二乙基亚硝胺诱发C3H/HeN小鼠肝癌模型的研究

[目的]建立C3H/HeN小鼠诱发性肝癌动物模型,为研究肝癌发病机理及开展肝癌药物治疗提供小鼠诱发性肝癌模型。[方法]取20只C3H/HeN小鼠作为模型组,每日喂予含30μg.mL-1二乙基亚硝胺(DEN)的饮水,连续23周后,观察其肝癌的发生情况。另取6只C3H/HeN小鼠作为正常组。[结果]造模23周后,模型组小鼠血清中ALP、ALT、AST、TBIL、肝脏指数、结节数和γ-GT活力显著增加(P<0.01),小鼠体重、血清中TP、ALB、BUN、CREA和肝脏中TP含量显著降低(P<0.01),存活15只小鼠中有13只肉眼能观测到肝癌发生,肝癌发生率为86.67%,小鼠肝脏表面较多结节,体积增大,表面粗糙、色彩暗淡,多个大小不一的灰白色圆形结节,组织学类型为肝细胞癌,其中以梁状型和腺样型居多。[结论]应用DEN诱发的小鼠肝癌,与人肝癌的发生过程相似,是一种较为理想的诱发性肝癌动物模型,但具体实验方法需进一步改良和研究。

TLR3和IRF3在华支睾吸虫感染C3H／HeN小鼠中表达的初步分析

目的 建立华支睾吸虫感染小鼠模型,初步分析TLR3、IRF3基因在小鼠肝脏中的表达情况.方法 随机选用健康雌性C3H/HeN小鼠感染华支睾吸虫建立感染模型,分别在感染第0、1、7、14、28、56、84天颈椎脱臼处死小鼠,取肝脏组织进行病理学观察,收集粪便检查华支睾吸虫虫卵.同时,采用逆转录聚合酶链反应（RT-PCR）检测肝脏中Toll样受体（TLRs）中的TLR3和IRF3的mRNA的表达情况.结果 自感染后第20~30天检查出华支睾吸虫虫卵;肝脏病理学结果显示,与正常组小鼠相比,随着时间的增加,感染组小鼠肝脏汇管区由少量炎症细胞浸润、胆管上皮反应性增生发展到在该区域出现大量纤维组织增生伴有炎症细胞浸润,表明华支睾吸虫感染C3H/HeN小鼠模型成功建立.与正常组相比,感染组自感染后第1天起TLR3和IRF3的mRNA表达均升高（P〈0.01）,均在第84天开始下降.结论 华支睾吸虫感染C3H/HeN小鼠后可激活TLR3-TRIF途径,提示TLR3-TRIF途径可能在华支睾吸虫致病过程中起了一定的作用.

利用组织芯片技术研究C57BL/6J和C3H/HeN小鼠放射性肺损伤进程差异及其机制

目的建立C57BL/6J和C3H/HeN两种小鼠放射性肺损伤进程相关组织芯片,并应用其研究FN、LN和a-SMA的表达变化及意义。方法采用20Gy60Coγ射线照射C57BL/6J和C3H/HeN两种小鼠复制动物模型,测定肺组织中羟脯氨酸含量,制备组织芯片,应用免疫组织化学(im-munohistochemistry,IHC)染色方法与图像分析技术定量检测纤连蛋白(fibronectin,FN)、层粘连蛋白(laminin,LN)和a-平滑肌肌动蛋白(alpha-smooth muscle actin,a-SMA)在放射性肺损伤进程中的表达变化。结果组织芯片制备成功,其HE和免疫组织化学染色结果与普通切片具有良好一致性。照射后1~6mC57BL/6J小鼠肺组织病变经历炎症期、增生期和纤维化期,胶原沉积增多,照后1~3mFN表达明显高于正常对照组,照后6m逐渐减少至正常,LN表达在照射后呈渐进性增加,a-SMA表达强于C3H/HeN小鼠;照射后1~6mC3H/HeN小鼠肺组织主要表现为间质性炎症改变,FN表达于照射后1~6m与正常对照组相比无明显变化,LN表达于照射后1~3m明显增强,6m逐渐减少。结论γ射线照...

