绿壳蛋和乌鸡蛋胆固醇含量的测定

为了研究绿壳蛋和乌鸡蛋的胆固醇含量,试验对比色法和高效液相色谱法进行比较后,选用高效液相色谱法对卢氏绿壳蛋鸡,丝羽乌骨鸡两个品种的鸡蛋胆固醇含量进行测定.试验结果表明:比色法的测定结果显著高于高效液相色谱法的测定结果(P<0.05);绿壳蛋和乌鸡蛋的胆固醇浓度分别为7.75 mg/g和8.99 mg/g,绿壳蛋胆固醇浓...     

鸡蛋胆固醇含量测定方法比较研究

试验随机选取了中华绿蛋鸡产的绿壳蛋和依莎褐蛋鸡产的褐壳鸡蛋各20枚,采用邻苯二甲醛分光光度计比色法和气相色谱法,测定鸡蛋中胆固醇的含量,比较两种方法在测定鸡蛋胆固醇含量上的差异。结果表明,用邻苯二甲醛比色法测得褐壳蛋蛋黄胆固醇含量176．79mg／枚,浓度为13．35mg／g。用气相色谱法测得胆固醇含量142．74mg／枚,浓度为9．69mg／g,二种方法测定的结果差异显著（P〈0．05）。用邻苯二甲醛比色法测得绿壳蛋蛋黄胆固醇含量158．12mg／枚,浓度为10．65mg／g。用气相色谱法测得胆固醇含量128．70mg／枚,浓度为8．54mg／g,二种方法测定的结果差异显著（P〈0．05）。     

鸡AIRC基因多态性及其对肌肉肌苷酸含量的遗传效应分析

以鸡AIRC基因为侯选基因,以丝羽乌骨鸡、萧山鸡、白耳鸡、藏鸡、隐性白羽鸡为试验材料,采用PCR-SS-CP方法对AIRC基因所有外显子及部分内含子区域进行SNPs检测,在外显子3和8中各发现1个单核苷酸多态位点.各种基因型与胸肌肌苷酸(IMP)含量的方差分析结果表明,外显子3中CC基因型个体的肌肉IMP含量显著高于TC和TT基因型个体,TC基因型个体也稍高于TT型,但差异不显著;外显子8中CG基因型个体的肌肉IMP含量显著高于GG和CC基因型个体,GG基因型个体的胸肌肌苷酸含量也显著高于CC型.外显子3和8的合并基因型对IMP含量也有显著的影响,合并基因型为CCCG的个体比TTCC合并基因型的个体高2.25mg·g-1,合并基因型的遗传效应大于最优秀的单个基因型效应.因此,可以利用该合并基因型对鸡的肉质风味性状进行标记辅助选择.     

鸡ADSL基因和GARS-AIRS-GART基因对鸡肉肌苷酸(IMP)含量的影响

以鸡ADSL基因、GARS-AIRS-GART基因为侯选基因,以隐性白羽鸡、丝羽乌骨鸡、萧山鸡、白耳鸡、藏鸡为试验材料,采用PCR-SSCP方法对ADSL外显子2、GARS-AIRS-GART基因5′侧翼序列进行SNPs检测。结果各发现了一个单核苷酸多态性位点。各种基因型与胸肌IMP含量的最小二乘分析结果表明:ADSL基因TT型个体的胸肌肌苷酸含量极显著地高于CC型、显著地高于CT型个体,CT型个体也高于CC型,但差异不显著;GARS-AIRS-GART基因TT型个体的胸肌肌苷酸含量极显著地高于CT型和CC型个体,CT型个体也高于CC型,但差异不显著。ADSL和GARS-AIRS-GART基因的合并基因型对IMP含量也有显著的影响,合并基因型为TTTT的个体IMP含量显著高于CCCC合并基因型的个体,高出1.584 mg/g,因此可以利用该合并基因型对鸡的肉质风味性状进行标记辅助选择。     

