Isolation of Lysozyme from Chicken Egg White Using Polyacrylamide-based Cation-exchange Cryogel

An effective cation-exchange chromatographic method for lysozyme isolation from chicken egg white is presented, using supermacroporous cryogel grafted with sulfo functional groups. The chromatographic processes were carried out by one-step and sequential elution, respectively. Sodium phosphate buffer （pH 7.8） containing different concentrations of NaC1 is used as elution agent. The corresponding breakthrough characteristics and elution behaviors in the cryogel bed were investigated and analyzed. Purity of lysozyme in the elution effluent was assayed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis （SDS-PAGE）. The maximum purity of the obtained lysozyme was about 96%, and the cryogel is demonstrated as a potential separation medium for purification of high-purit lysozyme from chicken egg white.

An Updated Review on Chicken Eggs: Production, Consumption, Management Aspects and Nutritional Benefits to Human Health

Ancestors of the modern chicken were domesticated from members of the Gallus genus probably 7 to 8 thousand years ago in southeastern Asia. Subsequently, they spread globally for meat and egg production. In the chicken egg, there is a balance of numerous, high-quality nutrients, many of which are highly bioavailable. The egg confers a multitude of health benefits to consumers emphasizing its classification as a functional food. Current global per capita egg consumption estimates approach 9 kg annually but vary greatly on a regional basis. This review deals with global production, consumption, and management aspects such as hygiene, feeding, and housing. Management aspects play key roles in the composition, quality, food safety, and visual (consumer) appeal of the egg. Also the manipulation of egg nutrients and value for human health is discussed.

Comparative Laying Performance, Egg Quality, Fertility and Hatchability of Guinea Fowl with Tilili, Horro and Potchefstroom Koekoek Chicken Breeds

A study was conducted to compare laying performance, fertility, hatchability, and egg quality of guinea fowl (GF) with Horro (HR) and Tilili (TL) local chicken and Potchefstroom Koekoek (PK) exotic chicken. Forty five layers from each genotype and 6 cocks from each chicken genotype and 9 cocks from GF were used in 3 replications in a completely randomized design. Commercial layer feed was used ad libitum for the study that lasted 29 weeks. Daily DM intake per hen was 85, 114, 103 and 137 g (SEM = 3.1) for GF, HR, TL and PK, respectively, and was in the order of GF < TL < HR < PK. Final body weight of hens was highest for PK (2490 g), intermediate for HR (1983 g) and lowest for TL (1671 g) and GF (1641 g). Egg number per production week followed a similar trend like that of DM intake and was 71, 101, 75 and 121 (SEM = 0.5) for GF, HR, TL and PK, respectively. Both fertility and hatchability of fertile eggs for GF were 57%, which were lower than the mean of chicken genotypes by 41% and 34%, respectively. Embryonic mortality was higher for GF (early, middle and late was 15.8%, 10.0%. and 17.4% respectively) compared to chicken genotypes. Chick weight was highest for PK, intermediate for HR and TL and lowest for GF;while chick length was in the order of PK > HR > TL > GF. Average egg weight was higher for PK eggs (46.4 g), intermediate for HR (43.5 g) and TL (42.3 g), and lowest for GF (35.9 g). Eggshell weight and thickness were higher for GF than chicken genotypes. Haugh unit was similar among genotypes. Such differences among poultry genotypes could be reflection of previous selection and breeding interventions, which are apparently more in chicken genotypes than GF. A possible more stressful condition of the confined environment for GF versus chicken genotypes could have also contributed to such differences. This study highlighted the need of implementing future selection and breeding schemes to improve the performance of GF and TL birds to the level achieved by other genotypes.

The egg or the chicken?

In this issue of the Journal of Geriatric Cardiology, Gao et al.,1 in a report of increased ostial pulmonary vein diameter by multislice CT angiography reported a statistically significant enlargement of the pulmonary veins in patients with congestive heart failure (CHF). This finding alone should not be of any surprise as anatomic remodeling and general dilation of the cardiac chambers are well described in patients with CHF.……

Hypertension and psychosocial factors: which came first,the egg or the chicken?

