Quarter and cow risk factors associated with the occurrence of clinical mastitis in dairy cows in the United Kingdom

Abstract

Quarter and cow risk factors associated with the development of clinical mastitis (CM) during lactation were investigated during a 12-mo longitudinal study on 8 commercial Holstein-Friesian dairy farms in the southwest of England. The individual risk factors studied on 1,677 cows included assessments of udder and leg hygiene, teat-end callosity, and hyperkeratosis; body condition score; and measurements of monthly milk quality and yield. Several outcome variables for CM were used for statistical analysis, which included use of generalized linear mixed models. Significant covariates associated with an increased risk of CM were increasing parity, decreasing month of lactation, cows with very dirty udders, and quarters with only very severe hyperkeratosis of the teat-end. Thin and moderate smooth teat-end callosity scores were not associated with an increased risk for CM. Cows that recorded a somatic cell count >199,000 cells/mL and a milk protein percentage <3.2 at the first milk recording after calving were significantly more likely to develop CM after the first 30 d of lactation. There was no association between cow body condition score and incidence of CM. Of the cases of CM available for culture, 171 (26.7%) were confirmed as being caused by Escherichia coli and 121 (18.9%) confirmed as being caused by Streptococcus uberis. Quarters with moderate and very severe hyperkeratosis of the teat-end were at significantly increased risk of clinical E. coli mastitis before the next visit. Quarters with very severe hyperkeratosis of the teat-end were significantly more likely to develop clinical Strep. uberis mastitis before the next visit. There were strong trends within the data to suggest an association between very dirty udders (an increased risk of clinical E. coli mastitis) and teat-ends with no callosity ring present (an increased risk of clinical Strep. uberis mastitis). These results highlight the importance of individual quarter- and cow-level risk factors in determining the risk of CM associated with environmental pathogens during lactation.

Management factors affecting udder health and effects of a one year extension program in organic dairy herds

“…investigations, teat cleanliness can be an indicator of hygiene in the cows' environment and good cubicle and barn hygiene were found to be correlated with good udder health (Bartlett et al, 1992;O'Reilly et al, 2006;Breen et al, 2009). In other studies, aspects of milking technology such as less frequent technology check, automatic cluster removal, high milking vacuum and cleanliness of milking parlor have been reported to have a negative influence on udder health (Østeras and Lund, 1988;Barkema et al, 1998), whereas in general, the factors of milking technology and feeding of lactating cows in the presented investigation show no significant association to udder health.…”

Identifying risk factors for poor hind limb cleanliness in Danish loose-housed dairy cows

“…An increased risk of high somatic cell count and intramammary infections has been associated with cows having dirty udders and legs (Schreiner and Ruegg, 2003;Ellis et al, 2007;Breen et al, 2009). …”

Mediation analysis to estimate direct and indirect milk losses due to clinical mastitis in dairy cattle

“…A third feature of the model was that loss in milk yield was expressed as a linear regression per day with respect to the time of diagnosis, adjusted for known control variables such as herd, parity, stage of lactation (Breen et al, 2009). Notwithstanding, the model was very simple and other putative risk factors, not already included in the model, could easily be tested.…”