赤水乌骨鸡SLCO1B3基因SNPs鉴定及与蛋品质的关联性分析

为了探究赤水乌骨鸡SLCO1B3基因外显子上的遗传变异位点对蛋壳颜色、蛋品质指标的影响，对300只赤水乌骨鸡SLCO1B3基因的功能突变位点EAV-HP进行基因分型，筛选出109只绿壳纯合基因型(SL/SL)的母鸡。通过直接测序方法鉴定纯合子基因型(SL/SL)个体的SLCO1B3基因外显子上存在的SNPs,并构建这些SNPs的双倍型，再与蛋品质指标进行相关性分析。结果表明：在赤水乌骨鸡SLCO1B3基因外显子上共检测到3个SNPs,第5外显子上的g.65235858G>A位点为非同义突变，突变后mRNA二级结构发生改变；关联性分析表明，赤水乌骨鸡SLCO1B3基因的这3个SNPs构建的双倍型对蛋壳颜色ΔL*值、蛋壳颜色Δb*值、蛋形指数有显著影响(P<0.05)。结果表明，SLCO1B3基因的遗传变异与蛋壳颜色、蛋形指数存在显著相关。     

鸡lmbr1基因外显子16的SNP检测和单倍型分析

外显子16是鸡lmbr1基因最大的外显子,本研究进行了该外显子在丝羽乌骨鸡和白洛克肉鸡间的SNP检测和单倍型分析。研究表明,鸡lmbr1外显子16的PCR-SSCP基因型在两个品种间的分布存在明显差异,测序从24个个体中检测到4个变异位点,其中T32C变异在两个品种间存在明显差异,丝羽乌骨鸡均含有32T(纯合的TT或杂合的TC),白洛克肉鸡在T32C位点都为纯合的CC;单倍型分析从24个个体中检测到5种单倍型,丝羽乌骨鸡和白洛克肉鸡的单倍型存在明显的差异,hap1和hap2是丝羽乌骨鸡的特异性单倍型,hap5是白洛克肉鸡的特异性单倍型,hap3和hap4主要存在于白洛克肉鸡中,在丝羽乌骨鸡中的比例极少。     

鸡lmbr1部分内含子的克隆及其单核苷酸多态性

以丝羽乌骨鸡和白洛克肉鸡的基因组DNA为模板,采用PCR产物直接测序的方法进行鸡lmbr1基因部分内含子的克隆、单核苷酸多态性检测。结果表明,试验克隆了鸡lmbr1基因的10～14及16内含子序列,共计4 610 kb,从丝羽乌骨鸡和白洛克肉鸡中检测到67个单核苷酸多态位点（SNPs）。将提交序列与NCBI上公布的红色原鸡基因组序列比较,在这6个内含子内发现40个变异位点,其中20个为新的SNPs。基因组结构分析表明,鸡lmbr1基因约60 kb,为人类lmbr1基因的28%,内含子外显子的剪接方式符合GT-AG法则。     

广西东兰乌鸡丝羽形成分子机制的研究

广西东兰乌鸡由片羽和丝羽两个品系组成。目前丝羽形成的分子机理还不清楚。以前的研究表明,丝羽乌骨鸡的丝羽是由PDSS2基因上游C103G的突变所导致。本研究的目的是探讨C103G是否也是广西东兰乌鸡丝羽形成的分子基础。取广西东兰乌鸡丝羽和个体和片羽个体各20个血样,常规酚仿法提取基因组DNA,然后PCR扩增含-103位点的PDSS2片段。结果发现,广西东兰乌鸡丝羽鸡20个样的-103位点全部为G碱基,而广西东兰乌鸡片羽鸡20个样的-103位点全部为C碱基。本研究的结果提示广西东兰乌鸡丝羽形成的分子机制与丝羽乌骨鸡的相一致。     

7种地方鸡蛋品质及繁殖相关基因分析

为探讨萧山鸡、仙居鸡、江山乌骨鸡、丝羽乌骨鸡、龙游麻鸡、灵昆鸡和白耳黄鸡7个地方鸡种的蛋品质差异，本研究选取199～201日龄7个品种鸡的鸡蛋各30个，检测其蛋品质相关指标并对繁殖相关基因进行分析。结果显示：仙居鸡平均蛋重低于其他6种地方鸡的平均蛋重（P<0.05）；龙游麻鸡的蛋白高度高于丝羽乌骨鸡（P<0.05）；丝羽乌骨鸡蛋黄颜色高于仙居鸡和白耳黄鸡（P<0.05）；龙游麻鸡鸡蛋哈氏单位高于白耳黄鸡、江山乌骨鸡和丝羽乌骨鸡（P<0.05）；仙居鸡、丝羽乌骨鸡和萧山鸡的蛋黄比例高于灵昆鸡和白耳黄鸡（P<0.05）;7个地方鸡品种的蛋品质在蛋壳强度上没有显著差异；仙居鸡平均产蛋量最高。仙居鸡垂体相关基因（如GNRH1、FSHβ和PRL）的表达高于除乌骨鸡外的其他鸡种，这可能与其较高的产蛋能力有关。本实验结果表明蛋品质性状在不同鸡种间差异显著且地方鸡种在蛋品质性状上有优异的潜能。     

