Analysis of Correlation between the Slaughter Performance and Meat Quality of Frizzle Chicken

[Objective]This study aimed to evaluate the meat quality of frizzle Chick-en, and to find out the correlation between the meat quality and slaughter perfor-mance. [Method] The slaughter performance such as live chicken weight, carcass weight, semi-eviscerated weight, eviscerated weight, chest muscle weight, leg mus-cle weight, abdominal fat weight and the meat quality indices like color, pH and shear force of 12-week-old frizzle chickens were measured to analyze the correla-tion between slaughter performance and meat quality. [Result] The carcass percent-age, semi-eviscerated percentage, eviscerated percentage, chest muscle percentage, leg muscle percentage, abdominal fat percentage, intramuscular fat width and subcu-taneous fat thickness of the male chickens were 89.76%, 81.54%, 67.53%, 7.82%, 11.29%, 2.42%, 0.69 cm and 0.48 cm, of female chickens were 89.78%, 80.87%, 62.94%, 6.19%, 9.92%, 3.91%, 0.78 cm and 0.61 cm. Some of these traits exhibit-ed significant difference between the male and female chickens （P〈0.05）. In male chickens, the chest muscle color, pH and shear force were 5.93, 6.15 and 3.72 kg, and the leg muscle color, pH and shear force were 6.18, 6.54 and 3.41 kg; in fe-male chickens, the chest muscle color, pH and shear force were 5.77, 6.05 and 3.41 kg, and the leg muscle color, pH and shear force were 6.03, 6.21 and 2.74 kg. The quality of chest and leg muscles of frizzle chickens significantly differed （P〈0.05）. Carcass weight had significant positive correlations with semi-eviscerated weight and meat color （P〈0.05）, and an extremely significant positive correlation with pH （P〈0.01）. Semi-eviscerated weight and pH value shared a significant posi-tive correlation （P〈0.05）. Eviscerated weight and leg muscle weight shared an ex-tremely significant negative correlation （P〈0.01）. Abdominal fat weight correlated sig-nificantly and negatively with shear force （P〈0.05）. Meat color and pH value had a significant positive correlation （P〈0.05）. [Conclusion] This study provides theoretical basis for the breeding of excellent chicken varieties producing high-quality meat.

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).

A significant quantitative trait locus on chromosome Z and its impact on egg production traits in seven maternal lines of meat-type chicken

Background:Egg production is economically important in the meat-type chicken industry.To better understand the molecular genetic mechanism of egg production in meat-type chicken,genetic parameter estimation,genome-wide association analyses combined with meta-analyses,Bayesian analyses,and selective sweep analyses were performed to screen single nucleotide polymorphisms(SNPs)and other genetic loci that were significantly associated with egg number traits in 11,279 chickens from seven material lines.Results:Yellow-feathered meat-type chickens laid 115 eggs at 43 weeks of age and white-feathered chickens laid 143 eggs at 60 weeks of age,with heritability ranging from 0.034–0.258.Based on meta-analyses and selective sweep analyses,one region(10.81–13.05 Mb)on chromosome Z was associated with egg number in all lines.Further analyses using the W2 line was also associated with the same region,and 29 SNPs were identified that significantly affected estimation of breeding value of egg numbers.The 29 SNPs were identified as having a significant effect on the egg number EBV in 3194 birds in line W2.There are 36 genes in the region,with glial cell derived neurotrophic factor,DAB adaptor protein 2,protein kinase AMP-activated catalytic subunit alpha 1,NAD kinase 2,mitochondrial,WD repeat domain 70,leukemia inhibitory factor receptor alpha,complement C6,and complement C7 identified as being potentially affecting to egg number.In addition,three SNPs(rs318154184,rs13769886,and rs313325646)associated with egg number were located on or near the prolactin receptor gene.Conclusion:Our study used genomic information from different chicken lines and populations to identify a genomic region(spanning 2.24 Mb)associated with egg number.Nine genes and 29 SNPs were identified as the most likely candidate genes and variations for egg production.These results contribute to the identification of candidate genes and variants for egg traits in poultry.

