Adding plant oils to dairy goat diets: effect on fatty acid content of milk fat

Abstract

The aim of this study was to investigate the effects of adding differently unsaturated vegetable oils to a dairy goat diet on fatty acid content of milk fat. Twelve Malagueña goats were randomly allocated to one of four treatments: no oil basal diet and the same basal diet supplemented with 48 g/d of high oleic sunflower oil, regular sunflower oil or linseed oil. The basal diet was made of alfalfa hay and a pelleted concentrate (30:70 w/w). The concentrate included the respective oils. Supplemented diets decreased medium chain saturated fatty acid content in milk fat (P < 0.05). High oleic sunflower oil increased stearic and oleic acid contents (P < 0.05) and did not affect neither the content of trans monounsaturated fatty acids of 18 carbon atoms nor conjugated linoleic acid content (P > 0.05). Regular sunflower oil increased C18:1t10, vaccenic and rumenic acid contents as well as linoleic to α-linolenic acid ratio (P < 0.05). Linseed oil increased vaccenic, rumenic and α-linolenic acid contents and substantially decreased linoleic to α-linolenic acid ratio (P < 0.05) without affecting C18:1t10 content (P > 0.05). It was concluded that compared to high oleic o regular sunflower oils, adding linseed oil in dairy goat diets modifies milk fat fatty acid content more favourably from the point of view of human health.