Effect of coagulase-negative staphylococci on somatic cell count in Dutch dairy herds

Abstract

The effect was quantified of coagulase-negative staphylococci (CNS) intramammary infections on quarter- and cow-level somatic cell count (SCC) and on bulk milk somatic cell count (BMSCC) in different BMSCC cohorts in Dutch dairy herds. Two datasets were used for this purpose. In the first dataset, on 49 randomly selected dairy farms a total of 4220 quarter milk samples of 1072 cows were collected of all cows and heifers with a test-day SCC 250 000 and 150 000 cells/ml, respectively, and of 25% of cows and heifers below these thresholds. In the second dataset, on 39 selected dairy farms a total of 8329 quarter milk samples of 2115 cows were collected of all cows with a test-day SCC 250 000 cells/ml following two consecutive SCC <250 000 cells/ml, and of heifers using the same SCC criteria but with a threshold of 150 000 cells/ml. These cows and heifers were defined as new high SCC. In both datasets, CNS was the most frequently isolated pathogen, 11% in the first dataset and 12% in the second dataset. In both datasets, quarters with CNS IMI had a lower SCC than quarters infected with major pathogens, and a higher SCC than culture-negative quarters. The same was found for SCC at cow level. Coagulase-negative staphylococci were more often found in quarters with SCC 200 000 cells/ml in dairy farms with a BMSCC<150 000 cells/ml compared with dairy farms with a higher BMSCC. Prevalence of CNS in cows and heifers with a high SCC was higher in dairy farms with a BMSCC <150 000 cells/ml compared with dairy farms with a medium or high BMSCC: 30, 19 and 18%, respectively. This indicates that CNS IMI as a cause of subclinical mastitis is relatively more important in dairy farms with a low BMSCC and may become a point of attention in udder health management on that type of farm.

The prevalence of heifer mastitis and its associated risk factors in Huanggang, Central China

“…Heifer mastitis is a complex disease, and the variation in the prevalence of mastitis between this study and the others might be due to differences in climate, season, and region, and environmental and management practices. Besides, differences in diagnostic techniques used and in cut points used to define "infection" likely contribute to the reported variation in prevalence and incidence of heifer mastitis (Sampimon et al 2010).…”

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

“…The diagnosis HSCLM was based on individual SCC results in heifers between 4 and 100 DIM and was defined as SCC >150,000 cells/mL at 1 or more of the regular test days (CRV, 2010;Sampimon et al, 2010). All test day results within the first 100 DIM were included because the majority of the IMI in that period probably originated from before, or at, calving (Bradley and Green, 2000).…”

“…The threshold that is used to diagnose a cow having SCLM varies among studies (Schukken et al, 2003;de Haas et al, 2008;Sampimon et al, 2010). In the Netherlands, a threshold of >250,000 cells/mL is commonly used to diagnose SCLM in multiparous cows, whereas >150,000 cells/ mL is used in heifers (CRV, 2010;Sampimon et al, 2010). Several studies describe the association between SCC in bulk milk and management characteristics (Barkema et al, 1998(Barkema et al, , 1999bDe Vliegher et al, 2004;Plozza et al, 2011).…”

“…However, the SCC of a cow with SCLM is too high. The threshold that is used to diagnose a cow having SCLM varies among studies (Schukken et al, 2003;de Haas et al, 2008;Sampimon et al, 2010). In the Netherlands, a threshold of >250,000 cells/mL is commonly used to diagnose SCLM in multiparous cows, whereas >150,000 cells/ mL is used in heifers (CRV, 2010;Sampimon et al, 2010).…”

Relação da idade na presença de bactérias resistentes a antimicrobianos em rebanhos leiteiros no Rio Grande do Sul

“…Pesquisadores estadunidenses de Ohio (Rajala-Schultz et al 2004) encontraram 43,9% de resistência a pelo menos um antibiótico por ECN, e indicam o uso de terapias no período seco como sendo fator de risco para o aparecimento de resistência (Rajala-Schultz et al 2009). Em estudo na Holanda, 30% de ECN foram resistentes a mais de um composto antimicrobiano em rebanhos leiteiros (Sampimon 2009). Estes resultados estão em consonância com um estudo que avaliou a correlação entre o uso de antimicrobianos veterinários e a resistência antimicrobiana em animais de produção de sete países europeus (Chantziaras et al 2014), sendo a Holanda um dos maiores consumidores de antimicrobianos e os países nórdicos, uns dos menores.…”