Influence of some environmental and paratipical factors on the somatic cells count in milk in black-and-white cows

Ivaylo Marinov, Dimo Dimov, Toncho Penev

Abstract: The aim of the present research was to study the influence of some environmental and paratypical factors on the somatic cells count (SCC) in milk in black-and-white dairy cows, Holstein-Friesian type. The survey included a total of 484 lactating cows from 8 cattle farms in Plovdiv region, Bulgaria, by using data from the monthly controls of their productive traits – a total of 3473 Test Day records. A statistically significant effect on the SCC in milk for Test Day of the factors herd, parity, calving season, month of Test Day recording and lactation stage was reported. In cows with larger number of parities, a higher SCC was reported compared to the younger ones. The highest was the SCC in cows at third parity (656.4 thousand/ml) and the lowest at first parity (263.9 thousand/ml). With the highest SCC were cows calved in summer (599.5 thousand/ml), and with the lowest – in winter (177.5 thousand/ml). SCC increased considerably in August and September (562.5 and 461.8 thousand/ml) and reached the highest values in October and November (806.4 and 910.9 thousand/ml). The lowest was the SCC during the winter months from December to February (from 104.8 to 151.6 thousand/ml). The highest SCC in milk was recorded in the first 90 days in milk (DIM) (from 800 to 700.0/ml). After this period, SCC was starting to decline, and after 200 DIM, values relative to normal udder health status of less than 200.0 thousand/ml were reached.

Keywords: calendar month; calving season; dairy cows; lactation stage; parity; SCC

Date published: 2019-12-30