从巨噬细胞极化角度分析不同油脂饮食对小鼠腹股沟皮下脂肪组织沉积的影响

为分析两种脂肪供能条件下3种不同油脂饮食对小鼠腹股沟皮下脂肪沉积及其巨噬细胞分型的影响,90只C57BL/6J小鼠被随机分为6组,分别饲喂低脂猪油（Lar-10%）、低脂菜籽油（Rap-10%）、低脂橄榄油（Oli-10%）、高脂猪油（Lar-30%）、高脂菜籽油（Rap-30%）和高脂橄榄油（Oli-30%）,16周后解剖取腹股沟皮下脂肪组织,并对其进行苏木精-伊红染色,活性氧（Reactive oxygen species,ROS）含量检测,M1、M2型巨噬细胞标记物（CD11c和CD206）荧光双染,并通过ELISA检测其含量。结果表明：1）在低脂饮食条件下,三种油脂对小鼠腹股沟皮下脂肪组织重量、脂肪细胞横截面积、腹股沟皮下脂肪ROS含量均无显著影响（P>0.05）;2）随着脂肪供能水平的提高,小鼠腹股沟皮下脂肪沉积显著增加（P<0.05）,在高脂饮食条件下,Lar-30%组的小鼠腹股沟皮下脂肪组织重量显著高于Rap-30%和Oli-30%组（P<0.05）,并且相对于其他两组,Oli-30%组小鼠腹股沟皮下脂肪组织中ROS含量极显著降低（P<0.01）;...     

A SIMPLE METHOD OF OBTAINING SINGLESPORE CULTURES

Rats first fed soybean oil and peanut oil diets, then subjected to the process of fat depletion through selective starvation, involving 23 to 27 per cent. loss in body weight, before being fed a "hardening" diet, yielded "harder" fats-fats of lower iodine number values-than the fats of rats which were not starved before being fed the carbohydrate-rich diet. In other words, through the process of starvation, the "soft" oily fat produced on diets containing soybean' or peanut oils is very largely removed, thereby permitting the deposit of a "hard" fat. To obtain a fat of equal "hardness" from rats which were not subjected to the starvation treatment would have required a much longer period of feeding of the diet rich in starch than was found necessary with rats after first being starved. The growth of recovery made by the rats of the starved lots was made on a low food intake. With the starved rats flrst fed peanut oil, the food intake of the carbohydrate-rich diet was less than with the non-starved group. The possible application of these findings to practical animal husbandry is obvious.     

Growth Response and Fatty Acid Composition of Juvenile Procambarus clarkii Fed Different Sources of Dietary Lipid

An experiment was conducted to evaluate the effects of feeding various sources of dietary lipidon weight gain, feed conversion, survival and fatty acid composition of juvenile red swamp crawfish, Procam-barus clarkii. Six semi-purified diets containing vitamin-free casein, defatted soybean meal, 0.5% cholinechloride, 0.5 % glycine and 0.5 % cholesterol were supplemented with 6.0 % of either anchovy oil, linseed oil,soybean oil, rapeseed oil, safflower oil or pork lard. Each diet was fed to crawfish (3.07±0.21 g averageweight) in three replicate aquaria for 60 days. Survival rate, weight gain and feed conversion were best forcrawfish fed the diet containing anchovy oil. Crawfish fed the linseed oil diet had the second highest weightgain, followed by crawfish on soybean oil, repaseed oil, safflower oil and pork lard diets, respectively. Feedconversion values were a reflection of weight gain. Results showed that both n-6 and n-3 fatty acids are dietaryessential for juvenile Procambarus clarkii, although n-3 fatty acids promoted faster growth than n-6. Howev-er, highly unsaturated fatty acids (HUFA) (20 : 5n-3 and 22 : 6n-3) had better growth-promoting effect than18 : 3n-3, due probably to the limited ability of crawfish to bioconvert fatty acids to polyenoic forms of longerchain length. The fatty acid composition of the crawfish generally reflected that of the dietary lipids, especial-ly for the diets containing unsaturated fatty acids.     