A型口蹄疫病毒A/HeN/1/2009株全基因组序列的测定及其基因特征分析

[目的]测定A型口蹄疫病毒A/HeN/1/2009株全基因组序列并分析其基因特征,为研究我国最近发生的A型口蹄疫病毒的致病性、流行规律以及筛选适用的疫情防控疫苗株奠定分子基础。[方法]应用RT-PCR方法,分段扩增、克隆A/HeN/1/2009株基因,并进行基因测序;借助DNAStar分子生物学软件,从分子流行病学角度分析A/HeN/1/2009株与参考毒株之间可能的遗传衍化关系。[结果]该毒株基因组全长8 171 nts[不包括poly(C)区段和poly(A)尾巴],其中5'-UTR和3'-UTR分别为1 080、92 nts,蛋白编码区为6 999 nts。分析A/HeN/1/2009株遗传衍化关系显示,该毒株划为东南亚拓扑型Laos03系的VN09亚系,同源性依次为87.3%～91.8%、93.7%～94.5%和96.9%～98.4%。[结论]VP1中A24V、N85R、S196T,3A中I61V、T128S、E147G和A134V在该毒群的进化过程中扮演重要角色;A/SH/1/2009株VP1 140-160基序为RSD。

Ascorbic acid synthesis and transportation capacity in old laying hens and the effects of dietary supplementation with ascorbic acid

Background: Laying hens over 75 weeks of age commonly show great declines in immunity and production performance.It is unclear whether these declines can be relieved by supplementing with ascorbic acid(AA) in feed.Two trials were conducted to investigate the synthesis and metabolism of AA in layers of different ages and the effects of dietary supplemental AA on the performance and the immune and antioxidant statuses of 78 weeks old hens.Methods: In Exp.1,equal numbers(24 hens) of 35 weeks old(Young) and 75 weeks old(Old) layers were fed the same diet without AA supplementation for 4 weeks.In Exp.2,360 healthy 78 weeks old laying hens were randomly assigned to 4 treatments(basal diet supplemented with 0,0.25,0.5,or 1 g AA/kg diet) in an 8-week feeding trial.Results: The old hens tended to have decreased L-gulonolactone oxidase(GLO) synthase activity in the kidney and liver than that of the young hens(P = 0.07 and P = 0.05,respectively).Compared with the young hens,the old hens had lower hepatic antioxidant capacity allowing for the lower thioredoxin(TXN),thioredoxin reductase(TXNR) and cytochrome b5 reductase(CYB5 R) gene expression(P < 0.05),whereas increased sodium-dependent vitamin C transporter(SVCT) 1 expression levels in the ileum and kidney and enhanced splenic and hepatic AA concentrations(P < 0.05).Dietary supplementation with AA significantly decreased GLO enzyme activity but increased splenic AA concentration and anti-bovine serum albumin IgG levels(P < 0.05) and tended to increase CD4+T lymphocyte numbers(P = 0.06) in serum.Supplementation of 0.25 g AA/kg diet significantly increased hepatic total antioxidant capacity(T-AOC,P < 0.05) relative to the control group.Conclusions: Laying hens could synthesize AA in both the kidney and the liver,though the GLO enzyme activities were 100 times greater in kidneys than in livers.The old laying hens had greater absorption and reabsorption capacity and higher AA retention in some tissues that did the young hens.Dietary supplementation of AA can improve the health of old layers by enhancing immunity and antioxidant capacity.

