The relationship of somatic cell count with milk yield and composition in different stages of lactation in Holstein cows

Abstract

Globally, the milk yield of Holstein cows has increased considerably, but this situation has reduced the cows’ tolerance to environmental factors and, thus, it has negatively affected udder health and milk quality. This study aimed to determine the influence of somatic cell count (SCC) on milk yield and its composition in early (200 days) between November 2019 and August 2020. The study material consists of 927 records of 132 Holstein cows raised on a commercial dairy cattle farm in the Kırşehir province of Turkey. SCC was categorized into three groups (200x103 cell/mL). SCC data were logarithmically transformed to log10 base. In the study, logSCC, test day milk yield (MY), fat content (FC), solidsnot-fat (SNF), protein content (PC), lactose content (LC), fat yield (FY), and protein yield (PY) were recorded as 5.12±0.01, 37.54±0.34 kg, 3.59±0.02%, 9.08±0.01%, 3.35±0.01%, 4.99±0.01%, 1.33±0.01 kg, and 1.26±0.01 kg, respectively. LogSCC, MY, FC, SNF, PC, LC, FY, and PY were significantly affected by the parity, lactation stage, and sampling season (P200x103 cells/mL. Consequently, it may be that milk loss related to an increase in SCC was, consequently, highest toward the end of lactation. As a result, we suggest that prevalence measures should focus on reducing the incidence of SCC toward the end of lactation in Holstein cows.