Infectious bronchitis (IB) is a highly contagious respiratory disease of chickens, which is caused by the infectious bronchitis virus (IBV). The innate immune response is crucial for antiviral infections and revealing the pathogenic mechanisms of IBV. In this study, we presents an evaluation of interferon (I, II and III IFNs) in renal and tracheal samples from chickens experimentally infected previously vaccinated or not. The results suggest differential expression of chicken interferon, among them type I IFN elaborate a major role in fighting off virus. And vaccine confers greater induction ability of innate immunity thereby vaccination prior infection occurs might be necessary. Above all, we found that IFN-λ also have an effect on IBV infection in trachea besides many other respiratory virus. This study provides the first comprehensive analysis of host-virus interactions of IBV with chicken innate immune response mediated by interferon in various groups.

Background Tibetan chickens living at high altitudes show specific adaptations to high-altitude conditions, but the epigenetic modifications associated with these adaptations have not been characterized. Results We investigated the genome-wide DNA methylation patterns in Tibetan chicken blood by using whole genome bisulfite sequencing. Generally, Tibetan chickens exhibited analogous methylation patterns to that of lowland chickens. A total of 3.92% of genomic cytosines were methylcytosines and 51.22% of cytosines in CG contexts were methylated, which was less than those in lowland chicken (55.69%). Moreover, the base adjacent to the methylcytosines of mCHGs in Tibetan chickens had a preference for T, which was different from that in lowland chickens. In Tibetan chickens, the methylation levels in the promoter were relatively low, while the gene body was also maintained in a hypomethylated state. DNA methylation levels in regions upstream of the transcription start site of genes were negatively correlated with the level of gene expression, and DNA methylation of gene body regions was also negatively related to gene expression. Conclusions We generated the genome-wide DNA methylation patterns in Tibetan chickens and our results will be helpful for future epigenetic studies related to adaptations to high-altitude conditions.

设施畜牧业是技术和资金密集型产业,发展设施畜牧业以科学技术的应用和大量资金投入为前提。本文根据四川省畜牧科学研究院家禽研究团队大量调研掌握的实际数据,以10万只规模蛋鸡场为例,从投资建场到产品销售各个环节,对比分析传统生产方式(采用开放式鸡舍)和设施化生产方式(采用标准化鸡舍)的投入产出情况,结果表明:标准化生产在环境控制、鸡群健康和生产性能、养殖效益等多方面均优于传统生产方式;两种生产方式的固定资产投资回报率分别为17.43%和12.96%,标准化鸡舍饲养4.05批鸡(5.7年)即可收回全部基础建设和设施设备投入费用,而开放式鸡舍需要饲养5.45批(7.7年)才能实现。

家鸡生长激素释放激素（GHRH）的成熟肽段区存在一个酰胺化位点,提示具27个氨基酸残基的羧基端酰胺化多肽(cGHRH 1-27NH2 )可作为家鸡生长激素释放激素受体（GHRHR）的配体.为验证该假说,利用pGL3-CRE报告基因系统,在培养的中国仓鼠卵巢细胞中,探究人工合成cGHRH 1-27NH2 多肽对家鸡两个GHRH受体的激活潜能.结果显示:cGHRH 1-27NH2 可高效激活家鸡两个GHRH受体,并且该多肽对GHRH一型受体(cGHRHR 1 :EC 50 :0.18 nmol/L)的激活效能略高于其对GHRH二型受体(cGHRHR 2 :EC 50 :0.32 nmol/L)的激活效能.这些研究结果清楚表明GHRH 1-27NH2 可作为家鸡两个GHRH受体的配体.

