亚麻籽对肉羊血清脂蛋白和脂肪代谢相关生化指标的影响

Effects of Flaxseed on Serum Biochemical Indices Related to Lipoprotein and Fat Metabolism of Meat Sheep

本试验旨在研究亚麻籽对肉羊血清脂蛋白和脂肪代谢相关生化指标的影响。选取12只体重相近的1岁羯羊，随机分成4组，每组3个重复，每个重复1只羊，对照组采用基础饲粮（无亚麻籽），试验组饲喂的亚麻籽分别采用生粒、炒粒、粉碎3种不同的加工方式。试验包括3个连续的4×4拉丁方试验，亚麻籽添加水平分别为75、150和225g／d。试验期180d，每个拉丁方试验60d，其中分为4期，每期15d。于3个拉丁方试验的各正试期的第2天，分别在饲喂亚麻籽后1．5、7．0、12．0和18．0h颈静脉采血，检测血清中脂蛋白代谢相关生化指标，同时检测225g／d亚麻籽拉丁方试验中血清脂肪代谢相关生化指标。结果表明：1）不同加工方式间比较，炒粒组血清高密度脂蛋白胆固醇（HDLc）、低密度脂蛋白胆固醇（LDLc）和载脂蛋白A（APO—A）浓度以及HDLc相对含量均极显著高于其他各组（P〈0．01），生粒组与粉碎组又极显著高于对照组（P〈0．01）。随着亚麻籽添加水平的增加，血清甘油三酯（TG）、HDLc、LDLc、极低密度脂蛋白胆固醇（VLDLc）和APO—A浓度以及HDLc相对含量均极显著增加（P〈0．01）。不同时间点间比较，饲喂后1．5—18．0h，血清TG、HDLc、VLDLc、APO—A和载脂蛋白B（APO—B）浓度以及LDLc和VLDLc相对含量都经历了先下降再上升而后再下降的波浪式变化过程，变化显著或极显著（P〈0．05或P〈0．01）。2）不同加工方式间比较，炒粒组血清胰岛素（INS）浓度和激素敏感脂肪酶（HSL）活性极显著高于其他各组（P〈0．01），生粒组和粉碎组极显著高于对照组（P〈0．01），而脂肪酸合成酶（FAS）活性变化趋势与之相反；对照组血清β-羟基β-甲基戊二酸单酰辅酶A还原酶（HMGR）活性极显著高于其他各组（P〈0．01），炒粒组和粉碎组极显著高于生粒组（P〈0．01）；血清乙酰辅酶A羧化酶（ACCase）活性为对照组〉粉碎组〉生粒组〉炒粒组，组间差异极显著（P〈0．01）。不同时间点间比较，饲喂后1．5～7．0h，3个试验组血清FAS和ACCase活性显著或极显著下降（P〈0．05或P〈0．01），饲喂后7．0～18．0h，显示逐渐上升的趋势，血清HSL活性和INS浓度变化趋势与之相反；而对照组的变化趋势与试验组趋势相反。总之，亚麻籽可强化机体HDLc营养的同时，极大地消弱LDLc对机体所带来的负面影响。同时，使肉羊血清中脂肪代谢相关生化指标得到显著改善。本试验条件下，炒粒的加工方式效果较好。

This experiment was conducted to study the effects of flaxseed on serum biochemical indices related to lipoprotein and fat metabolism of meat sheep. Twelve 1-year-old wethers with similar body weight were ran- domly divided into four groups with three replicates in each group and one sheep per replicate. Sheep in control group were fed a basal diet （without flaxseed）, and the flaxseed for sheep in experimental groups were pro- cessed under three different modes, which were uncooked grain, saute grain and grounding, respectively. The experiment was consisted of three successive 4 × 4 Latin square tests, and the supplemental levels of flaxseed were 75, 150 and 225 g/d, respectively. The experiment lasted for 180 days with 60 days and four stages （ 15 days per stage） in each Latin square test. Lipoprotein metabolism related biochemical indices were detected from venous blood samples which were collected at 1.5,7.0.12.0 and 18.0 hours after feeding on the second day of every formal experiment period of the three Latin square tests, and fat metabolism related biochemical indices were detected in the 225 g/d flaxseed Latin square test. The results showed as follows ： 1 ） compared a- mong different processing modes, serum high density lipoprotein cholesterin （HDLc）, low density lipoprotein cholesterin （LDLc） and apolipoproteins A （APO-A） concentrations and HDLc relative content in saute grain group were significantly higher than those in the other groups （ P 〈 0.01 ）, and those in uncooked grain and grounding groups were significantly higher than those in control group （P 〈0.01 ）. With the increase of sup- plemental level of flaxseed, serum triglyceride （ TG）, HDLc, LDLc, very low density lipoprotein cholesterin （VLDLc） and APO-A concentrations, and HDLc relative content were all significantly increased （P 〈0.01 ）. Compared among different time points, serum TG, HDLc, VLDLc, APO-A and apolipoproteins B （APO-B） concentrations, and LDLc and VLDLc relative contents experienced an extent of down-up-down during 1.5 to 18.0 hours after feeding. 2 ） Compared among different processing modes, serum insulin （INS） concentration and hormone-sensitive triglayceride lipase （HSL） activity in saute grain group were significantly higher than those in the other groups （ P 〈 0.01 ）, and those in grinding and uncooked grain groups were significantly higher than those in control group （ P 〈 0.01 ）, however, fatty acid synthase （FAS） activity showed a con- verse tendency ; serum 3-hydroxy-3-methylglutaryl-CoA reducase （HMGR） activity in control group was sig- nificantly higher than that in the other groups （ P 〈 0.01 ）, and that in saute grain and grinding groups was sig-nificantly higher than that in uncooked grain group （ P 〈0.01 ） ; serum acetyl-CoA carboxylase （ACCase） ac- tivity was control group 〉 grinding group 〉 uncooked grain group 〉 saute grain group, differences among groups were significant （ P 〈 0.01 ）. Compared among different time points, during 1.5 to 7.0 hours after feeding, serum FAS and ACCase activities in three experimental groups were significantly decreased （ P 〈 0.05 or P 〈0.01）, and during 7.0 to 18.0 hours after feeding, they were gradually increased, however, serum HSL activity and INS concentration exhibited a converse tendency; the above indices related to fat metabolism in control group changed on the contrary with experimental groups. In conclusion, flaxseed can strongly im- prove HDLc nutritional value and weaken positive effects resulting from LDLc on body. At the same time, flaxseed also can improve fat metabolism related serum biochemical indices obviously. Under conditions in the present experiment, the optimal processing mode is saute grain.