Effects of Different Dietary Energy and Protein Levels on Meat Performance and Meat Quality of Jinghai Yellow Chickens

To investigate the effect of different dietary energy and protein levels on meat performance and meat quality of Jinghai yellow chickens, 480 43-day old Jinghai yellow chickens with similar weight were randomly divided into four experimental groups： experimental group 1 （protein 15%, metabolic energy 9.95 MJ/kg）, experimental group 2 （protein 16%, metabolic energy 10.95 MJ/kg）, experimental group 3 （protein 17%, metabolic energy 12.65 MJ/kg） and experimental group 4 （ protein 18%, metabolic energy 13.95 MJ/kg）, respectively. All chickens were slaughtered at 112-day old. The breast and leg muscles of Jinghai yellow chickens were collected, to determine the slaughter performance, conventional meat quality and muscle chemical indicators. The results indicated that dressing-out percentage and eviscerated yield percentage in four experimental groups were above 87.27% and 67.00%, respectively; other slaughter performance indicators exhibited no significant differences among various groups （P 〉 0.05 ） ; breast muscle color of hens in experimental group 4 varied significantly from that in other three groups （ P 〈 0.05 ） ; leg muscle color of hens in experimental group 2 varied extremely significantly from that in other three groups （ P 〈 0.01 ） ; water-holding capacity of breast muscles of hens in experimental group 3 was significantly higher than that in experimental group 4 （P 〈 0.05 ） ; thiamine content of breast muscles of cocks in experimental group 3 was significandy higher than that in experimental group 2 （ P 〈 0.05 ） ; however, other properties exhibited no significant differenees among various groups （P 〉 0.05 ）.

Effects of Nano Chinese Herbal Medicine Feed Additive on Growth Performance,Meat Quality and Disease Resistance of Chickens

[Objectives]To explore the effects of nano compound Chinese herbal medicine feed additive on growth performance,meat quality and disease resistance of chickens.[Methods]Chickens were fed with nano compound Chinese herbal medicine feed additive developed by Hunan Polytechnic of Environment and Biology,including 120 chickens in the treatment group and 120 chickens in the control group(CK).The growth performance indices(body weight gain,feed to gain ratio and slaughter index),meat quality indices(pH value,color,drip loss,shear force)and disease resistance indices(morbidity and mortality)of the chickens in the treatment and CK groups were recorded and determined,respectively.[Results]The inclusion of 2%nano compound Chinese herbal medicine feed additive in the diet significantly increased the growth rate,reduced the feed-to-gain ratio and improved the meat quality of the chickens.Supplementing Chinese herbal medicine could increase the pH value and reduce the drip loss and shear force of chicken meat.At the same time,the body's immune function,antioxidant level and resistance against diseases of the chickens fed with nano compound Chinese herbal medicine feed additive were improved.[Conclusions]The inclusion of nano compound Chinese herbal medicine feed additive in the diet can improve the growth performance,meat quality and disease resistance of chickens.

Effect of dietary arginine to lysine ratios on productive performance,meat quality,plasma and muscle metabolomics profile in fast-growing broiler chickens

