Characteristics of Deposition of Inosine Monophosphate(IMP) and Intramuscular Fat(IMF) in Muscles of Jinghai Yellow Chicken and Its Crossbreeds

[Objective] This study aimed to investigate the characteristics of deposition of inosine monophosphate （IMP） and intramuscular fat （IMF） in muscles of Jinghai yellow chickens and its crossbred.[Method] The characteristics of IMP and IMF deposition of 112-day-old Jinghai yellow chickens （J×J） and its two different 70-day- old crossbreeds （J×B and B×B） were analyzed. The IMP content in breast muscle and leg muscle were determined by HPLC. [Result] The contents of IMP and cor- rected inosine monophosphate （IMPc） in breast muscle were significantly or ex- tremely significantly higher than that in leg muscle of the chickens in the three groups whether in male or female chickens （P〈0.05 or P〈0.01）. There were no sig- nificant difference in the contents of IMP and IMPc between hens and roosters （P〉 0.05）. The fresh degree of breast muscle and leg muscle was 96,11%-98.16% and 87.22%-93.07%, respectively. And the fresh degree of breast muscle was higher than that of leg muscle. In the three groups, the IMF content in leg muscle was significantly higher than that in breast muscle whether in male or female chickens （P〈0.05）. The contents of IMF in breast muscle and leg muscle were 0.36%-0.75% and 1.84%-2.38%, respectively. The iMP content in breast muscle of chickens in Bx J group was extremely significantly higher than that in breast muscle of chickens in JxJ group （P〈0.01）, but the contents of IMPc and iMF of breast muscle and leg muscle of the chickens in the three groups had no significant difference （P〉0.05）. [Conclusion] To sum up, the freshness and flavor significantly differ between the breast muscle and leg muscle of chickens, but show no significant difference among the three groups.

Effects of Astragalus Powder on Serum Lipid and Body Fat Content of Fast Large-scale Quality Chickens

[ Objective] To study the effects of astragalus powder on serum lipids and body fat contents of fast large-scale quality chickens, and thus provide a theoretical basis for its application in poultry production,[ Method ] All the 180 1-day-old healthy Liangfeng chickens were randomly divided into six groups. Group 1 was the control group, fed with basal diet; group 2, group 3 and group 4 were fed with basal diet added with 0.75%, 1.0% and 1.25% astragalus powder, respectively; group 5 and group 6 were separately fed with basal diet added with 1.0% and 1.25% astragalus pow- der, but the astragalus powder was used for 10 d and then was forbidden for 10 d in turn during the whole experiment. The content of triglyceride （TG）, total cholesterol （TCHO）, high-density lipoprotein-Cholesterol （ HDL-C）, and low-density lipoprotein-Cholesterol （LDL-C） were respectively determined when the chickens were 35-day-old and 63-day-old, while the percentage of abdominal fat （PAF） as well as intramuscular fat （IMF） and subcutaneous fat ply （SFP） was measured when the chickens were 63-day-old. [ Result] In 35-day-old chickens, the levels of TCHO were sig- nificantly or very significantly lower in group 3, group 4, and group 6 than in control group （ P 〈0.05 or 0.01 ） ; the levels of LDL-C significantly lower in group 3 and group 6 （ P〈0. 05） ; the level of HDL-C significantly higher in group 5 （P〈0.05）. In 63-day-old chickens, the levels of TCHO and LDL-C were significantly or very significantly lower in group 3, group 4, and group 5 than in control group （ P 〈 0.05 or 0.01 ） while the levels of HDL-C were significantly higher in these groups; the PAF was significantly lower in group 3 （ P 〈 0.05）. [ Condasion] Astragalus powder should re- duce the levels of TG, TCHO and LDL-C, promote HDL-C content, and also play a certain regulative role in deposition of abdominal fat.