不同锰源对肉鸡胴体性能和肌肉品质的影响

 【目的】用336只1日龄AA肉公鸡进行试验，研究饲粮添加不同锰源对肉鸡胴体性能、肌肉品质、腹脂和肌肉中相关酶活性及肌肉中MnSOD mRNA水平的影响。【方法】采用3×3两因子安排的完全随机设计，将试鸡按体重随机分为7个处理组，分别饲喂不添加锰的玉米-豆粕型基础饲粮和在基础饲粮中以无机硫酸锰、氨基酸锰A（Mn AA A）和氨基酸锰B（Mn AA B）形式分别添加100和200mg•kg-1锰的试验饲粮，试验期为42 d。【结果】添加锰对肌肉pH、滴水损失、剪切力、肌间脂肪、L* 值、a* 值等均无显著影响 (P﹥0.10)；各添加锰组鸡腹脂率、腹脂脂蛋白脂酶（LPL）和苹果酸脱氢酶（MDH）活性及腿肌丙二醛（MDA）含量显著低于未添加锰的对照组 (P﹤0.10)，添加Mn AA A组和添加Mn AA B组腹脂LPL活性均显著低于添加MnSO4组（P﹤0.05）；各添加锰组腹脂激素敏感脂酶（HSL）活性、胸肌和腿肌细胞线粒体中MnSOD活性和MnSOD mRNA水平均显著高于未添加锰的对照组（P﹤0.02）， 添加Mn AA A组腿肌细胞线粒体中MnSOD mRNA水平显著高于添加无机硫酸锰组（P﹤0.02）。【结论】中等络合强度有机锰（Mn AA A）比无机硫酸锰更能有效降低肉鸡腹脂LPL活性及增强腿肌细胞线粒体中MnSOD的基因表达,并进而改善了肉鸡胴体性能和肌肉品质。     

不同脂肪源对异育银鲫形体与血液生化指标的影响

在基础料中分别添加4%的鱼油、豆油、猪油、花生油和混合油(鱼油、豆油、猪油质量比为3∶4∶3),制成5种等氮试验饲料,饲喂初始体质量为(6.04±0.05) g 的异育银鲫60 d,以考察5种脂肪源对异育银鲫形体指标和血清生化指标的影响.结果表明:猪油组的肝体指数与脏体指数均最高,猪油组肝体指数显著高于鱼油组,猪油组脏体指数显著高于混合油组(P<0.05);各试验组鱼体肥满度差异不显著(P>0.05);各试验组总蛋白(TP)含量和白蛋白(ALB)含量的变化趋势相似,均为鱼油组显著高于猪油组(P<0.05),其余各组之间差异不显著(P>0.05);各试验组谷草转氨酶(AST)活性和谷丙转氨酶(ALT)活性的变化趋势相似,均为猪油组显著高于鱼油组(P<0.05),其余各试验组之间差异不显著(P>0.05);鱼油组甘油三酯(TG)含量最低,豆油组其次,均显著低于混合油组(P<0.05);鱼油组高密度脂蛋白(HDL–C)含量最高,花生油组其次,均显著高于猪油组(P<0.05);各试验组球蛋白(GLB)、胆固醇(CHO)、葡萄糖(BGLU)、低密度脂蛋白(LDL–C)、皮质醇、胰高血糖素(Glu)和胰岛素(Ins)的含量和碱性磷酸酶(AKP)活性差异不显著(P>0.05).在本试验5种脂肪源中,鱼油对异育银鲫形体与血液生化指标的作用效果最好,豆油、花生油和混合油其次,猪油最差     

Liquid Chromatography-mass Spectrometry Analysis on Effect of Roughage Types on Liver Metabolic in Dairy Cows