In this issue of the Journal of Geriatric Cardiology,the article of Yu, et al1 presents an intriguing issue in the field of hypertension treatment and pathophysiology.……

Bacteriological and pathological studies of egg peritonitis in Commercial layer chicken in Namakkal area

Objective:To detect the various bacteriological agents and pathological changes in commercial layer chicken affected with egg yolk peritonitis in Namakkal region of India.Methods:A total of 6572 layer chicken from 85 commercial farms were subjected for the study,out of which 1715 showed various types of oviduct almoimalities.Among the 1715,264 birds from six farms were identified as egg peritonitis on the basis of postmortem examination.Trachea,lung,heart blood,liver,peritoneal exudate,oviduct(infundibulum,magnum,uterus)and cloacal swabs were collected from the 264 birds with egg peritonitis lesion for screening of bacterial agents.Signalment,clinical signs and pathological changes were recorded in the affected flocks.Result:The results of the present investigation indicated that the E.coli associated egg peritonitis was responsible for 15.39%of the reproductive tract abnormalities in commercial layers between 21 and 80 week of age.In the affected flocks egg production drop and mortality varied from 3%to 20%and 0.5%to 7.0%respectively.It was noticed during peak egg production(21 to 60week)and southwest monsoon season(58%).Statistical analysis of age,season and egg production by Chi square test of independence revealed highly significant difference.E.coli was isolated as a pure culture and concurrent with other bacterial agents in 226 and 38 birds respectively.Among the fifteen E.coli serotypes identified serotype O_(166),O_(?)and O_(111)were predominant.Necropsy examination of affected birds revealed the presence of amorphous or insipissiated yolk material in the abdominal cavity with inflammatory changes in the ovary,oviduct and intestine.Microscopically the oviduct surface epithelium showed degeneration and desquamation,moderate to marked infiltration of inflammatory cells especially heterophils and lymphocytes in various regions and lumen contained serofibrinous exudate,inflammatory and desquamated epithelial cells with bacterial microcolonies.Ovarian follicles revealed hyperemia,degeneration of granulosa cells and infiltration of inflammatory cells.Intestine showed degenerative,necrotic and inflammatory lesion.Conclusion:The findings of this study showed that the egg peritonitis might be caused by either the translocation of intestinal E.coli into the peritoneal cavity or by the movement of cloacal E.coli into the oviduct followed by ascension of these bacteria up the oviduct,through the infundibulum,and into the peritoneal cavity.To control the egg peritonitis faecal contamination with E.coli should be minimized.

Correlation between Egg Production Traits and Broodiness Traits in Shiqiza,Langya and Luqin B2 Chickens

[ Objective] To investigate the relationship between the egg production traits and broodiness of Shiqiza, Langya and Luqin B2 chickens. E Method] Three chicken breeds, Shiqiza chickens （a breed preserved by Shandong Academy of Agricultural Sciences）, Langya chickens （a local breed in Shandong Province） and Luqin B2 chickens （a cultivated breed） were selected. Then their broodiness traits were observed and the egg productions were analyzed. Finally, the relationships between the egg production traits and broodiness were analyzed by SAS software. [ Result] The Shiqiza, Langya and Luqin B2. chickens were broody and their broodiness rate was 15.80%, 2.24% and 6.95%, respectively. Compared with the non-broody chickens, the egg productions of Shiqiza, Langya and Luqin B2 chickens were respectively decreased by 17.16%, 1.53% and 10.8% at the age of 43 weeks. The three breeds had significant differences in repeats of broody cycles （ P 〈 0.05）, and extremely significant differences in the broodiness duration, the the first day of broodiness, the age at the first egg, total amount of abnormal eggs and amount of double- yolked eggs （P 〈 0.01 ）. [Conclusion] The broodiness is a main factor affecting egg production traits. The degree of effects of broodiness on egg production traits is decreased successively in Shiqiza chicken, Luqin B2 chicken and Langya chicken.

