Incidence of subclinical mastitis in Dutch dairy heifers in the first 100 days in lactation and associated risk factors

Abstract

Heifer mastitis is a problem and risk factors may differ between heifers and older cows. The aim of this study was to estimate the heifer subclinical mastitis (HSCLM) incidence based on elevated somatic cell count (SCC) in the first 100 d in lactation and the associated risk factors in Dutch dairy herds. In 2008, 173 farmers filled in a questionnaire regarding housing and herd management factors potentially related to udder health. In addition, monthly milk production and SCC data from all cattle were provided by the Dutch Royal Cattle Syndicate (CRV, Arnhem, the Netherlands). Heifer subclinical mastitis incidence was calculated at the herd level as the number of heifer cases divided by the number of heifers at risk in the first 100 d in milk. Linear regression models were used for the analyses. On average, 25.5% [95% confidence interval (CI): 23.9 to 27.0%] of the heifers had subclinical mastitis. Heifers with a high SCC (>150,000 cells/mL) on the first test day after calving that returned to SCC levels below the cut-off continued to have a higher SCC throughout the study period compared with heifers with a low SCC (≤150,000 cells/mL) at the first test day after calving. Housing heifers together with lactating cows close to calving was protective from HSCLM incidence compared with separate housing (−4.5%; 95% CI: −8.7 to −0.2%). In addition, herds in which the farmer removed supernumerary teats of calves had a 7.0% (95% CI: 2.8 to 11.3%) lower HSCLM incidence and day and night grazing was also protective (−5.9%; 95% CI: −10.6 to −1.3%). Herds that were milked with an automatic milking system had, on average, a 6.9% (95% CI: 2.2 to 11.5%) higher HSCLM incidence and submitting milk samples for bacteriological culturing in the previous year was also associated with a higher HSCLM incidence (4.1%; 95% CI: 1.1 to 7.1%). Heifer subclinical mastitis is prevalent in all dairy herds, with a large variation in incidence. A high SCC in heifers at the first test day after calving appears to indicate a prolonged effect on udder health. Several management factors were found to be associated with HSCLM incidence that may help in reducing HSCLM.

Prevalence and Antimicrobial Resistance Assessment of Subclinical Mastitis in Milk Samples From Selected Dairy Farms

“…It has also been described in humans as the major cause of nosocomial and community acquired infections (Chaudhary and Payasi, 2013). Most of the organisms isolated from this study have also been reported as either contagious or environmental pathogens that are found in raw milk from different parts of the world (Waller et al, 2011;Hogan et al, 2011;Santman-Berends et al, 2012;Hill et al, 2012;Oliver and Muranda, 2012;Chaudhary and Payasi, 2013). Staphylococcus and Corynebacterium species are considered before as minor pathogens found in milk; but, have now became more common as mastitis causing organisms (Oliver and Muranda, 2012).…”

“…Salmonella, Listeria, Pseudomonas, Corynebacterium, Campylobacter and Micrococcus species have also been reported in raw milk worldwide (Waller et al, 2011;Hill et al, 2012;Santman-Berends et al, 2012;Bracke et al, 2013). Subclinical mastitis is the most common form of mastitis among dairy cattle (Salvador et al, 2012), with a prevalence of about 40-50 times more than the clinical mastitis (Roy et al, 2009;Mekibib et al, 2010); which attracts for prompt attention in the dairy industry.…”

The association between the somatic cell count and isolated microorganisms during subclinical mastitis in heifers in Jordan

“…A high prevalence of environmental pathogens is suggestive of poor cleaning and preparation of the udder before milking. Contaminated bedding, dirty environments, and colonisation of teat skin and teat injuries are potential sources of environmental pathogens (Santman-Berends et al 2012).…”

“…Intramammary infections in heifers in early lactation potentially cause severe economic losses (Seegers et al 2003;De Vliegher 2005a) because of detrimental effects on udder development and future production leading to an increased risk of premature removal from the herd (Rupp et al 2000;Waage et al 2000;Oliver et al 2003;De Vliegher et al 2005a;De Vliegher et al 2005b;Santman-Berends et al 2012;Archer et al 2013). The prevalence of subclinical mastitis in heifers varies widely among studies and ranges from 12% to over 57% of quarters infected (Barkema et al 1999b;De Vliegher et al 2001;Bowers et al 2006;Andersen et al 2010;Santman-Berends et al 2012).…”

“…The prevalence of subclinical mastitis in heifers varies widely among studies and ranges from 12% to over 57% of quarters infected (Barkema et al 1999b;De Vliegher et al 2001;Bowers et al 2006;Andersen et al 2010;Santman-Berends et al 2012). Coagulase-negative Staphylococci (CNS) are the most prevalent cause of subclinical mastitis in heifers.…”