The major objective of this study was to determine the effect of corn straw or mixed diet on the small molecule metabolites of liver and milk production of healthy Chinese Holstein cows during lactation.In this study,metabolomic methods based on ultra performance liquid chromatography-mass spectrometry (LC-MS) were used to study the liver metabolites of dairy cows fed on corn straw diet or mixed diet.Ten healthy Chinese Holstein cows were randomly assigned to two groups,under the same management condition,fed different diets respectively,corn straw group (CS) or a mixture of alfalfa hay and Chinese wild rye hay mixed forage group (MF).All the cows were fed for 8 weeks and recorded body weight,dry matter intake,body condition score,fat,protein,lactose,milk yield and the total solids.Livers were sampled from each cow through a liver puncture needle for analysis of a significant difference in small molecule metabolites in cow liver samples from the two different diets.The results suggested that different diet types had significant effects on liver metabolism and milk components in dairy cows.The contents of milk fat,the total solids,milk protein,lactose,dry matter intake (DMI),milk yield,milk protein (%),lactose (%) and milk fat (%) of the corn straw group were significantly lower than those of the mixed forage group (p0.05);the contents of phosphatidylcholine (PC),histidine,hypoxanthine and mridine in liver tissues of the corn straw group were significantly lower than those in the mixed forage group (p0.05);acetylcarnitine,uric acid,triacylglycerol (TG),acetal phosphatidylcholine (plasmenyl-PC),acetalphosphatidylethanolamine (plasmenyl-PE) and sphingomyelin (SM) of the corn straw group were significantly higher than those in the mixed forage group (p0.05).In summary,cows fed on mixed forage diet significantly improved milk yield and lactation performance clearly.     

全脂大豆对肉仔鸡生产性能的影响

研究了生,熟全脂大豆对肉仔鸡不同生长发育阶段的影响,将２８０只１日龄艾维茵（Ａｖｉａｎ）肉鸡雏随机分成７组,每组４个重复小群,每个重复小群１０只鸡雏,饲喂含１５％熟大豆,１５％生大豆的试验日粮和对照（豆粕＋豆油）日粮。结果表明：饲喂生大豆饲粮肉仔鸡日增重比饲喂对照和熟大豆饲粮肉仔鸡日增重分别降低了６．５９％,１０．７３％,其饲料效率降低了１０．５２％．６．４８％。     

鱼油或共轭亚油酸对小鼠卵母细胞体外发育能力和线粒体功能的影响

为研究富含n-3或n-6多不饱和脂肪酸(polyunsaturated fatty acid,PUFA)日粮对小鼠卵母细胞体外发育和线粒体功能的影响,把90只14g左右昆明雌鼠随机分为3组,分别饲喂40g/kg豆油日粮,40g/kg鱼油日粮或40g/kg共轭亚油酸(conjugated linoleic acid,CLA)日粮30d;注射雌激素诱导小鼠超数排卵后,检测卵母细胞活性线粒体分布、线粒体钙浓度、膜电位以及脂肪滴分布;利用体外受精技术,评价卵母细胞体外发育能力。结果表明:相对于每个活性线粒体的分布,饲喂鱼油日粮的小鼠卵母细胞内层钙的分布比豆油日粮组有所升高(P<0.05),但是各组卵母细胞的活性线粒体比例和膜电位均没有显著性改变。另外,鱼油日粮组小鼠卵母细胞内脂滴密集,而CLA日粮组小鼠卵母细胞脂肪滴分布不均匀,每个卵母细胞所含脂肪较少。各日粮组卵母细胞受精率(2-细胞)没有显著性差异,但是CLA日粮组受精卵发育至桑葚胚和囊胚的比率分别比豆油组降低51.80%(P<0.05)和62.19%(P<0.05),比鱼油组降低52.97%(P<0.05)和60.89%(P<0.05)。因此,小鼠饲喂鱼油日粮可扰乱卵母细胞内钙平衡,但未改变其体外发育能力;CLA日粮可能通过促进卵母细胞内脂肪的降解从而降低受精卵体外发育率。     