Identification and characterization of genes that control fat deposition in chickens

Background： Fat deposits in chickens contribute significantly to meat quality attributes such as juiciness, flavor, taste and other organoleptic properties. The quantity of fat deposited increases faster and earlier in the fast- growing chickens than in slow-growing chickens. In this study, Affymetrix Genechip~ Chicken Genome Arrays 32773 transcripts were used to compare gene expression profiles in liver and hypothalamus tissues of fast-growing and slow-growing chicken at 8 wk of age. Real-time RT-PCR was used to validate the differential expression of genes selected from the microarray analysis. The mRNA expression of the genes was further examined in fat tissues. The association of single nucleotide polymorphisms of four lipid-related genes with fat traits was examined in a F2 resource population. Results： Four hundred genes in the liver tissues and 220 genes hypothalamus tissues, respectively, were identified to be differentially expressed in fast-growing chickens and slow-growing chickens. Expression levels of genes for lipid metabolism （SULTIB1, ACSBG2, PNPLA3, LPL, AOAH） carbohydrate metabolism （MGAT4B, XYLB, GBE1, PGM1, HKDCl）cholesttrol biosynthesis （FDPS, LSS, HMGCR, NSDHL, DHCR24, IDI1, MEI） HSD17B7 and other reaction or pro- cesses （CYPIA4, CYP1A1, AKR1BI, CYP4V2, DDO） were higher in the fast-growing White Recessive Rock chickens than in the slow-growing Xinghua chickens. On the other hand, expression levels of genes associated with multicellular organism development, immune response, DNA integration, melanin biosynthetic process, muscle organ develop- ment and oxidation-reduction （FRZB, DMD, FUT8, CYP2C45, DHRSX, and CYP2C18） and with glycol-metabolism （GCNT2, ELOVL d, and FASN）, were higher in the XH chickens than in the fast-growing chickens, fiT-PCR validated high expression levels of nine out of 12 genes in fat tissues. The G1257069A and T1247123C of the ACSBG2 gene were significantly associated with abdominal fat weight. The G4928024A of the FASN gene were significantly associ- ated with fat bandwidth, and abdominal fat percentage. The C4930169T of the FASN gene was associated with ab- dominal fat weight while the A59539099G of the ELOVL 6 was significantly associated with subcutaneous fat. The A8378815G of the DDT was associated with fat band width. Conclusion： The differences in fat deposition were reflected with differential gene expressions in fast and slow growing chickens.

A selected population study reveals the biochemical mechanism of intramuscular fat deposition in chicken meat

Background:Increasing intramuscular fat(IMF)is an important strategy to improve meat quality,but the regulation mechanism of IMF deposition needs to be systematically clarified.Results:A total of 520 chickens from a selected line with improved IMF content and a control line were used to investigate the biochemical mechanism of IMF deposition in chickens.The results showed that the increased IMF would improve the flavor and tenderness quality of chicken meat.IMF content was mainly determined both by measuring triglyceride(TG)and phospholipid(PLIP)in muscle tissue,but only TG content was found to be decisive for IMF deposition.Furthermore,the increase in major fatty acid(FA)components in IMF is mainly derived from TGs(including C16:0,C16:1,C18:1n9c,and C18:2n6c,etc.),and the inhibition of certain very-long-chain FAs would help to IMF/TG deposition.Conclusions:Our study elucidated the underlying biochemical mechanism of IMF deposition in chicken:Prevalent accumulation of long-chain FAs and inhibitions of medium-chain FAs and very long chain FA would jointly result in the increase of TGs with the FA biosynthesis and cellular uptake ways.Our findings will guide the production of high-quality chicken meat.