Dietary betaine activates hepatic VTGⅡexpression in laying hens associated with hypomethylation of GR gene promoter and enhanced GR expression

Background: Vitellogenin(VTG) is a precursor of egg yolk proteins synthesized within the liver of oviparous vertebrates. Betaine is an important methyl donor that is reported to improve egg production of laying hens with an unclear mechanism. In the present study, we fed betaine-supplemented diet(0.5%) to laying hens for 4 wk and investigated its effect on VTGII expression in the liver.Results: Betaine did not affect chicken weight, but significantly(P < 0.05) increased egg laying rate accompanied with a significant(P < 0.05) increase in hepatic concentration and plasma level of VTGI. Plasma estrogen level did not change,but the hepatic expression of estrogen receptor α(ERα) mR NA was significantly(P < 0.05) up-regulated. Betaine did not affect the protein content of ERα, but significantly(P < 0.05) increased hepatic expression of glucocorticoid receptor(GR)at both mR NA and protein levels. Also, ERα/GR interaction tended to be enhanced in the liver nuclear lysates of betainesupplemented hens as determined by co-immunoprecipitation. Furthermore, dietary betaine supplementation significantly increased(P < 0.05) the hepatic expression of methyl-transfer enzymes, such as BHMT, GNMT, and DNMT1,which was associated with higher SAM/SAH ratio and hypomethylation of GR promoter regions.Conclusions: Betaine activates hepatic VTGII expression in association with modified DNA methylation of GR gene promoter, GR expression and ERα/GR interaction. Activation of hepatic VTGII expression may contribute, at least partly, to improved egg production in betaine-supplemented hens.

Effect of dietary nonphytate phosphorus on laying performance and small intestinal epithelial phosphate transporter expression in Dwarf pink-shell laying hens

This study examined the effects of various levels of dietary nonphytate phosphorus on laying performance and the expression patterns of phosphorus metabolism related genes in Dwarf pink-shell Jaying hens. A total of 405 28-week-old Dwarf pink-shell laying hens were fed the same corn-soybean basal meals but containing 0.20%, 0.25%, 0.30%, 0.35% or 0.40% nonphytate phosphorus. The results showed that feed intake, egg production, and average egg weights were quadratically correlated with dietary nonphytate phosphorus content （P 〈 0.05）, and the highest egg production, feed intake and average egg weights were achieved when dietary nonphytate phosphorus was at 0.3% （P 〈 0.05）. mRNA expression of intestinal sodium phosphorus co-transporter linearly decreased when dietary nonphytate phosphorus increased, mRNA and protein expression of intestinal calbindin and vitamin D receptor correlated quadratically with dietary nonphytate phosphorus, and the highest expression was found when dietary available phosphorus was at 0.2,5% to 0.3%. In conclusion, the ideal phosphorus requirement for Dwarf pink-shell layer hens is estimated to be 0.3% in a corn-soybean diet. With this level of phosphorus supplementation, calbindin and vitamin D receptor reached their highest expression.

TLR5在华支睾吸虫感染C3H/HeN小鼠肝脏中表达的初步分析 TLR5在华支睾吸虫感染C3H/HeN小鼠肝脏中表达的初步分析

目的 分析小鼠华支睾吸虫感染后小鼠肝脏中Toll样受体5（TLR5）的表达情况.方法 随机选取C3H/HeN雌性小鼠,经口感染35个华支睾吸虫囊蚴建立感染模型.分别在感染0（对照组）、1、7、28、56、84天处死小鼠,取肝脏组织行如下处理：①苏木精-伊红（H-E）染色观察小鼠肝脏病变;②采用免疫组织化学染色观察小鼠肝脏组织TLR5表达情况;③采用逆转录聚合酶链反应（RT-PC R）检测肝脏中TLR5的表达水平.结果 ①肝脏病理结果显示,与对照组小鼠相比,感染第1、7天小鼠肝脏汇管区出现炎症细胞浸润,第28天可观察到肝细胞排列紊乱,出现纤维组织增生和胆管增生;②免疫组织化学染色显示,TLR5在感染华支睾吸虫第1天、7天、28天的小鼠肝内表达增高,其主要表达于汇管区肝细胞、肝胆管上皮细胞和纤维化区域的成纤维细胞;③RT-PCR结果显示,小鼠肝脏中TLR5 mRNA表达量在感染第1天、7天、28天明显高于对照组.结论 C3H/HeN小鼠感染华支睾吸虫可上调肝脏组织TLR5的表达,提示TLR5可能在宿主抵抗华支睾吸虫感染中起着一定的作用。