羟基蛋氨酸钙对鲤生长性能和白肌营养组成的影响

分别以豆粕或鱼粉加豆粕为主要蛋白源配制等氮、等能的豆粕基础饲料或鱼粉饲料,并在豆粕基础饲料中分别添加不同水平的羟基蛋氨酸钙（MHA-Ca）（0．045％、0．090％、0．135％和0．180％）作为实验饲料。以基础饲料组和鱼粉组为对照,饲喂鲤（47．12±2．54）g8周,测定实验鱼的体长、体重,并计算存活率、相对增重率、相对增长率、饲料系数和蛋白质效率。同时取实验鱼的白肌,测定其水分、粗蛋白、粗脂肪和粗灰分的含量。结果表明,0．135％MHA-Ca组的相对增重率和相对增长率显著地高于豆粕基础饲料组（P〈0．05）,但与鱼粉组和其他MHA-Ca组没有显著性差异;在豆粕基础饲料中添加0．135％MHA-Ca,饲料利用效率和蛋白质效率显著地增加（P〈0．01）,但饲料系数和蛋白质效率与鱼粉组之间无显著性差异（P〉0．05）。同豆粕基础饲料组相比,0．090％和0．135％MHA-Ca组鲤肌肉蛋白质含量显著增加（P〉0．05）,但与鱼粉组相比无显著性差异（P〉0．05）。同豆粕基础饲料和鱼粉饲料相比,豆粕基础饲料中添加不同水平的MHA-Ca对鲤白肌中水分、脂肪、灰分含量无显著影响（P〉0．05）。     

羟基蛋氨酸钙对鲤生长性能和白肌营养组成的影响

分别以豆粕或鱼粉加豆粕为主要蛋白源配制等氮、等能的豆粕基础饲料或鱼粉饲料，并在豆粕基础饲料中分别添加不同水平的羟基蛋氨酸钙（MHA-Ca）（0．045％、0．090％、0．135％和0．180％）作为实验饲料。以基础饲料组和鱼粉组为对照，饲喂鲤（47．12±2．54）g8周，测定实验鱼的体长、体重，并计算存活率、相对增重率、相对增长率、饲料系数和蛋白质效率。同时取实验鱼的白肌，测定其水分、粗蛋白、粗脂肪和粗灰分的含量。结果表明，0．135％MHA-Ca组的相对增重率和相对增长率显著地高于豆粕基础饲料组（P〈0．05），但与鱼粉组和其他MHA-Ca组没有显著性差异；在豆粕基础饲料中添加0．135％MHA-Ca，饲料利用效率和蛋白质效率显著地增加（P〈0．01），但饲料系数和蛋白质效率与鱼粉组之间无显著性差异（P〉0．05）。同豆粕基础饲料组相比，0．090％和0．135％MHA-Ca组鲤肌肉蛋白质含量显著增加（P〉0．05），但与鱼粉组相比无显著性差异（P〉0．05）。同豆粕基础饲料和鱼粉饲料相比，豆粕基础饲料中添加不同水平的MHA-Ca对鲤白肌中水分、脂肪、灰分含量无显著影响（P〉0．05）。     

不同饲料蛋白质水平条件下L-肉碱对鲤鱼生长和肌肉营养成分的影响

在不同饲料蛋白质水平（28％，32％，36％）条件下，于饲料中分别添加0，50，10，150，200，250mg/kgL肉碱，研究其对鲤鱼（Cyprinus carpioL.）生长和肌肉营养成分的影响。结果表明，试验期末添加150mg/kgL－肉碱处理组鲤鱼体重最大，低蛋白水平饲料添加L－肉碱后鲤鱼增重率最大，肌肉业蛋白质含量相对增加了3．13％，肌肉粗脂肪含量相对降低了11．45％，与对照组相比差异极显著。在不同饲料蛋白质含量相对增加了3．13％，肌肉粗脂肪含量相对降低了11．45％，与对照组相比差异极显著。在不同饲料蛋白质含量条件下，添加外源性L－肉碱可明显促进鲤鱼的生长，改善肉质质量，在较低蛋白质含量饲料中添加一定量L－肉碱，可使鲤鱼的生长速度和肌肉营养成分达到较高蛋白质含量饲料的水平。     

