Study On Fatty Acid Contents And ELOVL2,ELOVL5 Gene Expression Patterns With Development Stages Of Erlang Mountainous Chicken Under Different Housing Sisterms

The reseach was conducted to study the effect of housing sisterm and age on the fatty acid metabolism of Erlang Mountainous chickens which were in breeding. The one generation offspring of Erlang Mountain chickens (SD02×SD03) were raised indoor floor from 0 week to 6 week, and then, they were rased in three kinds of housing sisterms (caged-feed, indoor floor, and outdoor access) randomly still 13 week. Ten chickens (♀5+♂5) of every housing sisterm were slaughtered to collect seven tissues (liver, brain, gonad, breast muscle, leg muscle, subcutaneous fat and abdominal fat) on 0,2,4,6,8,10, 13 week. The study used the quantitative Real-Time PCR (qRT-PCR) method to test the expression quantity of ELOVL2 and ELOVL5 gene in different tissues and at different growth points under different housing sisterms, utilized Enzyme-linked immuno-sorbent assay method to determine the contents of 17 fatty acids in breast muscle in different housing sisterm chinkens on 8,10,13 week, and used SAS8.0 to analyzed the datas.The effect of housing sisterm and age on the contents of fatty acids showed that: There were different in contents of fatty acids in breast muscle of Erlang mountainous chickens. The content of C24:0 was the highest and C14:0 was the lowest in SFA, the content of C18:1 was the highest in MUFA, and six kinds of PUFA, the content of C20:4 was the lowest, but C18:3n-6 was the highest. Housing sisterm effected great significantly the contents of C26:0, C16:1, C18:3n-3, C20:4, EPA and DHA (p≤0.01), and influnced significantly the contents of C18:1 and C22:1. The content of C26:0 of in outdoor access chickens was higher significantly than caged feed chikens (p<0.05), while C16:1 in outdoor access was great significantly higher than caged feed and indoor floor chicken (p≤0.01). The content of C18:1 and C20:4 of caged feeding chiken were respectively higher significantly and great significantly than the other two housing sisterm chickens. But C18:3n-3 and EPA of caged feed chiken was higher great significantly than outdoor access chicken. DHA was the highest in indoor floor chickens, and it was higher great significantly than caged chickens (p<0.01). Age effected the contents of C16:0, C24:0, C26:0, C14:1, C18:3n-6, C20:4, C20:5 great significantly(p<0.01). C26:0 was increased but C20:5 was decreased with the age increasing. EPA was the highest in 8 week chicken and higer great significantly than 10 and 13 week chickens.The expression patterns of ELOVL2 and ELOVL5 gene and the roles of the genes in Erlang Mountainous chickens showed that:ELOVL2 and ELOVL5 were highly expressed in liver and brain, ELOVL2 was lowly expressed in gonad, breast muscle, and leg muscle and lowest expressed in subcutaneous fat and abdominal fat. ELOVL5 was lowly expressed in breast muscle, leg muscle subcutaneous fat and abdominal fat. ELOVL5 was highly expressed in gonad at 10 and 13 week chickens. ELOVL2 and ELOVL5 were played different roles in different tissues. It was can be speculate that ELOVL2 was first important gene for fatty acid synsesis in brain and ELOVL5 played important role in gonad, subcutaneous fat and abdominal fat from the ratio of relative quantity of ELOVL2 gene to ELOVL5. It was probable that ELOVL2 was related with the synsesis of C16:1, C20:4 and ELOVL5 was took part in the synsesis parthway of C20:4�'C20:5�'C22:6.The effect of housing sisterm and age on the gene expression of ELOVL2 and ELOVL5 showed that:The indoor floor housing sisterm was benefit for ELOVL2 gene expression in liver, gonad, and leg muscle of Erlang Mountain chicken, and higher significantly (p<0.05), great signiicantly (p<0.01) and significantly (p≤0.05) respectively than caged feed and outdoor access chickens. At the same time, the indoor floor housing sisterm was also benefit for ELOVL5 gene expression in breast-muscle, leg muscle and subcutaneous fat, and higer separately great significantly than the other housing sisterm chickens (p<0.01). The quantity of ELOVl2 expression in liver, gonad, breast-muscle, leg muscle and subcutaneous fat were incressed with the the age increasing. The quantity of expression ELOVl5 gene expression in liver was decreased but increased in gonad and breast-muscle with the age increasing.