Integration of association and computational methods reveals functional variants of LEPR gene for abdominal fat content in chickens

Leptin receptor(LEPR)plays a vital role in obesity in humans and animals.The objective of this study is to assess LEPR functional variants for chicken adipose deposition by integration of association and in-silico analysis using a unique chicken population,the Northeast Agricultural University broiler lines divergently selected for abdominal fat content(NEAUHLF).Five online bioinformatics tools were used to predict the functionality of the single nucleotide polymorphisms(SNPs)in coding region.Further,the possible structure–function relationship of high confidence SNPs was determined by bioinformatics analyses,including the conservation and stability analysis based on amino acid residues,prediction of protein ligand-binding sites,and the superposition of protein tertiary structure.Meanwhile,we analyzed the association between abdominal fat traits and 20 polymorphisms of chicken LEPR gene.The integrated results showed that rs731962924(N867I)and rs13684622(C1002R)could lead to striking changes in the structure and function of proteins,of which rs13684622(C1002R)was significantly associated with abdominal fat weight(AFW,P=0.0413)and abdominal fat percentage(AFP,P=0.0260)in chickens.Therefore,we are of the opinion that rs13684622(C1002R)may be an essential functional SNP affecting chicken abdominal fat deposition,and potentially applied to improvement of broiler abdominal fat in molecular marker-assisted selection(MAS)program.Additionally,the coupling of association with computer electronic predictive analysis provides a new avenue to identify important molecular markers for breeders.

The Study on Correlation Analysis of Single Nucleotide Polymorphism of IGF2 Gene and Body Fatness Traits in Chicken

Insulin-like growth factor Ⅱhas profound effects on the growth and differentiation of animal embryo. Some researches indicated that it affects the fat metabolism of poultry. This study was designed to investigate the effect of IGF2 on chicken fatness traits. Broiler, Hyline Brown layer and three native breeds (Shiqiza, Beijing You, Baier) were used in this research. Body weight and body composition traits were measured in broiler line at the age of 7 weeks. Primers for exon2 in IGF2 were designed from database of chicken genomic sequence. Polymorphisms were detected by PCR-SSCP and DNA sequencing. The total χ2 test results showed that there was a significant difference (P < 0.01) in the frequency of genotype among breeds. A C/G mutation at base position 139 was found among individuals in broiler line and the least square analysis showed that BB genotype birds had significant lower (P <0.05) abdominal fat weight and percentage of abdominal fat than AA or AB genotype birds. From the results we can conclude putatively that IGF2 gene is the major gene affecting the fatness traits of chicken or it links with the major gene, and the mutation could be used as the molecular genetic marker to select the chicken for low abdominal fat.

The Change of Plasm a very Low Density Lipoprotein Concentration Pre-or Post-Feeding and in Conrrelation with Body Fatness Traits in Broiler Chickens

Blood samples were taken from birds,from a commercial line of broiler chicken,being in a fully fed state and in fasting state for 2,4,6 hours respectively at 49 d of age and plasma very low density lipoprotein(VLDL) concentration was measured with turbidimetric assay.The experiment results showed that the variation coefficients of plasma VLDL concentration mersured at four different times were 58.11%,74.39%,69.70%,47.83%,respectively for male broilers,and 41.82%,60.87%.59.26%,50.0%for female broilers respectively.Plasma VLDL concentration decreased with the fasting time.There was a significant positive phenotypic correlation between abdominal fat weight,percentage of abdominal fat and plasma VLDL concentration for the birds being in fully feeding state,and the correlation decreased or no longer existed for the bired being in fasting state.The conclusion was that for practically application of plasma VLDL content selected in broiler chicken breeding,blood samples should be collected from birds being in feeding state.

Maillard Products Formed from Chicken Fat Oxidants and Amino Acids Act as a Flavor Enhancer in Comminuted Chicken Products