饲料中脂肪含量对花生长性能的影响

在水温23±5℃下,将体重14．38g的花鲭（Hemibarbus maculates）鱼种放养在18个60cm×60cm×120cm的网箱中,网箱放在室外2个6．0m×2．0m×1．2m的流水池中,投喂以鱼粉、玉米蛋白、豆粕和棉粕为蛋白源,以豆油为脂肪源配制成脂肪含量为5．20％、7．21％、9．23％、11．18％,13．21％和15．20％的6种等氮半纯化饲料,每种饲料3个重复。100d的饲养试验表明,饲料脂肪水平低于11．18％时,特定生长率、饲料转化率、蛋白质效率和营养物质消化率与饲料脂肪水平呈正相关,各组间肌肉和肝胰脏的粗脂肪含量无显著差异（P〉0．05）;饲料脂肪水平高于11．18％时,特定生长率、饲料转化率和蛋白质效率与饲料脂肪水平呈负相关,各组间肌肉和肝胰脏的粗脂肪含量差异显著（P〈0．05）。花鲭摄食脂肪含量为11．18％的饲料时,特定生长率、蛋白质效率最高,饲料系数最低,与饲料脂肪水平为5．20％和15．20％的试验组间差异显著（P〈0．05）。肌肉渗出性损失和肝体比随饲料脂肪水平的增加而逐渐升高。综合各项指标,推荐1龄花鲭鱼种饲料脂肪水平为9．20％-11．18％。     

不同形态锰对肉仔鸡脂肪代谢关键酶活性及其基因表达的影响

 【目的】研究添加不同形态锰及锰水平对肉仔鸡脂肪代谢关键酶活性及其mRNA水平的影响。【方法】试验采用2×2（两种锰源×两个锰添加水平）两因子完全随机设计,另加一个不添加锰的对照组。将240只1日龄AA肉公鸡按体重随机分为5个处理组,每组设8个重复,每个重复6只鸡,分别饲喂不添加锰的玉米-豆粕型基础饲粮（对照组）和在基础饲粮中分别添加100和200 mg•kg-1锰（源于硫酸锰（MnSO4•H2O）和氨基酸锰（Mn AA））的饲粮,试验期42 d。【结果】添加锰对腹脂率无显著影响（P＞0.10）,但添加锰组有降低腹脂率的趋势（P=0.103）;肝脏脂肪酸合成酶（FAS）和苹果酸脱氢酶（MDH）及腹脂激素敏感脂酶（HSL）活性不受添加锰源及锰源与锰水平互作的影响（P＞0.10）,但受到添加锰水平的显著影响（P＜0.10）;添加100 mg•kg-1锰组FAS活性显著低于对照组（P＜0.10）,添加100和200 mg•kg-1锰组肝脏MDH活性显著低于对照组（P＜0.01）,而两个添加锰水平组间无显著差异（P＞0.10）;添加200 mg•kg-1锰组腹脂HSL活性显著高于对照组（P＜0.05）和添加100 mg•kg-1锰组（P＜0.10）,添加100 mg•kg-1锰组较对照组无显著差异（P＞0.10）;添加锰源及锰源与锰水平互作对肝脏FAS和MDH及腹脂FAS和LPL mRNA水平均无显著影响（P＞0.10）,但添加锰水平显著降低肝脏MDH mRNA水平（P＜0.01）,而对肝脏FAS及腹脂FAS和LPL mRNA水平无显著影响（P＞0.10）;添加100 mg•kg-1和200 mg•kg-1组肝脏MDH mRNA水平都显著低于对照组（P＜0.01）,但是这两个添加锰水平组间无显著差异（P＞0.10）。【结论】 添加锰可以通过降低肝脏FAS和MDH活性及提高腹脂中HSL活性来降低肉仔鸡腹脂沉积,而锰可能通过降低肝脏MDH mRNA水平来降低其酶活性,有机锰和无机锰在以上作用效果方面无差异。     