Incubation Effect on Eggs of Tibetan Chicken under Low Altitude Condition

[ Objective] In order to study incubation conditions of Tibetan chickens in low altitude areas. [ Method] Eggs of Tibetan chicken were transported to low altitude areas in highland areas for artificial hatching. [ Results] The results showed that the average hatching rate of fertilized eggs was 85.33% ; the average healthy chick rate was 91.77 % ; the average primary body mass was 31.2l g. Hatching rate of eggs in group 2 was the highest, which reached 90.52%, the aver- age egg mass was 43.25 g and the average egg shape index was 1.32. Hatching rate of eggs in group 2 was 13.11% and 2.47% higher than that in group 1 and group 3 respectively, which was 5.19% higher than the average value. Hatching rate and healthy chick rate of eggs in group 2 also showed the same trend. [ Conclusion] High hatching effect could be obtained under the better hatching condition in low altitude areas in highland areas.

Effects of NPY Gene on Total Number of Eggs at 300 Days of Age in Donglan Black-bone Chicken

In this study, PCR-RFLP technique was employed to detect the genetic polymorphism of NPY gene and analyze the effects of various genotypes on the total number of eggs at 300 days of age in 135 Donglan black-bone chicken. According to the results, there were three genotypes （AA, AB and BB） of NPYgene in Donglan black-bone chicken group. Different genotypes exhibited significant effects （P 〈 0. 05 ） on the total number of eggs at 300 days of age. The total number of eggs at 300 days of age of AA genotype was significantly higher than that of BB genotype （P 〈 0. 05）. Therefore, the polymorphic site of NPY gene could be used as a candidate molecular marker that affects egg laying in Donglan black-bone chicken.

Correlation between DRD2 Gene Polymorphism and Early Egg Production Performance of Libo Yaoshan Chicken

To improve egg production performance of local chicken breed in Guizhou Province, Libo Yaoshan chicken, with dopamine receptor 2 （ DRD2 ） as one of the candidate genes, we detected its genetic variation in 196 Libe Yaoshan hens using PCR-SSCP （single-strand conformation polymorphism） and sequencing method, and analyzed the correlation between genetic variation and egg production traits. The results showed that TT and TG genotypes in mRNA SNlX）62 （C→T） loci of the DRD2 gene had extremely significant difference in egg production at 38 weeks age （P 〈0.01 ）, and significant difference in egg weight at 300 days age （P 〈0.05 ）. The single nucleotide polymorphisms （SNPs） mutation induced synonymous mutation of the 312th amino acids （leucine） in DRD2 protein, from L （CTG） to L （TI＇G）. The mRNA SNP962 （C→T） loci had a larger genetic effect on egg production at 38 weeks age, and could be used as a molecular marker in early breeding of Libo Yaoshan chicken.

Sensory Characteristics, Nutritional Composition, and Quality of Eggs from Different Chickens

The present study evaluated the sensory, composition, and quality of eggs from Cosmopolitan (C), Improved Horro (H), ♂ Improved Horro * Cosmopolitan ♀ (HC), ♂ Cosmopolitan * Improved Horro ♀ (CH), Indigenous(L), and Koekoek (KK) genotypes. A completely randomized design was used in the study. A total of 108 (18/genotype), 180 (30/genotype), and 90 (15/genotype) eggs were used for the sensory, composition, and egg quality tests, respectively. All data were analyzed following the GLM model using SAS software. The boiled and scrambled eggs from L, H, and C were (P ≤ 0.001) preferred followed by CH, HC, and KK. Results showed that KK, HC, CH, and C eggs were higher in moisture, crude fat, crude ash, and crude fiber, but these traits were found lower in H and L genotypes. A significantly highest crude protein was observed in L (21.19 ± 0.19) genotype, with higher in H (20.62 ± 0.26), intermediate in HC (19.96 ± 0.29), C (19.85 ± 0.10), and CH (19.40 ± 0.37), whereas the eggs from KK genotype had the lowest crude protein content (18.69 ± 0.20). The egg quality was (P = 0.001 - 0.01) affected across traits except for eggshell indices (P > 0.05). The genotypes with a negative significant correlation with crude protein had a positive significant correlation with almost all composition and egg external quality traits. The genotypes with positive significant correlations of egg weight had positive significant correlations with most internal egg quality traits except that of yolk weight ratio, yolk albumen ratio, and yolk color. Conclusively: the eggs of L, H, and C genotypes were best favored followed by CH and C, but the KK genotype was the least favored, and these differences were deemed due to genetic variations, and interventions. Furthermore, the eggs laid from genotypes with deep yellow yolk color might be the most nutritious. It could also necessitate future breeding and dietary studies.