Lipid oxidation and degradation are generally recognized as unfavorable reactions in food processing. However, lipids can be utilized to produce meat-like flavorings through reaction with amino acids after degradation to carbonyls such as aldehydes and ketones. The fatty acids in chicken fat mainly comprise palmitic acid, oleic acid and linoleic acid. After being heated at 120 ~C for 3 h, the degraded carbonyls of chicken fat were reacted with cysteine, alanine, glycine and thiamine to form a chicken-like flavoring. The key aromatic components of the flavoring were identified by GC-MS. In the overall volatile profile, 22 kinds of compound were detected, among which 2-furanmethanol was formed by the Maillard reaction, 1-（2-furanyl）-ethanone by cyclization and 2,4,6-trimethyl-l,3,5-trithiane by the Strecker degradation of cysteine. Dihydro-2-methyl-3（2H）-furanone, dihydro-2-methyl- 3（2H）-thiophenone, 2-acetyl-lH-pyrroline and 4-methyl-5-thiazoleethanol were the degradation products of thiamine. The prepared chicken flavoring was added to comminuted chicken product （CCP）. GC-MS analysis and sensory evaluation showed that the flavor and odor of the CCP were greatly enhanced.

AMPK Subunit Expression Regulates Intramuscular Fat Content and Muscle Fiber Type in Chickens

The objective of this study was to assess the role of AMPK in intramuscular fat(IMF) and fiber type in chicken muscle. The chickens were slaughtered and their muscles were collected at the ages of 4, 8, and 16 weeks so as to determine the IMF contents, as well as the expression levels of AMPK subunits, regulators of adipogenesis. In addition, the myosin heavy chains(My HCs) in thigh muscle tissues were also measured. The results showed that the IMF contents in 16-week old chickens were higher than those in 4 and 8-week-old chickens(P<0.05).The expression levels of fatty acid synthase(FAS) and fatty aicd translocase CD36(FAT/CD36) m RNA were increased significantly in samples collected at the ages of4 and 16 weeks(P<0.05). The expression levels of My HC IIa and IIb differed significantly among all the developmental stages(P <0.05). The AMPKα2, AMPKγ1,and AMPKγ3 m RNA levels were dramatically decreased with the increase of age(P <0.05). To examine the role of AMPK in adipogenesis regulation, the SV cells were cultured in an adipogenesis medium and treated with AICAR and Compound C respectively, the specific activator and inhibit of AMPK. The Compound C induced dramatically a greater expression of C/EBPβ, SREBP1 and PPARγ(P <0.05). In conclusion, the expression of AMPKα2, AMPKγ1, and AMPKγ3 m RNA is significantly correlated with the adipogenesis in skeletal muscle of chickens.

Potential regulation of linoleic acid and volatile organic compound contents in meat of chickens by PLCD1

Omega-3(linolenic acid(ALA),docosapentaenoic acid,eicosapentaenoic acid)and omega-6(linoleic acid(LA),arachidonic acid)polyunsaturated fatty acids are essential for health and normal physiological functioning in humans.Here we report a genome-wide association study(GWAS)on LA content in chicken meat.The 19 significant single nucleotide polymorphisms(SNPs)identified by the GWAS approach were annotated in VILL,PLCD1 and OXSR1 genes with highly polymorphic linkage blocks,and explained 4.5%of the phenotypic variation in the LA content.Specifically,the PLCD1 mRNA expression level was negatively correlated with the LA content,and significantly higher in chickens with low LA content than in those with high LA content.In addition,PLCD1 was found to be involved in metabolic pathways,etc.Furthermore,the LA content was correlated with volatile organic compounds(e.g.,octanal,etc.),but no relationship was found with intramuscular fat and triglycerides in chicken meat.The results indicated that there are key SNPs in PLCD1 that regulate the content of LA,and it has no significant effect on fat deposition,but may affect the content of volatile organic compounds(VOCs).