Effect of Supplemental Oregano Essential Oils in Diets on Production Performance and Relatively Intestinal Parameters of Laying Hens

This study was designed to investigate the effects of dietary oregano essential oils on 150 30-week-old Hy-Line Layers’ productive performance, egg quality characteristics, cecal microbiota, digestive enzyme activities, mucosa structure of the duodenum and jejunum and glucose and small peptides transporters expression in the duodenum and jejunum. All hens were allocated into one of five different groups: negative control (NC;basal diet only), antibiotics control (CS;basal diet plus 100 mg/kg of 10% colistin sulfate) and treatments I, II, and III (basal diet supplemented with 50, 100 and 150 mg/kg oregano essential oils, respectively). The results showed that the laying rate, average egg weight, feed conversion ratio and the activities of amylase and trypsin were significantly improved by a diet supplemented with 100 mg/kg oregano essential oils (P 0.05), significantly increased duodenum villus-height-to-crypt-depth ratios (P 0.05).

Effects of Fermentation Product Containing Phytase on Productive Performance,Egg Quality,and Phosphorous Apparent Metabolism of Laying Hens Fed Different Levels of Phosphorus

This study investigated the effects of fermentation product containing phytase （FPP） that was fermented using waste vinegar residue （WVR） as substrate from Aspergillusficuum NTG-23 on productive performance, egg quality, and phosphorus apparent metabolism of laying hens. First, 375 22-wk-old Jinghong hens were allocated into 5 treatments （5 replicates of 15 hens each） in an 8-wk experiment for evaluating the parameters of productive performance, egg quality, serum, and tibia. Experimental diets contained 4% FPP and 96% corn-soybean diet. The levels of dicalciurn phosphate （DCP） were 1.34, 1.01, 0.67, 0.34 and 0%. Next, thirty 31-wk-old Jinghong hens were fed 5 types of diets for evaluating phosphorous apparent metabolism rate. Egg productive rate, egg weight, feed conversion ratio, Haugh unit, egg albumen height, serum calcium, tibia ash, tibia ash calcium and tibia breaking strength were not different significantly among 5 treatments. The significant difference of average daily feed intake was not appeared when the DCP content of corn-soybean-FPP diet was reduced to 0.67%; the eggshell hardness, eggshell thickness and serum phosphorus were not reduced significantly until the DCP content of corn-soybean-FPP diet was reduced to 0.34%. The yolk color was improved when the laying hens fed deficient DCP corn-soybean-FPP diet. A 22.14% reduction in excreta phosphorus was observed when the laying hens fed low phosphorus （0.67% DCP） corn-soybean-FPP diet. A 30% elevation of phosphorus apparent metabolism rate was obtained when the DCP content of corn-soybean-FPP diet was decreased from 1.34 to 1.01%. The reducing cost of layer diet was totalized about 120 CNY 1000 kg1 diet when the content of DCP was 0.67% in corn-soybean-FPP diet. These results indicated that FPP could be applied in laying hen as a potential, cost-effective and rational application of WVR.