Associations of Gonadotropin-Releasing Hormone Receptor (GnRHR) and Neuropeptide Y(NPY) Genes’Polymorphisms with Egg-Laying Traits in Wenchang Chicken

Single nucleotide polymorphisms （SNP） of chicken gonadotropin-releasing hormone receptor （GnRHR） and neuropeptide Y （NPY） were selected to identify the genotypes of Wenchang （Chinese indigenous breed） chicken with restricton fragment length polymorphisms. The associations of the SNPs with the total egg production （NE）, average days of continual laying （ADCL）, and number of double-yolked eggs （DYE） traits were analyzed. The frequency of restriction enzyme A/a alleles in the population was for GnRHR 0.69 （Bpu1102 Ⅰ A） and 0.31 （Bpu1102 Ⅰ a） and for NPY 0.46 （Dra Ⅰ B） and 0.54 （Dra Ⅰ b）. Trait data from a total of 120 hens, which were purebred introduced from Hainan Province, China from one generation were recorded. Two significant effects of genes＇ marker were found： for GnRHR and number of eggs （dominant; t= 2.67, df= 116） and NPY and number of eggs （additive; t= 1.97, df= 116）. The current research supports the effects of GnRHR and NPY genes on egg-laying traits of chickens.

重庆市部分区县鸡肉和鸡蛋兽药残留监测分析及膳食暴露风险评估

目的:了解重庆市部分地区鸡肉和鸡蛋食品中15种兽药残留情况,并评估人体摄入健康风险。方法:2021—2023年,在重庆市17个区县的商场超市、农贸市场随机抽取鸡肉、鸡蛋样品共计107份,采用液相色谱-质谱/质谱法测定鸡肉及鸡蛋中6种喹诺酮类、2种四环素族类、1种硝基咪唑类、2种酰胺醇类抗生素及4种抗球虫药含量。根据重庆市居民的饮食消费情况,采用点评估法和食品安全指数法对鸡肉和鸡蛋中兽药的暴露风险进行评估。结果:76份鸡蛋样品兽药残留检出率为25.00%(19/76),不合格率为2.63%(2/76);鸡肉样品兽药残留检出率为70.97%(22/31),不合格率为0%(0/31);鸡蛋及鸡肉中检出率较高的多西环素,食品安全指数均值分别为0.000 293和0.000 119,最大值分别为0.002 710和0.001 770,均远低于1。结论:重庆市部分区县鸡肉及鸡蛋中兽药残留有不同程度的检出,部分样品不合格,但总体风险较低,健康危害在可接受范围。

基于机器学习的地方鸡产蛋曲线拟合探索

[目的]本研究探索以机器学习方法对2个地方鸡品系周产蛋率建模,并将其与非线性回归方法比较,旨在提高养鸡生产中产蛋曲线的拟合精度。[方法]产蛋数据采集自地方鸡杂交组合试验群,自22周龄开始统计产蛋数,至50周龄截止。试验鸡于全封闭鸡舍单笼饲养,产蛋期人工补光16 h。试验鸡分为两组,每组150只鸡。第Ⅰ组是黄羽肉鸡合成系,第Ⅱ组是兼用型地方鸡种。以IBM SPSS Statistics 21.0软件中的非线性回归方法拟合产蛋曲线,所用模型包括Logistic模型、McNally模型、杨宁模型以及Grossman模型。以MATLAB R2014a构建机器学习模型,神经网络选用多层感知器,用300次迭代的拟牛顿法训练数据。以贝叶斯最小二乘支持向量机构建产蛋模型,针对正则项系数和核函数参数进行优化。[结果]依据MSE、R 2、AIC评判标准,Grossman模型在4种非线性回归模型中拟合度最好,McNally模型表现最差。McNally模型预测的高峰产蛋率偏离真实值;Logistic模型、杨宁模型以及Grossman模型高峰产蛋率统计值与真实值基本相符。两组试验鸡的模型参数不同,Ⅱ组持续产蛋能力优于Ⅰ组。基于MSE、R 2以及图形评估结果,神经网络优于传统的非线性方程拟合,而支持向量机略好于神经网络。优化后神经网络参数为2个隐藏层,每个隐藏层包含5个神经元。第Ⅰ组支持向量机的正则项系数为30.97,核参数为0.0701;第Ⅱ组支持向量机的正则项系数为566.53,核参数为0.1754.[结论]机器学习方法可用于产蛋模型构建,相比于传统单变量回归方法,机器学习方法可加入更多变量,提供更准确的预测。