CircDOCK7 facilitates the proliferation and adipogenic differentiation of chicken abdominal preadipocytes through the gga‑miR‑301b‑3p/ACSL1 axis

Background Abdominal fat deposition depends on both the proliferation of preadipocytes and their maturation into adipocytes,which is a well-orchestrated multistep process involving many regulatory molecules.Circular RNAs(circRNAs)have emergingly been implicated in mammalian adipogenesis.However,circRNA-mediated regulation in chicken adipogenesis remains unclear.Our previous circRNA sequencing data identified a differentially expressed novel circRNA,8:27,886,180|27,889,657,during the adipogenic differentiation of chicken abdominal preadipocytes.This study aimed to investigate the regulatory role of circDOCK7 in the proliferation and adipogenic differentiation of chicken abdominal preadipocytes,and explore its molecular mechanisms of competing endogenous RNA underlying chicken adipogenesis.Results Our results showed that 8:27,886,180|27,889,657 is an exonic circRNA derived from the head-to-tail splicing of exons 19–22 of the dedicator of cytokinesis 7(DOCK7)gene,abbreviated as circDOCK7.CircDOCK7 is mainly distributed in the cytoplasm of chicken abdominal preadipocytes and is stable because of its RNase R resistance and longer half-life.CircDOCK7 is significantly upregulated in the abdominal fat tissues of fat chickens compared to lean chickens,and its expression gradually increases during the proliferation and adipogenic differentiation of chicken abdominal preadipocytes.Functionally,the gain-and loss-of-function experiments showed that circDOCK7 promoted proliferation,G0/G1-to S-phase progression,and glucose uptake capacity of chicken abdominal preadipocytes,in parallel with adipogenic differentiation characterized by remarkably increased intracellular lipid droplet accumulation and triglyceride and acetyl coenzyme A content in differentiated chicken abdominal preadipocytes.Mechanistically,a pull-down assay and a dual-luciferase reporter assay confirmed that circDOCK7 interacted with gga-miR-301b-3p,which was identified as an inhibitor of chicken abdominal adipogenesis.Moreover,the ACSL1 gene was demonstrated to be a direct target of gga-miR-301b-3p.Chicken ACSL1 protein is localized in the endoplasmic reticulum and mitochondria of chicken abdominal preadipocytes and acts as an adipogenesis accelerator.Rescue experiments showed that circDOCK7 could counteract the inhibitory effects of gga-miR-301b-3p on ACSL1 mRNA abundance as well as the proliferation and adipogenic differentiation of chicken abdominal preadipocytes.Conclusions CircDOCK7 serves as a miRNA sponge that directly sequesters gga-miR-301b-3p away from the ACSL1 gene,thus augmenting adipogenesis in chickens.These findings may elucidate a new regulatory mechanism underlying abdominal fat deposition in chickens.

Transesterification Reaction of Waste Cooking Oil and Chicken Fat by Homogeneous Catalysis

In the last years, biodiesel production has been on a steady increase due to it is renewable and biodegradable fuel. The process to obtain biodiesel can be carried out using different raw materials. It is conlmonly performed by transesterification reaction of vegetable oils with methanol and using a homogeneous or heterogeneous catalyst. This work seeks to compare the results produced in transesterification of wasted cooking oil and chicken fat by homogeneous catalysis with NaOH. Due to in each case triglyceride comes from different raw materials, operation conditions differ slightly, which is more evident in the values used for the temperature. For chicken fat was used temperature variations between 35 ℃ and 55 ℃, varying catalyst in percentages between 0.3% and 0.7% with a molar ratio 6：1 in all cases and a reaction time of I h. Likewise, the conditions used in the tmnsesterification process of waste cooking oil were temperature between 50 ℃ and 60 ℃ with a molar ratio 6/1 and 9/1 for alcohol and oil, and catalyst percentage between 0.5% and 0.7% by weight. The yields obtained were between 78% and 94%, or 83% and 95%, for chicken fat and wasted cooking oil, respectively.