Background: Due to the important functions of arginine in poultry,it should be questioned whether the currently adopted dietary Arg:Lys ratios are sufficient to meet the modern broiler requirement in arginine.The present study aimed,therefore,to evaluate the effects of the dietary supplementation of L-arginine in a commercial broiler diet on productive performance,breast meat quality attributes,incidence and severity of breast muscle myopathies and foot pad dermatitis(FPD),and plasma and muscle metabolomics profile in fast-growing broilers.Results: A total of 1,170 1-day-old Ross 308 male chicks was divided into two experimental groups of 9 replicates each fed either a commercial basal diet(CON,digestible Arg:Lys ratio of 1.05,1.05,1.06 and 1.07 in each feeding phase,respectively) or the same basal diet supplemented on-top with crystalline L-arginine(ARG,digestible Arg:Lys ratio of 1.15,1.15,1.16 and 1.17,respectively).Productive parameters were determined at the end of each feeding phase(12,22,33,43 d).At slaughter(43 d),incidence and severity of FPD and breast myopathies were assessed,while plasma and breast muscle samples were collected and analyzed by proton nuclear magnetic resonancespectroscopy.The dietary supplementation of arginine significantly reduced cumulative feed conversion ratio compared to the control diet at 12 d(1.352 vs.1.401,P < 0.05),22 d(1.398 vs.1.420; P < 0.01) and 33 d(1.494 vs.1.524; P < 0.05),and also tended to improve it in the overall period of trial(1.646 vs.1.675; P = 0.09).Body weight was significantly increased in ARG compared to CON group at 33 d(1,884 vs.1,829 g; P < 0.05).No significant effect was observed on meat quality attributes,breast myopathies and FPD occurrence.ARG birds showed significantly higher plasma concentration of arginine and leucine,and lower of acetoacetate,glutamate,adenosine and proline.Arginine and acetate concentrations were higher,whereas acetone and inosine levels were lower in the breast of ARG birds(P < 0.05).Conclusions: Taken together,these data showed that increased digestible Arg:Lys ratio had positive effects on feed efficiency in broiler chickens probably via modulation of metabolites that play key roles in energy and protein metabolism.

Investigation of physicochemical,microbiological and sensorial properties for organic and conventional retail chicken meat

In this study,the commercially available chicken thigh and breast meat produced by organic and conventional methods were investigated in terms of physicochemical,microbiological and sensorial properties.The organic chicken breasts had higher fat content than the conventional chicken breasts.The protein content of organic thighs was higher than conventional thighs.Organic chicken meat contains more mineral substances than conventional chicken meat and has higher pH value,cooking loss and water holding capacity.Alpha-linoleic acid,docosahexaenoic acid was found to be higher in organic chicken meat.Salmonella spp.was detected in all conventional chicken and 66.66%of organic chicken.

Comparative Analysis of Slaughter Performance and Meat Flavor Traits of Quality Chicken under Cage Rearing and Free-range Farming Conditions

[Objective]The paper was to compare the slaughter performance and meat flavor of quality chicken under cage rearing and free-range farming conditions.[Method]A total of 4001-day-old cocks,S07 line cultivated by Sichuan Dahen Poultry Breeding Co.,Ltd.(bred for 4 succes-sive generations),were kept in cages until the end of 5 weeks of age,which were then divided into cage rearing and free-range farming groups.All cocks were fed with the same diet,and slaughter tests and meat quality analysis were carried out at the end of 10 and 22 weeks of age,respectively.[Result]The live weight,carcass weight and abdominal fat percentage in cage rearing group were significantly higher than those in free-range farming group(P<0.01),and the percentage of half-eviscerated yield and percentage of eviscerated yield in cage rearing group were significantly higher than those in free-range farming group(P<0.05),but there were no significant differences in dressing percentage,percentage of leg muscle and per-centage of breast muscle.The intramuscular fat(IMF)content and muscle fiber density of chicken in cage rearing group were significantly higher than those in free-range farming group(P<0.01),but there was no significant difference in inosinic acid(IMP)content.The content of IMF and IMF increased with the increase of feeding age,but the deposition rate of intramuscular fat was higher than that of IMF in late feeding period.[Conclusion]The study will provide reliable guidance for production and market consumption of high quality chicken.

Effects of Moringa (Moringa oleifera Lam.) Leaf Meal on Performance, Carcass, Organs, Eggs and Meat of Japanese Quails

