Tsiplakou Eleni, Zervas Georgios
Department of Animal Nutrition, Agricultural University of Athens, Iera Odos 75, 118 55 Athens, Greece.
J Dairy Res. 2008 Aug;75(3):270-8. doi: 10.1017/S0022029908003270. Epub 2008 Jun 2.
Olive tree leaves (OTL) and grape marc (GM) are by-products with high linolenic (LNA) and linoleic (LA) acid content, respectively, which can be used as dietary ingredients to increase the cis-9 trans-11 conjugated linoleic acid (CLA) content of milk fat in sheep and goats. An experiment was conducted with 16 Friesian ewes and 16 Alpine goats to study the effect of OTL and GM inclusion in sheep and goat diets on their milk fatty acid profile, with emphasis on cis-9, trans-11 CLA and vaccenic acid (VA). Ewes and the goats were fed the control (C) diets from parturition to the 90 days in milk (DIM) and then both groups were divided into two sub-groups (treatments). The control groups of both species continued to be fed the C diets, whereas the treated groups were gradually switched over a 2-week period (DIM=91-105) from the C diets to that of treatment 1, which contained air-dried OTL. These OTL diets were fed ad libitum for 1 month (DIM=106-135). After that period, the same treated groups, after 2 weeks of gradual adaptation (DIM=136-150), were switched to treatment 2, which contained air-dried GM. The GM diets were fed ad libitum for 1 month (151-180 DIM). Concentrations of polyunsaturated fatty acids (PUFA) and mono-unsaturated fatty acids increased significantly in milk fat of sheep fed OTL v. C. For goats, only the PUFA in milk fat was increased by feeding OTL compared with C. Relative to C, GM increased significantly the concentration of PUFA only in milk fat of sheep. OTL and GM diets increased the cis-9, trans-11 CLA and VA content in milk fat, compared with C, only in sheep. GM caused a sharp increase in 18:0 only in sheep milk fat, while the OTL diet increased significantly the 18:0 in milk fat of goats. GM and OTL diets also had opposite effects on the 18:1/18:0 ratio of sheep milk fat. In conclusion, OTL and GM, when included in sheep diets altered the milk fatty acid profile with a pronounced increase in cis-9, trans-11 CLA and VA contents. The results show that the response of sheep and goats to OTL and GM diets was different, suggesting a species difference that needs further investigation.
油橄榄树叶（OTL）和葡萄皮渣（GM）分别是富含亚麻酸（LNA）和亚油酸（LA）的副产品，可作为膳食成分用于提高绵羊和山羊乳脂肪中顺-9反-11共轭亚油酸（CLA）的含量。用16头弗里斯兰母羊和16只阿尔卑斯山羊进行了一项实验，以研究在绵羊和山羊日粮中添加OTL和GM对其乳脂肪酸谱的影响，重点关注顺-9，反-11 CLA和vaccenic酸（VA）。母羊和山羊从分娩到产奶90天（DIM）期间饲喂对照（C）日粮，然后将两组均分为两个亚组（处理组）。两个物种的对照组继续饲喂C日粮，而处理组在2周内（DIM = 91 - 105）从C日粮逐渐转换为含有风干OTL的处理1日粮。这些OTL日粮自由采食1个月（DIM = 106 - 135）。在此期间之后，相同的处理组在经过2周的逐渐适应（DIM = 136 - 150）后，转换为含有风干GM的处理2日粮。GM日粮自由采食1个月（151 - 180 DIM）。与C日粮相比，饲喂OTL的绵羊乳脂肪中多不饱和脂肪酸（PUFA）和单不饱和脂肪酸的浓度显著增加。对于山羊，与C日粮相比，仅饲喂OTL可使乳脂肪中的PUFA增加。相对于C日粮，GM仅使绵羊乳脂肪中的PUFA浓度显著增加。与C日粮相比，OTL和GM日粮仅在绵羊中增加了乳脂肪中顺-9，反-11 CLA和VA的含量。GM仅使绵羊乳脂肪中的18:0急剧增加，而OTL日粮显著增加了山羊乳脂肪中的18:0。GM和OTL日粮对绵羊乳脂肪的18:1/18:0比值也有相反的影响。总之，当OTL和GM包含在绵羊日粮中时，会改变乳脂肪酸谱，使顺-9，反-11 CLA和VA含量显著增加。结果表明，绵羊和山羊对OTL和GM日粮的反应不同，这表明存在物种差异，需要进一步研究。
