engleski

Milk components, SOD activity and oxidative stability of milk in two breeds of dairy goats

The milk components, concentration of TBARS and activity of SOD in raw milk of 14 dairy goats, in the late stage of lactation, were studied. The nutritional status by means of protein and urea content in milk was also evaluated. The milk samples, seven each of Saanen and Alpine goats, from the same farm, were collected and analysed separately for the milk fat, milk protein, solids-non fat (SNF), lactose, urea and somatic cell count (SCC). The SOD activity and TBARS concentration was measured in raw milk, two and 14 hours after the collection and cold storage. No significant differences between breeds regarding the milk components were detected. In all goats, low average milk fat, SNF and lactose content was determined with higher individual variations in SCC in Saanen goats. The TBARS concentration and SOD activity did not differ significantly between breeds, but SOD activity was significantly higher two hours, and TBARS concentration 14 hours after the collection in alpine goat milk samples. TBARS was negatively correlated with urea concentration (r = -0, 85 ; p<0, 05) for Alpine goats and positively correlated with protein and SCC in milk of Saanen goats (r = 0, 87 ; 0, 98 ; p<0, 05). The energy shortage and protein overplus in the diet of Alpine goats might have caused the higher degree of lipid oxidation, probably, due to the higher concentration of unsaturated fatty acid and lower antioxidants concentration in milk.

Dairy goats; Milk composition; Antioxidants

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