

Relationship between the probability of veterinary-diagnosed bovine mastitis occurring and farm management risk factors on small dairy farms in Austria

“…In fact, it is likely that the opposite is actu-ally the case, and it is reasonable to assume that these farms are those with inherent mastitis problems and have increased their testing regimen to improve mastitis detection. Similar results have been reported for freestalls in Switzerland, where the mastitis incidence risk ratio was lower (0.61, P = 0.01) when bacteriological cultures were reportedly never done compared with the reference value of always or occasionally done (Gordon et al, 2013) and in a further Swiss study where subclinical mastitis was less likely to occur on farms with a moderate compared with good level of hygiene (Doherr et al, 2007).…”

“…Similar findings have been reported in other studies of udder health in small dairy farms. For example, a Finnish study (largest herd size category: >60 cows) reported average herd size as having no effect on subclinical mastitis (OR = 1.003), whereas a Swiss study found that a herd size of >27 dairy cows and heifers increased the odds of subclinical mastitis occurring compared with smaller herds (<20 head; Doherr et al, 2007;Hiitiö et al, 2017). Dairy farms in other European countries often have much larger herds, with surveys from 2016 to 2017 reporting a mean of 61.9 cows per herd in Germany, 93.8 cows per herd in the Netherlands, and 146 cows per herd in the United Kingdom compared with just 21.3 cows per herd in Austria at that time (Barkema et al, 2015;AHDB Dairy, 2018;BMEL Statistik, 2018;CRV, 2018;ZAR, 2018).…”

Long-term alteration of follicular steroid concentrations in relation to subclinical endometritis in postpartum dairy cows1

“…Decreased albumiu couceutratiou was ouly at d 21 postpartum and may indicate that scEndo cows were responding to mild inflammation because albumin is decreased in response to the production of acute-phase proteius (Fleck, 1989;Bertoui et al, 2008) aud prolouged chauge in albumin concentration occurs after an inflammatory event (Nicholson et al, 2000). Greater milk albumin concentration is also associated with a reduced risk of subcliuical mastitis (Doherr et al, 2007) and several studies ideutified a positive associatiou of milk proteiu couteut with iucreased submission rate and pregnancy rate to first service (Morton, 2000;Buckley et al, 2003).…”

Dynamics of mammary infections in organic dairy farms in Northern Spain

“…Limited information is available in the literature comparing the mastitis prevalence in organic and conventional systems worldwide, however, in contrast to some inconsistencies among studies when comparing SCC, virtually all studies have reported fewer cases of clinical mastitis for organic when compared to conventional farms (for review see Ruegg, 2009). A completely different scenario has been observed for the subclinical mastitis, which is assumed to be a frequent problem in organic farming (Krutzinna et al, 1997;Weller & Davies, 1998;Busato et al, 2000;Fehlings & Deneke, 2000;Hovi & Roderick, 2000;Zwald et al, 2004;Roesch et al, 2006Roesch et al, , 2007Doherr et al, 2007). Environmental pathogens are generally associated with higher percentages of clinical mastitis than contagious pathogens (Bradley et al, 2007).…”