The quality of cow milk and its composition in relationship to metabolic disorders of dairy cows performed by metabolic profile test | Kvalita mlieka a jeho zloženie vo vzťahu k metabolickým ochoreniam dojníc prostredníctvom metabolického profilového testu

The aim of our study was to determine selected biochemical parameters in the blood, urine and milk of dairy cows and their evaluation in metabolic profile test. Fifteen dairy cows from selected agricultural farms were divided into three groups as follow: group 1.- 3-4 weeks after calving (the beginning of lactation), group 2. - 3-4 months after calving (the middle of lactation), and group 3. - 2-3 weeks before calving (the dry period). Concentrations of selected biochemical parameters in the blood (aspartate aminotransferase – AST, urea, total proteins - TP, glucose, and cholesterol), urine (calcium - Ca, phosphorus - P, urea and pH), and milk (fats, proteins, lactose, Somatic Cell Count, urea, milk freezing point) were measured. Total protein concentration in blood (71,40 plus-minus 4,98 g per l) was significantly lower at the beginning of lactation (p less than 0,05) in comparison with the middle of lactation (87,60 plus-minus 6,54 g per l). However, concentration of AST (1,85 plus-minus 0,48 MUkat per l) was significantly higher (p less than 0,01) at the beginning of lactation than in the dry period (1,07 plus-minus 0,23 MUkat per l). Concentration of cholesterol (3,54 plus-minus 0,73 mmol per l)in the middle of lactation was significantly higher (p less than 0,01) than those at the beginning of lactation (1,92 plus-minus 0,49 mmol per l). The highest statistic significant difference (p less than 0,001) was measured in glucose ((3,97 plus-minus 0,19 mmol per l) in dairy cows in the middle of lactation in comparison with dairy cows at the beginning of lactation (2,84 plus-minus 0,51 mmol per l). Concerning indicators of urine, lower statistic significant difference (p less than 0,05) was measured in pH in dairy cows at the beginning of lactation(7,92 plus-minus 0,44 logmolc) and in the middle of lactation (8,43 plus-minus 0,05 logmolc) but also at the beginning of lactation (7,92 plus-minus 0,44 logmolc) in comparison with dry period (8,54 plus-minus 0,06 logmolc). Based on the analysis of other biochemical indicators, an another statistically difference (p less than 0,05) was detected in milk for lactose in the dairy cows at the beginning of lactation (4,70 plus-minus 0,06 g per 100g) in the middle of lactation (4,95 plus-minus 0.14 g per 100g). Some other symptoms leading to sub-clinical diseases, besides worsening the technological quality of the cow milk, were found.