There are several reports on the utilisation of Moringa oleifera in poultry diets due to its essential bioactive compounds yet,little is known about its influence on Japanese quail eggs and meat qualities.Hence,the need to examine performance,eggs and meat qualities of Japanese quail hens fed M.oleifera leaf.To achieve this,240 Japanese quail chicks were allocated to three dietary treatments:D1:control,0.0%(without M.oleifera leaf meal),D2:(0.5%M.oleifera leaf meal)and D3:(1%M.oleifera leaf meal).Data on performance,carcass,organs,eggs and meat qualities were collected and subjected to ANOVA at 0.05.Results revealed that feed consumption was lowest(2,701g)in D1 and highest(2,800g)in D2,carcass weight varied from 100-100.67g,thigh weight(12.66-13.58g)and breast weight was highest(40.41g)in D3.Liver weight was lowest(3.25g)in D1,kidney was largest(0.91g)in D3 whereas,the heart,gizzard and spleen weights ranged from 1.00-1.16g,3.08-3.50g and 0.04-0.08g,respectively.In the eggs,crude protein(10.94%),crude fat(6.71%),ash(1.36%),high-density lipoprotein(96.12mg/100g)and low-density lipoprotein(120.67mg/100g)were highest in D1.Total cholesterol(364.08mg/100g)and triglycerides(147.27mg/100g)were least in D1 and the caloric value varied from 1.46-1.47kcal/g.In the meat,crude protein(17.14%)and energy value(1.96kcal/g)were best in D2 but,crude fat(12.62%),ash(2.85%)and carbohydrates(1.31%)were superior in D3.In both eggs and meat,no crude fibre(0.0%)was detected.In any case,all the parameter values were within the normal ranges given in healthy Japanese quails at similar age.Consequently,addition of M.oleifera leaf meal at 1.0%to Japanese quail diets might not depress performance,affect carcass quality,cause organs dysfunctions but may improve nutritional quality of the eggs and meat.

Effects of Different Rearing Modes on the Muscular Histological Traits and Meat Tenderness of Chicken

[ Objective] The aim of this experiment was to explore the effects of different rearing modes on muscle histological traits and muscle ten demess and to provide theoretical basis for regulating chicken meat quality. [ Method] The effects of outdoor rearing, indoor rearing and cage rea ring modes on the muscular histological traits and meat tenderness of Hetian chicken at the age of 8 weeks, 12 weeks and 16 weeks were re searched. [Result] The results showed that the breast and thigh muscle fibre diameter and muscle shear force of outdoor rearing chicken were sig nificently higher than that of cage rearing chicken （ P 〈 0.05）, and muscle fibre density was significantly lower than that of cage rearing chicken （ P 〈 0.05）. With aging, the muscle fibre diameter and shear force increased and muscle fibre density decreased （ P 〈 0.05）. The muscle fibre di ameter and shear force of male were higher than that of female. The correlation analysis showed that the breast muscle shear force had a signifi cantly positive relation with fibre diameter and negative relation with fibre density （ P 〈 0.05）, but thigh muscle shear force had an insignificantly pos itive relation with fibre diameter and fibre density. [ Condusion] Muscular histological traits varied in different rearing modes, and the outdoor rearing promoted the muscular fibre development and increased the muscular shear force.

Effects of Chinese Medicine Additive on Promoting Production of Meat Hybrid Chicken and Its Action Mechanism

[ Objective] The aim was to study the effects of Chinese medicine additive HMS on promoting the production of meat hybrid chicken and its action mechanism, so as to provide a scientific basis for the promotion effects of Chinese medicine additive on production. [ Method] Meat hybrid chickens, 7 day-old with similar weight, were randomly divided into four groups. And Chinese medicine feed additive HMS was added to the diet of each group at different proportions. All the chickens were weighed before the test as well as at the end of the 2nd, 3rd, 4^th and 5^th week. The feed consumption was also recorded during the test. Before slaughter, serum samples were collected from the randomly selected chickens for the deter- mination of serum biochemical indexes. Their bursae of Fabdcius and spleens were collected and weighed in order to determine the indexes, of im- mune organs. [ Result] HMS significantly reduced the feed conversion ratio （ P 〈 0.05 ）, very significantly reduced the feed consumptioh （ P 〈 0.01 ）, very significantly improve the content of serum high-density lipoprotein （ P 〈 0.01 ）, significantly increased the activity of serum alkaline phos- phatase （ P 〈 0.05）, very significantly reduced the content of serum urea nitrogen and uric acid （ P 〈 0.01 ）, and significantly reduced the level of serum cholesterol （ P 〈0.05）. There were no significant difference between the test groups and the control group （ P 〉 0.05） in the increase of im- mune organ indexes, but the index of immune organs has increasing trend. [ Conclusion] HMS reduces feed consumption and feed conversion rati- o, improves the feed utilization, and has a role in promoting production. The possible mechanism may be HMS improving the activity of serum alka- line phosphatase and the level of serum high-density lipoprotein, as well as reducing the content of serum cholesterol, urea nitrogen and uric acid in meat hybrid chickens.

