| Three combinations(princess chicken,kirin chicken and hybrid of princess chicken(♂) and kirin chicken(♀) were built to measure and comparatively analysis appearance characteristics and growth performance,body size and slaughter performance, muscle meat quality,blood physiological and biochemical indicators,egg quality to study effect of hybridization.The experiment lasted for 43 weeks.540 chickens(male and female in half)hatched were randomly divided three groups in every gender and every repeat were 30 chickens.At the same time using real-time fluorescent quantitative PCR technology was used to measure delta 6-fatty acid dehydrogenase gene expression level in three combinations’ different stages of growth of each organization and reveal the differences of scheduling and organization of delta 6-fatty acid dehydrogenase gene expression,and study correlation analysis delta 6-fatty acid dehydrogenase gene expression levels with contents of the long-chain polyunsaturated fatty acids in muscle to explore the regulatory mechanism in fat metabolism.The specific test results were as follows:1.Appearance characteristics and growth performance There was significant difference in body weight of 16-week-old chickens(in the same gender).Body weight of three groups followed decreasing as an order of kirin chicken(1810.20g♂/1450.00g♀),hybrid chicken(1464.81g♂/1312.00g♀)and princess chicken(1222.61g♂/1007.00g♀);Feed conversion of three groups followed decreasing as an order of princess chicken(4.66♂)>hybrid chicken(4.31♂)>kirin chicken(3.36♂)and princess chicken(4.59♀)>kirin chicken(4.53♀)>hybrid chicken(4.19♀).2.Body size and slaughter performance(1)Body size There were significant difference in shank length and shinbone girth between different varieties and genders.(2)Slaughter performance The slaughter rate and eviscerated rate were determinated,respectively,male:kirin chicken(91.80%,61.98%),princess chicken(90.15%,63.96%),hybrid chicken(91.09%,61.58%);female:kirin chicken(90.83%,61.35%),princess chicken(88.05%,60.16%),hybrid chicken(89.36%,61.75%).The male hybrid chicken was higher than princess chicken among the alive weight, slaughter weight,semieviscerated wei-ght,eviscerated weight,abdominal fat weight,abdominal fat rate,chest and leg muscle weight,leg muscle rate, width and thickness of fat,and most of the indicators reached significant or extremely significant level(P<0.05,P<0.01).at the same time the hybrid chicken reduced part of fat indicators in the kirin chicken.3.Muscle meat quality(1)Sensory values There were no significant difference in the fresh colour and p H of three combinations.Princess chicken breast muscle and kirin chicken leg muscle shear force is the lowest among three combinations, respectively.(2)Muscular histological characteristic There were remarkable differences in muscle fiber characteristics of varieties among three combinations.Muscle fiber diameters between breast muscle and leg muscle:kirin chicken(male:14.07/17.84;female:16.93/17.63)>hybrid chicken(male:13.99/17.70;female:15.59/17.41)>princess chicken(male:12.92/16.83;female:14.10/15.60).Muscle fiber density between breast muscle and leg muscle:kirin chicken(male:685.99/300;female:401.05/378.12)<hybrid chicken(male:720.20/344.35;female540.23:/380.12)<princess chicken(male:780.20/501.55;female:650.11/530.11).(3)Muscle fatty acids traits The proportion of unsaturated fatty acid significantly was higher than that of saturated fatty acids,at the same time mustard acid content was extremely low.The essential fatty acids of breast muscle in princess chicken and hybrid chicken were significantly higher than that of kirin chicken.The essential fatty acids of the leg muscle of male princess chicken was the highest of the three combinations.4.Blood physiological and biochemical indexesThere were significant difference in blood physiological and biochemical indexes of three combinations,hybrid chickens was kirin chicken and princess chicken in the middle in many physiological and biochemical indexes.5.Egg quality traits The egg weight,yolk weigh,albumen weigh,shell thickness and shell strength of princess chicken were significantly lower than those of kirin chicken(P<0.05), shell weight and percentage of shell were very significantly lower than those of kirin chicken(P<0.01),but albumen height and haugh unit were very significantly higher than those of kirin chicken(P<0.01).Hybrid chicken eggs in most eggs quality traits were significantly or very significantly higher than those of the princess chicken and kirin chicken(P<0.05 or P<0.01).6.Studying the spatiotemporal expression of delta 6-fatty acid dehydrogenase geneDelta 6-fatty acid dehydrogenase gene had the highest expressional level in the liver,low expressed in muscular stomach.There were remarkable positive correlation bet-ween delta 6-fatty acid dehydrogenase gene expression levels and contents of the C25:0 and C20:3 in muscle,so it would benefit the synthetic of C25:0and C20:3.The gene expression levels directly affected on the strength of the fatty acid synthesis and affecting the flavor of meat ultimately. |
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