Characterization of the milk lipid fraction in non-dairy sheep breeds

Abstract

Abstract. Studies regarding the composition of milk fat are mostly conducted on dairy breeds. The aim of our studies was to evaluate the fatty acid, cholesterol and phospholipid amount in the milk of two non-dairy sheep breeds. The study was conducted on 60 ewes (Żelaźnieńska strain of Polish Lowland sheep -30 ewes; Wrzosówka breed -30 ewes) from one flock which were kept under the same conditions and maintenance. There were no differences in the amount of the basic components of milk in these two breeds. In the lipid fraction of Wrzosówka sheep (a more primitive breed), higher amounts of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) (P ≤ 0.05), a higher amount of polyunsaturated fatty acids (PUFAs) n-3 (P ≤ 0.01) and a lower ratio of n-6 / n-3 (P ≤ 0.01) were recorded compared toŻelaźnieńska sheep. The milk oḟ Zelaźnieńska sheep had a higher amount of cholesterol (P ≤ 0.05). There were no differences in concentrations of phospholipids.With regard to the two non-dairy sheep breeds, a higher amount of PUFAs n-3 and a more favorable ratio of n-6 / n-3 was observed in the milk of the more primitive breed (i.e., Wrzosówka sheep).

Utilization of Wool Integral Lipids to Determine Milk Fat Content in Suffolk Down Ewes

“…These FAs were also detected in cattle hair and result from the direct uptake of FAs from the gut, which are delivered to the organs via blood [14]. A higher content of PUFAs, especially C18:3n3, was reported in milk fat from non-dairy sheep during grazing [6]. This is likely due to the higher concentration of C18:3n3 and C18:2n6c FAs in the pasture.…”

“…5 PUFA: polyunsaturated fatty acids, sum of C18:2n6c + C18:3n3 + C20:3n6 + C22:2 + C22:6n3. 6 DI C14: desaturase index C14 = C14:1/(C14:0 + C14:1). 7 DI C16: desaturase index C16 = C16:1/(C16:0 + C16:1).…”

“…In fact, an increase in cheese varieties from manufacturers using sheep milk has been observed in Chile; however, the production system varies according to the country; e.g., in Chile, sheep production is based largely on grazing systems, whereas in Spain, for example, sheep cheese is produced throughout the year, leading to intensification and the need for reproductive management [4]. This significant growth in sheep cheese production has stimulated research into sheep milk production with various breeds and production systems [5,6].…”

The changes in the milk composition and its lipid fraction during the rearing of lambs in non-milked sheep

“…Content of sheep's milk and the milkfat composition may depend on many factors, i.e. breed, diet, age of ewes, as well as the stage of lactation (Atti et al 2006, De La Fuente et al 2009, Rozbicka-Wieczorek et al 2015).…”