Effect of Betaine on the Regulation of the Lipid Metabolism in Laying Hen

The experiment was conducted to investigate the effects of betaine on lipid metabolism of laying hens. 1 600 ISA brown laying hens of 20 weeks of age were alloted randomly into 4 groups each with 4 replicates of 100 layers, the layers were given a corn-soybean basal diet with 0,400,600 and 800 mg/kg betaine re-spectirely. Results indicated that supplementation of 600 mg/kg betaine significantly improved lay performance, and increased egg production 8.67% (P<0.04), decreased feed/egg ratio by 9.02%(P<0.03) compared with control, but there were no significant differences in egg weight and feed intake. It was found that supplementation of 600 mg/kg betaine decreased weights of abdominal fat by 19.63%(P<0.02)and 22.35% (P<0.02), and decreased liver fat by 8.52%(P<0.05) and 16.28%(P<0.01) in 50 and 70 weeks of age respectively. Compared with control, in 70 weeks of age, activity of LPL in abdominal fat was decreased by 44.83% (P<0.01), HSL activity in abdominal fat increased by 50.0% (P<0.02), and MDH activity in liver was decreased by 28.74 % (P < 0.03). Supplementation of 600 betaine increased levels of T3 by 43.29 % (P < 0.05) and 43.95 % (P < 0.02) in 50 and 70 weeks of age respectively, and increased the concentration of cAMP in hypothalamus and anterior pituitary by 59.89% (P<0.01) and 24.03% (P<0.05) respectively in 70 weeks of age. The concentration of serum gluclose (GLU) , FFA and phospholipid were increased by 44.50% (P<0.03), 19.66%(P<0.03) and 71.66% (P<0.01) in 50 weeks of age. The concentration of serum gluclose (GLU), FFA and phospholipid were increased by 16.25%(P<0.05),22.51%(P<0.02) and 22.42%(P<0.01) in 70 weeks of age.

Sexual maturation in hens is not associated with increases in serum leptin and the expression of leptin receptor mRNA in hypothalamus

Background： In mammals, leptin is an attractive candidate for mediating the metabolic signal and the reproductive function via the specific receptor in hypothalamus. However, till now, the role of leptin on reproduction in birds is less well established. This experiment was conducted to elucidate the role of leptin on the onset of reproduction in bird, as a first step, to detect the changes of peripheral leptin and leptin receptor mRNA expression in hypothalamus between mature and immature hens at the same age. 120 ISA brown pullets at D60 were allocated randomly into two groups, long light （LL） group being raised under artificial light regimes with incrementally increased light phase （from 8 L：]6D to 14 L：]2D） and short light （SL） group raised on consistent light （8 L：16D） for 12 wk. Results： The results showed that pullets in LL group reached sexual maturation 15 d earlier than those in SL group. Serum E2 showed a significant increase with age, but no difference was observed between two groups. Serum leptin concentration decreased significantly from D112 to D136 in LL, and was markedly higher in LL group than that in SL at D112, while there was no significant difference between two groups at D136. Leptin receptor and GnRH-I mRNA expression in hypothalamus were significantly increased with age, yet there was no significant difference between SL and LL chickens at the same age. The expression of FSH-13 and LH-13 mRNA in pituitary was increased with age but did not show significant difference between LL and gland, and decreased from D112 to D136 in LL but not groups at the same age. SL group. GnfiH-I mRNA expression was very rich in pinea n SL group, and there was no difference between two Conclusions： These results indicate that the earlier sexual maturation in hens induced by long-light regime is not accompanied with an increase in serum leptin or leptin receptor gene expression in hypothalamus, or genes expression in HPG axis.

Application of Several Additives Instead of Antibiotics in the Production of Laying Hens

[ Objective ] The test was conducted to study the effect of three different additives instead of antibiotics in the production of laying hens. [ Method ] Basal diets in four test groups were added with 0. 015 % oxytetracycline, 0. 01% microecological preparation, 0.2% fulvic acid, and 0. 1% Chinese herbal medi- cine extract respectively, and laying hens in control group were fed with basal diets. Effect of four different additives on performance and egg quality were studied under the temperature of 28.6℃. [ Result] The average egg-laying rate and feed-egg ratio in groups 2, 3 and 4 were significantly better than those in control group and group 1 （P 〈 0.05 ）. The contents of fat and cholesterol in eggs in groups 2, 3 and 4 were lower than those in control group and group 1. And the fat content of eggs in group 4 was 13.42% lower than that in control group, the difference was significant （ P 〈 0.05 ）. The protein contents in groups 2, 3 and 4 were signifi- cantly higher than those in control group and group 1 （P 〈 0.05 ）. [Condusion ] Microecological preparation, fulvic acid and Chinese herbal medicine extract could replace antibiotics to be applied in the production of laying hens.

