Incidence and duration of increased somatic cell count in Swedish dairy cows and associations with milking system type

Abstract

Mastitis is one of the most costly diseases in dairy cows worldwide. Increased somatic cell count (SCC) is an indication of mastitis, often subclinical, which implies bacterial infection without clinical signs of inflammation. The aim was to investigate the occurrence of elevated udder SCC (defined as ≥200,000 cells/mL) over the lactation period, and before and after the dry period, for cows of different parity. The aim was also to analyze the association between prevalence and incidence of increased udder SCC and information on cow and herd level, such as breed and milking system type. Data were extracted from the Swedish Official Milk Recording Scheme between January 1, 2008, and December 31, 2011, including all herds with a yearly average of >60 cows. The data include descriptive information on herd and cow level and the results from the systematic test milking. The data included the following: for 2009, 239,182 cows in 1,633 herds; for 2010, 251,852 cows in 1,680 herds; and for 2011, 247,746 cows in 1,596 herds. The results show a peak in elevated udder SCC during the late summer season and that the highest proportion of cases occurs during the first lactation month; the latter was most prominent for primiparous cows. Forty-seven percent of all cows with elevated SCC recovered during dry period (went from high to low SCC), whereas 34% of all cows with low SCC before the dry period had an elevated SCC at first testing after calving. For first lactation cows, 19% had an elevated SCC at first test milking. When the outcomes for the 3 consecutive years were reanalyzed, it was confirmed that the effect of fixed factors such as breed, milk yield, and parity did not change over time, whereas the effect of milking system type did. For the incidence of becoming a new case and the prevalence of cows with elevated udder SCC, automatic milking system (AMS) was associated with reduced SCC in 2009 but associated with increased SCC in 2011. Regarding the proportion of new cases of elevated SCC per cow and year, AMS appeared to be a risk factor for all 3 yr, but the effect decreased over time. The shift for AMS from protective to risk factor regarding incidence of new cases and number of recordings with elevated SCC might reflect a change of the AMS population over these years. The findings indicate the need for appropriate udder health management customized to the system.

Composition and properties of bovine milk: A study from dairy farms in northern Sweden; Part I. Effect of dairy farming system

“…The dominant breed on most farms was SH (19 farms), whereas Swedish Jersey (SJB) was only reported as dominant on 1 of the participating farms. These figures correspond well with data in the Swedish official cow-recording scheme (Växa Sverige, 2017) and with findings by Frössling et al (2017), who reported SH to be the most common breed (50% of the dairy cow population in Sweden), followed by Swedish Red (SRB; 44%). In contrast, SJB and Swedish Polled (SKB) are rare dairy breeds in Sweden (Växa Sverige, 2017).…”

“…Higher SCC was suggested to be linked to several factors, some related to AMS per se (e.g., variation in the length of milking interval), whereas other factors were related to herd management on AMS farms. Using data from the Swedish Official Milk Recording Scheme, Frössling et al (2017) also showed that a higher incidence of elevated SCC was associated with milk from AMS farms. Persson Waller et al (2009), reported that milk from SRB cows had lower SCC compared with SH milk due to better udder health, inherent mastitis resistance, and efficient immune defense.…”

Efficacy Prediction of Four Pharmaceutical Formulations for Intramammary Administration Containing Aloe vera (L.) Burm. f. Combined With Ceftiofur or Cloxacillin in Lactating Cows as an Alternative Therapy to Treat Mastitis Caused by Staphylococcus aureus

“…It is worth noting that a common indicator to assess milk quality, hygiene, udder health, and dairy cow welfare is the SCC, which allows detecting an infected udder quarter when its value reaches the threshold of 200,000 cells/ml, even before the affected quarter shows clinical signs of infection (63). These somatic cells include both those shed from the secretory tissue as well as leukocytes, and though the latter are mostly fighting infections, they also help with the repairing of damaged tissues, increasing their numbers along with the inflammatory response of the udder (64)(65)(66).…”

Comparison of yield, composition and quality of milk of Polish Holstein-Friesian cows in conventional and automatic milking systems

“…Nevertheless, the impact of milking system on milk hygiene is not unequivocal. Frössling et al (2017) also obtained ambiguous resultsa significant decrease of SCC in milk after AMS installation was observed only in some years. Considering above-mentioned ambiguity of the results described in the literature, it can be concluded that further studies in this area are still justified.…”

“…Somatic cell count (SCC) in cows' milk, one of the functional traits, is conditioned by various genetic and non-genetic factors (Frössling et al, 2017;Sitkowska et al, 2017).…”