油脂来源及使用量对小鼠生长、健康、血脂和肝脏胆固醇代谢指标的影响

【目的】观察饲料中添加不同种类和不同剂量的油脂对小鼠生长性能、健康状态、血脂指标和肝脏胆固醇代谢关键基因相对表达量的影响,探讨日粮中不同油脂来源及使用量对肝脏胆固醇代谢的作用机制,为哺乳动物筛选较为适宜的油脂类型及其添加量提供理论参考。【方法】试验选取3周龄体重16-19 g的健康昆明种小鼠48只,随机分为4组,每组4个重复,每个重复3只。4组分别饲喂正常小鼠饲料（对照组）和添加4%豆油（B组）、4%乳化椰子粉（L组）以及8%乳化椰子粉（H组）的饲料14 d。试验期间,记录每天的饲喂次数、每次饲喂量、饲料剩余量,所有试验动物均自由采食和饮水。分析试验期间小鼠的体重变化和平均日采食量（ADFI）、平均日增重（ADG）以及料重比（F/G）等生长性能指标,分析小鼠的血液分布和健康指数等健康状态指标,测定小鼠的肝脏重以及甘油三酯（TG）、总胆固醇（TC）、高密度脂蛋白胆固醇（HDL-C）、低密度脂蛋白胆固醇（LDL-C）等血清脂质指标,运用实时荧光定量PCR技术检测小鼠肝脏组织中胆固醇7-α羟化酶（CYP7A1）、低密度脂蛋白受体（LDLR）和3-羟-3-甲基戊二酸单酰辅酶A还原酶（HMGCR）这3个基因的mRNA表达水平。【结果】①生长性能方面,添加4%豆油组的小鼠体重变化、平均日采食量和肝脏脏器指数与对照组差异显著（P＜0.05）,而平均日增重、料重比和肝脏重与对照组差异不显著（P＞0.05）;添加4%乳化椰子粉组的小鼠各生长性能指标与对照组差异不显著（P＞0.05）;8%乳化椰子粉显著提高小鼠的平均日采食量（P＜0.05）,其他指标差异不显著（P＞0.05）。②健康状态方面,各试验组小鼠的血液分布和健康指数与对照组相比均无显著性差异（P＞0.05）。③血脂指标方面,与对照组相比,添加4%豆油显著降低了小鼠血清中TC和HDL-C含量（P＜0.05）,对TG和LDL-C的影响差异不显著（P＞0.05）,添加4%乳化椰子粉对小鼠的各项血脂指标均无显著性影响（P＞0.05）,添加8%乳化椰子粉能显著降低血清TC含量（P＜0.05）,但对TG、HDL-C和LDL-C无显著性影响（P＞0.05）;④肝脏胆固醇相关基因方面,添加8%乳化椰子粉组肝脏中CYP7A1基因mRNA表达量显著高于对照组（P＜0.05）,而4%豆油组和4%乳化椰子粉组与对照组相比无显著差异（P＞0.05）。肝脏HMGCR基因和LDLR基因mRNA表达水平与对照组差异不显著（P＞0.05）。【结论】日粮中添加豆油增加了小鼠日采食量和体重等指标,降低了血清总胆固醇和高密度脂蛋白胆固醇;高剂量乳化椰子粉的添加提高了小鼠日采食量,降低了血清总胆固醇,并增加了肝脏CYP7A1基因mRNA的表达。相比于添加高剂量乳化椰子粉,低剂量乳化椰子粉在改善小鼠脂代谢方面应用效果并不好。添加油脂可能是通过调控肝脏中胆固醇代谢相关酶的基因表达量来影响小鼠肝脏胆固醇的代谢,从而维持体内的胆固醇代谢的稳态。     

大口黑鲈饲料中2种植物性蛋白质混合物替代鱼粉的研究

为了探讨在大口黑鲈饲料中去皮豆粕分别与玉米蛋白和大米蛋白组成的2种植物性蛋白质混合物替代鱼粉的可行性,分别于含45%和30%鱼粉的配方中配比上述2种植物性蛋白质混合物,配制成4种等氮等能的饲料。用上述饲料饲养初始体质量为(58.69±0.07)g的大口黑鲈53 d。结果显示:30%鱼粉组的终末体质量和特定生长率显著高于45%鱼粉组(P0.05),而饲料效率、蛋白质效率、蛋白质消化率和氨基酸消化率之间无显著性差异(P0.05)。玉米蛋白组的饲料效率和蛋白质效率显著高于大米蛋白组(P0.05),而摄食量显著低于大米蛋白组(P0.05)。全鱼和肌肉的粗蛋白质、粗脂肪、水分和灰分各组间差异不显著(P0.05)。30%鱼粉组的血清溶菌酶活性和血清蛋白含量显著高于45%鱼粉组(P0.05),而玉米蛋白组和大米蛋白组对血清溶菌酶活性和血清蛋白含量的影响差异不显著(P0.05)。红细胞数和红细胞压积各组间差异不显著(P0.05)。本研究表明,去皮豆粕分别与玉米蛋白和大米蛋白组成的植物性蛋白质混合物可以使大口黑鲈饲料中的鱼粉含量由45%降至30%;去皮豆粕与玉米蛋白组成的植物性蛋白质混合物的替代效果优于去皮豆粕与大米蛋白组成的植物性蛋白质混合物。     

