| In order to explore the influences of different feed restriction ways on growth performance,slaughterhouse index,visceral organ indexes,skeletal traits,intestinal structure and mitochondrial gene expression effect of Arbor Acres chickens,two experiments were designed in this experiment:Test one Effects of Feed Restriction Ways on the Growth Performance,Slaughter Performance and intestinal structure of Arbor Acres ChickensEighty 7-day-old Arbor Acres chickens were fed in our experiment.The chickens were randomly assigned to 4 groups: Ad libitum group(control group),quantitive restriction group(free feed intake from eight am to one pm,other time fasting),energy restriction group(restriction of 15% metabolizable energy in the diet)and protein restriction group(restriction of 15% protein in the diet),with 20 replicates per group,cock and hen in half.All chickens were fed by individual cage.The test begined at 8-day-old in chickens.Feed restriction stage was from 8 to 21 days of chicken(14 d)and compensatory growth stage was from 22 to 42 days of chicken(21 d).Four cocks and four hens of each group were selected to slaughter at 21-day-old and 42-day-old of chicken,respectively.The chest muscle weight,leg muscle weight,abdominal fat weight,heart weight,liver weight,spleen weight,thymus weight,bursa of fabricius weight,muscular stomach weight,glandular stomach weight,tibia weight,femur weight,and length and diameter of the tibia and femur were measured,respectively.In addition,the duodenum,jejunum and ileum segments were taken to make intestinal tissue slices to measure villus height,crypt depth,intestinal wall thickness and mucosal thickness index.The results showed as follows:(1)In growth performance,the average daily gain of chickens in the three feed restriction groups after limited feeding was significantly lower than that of ad libitum group(P>0.05),and the feed gain ratio was significantly greater than ad libitun group(P<0.05).After compensatory growth,the average daily feed intake,average daily gain and feed gain ratio of chickens from four groups were not significant(P>0.05).The final weight of chickens in feed intake restriction group was significantly lower than ad libitum group(P<0.05),which was the lowest in four groups.In the whole period,there was no significant difference in feed gain ratio among four groups(P>0.05),mainly embodies as Quantitive group < Protein restriction group <Energy restriction group <Ad libitum group.(2)In slaughterhouse index,the effect of group on slaughterhouse index of 21 d Arbor Acres chickens was very significant(P<0.01).After feed restriction,there was a significant difference in slaughter index between feed intake restriction group and ad libitum group of chickens(P<0.05).After 21 d compensatory growth,the abdominal fat ratio of three restriction groups of chickens was higher than ad libitum group,but there was no significant difference compared with ad libitum group(P>0.05).(3)In visceral organ indexes,the spleen index and thymus index among three restriction groups were lower than ad libitum group.And the muscular stomach index and glandular stomach index were higher than ad libitum group.There was no significant difference in the partial visceral organ indexes at 42 d between the three feed restriction groups and the ad libitum group(P>0.05).(4)In skeletal traits,the tibia weight,tibia length and femur length at 21 d in the three feed restriction group were lower than those in ad libitum group.the tibia weight and femur weight at 42 d in the three feed restriction group were lower than those in ad libitum group.There was no significant difference in the partial skeletal traits at 42 d between the three feed restriction groups and the ad libitum group(P>0.05).(5)In intestinal structure,the development of small intestine in the chickens at 21 d from restriction groups mostly showed villus height reduction,crypt depth increased,V/C decreased,intestinal wall thickness and mucosal thickness decreased.After compensatory growth,the villus height and V/C of chickens at 42 d from three feed restriction groups tended to increase,but the intestinal wall thickness and crypt depth decreased.The results showed that the average daily gain,abdominal fat ratio,visceral organ weight,some skeletal traits and intestinal structure indexes through the three restriction ways were lower in the early growth stage.After 21 d compensatory growth,the growth performance,some visceral index and some skeletal traits of the three feed restriction groups reached the control level,all of which showed compensatory growth effect.The relative growth rate of the chicken was the fastest in feed intake restriction group.The intestinal structure of chicken was better than control group after the compensatory growth.Test two Effects of Different Feed Restriction Ways on Mitochondrial Gene Expression in Arbor Acres ChickensIn order to study the effects of different feed restriction ways on mitochondrial gene expression in Arbor Acres chicken,the test collected heart,liver,spleen,breast muscle,leg muscle from 21 d,42 d healthy Arbor Acres chicken.There were 4 sample cocks and 4 sample hens in three feed restriction groups and control groups at each stage,and single individuals were repeated units.The total RNA was extracted from the above tissues,and the genomic DNA was removed to reverse transcription to c DNA.According to the mitochondrial related genes(ATP6,ND6,ND2)and reference gene(18Sr RNA)sequences of primers and probes were designed.Builded standard curves for making gene standard products.Quantitative analysis of candidate genes was performed by probe quantitative PCR.The results of the test were as follows:(1)The relative expression of ATP6 gene in the heart,liver,spleen and breast muscle of chickens at 21 d from the three feed restriction groups were not significant differences compared with the ad libitum group(P>0.05).The relative expression of ATP6 gene in the heart,liver,spleen and leg muscles of chickens at 42 d from the three feed restriction groups were no significant differences compared with the ad libitum group(P>0.05).The relative expression of ATP6 gene in chicken breast muscle was significantly higher than that in the other three groups(P<0.05).(2)The relative expression of ND6 gene in the heart,liver,chest muscle and leg muscle of chickens at 21 d from the three feed restriction groups were no significant differences compared with the ad libitum group(P>0.05).The relative expression of ND6 gene in the heart,liver,spleen,chest muscle and leg muscles of chickens at 42 d from the three feed restriction group were no significant differences compared with the ad libitum group(P>0.05).(3)The relative expression of ND2 gene in the heart,liver,spleen and leg muscles of chickens at 21 d from the three feed restriction groups were no significant differences compared with the ad libitum group(P>0.05).The relative expression of ND2 gene in the breast muscle of chickens at 21 d from the quantitive restriction group was significantly higher(P<0.05).The relative expression of ND2 gene in the heart,liver and leg muscles of chickens at 42 d from the three feed restriction groups were no significant differences compared with the ad libitum group(P>0.05).The relative expression of ND2 gene in the spleen of cocks at 42 d from the protein restriction group was significantly decreased(P<0.05),and the relative expression of ND2 gene in the breast muscle of chicken at 42 d from the energy restriction group was significantly increased(P<0.05).This test through different restriction ways for quantitative Arbor Acres chickens mitochondrial related gene analysis,provided important information for the study of three kinds of restriction method for power supply of Arbor Acres chicken mitochondria.These provided a theoretical basis for animal husbandry to further study the feed restriction and compensatory growth from the molecular level. |
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