Effect Of The Ratio Of Dietary ω-6/ω-3 PUFA On Growth Performance Tissue Fatty Acid And Lipid Metabolism In Meat-Type Ducks

This experiment was conducted to analysis the fatty acids composition of different enterprises fattened duck.Effect of the ratio of dietary ω-6/ω-3 PUFA on growth performance,tissue fatty acid and lipid metabolism in meat-type ducks was carried out the research.This study provides scientific data for rational use in the production of ducks in the scientific breeding,breeding and feeds;also provides some basic information for the study of equilibrium fatty acid ratio model.The experiment consists of two parts: The first part,fattening duck feed was collected with 8 enterprises,each enterprise was randomly collected 6 samples,determination of crude fat and fatty acid.The second part,feeding experiment,this experiment was adopted one–factor completely random design.A total of 3168 15-d-old ducks were randomly allotted into 6 treatments with 6 replicates,per treatment with 88 ducks per replicate.The 6 experimental diets were the control diet co ntaining ω-6/ω-3 PUFA ratio 13:1 and the diets from 2 to 6 treatments containing ω-6/ω-3 PUFA ratio of 10:1,8:1,6:1,4:1 and 2:1 by supplementation with the linseed oil 0.12,0.24,0.43,0.78 and 1.60%,respectively.The experiment lasted for 4 weeks.(1)There was significant difference between the enterprise with duck feed composition of fatty acids,contains more n-6 PUFA,less n-6 PUFA content,and the ratio had difference significantly,UFA was 2~5 times SFA.(2)Dietary ω-6/ω-3 PUFA ratios had no effects on growth performance of duck from 15 to 42 of age(P>0.05).(3)Dietary ω-6/ω-3 PUFA ratios for duck dressing percentage,half eviscerated ratio and the whole eviscerated ratio in 13:1 and 2:1 group was significantly higher than other groups(P<0.05);Breast muscle,thigh muscle and abdominal fat rate had no significant difference(P>0.05);Cardiac index in 6:1 group was significantly higher than the other groups,liver index 2:1 group was significantly higher than other groups(P<0.05);6:1 and 13:1 thymus index were significantly higher than other groups(P<0.05).(4)Dietary ω-6/ω-3 PUFA ratios had effects on digestive organs development and intestinal mucosal morphology of duck(P<0.05),in the intestinal mucosa form 6:1 treatment group significantly increased villus length,muscle thickness,villus length/crypt depth and reduced crypt depth(P<0.05).(5)Dietary ω-6/ω-3 PUFA ratios had effects on ALB,GTP,GOT,GOT/GTP and LD of duck(P<0.05).6:1 treatment group of TG,TC and LDL content were relatively low,HDL content was relatively high.(6)Dietary ω-6/ω-3 PUFA was 6:1that reduced the fat content of the three tissue;Liver TC in 8:1 and 2:1 had significantly lower than other groups(P<0.05),TG in 2:1 group was lower than the 6:1 and 4:1 group(P<0.05);liver cells was evident impaired in 13:1 group.(7)The concentration of ω-3 PUFA was linearly raised(P<0.01)and the ω-6 and ω-6:ω-3 PUFA linearly decreased in the liver and muscle of ducks(P<0.01)with decreasing dietary ω-6/ω-3 PUFA ratios.(8)The expression of SREBP-1c and PPARγ mRNA reduced and the positive rate of SREBP-1c immunohistochemistry improved in the liver of ducks in the diet with ω-6/ω-3 PUFA of 6:1.(9)Dietary ω-6/ω-3 PUFA ratios had no effects on liver FAT,LPL,ACC and FAS the expression of mRN A of duck(P>0.05).The FADS2,ELOVL5,FADS1 and ELOVL2 expression in the livers of the ducks showed quadratic curve increased with decreasing of the dietary ω-6/ω-3 PUFA ratios,expression of four genes were inhibited in 13:1 group.In summery,dietary fatty acid composition of enterprise fattening ducks was serious different;Under the experimental conditions,the appropriate dietary ratio of ω-6/ω-3 PUFA(6:1)could reduce the fat deposition and the production of ducks ω-3 PUFA rich in high-quality duck meat products,and could effectively reduce the expression of genes related to fat metabolism and enhance the expression of genes related to fatty acid synthesis.