Effect of Dietary Fat Sources on the Fatty Acid Composition and Sensory Characteristics of Chicken Meat

The research was carried out in two experiments on Ross 308 male hybrid chickens. Chickens were divided into five groups （five dietary treatments differing in source and concentration of plant oil and fish oil）. Feeding chickens with diets of determined composition from 22nd to 42nd day of fattening resulted in altered fatty acid profile in white meat and dark meat, and in significantly lowered n-6/n-3 polyunsaturated fatty acids （PUFA） ratio in white meat. Increase of n-3 PUFA concentration in diets resulted in statistically significant （P = 0.001） increase of n-3 PUFA, as well as in decrease （P = 0.02） of n-6 PUFA in white and dark chicken meat in the 1 st experiment. The 2nd experiment resulted in statistically significant increase of n-3 PUFA concentration in white and dark chicken meat （P 〈 0.001）, and n-6 PUFA concentration decreased only in dark chicken meat （P 〈 0.001）. The increase of PUFA in both experiments was accompanied with decrease of saturated fatty acids （SFA） concentration in chicken meat. Although all experimental treatments were assessed as having more fishy odour and flavour than the control sample, statistically significant difference between samples was found only for fishy flavour in dark meat （P 〈 0.05）. In the 2nd experiment, where the feeding treatment was altered seven days before chickens＇ slaughtering （fish oil was omitted）, the intensity of fishy odour and flavour was assessed with ＂none＂ to ＂slightly noticeable＂ （P 〉 0.05）. In order to produce chicken meat as functional product, it is possible to reach balance between high n-3 PUFA concentration and satisfactory sensory traits characteristics of chicken meat.

脱氢表雄酮改善高脂饲料诱导的肉鸡肝损伤和炎症反应

目的:探讨脱氢表雄酮(Dehydroepiandrosterone,DHEA)对饲喂高脂饲料肉鸡生长性能、肉质、肝损伤和炎症反应的影响。方法:选择200只15日龄青脚麻鸡,随机分为5组,其中对照组(CK组)饲喂基础饲料,高脂饲料组(HFD组)、DHEA低剂量干预组(L-DHEA组)、DHEA中剂量干预组(M-DHEA组)、DHEA高剂量干预组(H-DHEA组)在饲喂高脂饲料的基础上同时添加0、5、15、45 mg/kg DHEA。试验期间,测定鸡的体质量、生长性能、屠宰率、胸肌pH、肉色、肝脏相对质量、肝脏出血分数及血清ALT、AST、胆碱酯酶(CHE)活性、血清总蛋白(TP)、白蛋白(ALB)、前白蛋白(PA)、尿酸、肌酐、C-反应蛋白(CRP)、白细胞介素-6(IL-6)含量等指标。结果:与对照组相比,高脂饲料能提高肉鸡的体质量、平均日增重、屠宰率、肝脏相对质量(P<0.05)和肝脏出血分数(P<0.05),但降低胸肌b^(*)值;同时,高脂饲料显著提高血清ALT活性(P<0.05)与CRP、IL-6水平。与HFD组相比,添加DHEA后饲喂高脂饲料肉鸡的体质量、日均体增重、料重比有降低趋势,而胸肌a^(*)、b^(*)值则有上升的趋势;同时,DHEA能够提高血清ALB、PA含量,并降低血清ALT、CHE活性和CRP、IL-6水平。结论:高脂饲料可诱导肉鸡发生肝脏损伤、炎症反应和FLHS,在高脂饲料中添加DHEA能够有效改善高脂饲料诱导的肉鸡肝损伤、炎症反应,缓解高脂日粮引起的鸡FLHS,DHEA添加量为15 mg/kg时综合效果更好。