Detection of Salmonella typhimurium in retail chicken meat and chicken giblets

Objective:To detect Salmonella typhimurium(S.typhimurium),one of the most frequently isolated serovars from food borne outbreaks throughout the world,in retail raw chicken meat and giblets.Methods:One hundred samples of retail raw chicken meat and giblets(Liver,heart and gizzard)which were collected from Assiut city markets for detection of the organism and by using Duplex PCR amplification of DNA using rfbj andfliC genes.Results:S.typhimurium was detected at rate of 44%,40%and 48%in chicken meat,liver and heart,respectively,but not detected in gizzard.Conclusions:The results showed high incidence of 5.typhimurium in the examined samples and greater emphasis should be applied on prevention and control of contamination during processing for reducing food-borne risks to consumers.

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.

The environmental influences on the bacteriological quality of red and chicken meat stored in fridges

Objective: To investigate the environmental influences on the bacteriological quality of red and chicken meats on fridges.Methods: The environmental health status was determined by reliable and valid researcher-made checklist.Then 264 samples were gathered in two phases(at the entrance and three months later) and examined for total bacteria count, Escherichia coli,Staphylococcus aureus and Salmonella spp.Results: The result revealed that the mean of total bacteria count, E.coli and S.aureus densities had significant differences in two steps on chicken and the red meat samples(P < 0.05).Among the environmental factors, sanitary status, temperature and personal hygiene had significant effects on total bacteria count and S.aureus densities in chicken samples(P < 0.05), and between wastewater and solid waste disposal with E.coli density in red meat samples(P < 0.05).Conclusions: The results implied that the bacteriological quality of red and chicken meat fluctuates with environmental status(especially temperature, sanitary status and personal hygiene).Regular control, improving of sanitary health, and staff training are necessary for elimination of bacterial contamination.

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.

Serum Biochemical and Meat Fatty Acid Profiles of Different Chicken Genotypes

Serum biochemical and meat fatty acid profile of different chickens were studied. A total of 144 mixed sex matured chickens of Cosmopolitan (C), Improved Horro (H), Cosmopolitan♂*Improved Horro♀(CH), Improved Horro♂*Cosmopolitan♀ (HC), Indigenous (L) and Koekkoek (KK) were used to determine serum biochemical, of which 36 chickens were also used for fatty acid profile study. Completely randomized design in 6 × 2 factorial arrangements was set up. Serum biochemical and fatty acid profiles were determined by Roche/Hitachi cobas c 501 and gas liquid chromatography (GC) procedures, respectively. There were significant differences (P ≤ 0.001) in Total cholesterol (TC), Triglyceride (TG), Low-density lipoprotein (LDL) and High-density lipoprotein (HDL) among genotypes and between sexes. HDL was inversely related with TC, TG and LDL. Male had significantly higher (P ≤ 0.001) TC, TG, LDL but lower HDL than female. SFA, (Myristic, Pentadecanoic and Palmitic acids) had significantly (P < 0.05) varied among genotypes. However, Margaric (P ≤ 0.01) and stearic (P ≤ 0.001) acids were significantly different between sexes. Myristoleic and Palmitoleic acids significantly vary (P ≤ 0.05) among genotypes and between sexes. Oleic (P ≤ 0.01) and Eicosenoic (P ≤ 0.001) significantly influenced by sex. Moreover, Linoleic had significantly (P ≤ 0.01) affected by genotypes. Nevertheless, α-linolenic acid significantly (P ≤ 0.01) varied between sexes. The serum biochemical differed across genotypes and between sexes. The difference in the number of carbons, double bond and position of the double bond could affect fatty acid profile among genotypes and between sexes. Chicken products with higher level TC, TG, LDL and SFA might affect human health problems. It could also be interesting topic for future studies.

