Administration of olive cake for ewe feeding: effect on milk yield and composition

Sixty Comisana lactating ewes were divided into three homogenous groups of twenty each, respectively, called "Control", "Olive" and "Olive + E". The last two groups where fed on a concentrate with 20% of partly-destoned olive cake. The animals of "Olive + E" group received an integration of 280 mg per head per day of tocopheryl acetate. Every 15 days, the individual milk yield was recorded, and further the chemical composition, the coagulation properties and the fatty acid composition of the milk were determined. Data were processed by GLM of SAS considering the variables: treatment and period. Administration of olive cake influenced the milk yield that was significantly higher in the "Olive" and "Olive + E" groups ("Control": 649 g per day; "Olive": 772 g per day; "Olive + E": 711 g per day). The significantly highest protein and casein percentages (P < 0.05) were observed in "Control" group. The lowest (P < 0.01) somatic cell count (SCC) was observed in the "Olive + E" group. As regards the clotting parameters, a significant (P < 0.01) decrease was observed for clotting time (r) in the "Olive + E" group, while no significant differences were observed for curd firming time (k(20)) and curd firmness (a(30)) parameters. The highest content of fatty acid classes was observed for saturated (P < 0.01) in "Control" group and for monounsaturated (P < 0.01) in "Olive" and "Olive + E" groups, the n-3 and n-6 polyunsaturated levels were similar in the different groups. The results showed the possibility of administration of olive cake for feeding ewes, considering the positive effects on the milk yield and no effects on the chemical composition and the clotting proper-ties, and also the improvement of the dietetic-nutritional characteristics testified by the increase of the unsaturated/saturated fatty acid ratio and by the decrease of the atherogenic and thrombogenic indices. (C) 2004 Elsevier B.V. All rights reserved.