去势对武定鸡胸肌组织脂质组成的影响

为揭示去势对鸡胸肌组织脂质组成的影响,试验采用索氏提取法和UHPLC/Q-TOF-MS检测技术对去势组和假手术组武定鸡肌肉组织进行肌内脂肪(IMF)含量测定和非靶向脂质组学研究。结果显示:去势组武定鸡胸肌组织IMF含量显著高于假手术组(P<0.05);脂质组学检测到21种脂质亚类和553个脂质分子,其中去势组胸肌组织单糖基神经酰胺(CerG1)、脂肪酸(FA)、溶血磷脂酰甘油(LPG)、溶血磷脂乙醇胺(LPE)、溶血磷脂酰丝氨酸(LPS)、辅酶(Co)、磷脂酰甘油(PG)、神经酰胺(Cer)、磷脂酰乙醇胺(PE)、鞘氨醇(So)、甘油二酯(DG)、心磷脂(CL)、磷脂酰胆碱(PC)、甘油三酯(TG)、酰基肉碱(AcCa)、磷脂酰肌醇(PI)和磷脂酰丝氨酸(PS)丰度上调,溶血磷脂酰胆碱(LPC)、鞘磷脂(SM)、溶血磷脂酰肌醇(LPI)、单半乳糖基二酰甘油酯(MGDG)丰度下调;筛选出16种差异脂质分子,其中去势组胸肌组织PE(18∶1p/20∶4)、PE(18∶0/18∶1)、PE(38∶2p)、PE(18∶0e/22∶6)、PC(38∶6)、PC(34∶1e)、PS(41∶4)、PS(18∶0/22∶4)、LPC(22∶5)、LPI(20∶4)、PI(16∶0/20∶4)、Cer(d18∶1/24∶1)、Cer(d18∶1/24∶1)、TG(16∶0/8∶0/16∶0)丰度上调,PC(39∶5)和PI(16∶0/20∶3)丰度下调(VIP>1,P<0.05)。结果表明,去势促进武定鸡胸肌组织IMF沉积,影响脂质组成,改善肉质特性。

林甸鸡腹部脂肪组织发育规律探究

肉鸡生产过程中腹脂过度沉积会造成生产效率下降等一系列问题。林甸鸡作为优质地方鸡种之一,产蛋、产肉性能优良,肉质鲜美,深受大众喜爱。为探究林甸鸡腹部脂肪组织发育规律,测定林甸鸡3~22周龄体重及腹脂重,观察并统计腹部脂肪细胞大小和数量,分析脂肪细胞特性与腹脂沉积之间关系。结果表明,林甸鸡在3~22周龄体重持续增长,腹脂重先升后降再升,腹脂率先降后升;3~10周龄脂肪细胞以增生为主,10~14周龄脂肪细胞以增大占优,19周龄后脂肪细胞增大和增生同时进行,但以增大为主。研究初步确定腹脂重与脂肪细胞特性回归模型,发现脂肪细胞体积对腹脂重的影响最大。试验结果为选育优质特色林甸鸡新品系提供理论参考。

不同品种乌鸡肌肉品质与仿生感官评价研究

本文旨在比较五种乌鸡胸大肌(泰和乌鸡、盐津乌鸡、沐川乌鸡、旧院黑鸡、略阳乌鸡)肌内脂肪含量、黑色素含量、氨基酸含量及电子感官仿生评价的差异,为地方乌鸡品质感官的进一步研究提供数据支撑。结果表明,五种乌鸡胸肌肌内脂肪含量、黑色素含量存在组间的差异,呈现不同的梯度差距;天冬氨酸、苏氨酸、丝氨酸、谷氨酸、丙氨酸、蛋氨酸、异亮氨酸、亮氨酸、酪氨酸、苯丙氨酸、赖氨酸、组氨酸、精氨酸、脯氨酸14种氨基酸的相对含量存在组间差异,其中略阳乌鸡与沐川乌鸡的氨基酸含量相对较高;电子舌分析发现乌鸡滋味主要是鲜味、鲜味回味与苦味,其中鲜味回味在品种间存在较大差异,泰和乌鸡与盐津乌鸡具有一定的涩味回味;电子鼻检测结果显示不同品种的乌鸡气味轮廓间存在有较大差异,盐津乌鸡与其他四种乌鸡间气味轮廓差距最大,在传感器响应上最小。综上,略阳乌鸡胸肌肉具有更好的品质,其具有更高的肌内脂肪、黑色素含量与氨基酸比例,并且电子感官仿生评价响应值都相对较高。同时,不同品种乌鸡都有其较突出的特点,本研究结果也为消费者选购乌鸡产品提供了一定的理论借鉴。