饲料中添加赖氨酸甲酯对草鱼生长相关指标的影响

选择健康草鱼Ctenopharyngodon idella 360尾（始重8．34g±0．02g）,按照养殖试验要求分成4组（对照组、A、B、C组）,每组设3个重复,每个重复组放30尾,分别投喂基础日粮（对照组,w（Lys）=1．25％）、添加赖氨酸盐酸盐日粮（A组,埘（Lys）=1．625％）和添加不同剂量赖氨酸甲酯盐酸盐日粮（B组,W（Lys）=1．50％;C组,w（Lys）=1．625％）。结果表明：添加赖氨酸甲酯后,B、C组草鱼的增重率、特定生长率、饲料转化效率和蛋白质效率显著提高（P〈0．05）;鱼体的蛋白质含量和蛋白质沉积率显著提高（P〈0．05）,体脂含量显著降低（P〈0．05）;血清中总蛋白和白蛋白含量显著提高（P〈0．05）,而尿素氮含量显著降低（P〈0．05）。添加晶体赖氨酸的A组,上述指标均未发生显著变化（P〉0．05）。对照组和A组草鱼摄食后,血清中游离赖氨酸、蛋氨酸和精氨酸浓度在1h左右达到高峰,而B、C组在3h左右达到高峰。     

Effect of Different Roughages on Milk Protein and Milk Fat Synthesis in Dairy Cows

The main purpose of this study was to determine the effect of a corn straw or mixed diet on milk production, milk composition and the expression of genes associated with lactation in mid-lactation Chinese Holstein cows. In this study, 10 healthy Chinese Holstein cows were randomly assigned to two groups and fed with different diets respectively, corn straw(CS) or mixed forage(MF) diet. CS group was fed roughage consisting of 53.8% corn straw only and the forge to concentrate(F : C) ratio [dry matter(DM)] was about 40: 60. MF group was fed roughage consisting of 3.7% Chinese wildrye and 23.4% alfalfa hay, the forge to concentrate(F : C) ratio(DM) was 70: 30. All the cows were fed 8 weeks and body weight, dry matter intake, body condition score, fat, protein, lactose, milk yield, total solid and somatic cell count(SCC) were recorded. Quantitative real-time PCR(q RT-PCR) was used to analyze cow mammary gland samples representing two different diets. The results suggested that different diet types had significant effects on milk yield, lactose, milk fat, milk protein, dry matter intake and somatic cell count in dairy cows, and cows fed MF diet improved milk production and lactation performance clearly(P0.05). In addition, m RNA expression of genes ACC, m TOR, STAT5, CSN2, PPARγ, FABP3 and PTEN in MF group was extremely significantly higher than that in CS group(P0.05). m RNA expression of AKT1, FAS, SCD and SREBP1 c in MF group was significantly higher than that in CS group(P0.01). In summary, the milk yield and composition in mixed forage group were significantly improved than those in corn straw group.     