Relationship between Oil Uptake and Moisture Loss during Deep Fat Frying of Deboned Chicken Breast Meat

The relationship between moisture loss and oil uptake at different combination of Frying Oil Temperatures (FOT) and time during deep-fat frying of chicken meat was investigated in this study. Chicken meat samples were diced and fried at different FOT (170°C, 180°C, and 190°C) in an industrial fryer for periods varying from 5 to 900 s. Fat analysis was accomplished in a soxhlet extraction apparatus with petroleum ether solvent. Prior to fat analysis samples were freeze dried and the moisture analysis was based on the standard AOAC standard method. The results show that a cook value of 415 s was found to give the most ideal sensory characteristics. The relationship between moisture loss and oil uptake during the initial phase of frying (°C and 190°C, respectively, and the rate (1.35 g/s) at FOT 170°C was significantly (P < 0.05) lower.

Comparative Growth Performance, Carcass Characteristics and Meat Quality of Local Horro and Exotic Cockerels of Tropical Origin Fed Growers Diet

Growth performance, carcass characteristics and meat quality of male chickens were evaluated using eight-week-old 360 cockerels from three exotic (Koekoek, Kuroiler and Sasso-R) and one Ethiopian indigenous (Horro) genotypes. Cockerels in each breed (90) were randomly allocated into three replications of 30 birds each and housed in deep litter pens for the experiment that lasted for 8 to 16 weeks. The experiment was arranged in a Completely Randomized Design. Seven birds per breed were slaughtered at the end to determine carcass yield, chemical composition and quality attributes of meat. The Kuroiler breed has higher body weight, body weight change (1621.8 g), average daily gain (28.9 g/day), daily feed consumption (127.4 g/day) and better feed conversion ratio (4.40) than other breeds. The Kuroiler breed has heavier slaughter weight (2716.3 g), dressed carcass weight (2201.0 g), eviscerated carcass weight (1905.1 g), breast weight (537.7 g), thigh weight (303.1 g) and drumstick weight (274.8 g) than other breeds. Total edible offal was higher for Kuroiler (324.2 g) and Sasso-R (306.1 g), intermediate in Koekoek (204.4 g) and low in Horro (152.4 g) breed. The relative proportion of breast and drumstick (% slaughter weight) were lower in Koekoek and Sasso-R (17.3 and 8.9) breeds, respectively. Abdominal fat weight (13.7 g and 1.02%) was lowest in Horro. Sasso-R showed higher percent edible offal weight (13.4%) than Horro breed (11.4%). The DM content in breast and thigh meat was higher for Horro breed than the rest. The CP content in the breast and thigh meat was lower for the Kuroiler and Koekoek breeds, respectively. Higher EE in the thigh meat was recorded for Sasso-R (8.9%), whereas, EE content in the breast meat was similar (3.4% - 3.7%) among the breeds. Flavor, tenderness, juiciness and general acceptability of breast and thigh meat were not affected by breed. The highest net return was observed in the Kuroiler breed. Based on the results obtained, it is suggested that the Kuroiler breed can be used for cockerel meat production in Ethiopia where intensive broiler production is not well developed.

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.

Glyoxal induced advanced glycation end products formation in chicken meat emulsion instead of oxidation

Advanced glycation end products(AGE) are potential harmful substances formed in the advanced Maillard reaction and increasingly investigated in muscle foods. However, the contribution of oxidation to the AGE formation is controversial. Moreover, reports on glyoxal(GO) induced AGE formation in chicken meat emulsion(CME) are limited. Thus, the effects of GO on emulsifying properties, rheological behavior and AGE formation in CME were investigated. Our findings exhibited that levels of Nε-carboxymethyllysine(CML) and Nε-carboxyethyllysine(CEL) were associated with lipid oxidation but not significantly(P > 0.05). Levels of AGE peaked when GO concentration ranged from 5 mmol/L(CML) to 10 mmol/L(CEL). The droplets’ aggregation associated with the disulfide bond when the concentration of GO was at 0.5–30 mmol/L while non-disulfide bond association occurred at 30–50 mmol/L GO concentration. In conclusion, compared to the effect of oxidation, GO exhibited the main role in the AGE formation of CME. This study will provide theoretical significance for further understanding and controlling the formation of AGE in CME.