鸡SCD和Sirt1基因的SNP搜寻及其遗传多样性分析

硬脂酰辅酶A去饱和酶（Stearoyl—CoA desaturase,SCD）和Sirt1基因是位于鸡6号染色体的两个与脂肪代谢相关的功能基因。本研究以泰和丝毛乌骨鸡、杏花鸡、隐性白洛克鸡为研究材料,利用DNA池比较测序技术对鸡SCD和Sirt1基因的整个编码区进行SNPs搜寻,共检测出鸡SCD基因SNPs 13个,其中5个编码区SNPs（cSNPs）,2个为错义突变,10个为新发现的SNPs;检测出鸡Sirt1基因SNPs35个,其中10个cSNPs,2个为错义突变,18个为新发现的SNPs,另外有3处插入／缺失多态。对SCDC．492G〉A和Sirt1 c．1753G〉A位点在隐性白洛克鸡、杏花鸡、泰和丝毛乌骨鸡、白耳黄鸡、康乐鸡、南城黑鸡等271个个体中进行了PCR—SSCP检测,发现它们具有丰富的多态性,为这个染色体区域进一步的关联性分析提供了新的标记。     

Correlations between breeder age, egg cholesterol content, blood cholesterol level and hatchability of broiler breeders

1. The research was carried out to investigate correlations between breeder age, egg cholesterol content, blood cholesterol level and hatchability of broiler breeders. 2. Egg cholesterol content increased with increased breeder age. The mean yolk cholesterol contents (mg per g yolk) were 10.47+/-0.28, 15.34+/-0.65 and 15.64+/-0.71 mg/g at 28, 45 and 65 weeks of age, respectively. 3. There were positive correlations between yolk weight and yolk cholesterol content (mg/g yolk) (r=01.941; P<0.01) and egg cholesterol content (mg/egg) (r=0.980; P<0.01). 4. Negative correlations were found between egg yolk cholesterol content and hatchability of fertile eggs (r=-0.345; P<0.05), fertility ratio (r=-0.609; P<0.01) and hatchability of total eggs (r=-0.574; P<0.01). 5. The mean blood cholesterol levels were 165.1+/-11.04, 166.5+/-11.97 and 179.5+/-11.33 mg/dl at 28, 45 and 65 weeks of age, respectively.     

Nutritive constituents of Silky fowl eggs: comparison with hen eggs of White Leghorn origin

In the present study, proportional parts, amounts of major constituents, vitamins, minerals and fatty acids composition of Silky fowl eggs were examined compared with those of hen eggs. The ratio of egg yolk weight to whole egg weight of Silky fowl egg was significantly larger than that of egg yolk of hen egg. The amount of cholesterol of Silky fowl eggs were significantly (P < 0.01) less than those of hen eggs. The amount of vitamins (B2, B6, D and E), calcium and potassium in Silky fowl eggs were significantly higher than those of hen eggs. Unsaturated fatty acids in Silky fowl eggs were 62.5% among total fatty acids, the unsaturated fatty acids of hen eggs were 53.9%. Especially, the contents of arachidonic acid, docosapentaenoic acid and docosahexaenoic acid in Silky fowl eggs were significantly larger than in hen eggs.     

Distribution of N-acetylneuraminic acid and sialylglycan in eggs of the Silky fowl

1. The distribution of sialic acid in the eggs of original Silky fowl was investigated. The sialic acid contents of the yolk, albumen and the chalaza of a single egg were 205.2, 11.96 and 0.83 mg, respectively. 2. The sialic acid content of the yolk of Silky eggs was 11.5-fold higher than that of a conventional domestic fowl yolk. 3. Sialic acid isolated from Silky yolk was entirely N-acetylneuraminic acid (NeuAc). No N-glycolylneuraminic acid or O-acetyl containing sialic acid was observed. 4. The structure of the major sialylglycan in Silky egg yolk was determined to be a disialyl-biantennary chain in which the NeuAc residues were alpha2-6 linked to glucose. No alpha2-3 linkage was observed. 5. Thus, the Silky fowl's egg provides an excellent source of NeuAc and sialylglycan.     