Study on the Relationship between Plasma very Low Density Lipoprotein Concentration and Egg Composition Traits in Layer Type Chickens

The chickens used in this study were from a pure line of brown shell egg-type (YAFA) female grandparents of 17-week-old. Plasma very low density lipoprotein (VLDL) concentration was measured with turbidimetric assay. The experimental results showed that there was a close relationship between plasma VLDL concentration and egg composition traits, and a positive phenotypic correlation trend was found between 29-week plasma VLDL concentration and 44-week yolk weight, and the genetic correlation coefficient was 0.234. Both the phenotypic and genetic correlations between 29-week plasma VLDL concentration and albumen weight were negative. Significant positive phenotypie correlations were, however, observed between yolk ratio, or the yolk/albumen ratio and 29-week plasma VLDL concentration, and their genetic correlation coefficients were 0.250 and 0.223, respectively.

复方中草药制剂对林下绿壳蛋乌鸡产蛋性能、蛋品质和血清生化指标的影响

本研究旨在探究日粮中添加不同水平的复方中草药制剂对林下绿壳蛋乌鸡产蛋性能、蛋品质、血清生化指标的影响。选取520日龄健康、体质量接近的绿壳蛋乌鸡560羽,随机分成4组,分别为对照组和试验Ⅰ组、Ⅱ组、Ⅲ组。对照组饲喂基础日粮,试验Ⅰ组、Ⅱ组、Ⅲ组分别在基础日粮中添加0.5%、1.0%、1.5%的复方中草药制剂,试验期45 d。结果显示,日粮中添加不同水平的复方中草药制剂对林下绿壳蛋乌鸡的平均蛋重、平均产蛋率、绿壳蛋破损率有显著影响,其中Ⅱ组平均蛋重显著高于对照组(P<0.05),Ⅰ组、Ⅱ组平均产蛋率显著高于对照组(P<0.05),Ⅱ组绿壳蛋破损率显著低于对照组(P<0.05);日粮中添加不同水平的复方中草药制剂对绿壳蛋蛋黄相对重、蛋白高度、蛋黄水分含量、蛋黄指数及哈氏单位有显著影响,其中Ⅱ组绿壳蛋蛋黄相对重显著高于对照组(P<0.05),Ⅰ组、Ⅱ组、Ⅲ组绿壳蛋蛋白高度显著高于对照组(P<0.05),Ⅱ组、Ⅲ组绿壳蛋水分含量显著低于对照组和Ⅰ组(P<0.05),Ⅱ组绿壳蛋蛋黄指数显著高于对照组、Ⅰ组、Ⅲ组(P<0.05),Ⅱ组绿壳蛋哈氏单位显著高于对照组和Ⅲ组(P<0.05);日粮中添加不同水平的复方中草药制剂对林下绿壳蛋乌鸡的血清总蛋白(TP)、球蛋白(GLO)、丙氨酸氨基转移酶(ALT)、胆固醇(TC)和甘油三酯(TG)有显著影响,其中Ⅰ组、Ⅱ组血清TP含量显著高于对照组(P<0.05),Ⅰ组、Ⅱ组、Ⅲ组血清GLO含量显著高于对照组(P<0.05),Ⅲ组血清ALT活性显著高于对照组和Ⅰ组(P<0.05),Ⅱ组血清TC和TG含量显著高于对照组(P<0.05)。综上,日粮中添加不同水平的复方中草药制剂能改善绿壳蛋乌鸡的产蛋性能、蛋品质及血清生化指标,且以1.0%添加量的复方中草药制剂效果最佳。

