Influence of udder secretion disorders of cows in first lactation on hygienic safety and quality of milk. [M.Sc. thesis] | Uticaj poremecaja sekrecije mlecne zlezde krava u prvoj laktaciji na higijensku ispravnost i kvalitet mleka. Magistarski rad
2010
Adamov, N.
In this thesis we examined samples of milk (n=518) on the following parameters: somatic cell count (SCC), total bacteria count (CFU and IBC), fat, protein, lactose and dry matter non fat (DMNF) contents, which was taken from primiparous cows divided in three groups depending on the day in lactation: first group (n=167) included primiparous cows that were 10-100 days in lactation, second group (n=176) 101-200 days in lactation and the third group (n=175) 201 and more days in lactation. The correlation coefficients (r) between SCC, IBC and CFU were positive and significant in all three groups of primiparous cows, which imply that the somatic cell count primarily depends on the infectious status of the mammary gland and all the other physiological and environmental factors have minor influence. The parameters that define the milk hygienic safety (SCC, IBC and CFU) were mostly negatively correlated with milk component contents (fat, protein, lactose and DMNF), except in the second group where positive correlations were observed between SCC and DMNF (r=0.24), and in the third group between SCC and protein content (r=0.03), IBC and fat (r=0.06), IBC and protein (r=0.20), IBC and lactose (r=0.02), CFU and fat (r=0.14) and CFU and protein content (r=0.17). Regardless if these parameters that define the milk hygienic suitability were positively or negatively correlated with milk component contents, the correlation coefficients were not signifiant in neither case, which implies that significant reduction of milk components synthesized in the mammary gland can be expected at somatic cell levels higher than 236.000/ml.
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