Effects of Egg Yolk Source on the Cryopreservation of Stallion Spermatozoa

Three experiments were conducted to determine whether replacement of chicken egg yolk, as a component of freezing extenders, with egg yolk from other avian species would improve the post-thaw motility and percentage of intact acrosomes of stallion spermatozoa. In the first experiment, substitution of chicken egg yolk with chukar egg yolk, as a component of the lactose-ethylenediaminetetraacetic acid extender, improved (P ≤ .05) the post-thaw motility of stallion spermatozoa. These results were not replicated in (IMV Technologies, Maple Grove, MN, USA) a more expansive study comparing 2%, 4%, 6%, or 8% egg yolk combined with INRA 96 when a “slow freeze” method was used, or the same substitution at levels ranging from 13% to 22% when egg yolk was combined with lactose-ethylenediaminetetraacetic acid for diluents used for a “fast freeze” method of cryopreservation. In the third study, egg yolks from regular and high omega-3 chicken eggs as well as from turkey, chukar, and mallard duck eggs were analyzed for lipid content and fatty acid profile. The yolk from the turkey eggs was higher (1,300 mg/100 g) and that from mallard ducks was lower (560 mg/100 g) in cholesterol as compared with the two types of chicken eggs and chukar egg yolk (range, 1,046-1,094 mg/100 g). In addition, the high omega-3 eggs did test higher for fatty acids (4.51 g/100 g) than other types of eggs (range, 0.28-0.73 g/100 g). Substitution of chicken egg yolk with turkey, but not duck, egg yolk resulted in higher post-thaw total motility (P ≤ .05) for spermatozoa obtained from two of the three stallions used in the third experiment.     

Effects of supplementary iodine on the performance and egg traits of laying hens

1. This experiment was carried out to determine the effects of dietary iodine supplementation on the performance and egg traits of laying hens. A total of 600 SHSY type brown layers aged 21 weeks of age were chosen at random from a large flock. They were randomly distributed into 30 pens at 20 hens per pen. Each treatment comprised 6 replicates of 20 layers in groups of 5 birds. The diets were supplemented with 0, 3, 6, 12 and 24 mg/kg iodine as calcium iodate. The experimental period lasted 30 weeks. 2. There were no significant differences among the groups in body weight, food consumption, egg production, food consumption per kg eggs, eggshell index, eggshell breaking strength, shell thickness or egg yolk index. 3. Supplementation of the diet with 12 mg/kg iodine increased food consumption per dozen eggs compared to the groups fed on diets supplemented with 0 and 6 mg/kg iodine. 4. Egg weight was less in groups fed on diets supplemented with 12 and 24 mg/kg iodine than in the group receiving no iodine supplementation. 5. Iodine supplementation to provide 12 and 24 mg/kg reduced egg albumen index and egg Haugh units. 6. There were no significant differences among the groups in egg cholesterol and egg yolk cholesterol contents. 7. The iodine concentrations in egg yolk, egg albumen and whole egg increased with increased iodine supplementation. 8. As a result, the 3 and 6 mg/kg iodine supplementation of diet could be used to enrich the eggs with iodine without any adverse effect on performance and egg traits.     

The effect of supplementing layer diets with shark cartilage or chitosan on egg components and yolk lipids