The calpain system, a Ca(2+)-activated protease family, plays an important role in postmortem tenderization of skeletal muscle due to its involvement in the degradation of important myofibrillar and associated proteins, as well as in cytoskeletal remodeling and regulation of muscle growth. In this study, we quantified the expression of calpastatin (CAST) in two Chinese chicken breeds (mountainous black-bone chicken breed (MB) and a commercial meat type chicken breed (S01)), to discern the tissue and age-related specific expression pattern and its potential role on muscle tissue metabolism. Real-time quantitative PCR (RT-qPCR) assay was developed for accurate measurement of CAST mRNA levels in various tissues from chicken with different ages (0, 2, 4, 6, 8, 10, and 12 week). CAST mRNA was detected in collected organs. The heart and leg muscle tissues had the highest expression of CAST than other tissues from the same chicken (P < 0.01). Age-related expression pattern of CAST gene was evident in breast muscle, liver, and brain tissues (P < 0.05), but not in heart and leg muscle tissues (P > 0.05). Overall, the CAST mRNA level exhibited a "rise-decline-rise-decline" developmental change in breast muscle and liver, with the highest expression at 2 weeks and the lowest expression at 8 weeks. The S01 chicken had significantly higher expression of CAST in breast muscle and heart than the MB chicken (P < 0.05) at 10 weeks. Our results suggested the CAST expression may be related to muscle fiber development.

Egg quality is key factor to egg quality parameters,including egg weight albumen height, haugh unit and blood meat the performance of broiler breeder. In this study, seven , egg shape index, eggshell strength, eggshell thickness, spots,were measured in four different strains （S01, S05, S06 and S08）parental stock of Dahen quality chicken.The results showed that there were significantly differences for egg weight, egg shape index, albumen height and haugh unit （P〈0.05） in different four strains, while there was no significantly difference for eggshell strength ,eggshell thickness and blood meat spots （P〉0.05）. The egg weight of S05 and S06 is lower than that of S08 and higher than that of S01.The egg shape index of S01 and S06 is lower than that of S08 and higher than that of S05.The albumen height and the haugh unit of S05 and S06 are higher than that of S01, while there was no significant difference for S08. These results indicated that there was significantly difference for egg quality in different strains of Dahen meat-quality breeders,and it provided the basic source for breed improvement.

<正>近两年来,四川省放养鸡产业不断扩大,持续升温,放养鸡已形成了稳定的消费市场和消费群体。需要指出的是,放养鸡生产是传统畜牧业向现代畜牧业过渡的一种养殖方式,其生产利用良好的生态环境,实施科学规范的饲养管理和卫生保健等

The goal of this study was to evalaute the meat quality of broiler chicken by defining Meat Quality Index (MQI). Meat quality is a complex trait which is consist of several meat quality indicators and affected by a series of factors. So, evaluation for the meat quality of broiler is indeed a difficult project In this study, the coupling model of Principal Component Analysis and Linear programming techniques for Multidimensional Analysis of Preferences (PCA-LINMAP) was constructed to evaluate meat quality performance of broiler chicken and 250 chickens both cocks and hens from 5 populations (S01, S02, S03, SOS, D99 developed by Dahen Poultry Breeding Company and Sichuan Animal Science Academy) were used as an application case, the eight main meat quality indicators of breast muscle and leg muscle were collected. About 4 representative indicators were selected by cluster analysis, they are crude fat, ultimate pH, muscle fibre number and drip loss. And then the meat quality index was constructed by PCA-LINMAP coupling model, the results show that the meat quality of S01 is the best, S03 came next, D99 came last and meat quality of female is superior to the cock in each line. Finally, the value range of MQI was identified based on its property. The PCA-LINMAP model made the evaluation for meat quality easily and the all main meat quality indicators were gathered to one integrated trait which could be contained in the breeding plan with other traits such as production and reproduction traits of broiler.

Myocyte-specific enhancer-binding factor 2A (MEF2A) gene is a member of the myocyte-specific enhancer-binding factor 2 (MEF2) protein family which involved in vertebrate skeletal muscle development and differentiation. The aim of the current study is to investigate the potential associations between MEF2A gene SNPs (single nucleotide polymorphisms) and the carcass traits in 471 chicken samples from four populations. Three new SNPs (T46023C, A72626G, and T89232G) were detected in the chicken MEF2A gene. The T46023C genotypes were associated with live body weight (BW), carcass weight (CW), eviscerated weight, semi-eviscerated weight (SEW), and leg muscle weight (LMW) (P < 0.05); the A72626G genotypes were associated with BW, CW, LMW (P < 0.01) and breast muscle weight (BMW), leg muscle percentage (LMP) (P < 0.05); whereas the T89232G genotypes were associated with carcass percentage (CP) and semi-eviscerated percentage (SEP) (P < 0.05). The haplotypes constructed on the three SNPs were associated with BW, CW, LMW (P < 0.01), SEW, BMW, CP (P < 0.05). Significantly and suggestive dominant effects of diplotype H1H2 were observed for BW, CW, SEW, BMW and CP, whereas diplotype H5H5 had a negative effect on BW, CW, SEW, BMW and LMW. Our results suggest that the MEF2A gene may be a potential marker affecting the muscle trait of chickens.

