title: Quality and fatty acid profile of the milk of indigenous goats subjected to different local diets in Tunisian arid lands.
abstract: The study tested the hypothesis that certain pastoral forages and olive by-products, available in arid areas, may positively influence fatty acid composition and physicochemical properties of goat's milk. Thirty indigenous goats (body weight = 25.2 kg; age = 4.1 years) were allocated to three groups. During 60 days, the goats received ad libitum either dried olive leaves + Stipa tenacissima (group OL), khortane grass hay (group Ko) or oat hay (control diet, group OH). Milk samples were collected and analysed for total solids, fat, protein, lactose and ash content and fatty acid profile. Average milk yield did not statistically differ among groups. Milk total solids from OL group were higher in comparison with Ko and C groups (15.3, 14.7 and 14.5%, respectively; p < 0.05). Fat content was also higher for the OL group as compared to the other groups (5.44 vs. 5.01 and 4.66%, respectively, for Ko and OH). No significant differences were observed for the milk content of lactose, protein and ash. The percentage of saturated fatty acids of total milk fat was higher in OL and Ko groups compared to the C group (p < 0.001); the milk whereof was characterized by the highest percentage of monounsaturated (p < 0.01) and total unsaturated fatty acids. Milk fat of Ko and C groups showed significantly higher proportions of rumenic (CLA cis-9 trans-11) and vaccenic acids (C18:1 trans-11) compared to OL milk. The feeding system based on Stipa tenacissima and dried olive leaves resulted in the milk lowest proportion of trans-fatty acids and the highest proportion of polyunsaturated ω3-fatty acids (p < 0.05).
authors.affiliation: Laboratory of livestock and Wild life, Institute of Arid Lands (IRA Medenine), Medenine, Tunisia.|Institut Supérieur Agronomique, Sousse, Tunisie.
authors.forename: N
authors.initials: N
authors.lastname: Ayeb
authors.affiliation: Department of Animal Production Research, AGRIS-Sardegna, Olmedo, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Addis
authors.affiliation: Department of Animal Production Research, AGRIS-Sardegna, Olmedo, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Fiori
authors.affiliation: Laboratory of livestock and Wild life, Institute of Arid Lands (IRA Medenine), Medenine, Tunisia.
authors.forename: S
authors.initials: S
authors.lastname: Khorchani
authors.affiliation: Laboratory of livestock and Wild life, Institute of Arid Lands (IRA Medenine), Medenine, Tunisia.
authors.forename: M
authors.initials: M
authors.lastname: Atigui
authors.affiliation: Laboratory of livestock and Wild life, Institute of Arid Lands (IRA Medenine), Medenine, Tunisia.
authors.forename: T
authors.initials: T
authors.lastname: Khorchani
mesh_terms: D000821:Animal Feed / Q000032:analysis*; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D003889:Desert Climate; D004032:Diet / Q000662:veterinary*; D005227:Fatty Acids / Q000737:chemistry* / Q000378:metabolism; D005260:Female; D006041:Goats / Q000502:physiology*; D008892:Milk / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry; D010944:Plants / Q000737:chemistry / Q000145:classification; D014416:Tunisia
chemical_list: D005227:Fatty Acids
keywords: arid land; fatty acids; goat production; local resource; milk quality