发酵牡丹籽粕对黄山黑鸡生产性能、蛋品质、蛋黄中脂肪酸含量及血清生化指标的影响

本试验旨在研究发酵牡丹籽粕对黄山黑鸡生产性能、蛋品质、蛋黄中脂肪酸含量及血清生化指标的影响。选取240日龄产蛋率及体重相近的黄山黑鸡864只,随机分为3组,每组4个重复,每个重复72只。对照组饲喂基础饲粮,试验组分别饲喂在基础饲粮中添加5%(5%FPSM组)和9%发酵牡丹籽粕(9%FPSM组)的试验饲粮。预试期1周,正试期8周。结果表明:1)与对照组相比,5%FPSM组的产蛋率显著升高(P<0.05),料蛋比和平均日采食量显著降低(P<0.05);9%FPSM组的产蛋率和平均日采食量极显著降低(P<0.01)。2)与对照组相比,9%FPSM组的蛋形指数显著升高(P<0.05),蛋壳颜色显著降低(P<0.05)。3)与对照组相比,5%FPSM组的蛋黄中ω-3多不饱和脂肪酸(PUFA)含量显著升高(P<0.05);9%FPSM组的蛋黄中总饱和脂肪酸(SFA)含量和ω-6/ω-3 PUFA显著或极显著降低(P<0.05或P<0.01),总PUFA和ω-3 PUFA含量显著或极显著升高(P<0.05或P<0.01)。4)与对照组相比,5%FPSM组的血清甘油三酯(TG)、免疫球蛋白A(IgA)、免疫球蛋白G(IgG)含量和碱性磷酸酶(ALP)活性及总抗氧化力(T-AOC)极显著升高(P<0.01),血清超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活性和免疫球蛋白M(IgM)含量极显著降低(P<0.01);9%FPSM组的血清低密度脂蛋白(LDL)、TG、尿素氮(UN)、IgA、IgM含量和ALP活性及T-AOC显著或极显著升高(P<0.05或P<0.01),血清高密度脂蛋白(HDL)和丙二醛(DMA)含量极显著降低(P<0.01)。由此可见,饲粮中添加5%的发酵牡丹籽粕可提高黄山黑鸡的生产性能;添加5%和9%的发酵牡丹籽粕可提高黄山黑鸡的蛋黄中ω-3 PUFA含量,提高机体抗氧化能力和免疫力。本试验条件下,黄山黑鸡饲粮中发酵牡丹籽粕的适宜添加比例为5%。

广西麻鸡卵巢组织中差异lncRNA筛选及ceRNA网络构建

【目的】筛选广西麻鸡卵巢中差异表达的长链非编码RNA(long non-coding RNA,lncRNA)、信使RNA(messenger RNA,mRNA)以及微RNA(microRNAs,miRNA),并进一步筛选出与鸡产蛋性状相关的lncRNA,为后期研究lncRNA对鸡产蛋性状的调控提供理论支持。【方法】根据广西麻鸡从开产到41周龄的产蛋情况筛选出高产和低产的广西麻鸡各3只,并以其卵巢组织为材料,进行转录组测序,使用edgeR和DEseq2软件从测序得到的数据中筛选出差异表达的lncRNA、mRNA以及miRNA,利用miRanda软件和lncRNA的顺式作用分别预测miRNA和lncRNA的靶基因,对差异lncRNA的靶基因进行GO功能和KEGG通路富集分析后,利用Cytoscape(v 3.8.2)软件构建竞争性内源RNA(ceRNA)网络图。利用实时荧光定量PCR验证转录组测序结果。【结果】本研究共获得广西麻鸡卵巢组织中438个差异表达的lncRNAs、18个差异表达的miRNAs以及301个差异表达的mRNAs。对上述差异表达的lncRNA的靶基因进行GO功能和KEGG通路富集分析后发现,其显著富集于激素分泌调节、中胚层形成、中胚层发育以及中胚层形态发生等与产蛋有关的生物过程,以及MARK、甘露糖O-聚糖的生物合成、卵母细胞减数分裂、孕激素介导的卵母细胞成熟以及促性腺激素释放激素等信号通路。通过GO功能和KEGG通路富集分析获得6个与产蛋性状相关的lncRNAs,分别是TCONS_00091814、TCONS_00051866、XR_006939520.1、XR_005839807.1、TCONS_00088588、TCONS_00037324。根据测序结果成功构建出包含9个miRNAs、60个lncRNAs和3个mRNAs的ceRNA网络图,且网络中所有的基因均在低、高产组中差异表达。所选差异表达基因实时荧光定量PCR结果与转录组测序的基因表达水平一致,说明转录组测序结果可靠。【结论】通过RNA测序技术从广西麻鸡卵巢中筛选到了一系列差异表达的lncRNA,并筛选出了6个可能与产蛋性状相关联的lncRNAs,为进一步提高鸡的产蛋性能提供了理论支持。