We quantified chicken calpain 2 (CAPN2) expression in two Chinese chicken breeds (mountainous black-bone chicken breed [MB] and a commercial meat type chicken breed [S01]) to discern the tissue and ontogenic expression pattern and its effect on muscle metabolism. Real-time quantitative PCR assay was developed for accurate measurement of the CAPN2 mRNA expression in various tissues from chickens of different ages (0, 2, 4, 6, 8, 10, and 12 weeks). Results showed that the breast muscle and leg muscle tissues had the highest expression of CAPN2 compared to the other tissues from the same individual (P < .05). Overall, the CAPN2 mRNA level exhibited a "rise" developmental change in all tissues. The S01 chicken had a higher expression of the CAPN2 mRNA in all tissues than the MB chicken. Our results suggest that chicken CAPN2 expression may be related to chicken breeds and tissues.

Body composition, fat deposition and meat quality are important traits in chickens. Melanocortin receptor (MCR) plays an important role in central melanocortin system (CMS) and muscle cells. The purpose of the present study was to analyze association of the MC3R and the MC4R genes with chicken carcass and meat quality traits. Using eight meat-type chicken populations constructed with 5 pure lines (developed from Chinese local breeds) and 3 crossbreeds (S01 x D99, S01 x S05, S 01 X S10), the association of 3 single nucleotide polymorphisms (SNP: MC3R-A1424G, MC4R-G923T and MC4R-C944T) of MC3R and MC4R gene with carcass and meat quality traits was studied. The results showed as follows: (I) the MC3R-A1424 G genotypes were significantly associated with most carcass, traits except for semi-eviscerated percentage and leg muscle percentage (LMP), the MC4R-G923T genotypes were significantly associated with live weight, carcass weight, leg muscle weight (LMW) and LMP, and the MC4R-C944T genotypes were not significantly associated with most carcass traits except for LMW and LMP; (2) to meat quality, the MC3R-A1424G genotypes significantly affected muscle crude protein (GP) value, and the allele A had positive additive effects on slaughter traits. The MC4R-G923T and the MC4R-C944T sites significantly affected muscle GP value and glutamic acid (Glu) value, (3) the haplotypes based on the 2 SNP of MC4R gene were also significantly associated with meat quality traits, but had no significant associations with carcass traits. The research built the base for further analysis on relation between genetic variation of MC3R and MC4R genes and the carcass and meat quality traits. and molecular marker's application in breeding.

本文选取大恒3个优质鸡品系与2个杂交组合的70日龄和91日龄鸡各100只,对胸肌肌苷酸和鲜味氨基酸的含量进行了比较.结果显示:胸肌肌苷酸和鲜味氨基酸在不同品系间差异达到显著水平(P＜0.05);不同日龄间,胸肌肌苷酸未达显著水平(P＞0.05);鲜味氨基酸中除S05未达显著水平外(P＞0.05).其余鲜味氨基酸均达到显著水平(P＜0.05);不同性别间,胸肌肌苷酸S01、S05差异达到显著水平(P＜0.05),其余胸肌肌苷酸含量也达到显著水平(P＜0.05);鲜味氧基酸未达显著水平(P＞0.05).

本研究选取四川大恒优质肉鸡S01、S05、S06和S05×S01和S06×S015个群体,比较分析2组杂交组合(S05×S01和S06×S01)的外观性状、成活率、孵化率、健雏率以及产肉性能等重要生产性能。结果表明:5个优质肉鸡群体外观性状与地方鸡种一致,成活率、孵化率和健雏率较高,产肉性能良好,适于规模化养殖;杂交组合S05×S01和S06×S01屠宰率都在85%以上,全净膛率在65%以上,产肉性能良好;杂交鸡S06×S01生长速度快,饲料报酬高,适宜对优质肉鸡生长速度要求高的市场推广应用,而杂交鸡S05×S01生长速度较慢,适宜于放养条件下对优质肉鸡生长速度要求不高的市场推广。

The tribological behaviors and phase transformation of single crystal silicon against Si3N4, Ruby and steel were investigated in this study. It was found that the strong chemical action between silicon and Fe was the key factor to the tribological behavior of silicon as slid against steel. SEM and Raman spectroscopy indicated that phase transformation of single crystal silicon occurred during the running-in period at low sliding velocity as slid against Si3N4 and Ruby, and gave birth to single or a mixture phase of Si-III, Si-XII and amorphous silicon. The high hardness of counterpart and the absence of chemical action between silicon and counterpart facilitated the phase transformation of single crystal silicon.