Evaluation of a laying-hen tracking algorithm based on a hybrid support vector machine

Background： Behavior is an important indicator reflecting the welfare of animals. Manual analysis of video is the most commonly used method to study animal behavior. However, this approach is tedious and depends on a subjective judgment of the analysts. There is an urgent need for automatic identification of individual animals and automatic tracking is a fundamental part of the solution to this problem.Results： In this study, an algorithm based on a Hybrid Support Vector Machine（HSVM） was developed for the automated tracking of individual laying hens in a layer group. More than 500 h of video was conducted with laying hens raised under a floor system by using an experimental platform. The experimental results demonstrated that the HSVM tracker outperformed the Frag（fragment-based tracking method）, the TLD（Tracking-Learning-Detection）,the PLS（object tracking via partial least squares analysis）, the Mean Shift Algorithm, and the Particle Filter Algorithm based on their overlap rate and the average overlap rate.Conclusions： The experimental results indicate that the HSVM tracker achieved better robustness and state-of-theart performance in its ability to track individual laying hens than the other algorithms tested. It has potential for use in monitoring animal behavior under practical rearing conditions.

Effects of dietary phosphorous supplementation on laying performance,egg quality,bone health and immune responses of laying hens challenged with Escherichia coli lipopolysaccharide

Background: Phosphorus is an essential nutrient to maintain poultry health and performance. The objective of this study was to evaluate the effect of dietary phosphorus levels on egg production, egg quality, bone health, immune responses of laying hens challenged with Escherichia coli lipopolysaccharide.Methods: Three hundred laying hens at 28 wk were randomly divided into 2 dietary treatments with 10 replicates of 15 birds. The wheat-soybean based diets contained either 0.12% or 0.4% non-phytate phosphorus(NPP). At 32 wk of age, all the birds of each dietary treatment were injected into the abdomen with 1.5 mg/kg body weight(BW) of either LPS or saline once a day at 24-h intervals for continuous 9 d. The performance of laying hens was evaluated for 9 d. The eggs after the fifth injection were collected to value the egg quality. Three hours after the first injection, blood was collected to measure serum metabolite and immune response associated parameters.Three hours after the fifth injection, the hens were euthanized to obtain tibia, cecal tonsils and jejunum.Results: Compared with saline-injected hens, LPS-injected hens had lower feed intake and egg production(P < 0.05).Eggshell thickness, strength, albumin height and Haugh unit were significantly increased in LPS-injected hens compared with saline-injected hens(P < 0.05). Furthermore, laying hens challenged with LPS had lower villious height/crypt depth ration than those received saline. Serum calcium, phosphorus and SOD activities significantly decreased in the LPS-injected hens compared with the control(P < 0.05). LPS up-regulated expression of IL-1β, IL-6 and IL-10 in cecum, and serum concentration of MDA, IL-1β and IL-6(P < 0.05), whereas 0.40% dietary non-phytate phosphorus supplementation significantly increased(P < 0.05) villi height/crypt depth ratio, decreased(P < 0.05) serum MDA and IFN-γ concentration compared with the 0.12% non-phytate phosphorus group.Conclusion: In summary, this study demonstrates that 0.40% dietary non-phytate phosphorus supplementation significantly increased calcium and phosphorus levels of eggshell, increased villi height/crypt depth ratio, decreased serum MDA and IFN-γ concentration compared with the 0.12% non-phytate phosphorus groups. The results indicate that high level of dietary non-phytate phosphorus exerts a potential effect in alleviating systemic inflammation of LPSchallenged laying hens.