不同日龄杏花鸡腹脂与皮下脂肪的脂肪酸差异分析

试验旨在研究不同日龄杏花鸡腹脂和皮下脂肪的脂肪酸组成和含量,为建立完整的杏花母鸡脂肪酸图谱提供理论依据。试验选取105日龄、120日龄、135日龄的杏花鸡母鸡作为三个日龄组,分别采集腹脂和皮下脂肪样品进行游离脂肪酸测定和差异分析。结果显示:杏花鸡腹脂和皮下脂肪的主要代谢物是油酸(C18∶1n9c)、亚油酸(C18∶2n6c)、棕榈酸(C16∶0)、硬脂酸(C18∶0)、花生四烯酸(C20∶4n6)、顺式-9-棕榈油酸(C16∶1);随日龄增长,杏花鸡腹脂和皮下脂肪的游离脂肪酸含量整体降低;三个日龄组杏花鸡腹脂和皮下脂肪的共同差异代谢物是顺式-10-十五碳烯酸。随日龄增长杏花鸡皮下脂肪油酸含量显著下降(P<0.05)。研究表明:不同日龄杏花鸡的棕榈酸(C16∶0)、油酸(C18∶1n9c)、亚油酸(C18∶2n6c)等部分脂肪酸含量存在显著差异,随着日龄增长,游离脂肪酸含量逐渐降低。

鸡油二次干法分提工艺优化及其对脂肪酸组成的影响

旨在为开发高附加值鸡油产品提供原料,以黄羽肉鸡腹脂为原料,利用二次干法分提技术提取富含不饱和脂肪酸的鸡液油。以鸡液油得率、碘值为评价指标,通过单因素试验和正交试验对一次干法分提和二次干法分提工艺条件进行优化,并对分提前后鸡油的脂肪酸组成进行分析。结果表明:一次干法分提最优工艺条件为冷却速率8℃/h、结晶温度24℃、养晶时间9h,在此条件下鸡液油得率为77.71%,碘值(I)为75.89g/100g,不饱和脂肪酸含量由原料粗鸡油的63.87%提高至70.44%;二次干法分提最优工艺条件为结晶温度16℃、冷却速率2℃/h、养晶时间15h,在此条件下鸡液油得率为78.85%,碘值(I)为81.52g/100g,不饱和脂肪酸含量为73.40%。综上,与原料粗鸡油相比,一次干法分提后鸡液油的不饱和脂肪酸含量有所提高,二次干法分提后鸡液油的不饱和脂肪酸含量进一步提高。

鸡胚胎期肌内脂肪形成lncRNA相关ceRNA网络构建

目的筛选鸡胚胎期肌肉差异表达长链非编码RNA(lncRNA)、微小RNA(miRNA)及mRNA,通过构建lncRNA-miRNA-mRNA竞争性调控网络,挖掘肌内脂肪形成的重要候选基因。方法分别采集玫瑰冠鸡、科宝鸡胚胎期的肌肉组织进行转录组测序,利用生物信息学方法筛选差异表达lncRNA、miRNA和mRNA,对差异表达基因GO富集及KEGG信号转导途径分析,同时预测lncRNA-miRNA、miRNA-mRNA之间的靶标关系,结合基因表达分析,构建可能与肌内脂肪形成相关的lncRNA-miRNA-mRNA竞争性调控网络,利用qRT-PCR验证测序数据的准确性。结果玫瑰冠鸡、科宝鸡的胸肌、腿肌间共差异表达的lncRNA、miRNA和mRNA分别是5个、225个和146个,GO和KEGG结果表明靶基因均富集在脂代谢或脂生成相关信号通路上,构建由4个lncRNA、6个miRNA和6个mRNA组成16个节点的ceRNA调控网络。结论成功构建鸡肌内脂肪形成相关ceRNA调控网络,为进一步探究肌内脂肪形成的相关分子调控机制提供参考依据,对今后优质肉鸡的选育奠定基础。