Effect of the feeding period on the chemical composition and fatty acid profile of milk from French Alpine dairy goats

• Autorzy: Czarniawska-Zajac S. , Brzostowski H. , Zielazny M.
• Języki publikacji: EN

Abstrakty

EN

The chemical composition and fatty acid profile of milk from French Alpine dairy goats, obtained during the period of summer feeding and winter feeding, were studied. Milk samples were collected at one-month intervals, to determine dry matter, solids non-fat, protein, fat, fatty acid profile, lactose, urea and somatic cell count. The fatty acid composition of milk fat was determined for particular experimental twice during lactation, i.e. in the middle of the winter season and in the middle of the summer season. It was found that goat’s milk produced in winter had higher levels of dry matter, fat, protein and urea, and a lower lactose content. Goat’s milk obtained over this feeding period had a higher urea content. The somatic cell count recorded in milk from the experimental goats remained within the physiological norms for goat’s milk. The feeding period had a significant effect on the fatty acid profile of goat’s milk. Milk produced in summer had higher levels of unsaturated fatty acids, especially polyunsaturated fatty acids, as well as a more favorable ratio between unsaturated fatty acids and saturated fatty acids, and a lower ratio between monounsaturated fatty acids and polyunsaturated fatty aThe chemical composition and fatty acid profile of milk from French Alpine dairy goats, obtained during the period of summer feeding and winter feeding, were studied. Milk samples were collected at one-month intervals, to determine dry matter, solids non-fat, protein, fat, fatty acid profile, lactose, urea and somatic cell count. The fatty acid composition of milk fat was determined for particular experimental twice during lactation, i.e. in the middle of the winter season and in the middle of the summer season. It was found that goat’s milk produced in winter had higher levels of dry matter, fat, protein and urea, and a lower lactose content. Goat’s milk obtained over this feeding period had a higher urea content. The somatic cell count recorded in milk from the experimental goats remained within the physiological norms for goat’s milk. The feeding period had a significant effect on the fatty acid profile of goat’s milk. Milk produced in summer had higher levels of unsaturated fatty acids, especially polyunsaturated fatty acids, as well as a more favorable ratio between unsaturated fatty acids and saturated fatty acids, and a lower ratio between monounsaturated fatty acids and polyunsaturated fatty acids. Goat’s milk obtained over this period had higher concentrations of linoleic acid (C18:2), linolenic acid (C18:3) and conjugated dienes of linoleic acid.

PL

Badano sk³ad chemiczny i profil kwasów tłuszczowych w mleku kóz rasy alpejskiej francuskiej pochodzącym z okresu żywienia zimowego i letniego. W próbkach mleka pobieranych w odstępach miesięcznych oznaczono zawartość: suchej masy, suchej masy beztłuszczowej, białka, tłuszczu, laktozy, mocznika i komórek somatycznych. Skład kwasów tłuszczowych tłuszczu mleka koziego dla poszczególnych kóz doświadczalnych ustalono dwukrotnie w okresie laktacji, tj. w połowie sezonu żywienia zimowego i żywienia letniego. Badania wykazały, że mleko kozie pozyskiwane w okresie żywienia zimowego charakteryzowało się wyższą zawartością suchej masy, tłuszczu i białka, a niższą zawartością laktozy. W mleku kóz z tego okresu żywienia wykazano wyższą zawartość mocznika. Liczba komórek somatycznych stwierdzona w mleku badanych grup kóz mieoeci się w granicach norm fizjologicznych, przyjętych dla mleka koziego. Badania wykazały wpływ sezonu żywienia na profil kwasów tłuszczowych mleka. Mleko kozie pochodzące z okresu żywienia letniego charakteryzuje się wyższym udziałem kwasów nienasyconych, a szczególnie wielonienasyconych. Mleko z tego okresu żywienia kóz odznaczało się korzystniejszym stosunkiem kwasów UFA do SFA, a także niższym stosunkiem kwasów MUFA do PUFA. W mleku z sezonu żywienia letniego stwierdzono wyższą zawartość kwasów: linolowego (C18:2), linoleinowego (C18:3) i sprzężonego dienu kwasu linolowego (SKL).

Słowa kluczowe

EN

winter feeding; feeding period; summer feeding; goat milk; French Alpine dairy goat; milk composition; dairy goat; fatty acid; chemical composition; animal nutrition

• Wydawca: -
• Czasopismo: Polish Journal of Food and Nutrition Sciences
• Rocznik: 2006
• Tom: 15/56
• Numer: Spec.Issue 1
• Opis fizyczny: p.51-55,ref.

Twórcy

autor

Czarniawska-Zajac S.

• University of Warmia and Mazury, Oczapowskiego 5, 10-719 Olsztyn, Poland

autor

Brzostowski H.

autor

Zielazny M.