饲粮代谢能和粗蛋白水平对产蛋后期双莲鸡生产性能、蛋品质和肝脏脂代谢的影响

试验旨在研究饲粮不同代谢能和粗蛋白水平对产蛋后期双莲鸡配套系生产性能、蛋品质、肝脏脂代谢的影响。试验选取240只健康、体重及产蛋率接近的40周龄双莲鸡产蛋母鸡,随机分为6组,每组4个重复,每个重复10只鸡。试验采取2×3双因素设计,代谢能(ME)设定为11.30和10.88 MJ/kg两个水平,粗蛋白(CP)设定为16.2%、15.2%和14.2%三个水平,预试期2周,正试期12周。结果显示:(1)粗蛋白水平对产蛋率、料蛋比、平均蛋重无显著影响(P>0.05),但11.30 MJ/kg代谢能水平可显著降低51~54周龄双莲鸡产蛋率和平均日产蛋量(P<0.05),并显著增加平均蛋重(P<0.05)。(2)饲粮代谢能和粗蛋白互作极显著影响46周龄鸡蛋蛋白高度和哈氏单位(P<0.01),并显著影响50周龄鸡蛋蛋黄颜色(P<0.05);10.88 MJ/kg代谢能水平54周龄鸡蛋哈氏单位、蛋黄比例显著高于11.30 MJ/kg代谢能水平(P<0.05),而46、54周龄鸡蛋蛋黄颜色和46、54周龄鸡蛋蛋壳厚度极显著低于11.30 MJ/kg代谢能水平(P<0.01),50周龄蛋壳厚度显著低于11.30 MJ/kg代谢能水平(P<0.05);16.2%粗蛋白水平46周龄鸡蛋哈氏单位显著高于14.2%粗蛋白水平(P<0.05),而54周龄鸡蛋蛋黄比例极显著低于15.2%和14.2%粗蛋白水平(P<0.01)。(3)10.88 MJ/kg代谢能水平双莲鸡血清、肝脏甘油三酯水平,肝脏相对重量和腹脂相对重量以及肝脏脂肪酸合成相关基因如SREBP-1c、ACACA、FAS、SCD1表达量均显著低于11.30 MJ/kg代谢能水平(P<0.01)。综合分析,本试验条件下双莲鸡配套系蛋鸡产蛋后期(42~54周龄)代谢能和粗蛋白水平分别以10.88 MJ/kg和16.2%为宜。

吉林地方黑羽鸡不同世代的产蛋性能及蛋品质对比

为了解吉林地方黑羽鸡产蛋性能和蛋品质,试验各选取240只120日龄F1、F2、F3三个世代黑羽鸡,测定产蛋性能及蛋品质。结果表明:与F代相比,F3代平均开产日龄显著提前8.7 d(P<0.05),年平均产蛋量F3显著提高7.3枚(P<0.05),种蛋受精率和受精蛋孵化率分别显著提高6.7%和4.8%(P<0.05)。三个世代的蛋重、蛋形指数、蛋壳厚度、蛋比重及蛋黄色泽无显著差异(P>0.05)。综上所述,三个世代中,F3代黑羽鸡产蛋性能最佳。