市场因素的影响使得肉鸡的最佳上市日龄不是停留在某一固定时刻,而需要根据行情进行调整才能获取最大的经济效益.本文通过微分建模结合L-M(Levenberg-Marquardt)算法建立了累积生长与肉鸡生产效益的耦合模型并推导出肉鸡最佳上市日龄,并将该模型应用于大恒D99系优质肉鸡,估测出该系公母鸡最佳出售时刻分别为11.15周龄和10.51周龄,每只鸡可获取的最大利润为9.35元和6.58元,结果表明肉鸡生长速生区末端为最适上市日龄.

SNPs (Single Nucleotide Polymorphisms) refer to the single nucleotide differences tit a certain location of genomic DNA, which become a new generation genetic marker after RFLP and SSRs due to its high accuracy and high stability. The linkage relationship between the disease locus and the SNP marker locus can be easily clarified by the transmission/disequilibrium test (TDT), however, the traditional TDT always assumed in these analyses that the genetic data are without errors, that is, there is not any miscoding of a person's correct marker genotype. Sources of error include nonpaternity. sample swaps in the lab. or genotyping errors. Obviously. there is an increase in the estimated recombination fraction between markets or between marker and disease, an increase in type I error rate, at decrease in power. and an incorrect estimation of background LD. The article proposed a general transmission/disequilibrium test allowe for random genotype errors, and then comparison of the two statistic methods was carried out.

以四川大恒家禽育种有限公司培育的8个优质肉鸡群体(5个品系和3个杂交组合)为材料,采用PCR-SSCP技术结合测序检测鸡ADSL基因外显子2与外显子9的单核苷酸多态性.结果表明:在所研究的群体中,腺苷琥珀酸裂解酶(ADSL)基因外显子2的3797位点发生C→T突变,外显子9的10225位点发生A→T突变;适合性检验显示,ADSL基因外显子2、外显子9各基因型频率除1个群体外均处于哈代-温伯格平衡;对群体各位点基因型频率分布进行计算,发现ADSL-3797和ADSL-10225 SNPs位点属于中度多态位点,多态信息含量分别为0.283和0.320.本研究为ADSL基因SNPs位点与优质肉鸡重要肉质性状的关联性研究奠定了基础.

The tribological behaviors and phase transformations of single-crystal silicon against Si3N4 with different sliding velocities and durations under low contact stress at room temperature were investigated. SEM and Raman analysis indicate that phase transformation was involved and characterized by plastically deformed area which consists of Si-III, Si-XII, and a-Si, especially in the early stage at the low sliding velocity. The plastically deformed layer was wiped off at high-velocity or long sliding duration. TEM analysis indicated that the wear debris consists of amorphous silicon.

Scratch tests on single crystal silicon under dry sliding and pentadecane lubrication are performed on a commercially available nano-scratch tester. Loads range of elastic, elasto-plastic deformation and fracture are classified according to depth-load curves. A fully plastic removal of single crystal silicon below critical load for fracture is observed under pentadecane lubrication, which is quite different from that under dry sliding. Raman micro-spectra indicate that the phase compositions of the scratched track under dry sliding consist of a number of phases, including Si-I, Si-III, Si-XII and a-Si, while the phase composition of the track under pentadecane lubrication consists of single a-Si. Based on the results obtained, a simple approach to fabricate amorphous silicon pattern on single crystal silicon is introduced and discussed.

历经20余年的我国优质肉鸡育种业,为畜牧业结构调整和家禽产业发展做出了巨大贡献.本文就今后优质肉鸡育种的总体思路、技术经济指标、育种规划、技术手段等方面进行了思考,提出了应注意的问题.