Comparative Studies Of The Suitable Energy Levels Of Three Types Yellow Broilers

Ank yellow broilers(quick-grow type), guangxi yellow chicks(slow-grow type) and anguang crossbred chicks (middle-grow type) were subjected to experiment with two factors at three levels of dietary energy and broilers type at 3 stages. Daily gain(DG), feed conversion rate(FCR), carcass quality and blood biochemical parameters were tested and analyzed at each test stage.Experiment 1: The results indicated that: (1) To guangxi yellow broilers, the difference of DG is not significant between energy levels(P>0.05), and FCR is significant between energy levels(P<0.05), witch is lowest in the middle energy level which is 2.02.;to the crossbred yellow broilers, DG and FCR are all significant between energy levels(P<0.05),and DG is highest in the middle energy level, FCR in the high energy level, 2.41, is higher significantly than in the low energy level; to Ank yellow broilers, DG and FCR are all highest in the middle energy level which reach to 22.34g/day and 1.88; (2) The energy level affect significantly the density of TG, LDL and BS(P<0.05), and with the increase of the energy level the density of TC. TG. LDL, VLDL decrease while the density of BS increase.Experiment 2: The results indicated that :(1) Dietary energy level effect significantly DG and FCR of this three type yellow broilers(P<0.05).To guangxi yellow broilers, with the increase of the energy level DG and FCR increase while DG is 21.83g/day and FCR is 2.38 in high energy level; to the crossbred yellow broilers,DG is highest in the middle energy level which is not significant between the middle and the high energy level, and FCR is highest in the high energy level, while DG is 30.28g/day and FCR is 2.56 ;to Ank yellow broilers, with the increase of the energy level DG increase while FCR decrease. (2) Dietary erengy level effect significantly CR and HER of guangxi, HER and SFR of the crossbred, andTER, SFD, SFR and IFW of anka(P<0.05).(3) With the increase of the energy level the density of TC, TG, LDL, VLDL decrease(P>0.05) while the density of BS increase. (P>0.05).Experiment 3: The results indicated that: (1) To Ank yellow broilers of 10 weeks old, DG is not difficult significantly between three energy levels(P>0.05), and FCR in the high energy level is higher significantly than the low and the middle energy leve(P>0.05)l, and DGis 36.63g/day in the low energy level .while FCR is 3.30. To guangxi yellow broilers of 12 weeks old, DG and FCR are diffirent significantly between erengy levels(P < 0.05),while DG (28.70g/day)and FCR(2.29) in the middle energy level are highest. To the crossbred broilers, with the increase of the energy level DG increase (P<0.05)and FCR decrease(P<0.05), and DG is 32.14g/day in the low energy level while FCR is 3.07. (2) Dietary erengy level do noteffect significantly slaughter permance of guangxi and the croosbred, while do affect significanty TER,BR and LMR of anka. To Guangxi yellow broilers, carcass rate and pectoral muscle rate are highest in the high energy level while leg muscle rate is highest in the medium energy level ,as follows 91.78%, 15.74% and 20.81%. To Ank-Guangxi yellow broilers, carcass rate and pectoral muscle rate are highest in the low energy level while leg muscle rate is highest in the medium energy level ,as follows 90.56%, 15.37% and 22.73%. To Ank yellow broilers, carcass rate and pectoral muscle rate are highest in the high energy level while leg muscle rate is highest in the medium energy level ,as follows 94.12%, 18.77% and 25.20%. (3) The contents of linoleic acid, linoleic acid, UFA and EFA .are all higher significantly in high erengy level than in low erengy level(P<0.05),.(4) The energy level affect significantly the blood biochemical traits(P<0.05), while with the increase of the energy level the density of TC, TG, LDL, VLDL decrease while the density of BS increase-Results of present study indicated that when daily gain and feed conversion rate as the measure index, in the starting period (0-4 weeks), the suitable dietary energy level of Guangxi yellow broilers, the crossbred bro...