Effect of dietary defatted diatom biomass on egg production and quality of laying hens

Background： This study was to determine if feeding laying hens with defatted diatom microalgal biomass （DFA） from biofuel production affected their egg production and health status. Methods： Five replicates of 5 individually caged ISA Babcock White leghorn hens were fed 4 diets, including a corn-soybean meal control diet, a diet containing 7.5% DFA substituting for soybean meal, and diets containing 7.5% or 15% DFA substituting for corn and soybean meal. Body weights, feed intake, feed conversion ratio （FCR）, rate of egg production, egg size, egg mass, and several characteristics of eggs were determined at 4 and 8 wk. Venous blood was sampled at 4 and 8 wk for measurement of 5 biomarkers of health. Results： The15% DFA diet decreased （P 〈 0.05） feed intake, egg production, and plasma uric acid concentrations as compared with the control diet, but increased （P 〈 0.05） egg albumen weight and height compared with the 7.5% DFA diets. The two levels of DFA produced dose-dependent （P 〈 0.05） changes in three color measures of egg yolk, without affecting four hen plasma biochemical indicators of health. Conclusions： Feeding laying hens with 7.5% DFA in the corn-soybean meal diet for 8 wk had no adverse effect on their health, egg production, or egg quality, but 15% inclusion reduced feed intake, egg production, and efficiency of feed utilization.

Effects of Quercetin on Performance and Lipid Metabolism in Laying Hens

Quercetin has a variety of biological activities. However, its application as a feed additive in poultry production is limited. In this study, the effects of quercetin on performance and lipid metabolism in Hessian laying hens were investigated and the possibility of quercetin to decrease cholesterol in eggs and Low Density Lipoprotein cholesterol（LDL-cholesterol） in laying hens were explored. A total of 240 laying hens at 29-week-old were randomly assigned to four treatments, with six replicates of 10 birds per replicate. The treatments were fed with basal diet supplemented with 0, 0.2, 0.4 and 0.6 g · kg-1 quercetin for 8 weeks. Layer performance, lipid concentration in livers, yolks and serum were measured at the end of the experiment. The results showed that laying rate had a quadratic correlation with the level of quercetin（p=0.056） and was maximized by the supplement level of 0.2 g · kg-1 diet. When the level of dietary quercetin increased, feed-egg ratio decreased. Crude fat and the total cholesterol of livers decreased by supplementation of quercetin. The total cholesterols of yolks also decreased and had a quadratic correlation with the levels of quercetin（p=0.019）. Insulin increased by supplement of quercetin. In conclusion, quercetin improved the performance and reduced egg yolk cholesterol by affecting serum hormone levels.

Effect of Quercetin on Egg Quality and Components in Laying Hens of Different Weeks

This trial was conducted to evaluate the effect of quercetin on egg quality and components in laying hens of different weeks. A total of 240 healthy Hessian laying hens at 29, 39-week-old with similar body weight and laying rate were randomly divided into four groups with six replicates of 10 each replicate, respectively. The treatments were fed with basal diet supplemented with 0, 0.2, 0.4 and 0.6 g-kg-1 quercetin for 8 weeks. The results showed that compared with the control, broken or soft shell rate significantly decreased at 0.2 and 0.4 g.kg-1 quercetin and eggshell thickness significantly increased at 0.4 g.kg-1 quercetin （P〈0.01） in laying hens at 39-47 weeks old; yolk protein significantly decreased at 0.6 g kg-1 quercetin （P〈0.05） in laying hens at 29-37 weeks old; while yolk protein significantly increased at three quercetin treatments in laying hens at 39-47 weeks old; yolk cholesterol significantly decreased by quercetin in laying hens at 29-37 weeks old （P〈0.05）; yolk total phospholipids significantly increased at 0.4 and 0.6 g kg-1 quercetin （P〈0.01） and yolk cholesterol significantly decreased at 0.6 g kg-1 quercetin （P〈0.05） in laying hens at 39-47 weeks old. In a word, quercetin affected egg quality and components to some extents in laying hens of different weeks, the older the hens became, the better improvement they would be. The optimum level of quercetin was 0.4 g kg-1 in the basal diet.