高脂饮食诱导大鼠肾损伤及其氧化应激水平的研究

目的:观察高脂饮食诱导健康Wistar大鼠的脂质肾毒性损伤及其氧化应激水平的变化,探讨氧化应激机制在其中的作用。方法:健康Wistar雄性大鼠16只,随机分为普通饲料组与高脂饲料组。普通饲料含热能308.98kcal/100g,高脂饲料在普通饲料基础上,添加20%猪板油,10%白砂糖,0.1%胆盐(w/w),含热能475.67kcal/100g。于实验第14周测定24h尿微量白蛋白、血脂、血糖并取肾组织检测羰基化蛋白和丙二醛(MDA)含量,并对肾脏病理形态学改变进行分析。结果:在14周时,高脂饲料组大鼠24h尿微量白蛋白、血脂以及肾组织羰基化蛋白和MDA含量明显高于普通饲料组(均P<0.01);病理形态学分析显示有肾小球球囊扩张、肾小球基底膜增厚、肾小球外系膜基质增生及肾小球局灶性节段性硬化;但2组大鼠空腹血糖、体质量及血清肌酐水平与普通饲料组相比差异无显著性(均P>0.05)。结论:高脂饮食诱导的高脂血症可导致健康大鼠的脂质肾毒性损伤,氧化应激很可能在其中发挥重要的作用。     

饲料中脂肪及乳化剂含量对仿刺参幼参生长和体组成的影响

在实验室条件下研究了饲料中脂肪及乳化剂含量对仿刺参Apostichopus japonicus幼参生长和体组成的影响。试验1,在11．5—21．5℃水温下,将体质量平均为2．71g的仿刺参放养在容量为50L的水槽（45cm×31cm×30cm）中,投喂以鱼粉和玉米蛋白为蛋白源,深海鱼油为脂肪源的膏状饲料（粗蛋白质的质量分数为19．8％,粗脂肪的质量分数分别为2．80％、3．65％、4．50％、5．35％、6．20％和7．05％）。经60d饲养,结果表明,饲料中脂肪的质量分数为6．20％时,幼参的特殊生长率、表观脂肪消化率与脂肪含量的乘积及体内高度不饱和脂肪酸含量最高。二次回归拟合曲线表明,幼参饲料中脂肪的适宜质量分数为5．35％-7．05％,最适为5．88％。试验2,饲料中蛋白质和脂肪质量分数分别为24％和5．0％（大豆油作为脂肪源）,在脂肪中分别加入0、5％、10％和15％的大豆卵磷脂作为脂肪乳化剂,饲养体质量平均为5．48g的仿刺参。经45d饲养,结果表明,10％的乳化剂组幼参的特殊生长率和脂肪表观消化率显著高于其他各组（P〈0．05）,该浓度的乳化剂对幼参肠道萎缩的抑制性效果较好。本研究表明：饲料中适宜的脂肪含量能有效地促进仿刺参的生长,提高体内多不饱和脂肪酸的含量（特别是在适宜的温度下）;饲料中含有丰富的多不饱和脂肪酸可促进仿刺参生长,增强其体质。     

Effect of oilseeds rich in linoleic and linolenic acids on milk production and milk fatty acid composition in dairy cows

Nine multiparous cows averaging 93±13 days in milk production (DIM) were used in a triple 3×3 Latin square design to determine the effects of feeding them whole roasted flaxseed, cracked roasted soybean and fresh alfalfa in the diet on milk production, milk fatty acid profiles and the digestibility of nutrients. Each experimental period lasted 30 d and a sample collection was performed during the last 7 d. The cows were fed on the control basal diet (CON) or diets containing whole roasted flaxseed (FLA) or cracked roasted soybean (SOY). All diets were fed as a total mixed ration (TMR) and had similar concentrations of crude protein (CP), Net Energy Lactation (NEL), acid detergent fibre (ADF) and neutral detergent fibre (NDF). The dry matter intake (DMI) was not significantly different (P>0.05), but tended to increase in FLA and SOY diets compared with the control (P>0.05). Cows in all treatments had a similar milk yield, although 4% fat corrected milk (FCM) yield was higher on the FLA and SOY diets than on the CON diet. Milk fat percentage (3.45%) increased in the FLA diet compared with the control (3.31%) and SOY diets (3.39%). Milk protein percentages were similar among the diets (P>0.05). There were similar digestibilities of DM, CP and ADF among the treatments and lower digestibilities of NDF and ether extract in the SOY diet compared with the CON diet. Feeding various oilseeds significantly increased the concentrations of C_18:1, C_18:3 and conjugated linoleic acid (CLA). The FLA diet decreased the ratio of omega-6 to omega-3 fatty-acids in the milk, which would improve the nutritive value of the milk.