1. An experiment was designed to evaluate the effects of the addition of shark cartilage (SC) or chitosan (CH) to layer diets on egg component weights, yolk lipids and hen plasma lipids. 2. Hy-Line laying hens (80) were used during a 56 d feeding trial. Treatments were: basal diet (BD), BD + 20 g/kg SC, BD + 30 g/kg SC, BD + 20 g/kg CH and BD + 30 g/kg CH. Eggs were analysed on d 14, 28, 42 and 56. 3. Egg weight and egg component weights were not affected by these treatments throughout the experimental period. 4. After 14d of experimental feeding, cholesterol levels were higher in eggs from birds given BD + 20 g/kg CH and BD + 30 g/kg CH than in those from birds given BD. 5. Furthermore, eggs from hens given BD + 20 g/kg SC or BD + 20 g/kg CH were higher in palmitic and stearic acids and lower in oleic acid than those from birds fed on BD. After 56 d feeding, however, palmitic and stearic acid contents in eggs from hens given any of the supplemented diets were lower than in those from hens given BD, and oleic acid in eggs from hens given BD + 20 g/kg SC, BD + 30 g/kg SC and BD + 30 g/kg CH was higher than in those from birds fed on BD. 6. Plasma cholesterol and triacylglycerol levels were not significantly affected by dietary treatment. 7. Shark cartilage or chitosan at up to 30 g/kg in layer diets did not affect egg component weights (yolk, white and shell) and total lipid contents. During the period from 42 to 56d of experimental feeding, diets containing up to 30 g/kg chitosan reduced egg yolk contents of cholesterol, palmitic and stearic acids and increased the content of oleic acid.     

Hypocholesterolemic effect of karaya saponin in Japanese laying quails (Coturnix coturnix japonica)

The effect of karaya saponin supplementation on the serum and egg yolk cholesterol and fatty acid composition in egg yolk were investigated in Japanese quails. A total of 80 Japanese quails aged 5 weeks were equally divided into four groups of 20. Four levels (0, 25, 50 and 75 mg/kg feed) of karaya saponin were included in the basal diet and experiment was lasted for 6 weeks. The cholesterol fractions in the egg yolk and serum were measured by enzymatic assay, and the fatty acid composition in egg yolk was determined by gas chromatography. The results revealed that the supplementation of 75 mg/kg karaya saponin significantly reduced (p < 0.05) cholesterol and triglycerides concentration in serum and egg yolk. High-density lipoprotein-cholesterol was increased, low-density lipoprotein-cholesterol and the atherogenic index were decreased (p < 0.05) by the dietary supplementations. Hepatic cholesterol was reduced (p < 0.05) by the 25 mg/kg karaya saponin. A higher degree of yolk colour was improved (p < 0.05) when 75 mg/kg saponin was supplemented in the diet. The concentration of polyunsaturated fatty acids (PUFA) in egg yolk was increased (p < 0.05) in a dose-dependent manner in quails fed the supplemented diet than the control diet. The ratio of PUFA to saturated fatty acids in egg yolk was improved (p < 0.05) by 75 mg/kg feed karaya saponin-supplemented diet. Therefore, the dietary supplementation of 75 mg/kg karaya saponin may be a feasible means of producing quail eggs with lower cholesterol and higher PUFA content for health conscious consumers.     

Comparison between wheat, triticale, rye, soyabean oil and strain of laying bird on the production, and cholesterol and fatty acid contents of eggs.

1. The effects of feeding three types of cereal grain (wheat, triticale or rye) and soyabean oil (0 or 20 g/kg) over a 12-week period on the production, yolk cholesterol and yolk fatty acid concentrations of three strains of laying pullets were studied. 2. Pullets fed on wheat- or triticale-based diets had higher body weight gains, egg productions, egg weights, egg mass and lower yolk cholesterol concentrations than pullets fed on rye-based diets. However, there were no significant differences between the cereals in yolk cholesterol content. 3. There were no significant differences between the three cereals in total food consumption of pullets nor of yolk weight nor yolk concentration of palmitic, stearic and oleic acids. 4. Pullets fed on triticale-based diets had higher yolk linoleic acid concentrations and lower yolk oleic acid: linoleic acid ratios than pullets fed on rye- or wheat-based diets. 5. Soyabean oil supplementation increased egg production, egg mass, yolk linoleic concentration and yolk unsaturated to saturated fatty acid ratio, but reduced yolk oleic acid: linoleic acid ratio. 6. There were differences between strains of pullets in weight gain, food consumption, rate of lay, egg weight and yolk cholesterol, but not in yolk fatty acid concentrations. 7. It was concluded that wheat- or triticale-based diets gave good production of eggs of lower cholesterol content, that soyabean oil supplementation gave eggs with a high unsaturated to saturated fatty acid ratio and that two strains of layers produced eggs with lower yolk cholesterol concentrations than a third strain.