Effects of Compound Acidifier and Probiotics on Production Performance,Blood Biochemical Indexes,Antioxidant Indexes and Salmonella Infection of Laying Hens

This study evaluated the effects of compound acidifier and probiotics on production performance, blood biochemical indexes, antioxidant indexes and Salmonella infection of laying hens. A total of 600 50-week-old healthy laying hens with similar laying rate were randomly assigned to four groups, 10 repeats each group, and each repeat contained 15 chickens. The laying hens in control group were fed a basal diet, and in the other three experimental groups were fed basal di- ets supplemented with 300 g/t probiotics, 0. 1% compound acidifier in the drinking water every other day, and 300 g/t probiotics ＋ 0.1% compound aeidifier in the drinking water every other day, respectively. After the feeding of 16 weeks, a total of 60 laying hens from control group were divided into four treatments as the same above for a 13-day long Salmonella challenge （1.3×10^8 CFU） trial. The results were shown as follows： no significant effects were observed on production performance, hemoglobin content, the superoxide dismutase activity and total antioxidant capacity of reproductive organ in compound acidifier and probiotics groups （ P 〉 0.05 ）. Dirty egg rate was significantly decreased in compound acidifier group, probiotics group and combination group of both （P 〈 0.05 ）. Compared with the control group, white blood cell count in probiotics group was significantly decreased （P 〈0.05 ）, and the immunoglobulin content in probiotics group tended to be increased （P = 0.061 ）. The malondialdehyde （MDA） content in oviduct isthmus of hens in compound acidifier group and combination group was significantly decreased compared with the control group （ P 〈 0.05 ）. The Salmonella positive rate in oviduct of hens in compound acidifier group was significantly decreased at the 7th and 14^th days （ P 〈0.05 ）, but that in probiotics group and combination group was not significantly different compared with control group （ P 〉 0.05 ）. In conclusion, compound acidifier and probiotics can improve health status of laying hens through decreasing the dirty egg rate and increasing antioxidant capacity and immunity of them, thus reducing Salmonella infection of body and eggs.

Effects of dietary CoQ₁₀and α-lipoic acid on CoQ₁₀levels in plasma and tissues of eggs laying hens

In this paper we described the effect of administrated CoQ10, and alfa-lipoic acid on the concentration of total CoQ10 inplasma end body tissues of eggs laying hens. Organisms raise a complex network of enzymes, metabolites and molecules with antioxidant activities in order to prevent oxidative damage of theirs bodies. Adequate blood concentrations of small weight molecules ingested with food and food additives are important for the proper functioning of the antioxidant defense. To test this hypothesis we prepared following experiment. Forty weeks old hens were selected from two genotypes;Ross 308 broiler mothers and Lohmann breed hens. Animals were fed for a period of 84 days. Concentrations of supplemented CoQ10 and ALAwere calculated from feed instruction tables so each hen received an average of approximately 5 mg of CoQ10 and 50 mg ofALAper kg of animal weight per day. During the experiment blood samples were taken and at the end of the experiment different body tissues (heart, liver, breast, legs) were collected and analyzed with originally developed HPLC-MS/MS method based selective ionization with LiCl on MRM scanning. We found a number of interesting and unexpected results. Supplemented CoQ10 increased concentrations of coenzyme CoQ10 inplasma and different hen’s tissues. Increased concentration of CoQ10 is the result of its transfer with chylomicrons from the digestive tract to various organs of the body and to the liver where exogenous and endogenous CoQ10 has been re-redistributed through lipoproteins. Supplemented ALA caused much greater concentration of CoQ10 indifferent tissues and plasma then CoQ10. Plausible explanation of our results is such that ALA may regenerates the antioxidants and accelerate the formation of endogenous CoQ10 which is distributed with lipoprotein carriers and increases overall concentration of CoQ10. Our experiments definitely show that Lipoic acid beside glutathione promotes also a synthesis of CoQ10 and increases the total concentration especially in liver and heart tissues.