Zecconi Alfonso, Dell'Orco Francesca, Vairani Diego, Rizzi Nicoletta, Cipolla Micaela, Zanini Lucio
Department of Biomedical, Surgical and Dental Sciences, University of Milano, Via Pascal 36, 20133 Milano, Italy.
Associazione Regionale Allevatori Lombardia, Via Kennedy 30, 26013 Crema, Italy.
Animals (Basel). 2020 Apr 1;10(4):604. doi: 10.3390/ani10040604.
The recent availability of a high-throughput milk analyzer performing a partial differential somatic cell count (DSCC) opened new opportunities in investigations on bovine udder health. This analyzer has a potential limitation on the accuracy of measurements when the somatic cell count (SCC) is below 50,000 cells/mL, values characterizing a good proportion of lactating cows in many herds. We obtained data for cows below this threshold, assessed the repeatability of these measurements and investigated the relationship between DSCC and udder health, milk composition and yield. Overall, 3022 cow milk test records performed on a Fossomatic™ 7/DC (Foss A/S, Hillerød, Denmark) were considered; 901 of them had an SCC ≤ 50,000 cells/mL. These latter samples were analyzed by qPCR to identify the presence of bacteria. Overall, 20.75% of the samples (187) were positive. However, the health status did not have any significant association with DSCC. The analysis of the association of DSCC on milk fat, protein and casein showed a significant decrease in their proportions as the DSCC increased, whereas it was not observed for milk yield and lactose. Therefore, DSCC in very low SCC cows may be suggested as a marker to identify early changes in milk composition.
最近，一种能够进行部分差分体细胞计数（DSCC）的高通量牛奶分析仪的出现，为牛乳房健康研究带来了新机遇。当体细胞计数（SCC）低于50,000个细胞/毫升时，该分析仪在测量准确性方面存在潜在限制，而在许多牛群中，这个数值表征了相当比例的泌乳奶牛。我们获取了低于此阈值的奶牛数据，评估了这些测量的重复性，并研究了DSCC与乳房健康、牛奶成分及产量之间的关系。总体而言，我们考虑了在Fossomatic™ 7/DC（丹麦希勒勒德市Foss A/S公司）上进行的3022份牛奶检测记录；其中901份的SCC≤50,000个细胞/毫升。对这些样本进行qPCR分析以鉴定细菌的存在。总体而言，20.75%的样本（187份）呈阳性。然而，健康状况与DSCC没有任何显著关联。对DSCC与乳脂、蛋白质和酪蛋白之间关联的分析表明，随着DSCC的增加，它们的比例显著下降，而牛奶产量和乳糖则未观察到这种情况。因此，对于SCC非常低的奶牛，DSCC可能被建议作为识别牛奶成分早期变化的一个指标。
