Piccinini Renata, Miarelli Maria, Ferri Barbara, Tripaldi Carmela, Belotti Michela, Daprà Valentina, Orlandini Silvia, Zecconi Alfonso
Università degli Studi di Milano, Dip. Patologia Animale, Igiene e Sanità Pubblica veterinaria, Sezione di Malattie Infettive Via Celoria 10-20133 Milano Italy.
J Dairy Res. 2006 May;73(2):129-33. doi: 10.1017/S0022029905001548. Epub 2006 Feb 14.
High somatic cell count (SCC) affects milk quality and cheesemaking, resulting in a reduction in cheese yield and quality. In dairy cows, quarter milk samples with > 200,000 cells/ml are considered to have subclinical mastitis, while there is much uncertainty on the corresponding levels of SCC in buffalo milk. In this study 30 lactating water buffaloes were selected and SCC, differential somatic cell counts and several whey components were tested in quarter milk samples to assess the relationship between inflammation markers and milk quality. Overall 236 quarter milk samples were considered. To evaluate the relationship between cellular markers (SCC, polymorphonuclear leucocytes, PMN, and N-Acetyl-beta-glucosaminidase, NAGase) and other milk components, three classes were defined (low, medium and high). Analysis of milk yield showed a significant reduction in the high class of each of the three markers chosen. Overall, the highest class was characterized by significant changes in milk composition and a lower milk quality. The presence of an inflammatory status of the udder was frequent after the first trimester of lactation and in buffaloes with two or more parturitions. This study showed that significant changes in milk components can be observed when SCC are > 400,000 cells/ml, PMN are > 50% and NAGase is > 100 units. These thresholds could be suggested as levels to define udder health status in buffalo cows.
高体细胞计数(SCC)会影响牛奶质量和奶酪制作,导致奶酪产量和质量下降。在奶牛中,每毫升细胞数超过200,000的乳房四分之一乳样被认为患有亚临床乳腺炎,而水牛奶中相应的SCC水平存在很大不确定性。本研究选取了30头泌乳水牛,对乳房四分之一乳样中的SCC、体细胞分类计数和几种乳清成分进行检测,以评估炎症标志物与牛奶质量之间的关系。总共考虑了236份乳房四分之一乳样。为了评估细胞标志物(SCC、多形核白细胞、PMN和N-乙酰-β-氨基葡萄糖苷酶、NAGase)与其他牛奶成分之间的关系,定义了三个类别(低、中、高)。产奶量分析显示,所选三种标志物中每一种的高类别均有显著下降。总体而言,最高类别表现为牛奶成分的显著变化和较低的牛奶质量。乳房炎症状态在泌乳前三个月后以及有两次或更多次分娩的水牛中很常见。本研究表明,当SCC超过400,000个细胞/毫升、PMN超过50%且NAGase超过100单位时,可观察到牛奶成分的显著变化。这些阈值可作为定义水牛乳房健康状况的水平建议。