| This study formulated corn-bean meal diets based on (digest ideal amino acids ) Baker mode of the university of Illinois, which lowered the level of diteary CP by 4% compared with NRC to evaluate the growth performance, carcass trait, immune organ, nitrogen balance, biochemical indicator ,serum free amino acids and meat quality of broilers with additions of Trp ,Arg ,Val ,Gly and small peptide into the low CP diets. This study included two experiments.Experiment 1,336 Arbor Acres broilers of 1 day-old were firstly fed 3 days, secondly they were randomly divided into 7 treaments with 8 replicates each treatment and 8 per replicate, the experiment lasted 21d .The ME of the 7 treaments were all 13.39 MJ/kg. The CP of the control group was 23%,the CP of the other six groups were 19%.When the level of CP reduced to 19%,the test group will have a lack of digest Trp by 0.02%,a lack of digest Arg by 0.25%, a lack of digest Val by 0.03%. The prevenient researchers repored that the growth performance of broilers would be reduced with decreasing dietary CP. This experiment with addition of Gly and small peptide in the low CP diets was to evaluate the effects of growth performents of broilers with addition of Gly and small peptide in the low CP diets.The test groupâ… a dded Trp,Arg and Val;The test groupâ…¡added Gly at the base of test groupâ… ;The test groupâ…¢added 0.5% small peptide at the base of test groupâ… ;The test groupâ…£a dded Arg and Val;The test groupâ…¤added Trp and Arg. The results indicated: (1) When the CP of diets reduced by 4%, the growth performents of broilers would reduce significantly (P<0.05),but the average daily gain of broilers would increase significantly (P<0.05) with the addition of Gly and small peptide, and the group of small peptide was better than the group of Gly, the group lacking of Arg have the highest feed: gain (F:G). (2)The reducing CP or the addition of Gly and small peptide had no significant effect on the left pectoral rate and the left crureus rate of the broilers(P>0.05);but the abdominal fat rate have no significant difference(P>0.05) as the CP of diets reduced by 4%, and the abdominal fat rate increased a little but have no significant difference (P>0.05)with adding Gly and small peptide. However, the abdominal fat rate of the last three groups in which AA were not balanced increased significantly(P<0.05), the group lacking Val had the highest abdominal fat rate.(3) Bursa of Fabricius index between the treaments had no significant difference(P>0.05);Spleen index in test group all reduced compared with the control group; The group of small peptide had the highest thymus index(P<0.05),the group lacking Arg had the lowest thymus index. (4) When the CP of diets reduced by 4%, the output of nitrogen reduced significantly(P<0.05). Relevantly, nitrogen deposition rate improved significantly(P<0.05); nitrogen deposition rate was highest with addition of Gly and small peptide; In the last three groups the nitrogen deposition rate of the group lacking Arg was lowest.(5) The serum total protein and albumin between all the treaments had no significant difference(P>0.05); The serum globulins in test group all reduced compared with the control group.(6) Triglycerides between all the treaments had no significant difference(P>0.05);With the dietary CP reducing , the serum uric acid leve reduced significantly(P<0.05). Compared with the test groupâ… , the serum uric acid leve in the group of small peptide increased significantly(P<0.05).The group lacking Val had the highest serum uric acid leve; With the dietary CP reducing or addition of AA and small peptide , the level of IGF-1 increased significantly(P<0.05), the group of Gly was highest,the group lacking Trp was lowest.Experiment 2, 252 Arbor Acres broilers of 22 day-old were randomly divided into 7 treaments with 6 replicates each treatment and 6 per replicate, the experiment last 21d.The ME of the seven treaments were all 13.39MJ/kg. The CP of the control group was 20%,the CP of the other six test groups were 16%. When the CP reduced to 16%,the test group would have a lack of digest Trp with 0.02%,a lack of digest Arg with 0.18%, a lack of digest Val with 0.02%. The prevenient researchers repored that the growth performance of broilers would be reduced with decreasing dietary CP. This experiment with addition of Gly and small peptide in the low CP diets was to evaluate the effects of growth performents of broilers with addition of Gly and small peptide in the low CP diets.The test groupâ… a dded Trp,Arg and Val;The test groupâ…¡a dded Gly at the base of test groupâ… ;The test groupâ…¢added 0.5% small peptide at the base of test groupâ… ; The test groupâ…£a dded Arg and Val;The test groupâ…¤added Trp and Val. The test groupâ…¥added Trp and Arg.The results indicate: (1)The feed: gain (F:G) between all the treaments had no significant difference(P>0.05). When the CP of diets reduced by 4%, the growth performents of broilers would reduce( ),but the average daily gain of broilers would increase with the addition of Gly and small peptide, and the group of small peptide was better than the group of Gly, the group lacking of Arg have a lowest average daily gain.(2) The left crureus rate and liver rate between all the treaments had no significant difference(P>0.05), the left pectorals rate reduced significantly(P<0.05). After adding Gly and small peptide, the left pectorals rate had improved, but still can not reach the level of the control group, the group lacking Arg had the lowest left pectorals rate. When the CP of diets reduced by 4%, the abdominal fat rate increased significantly(P<0.05), the group lacking Val had the highest abdominal fat rate, secongly the group of small peptide.(3) Bursa of Fabricius index between the treaments had no significant difference(P>0.05);Spleen index in test groups all reduced significantly(P<0.05) compared with the control group; When the CP of diets reduced by 4%, the thymus index reduced significantly(P<0.05). After adding Gly and small peptide, the thymus index increased significantly(P<0.05). The group lacking Val had a lowest thymus index. (4) When the CP of diets reduced by 4%, the output of nitrogen reduced significantly(P<0.05). Relevantly, nitrogen deposition rate improved significantly(P<0.05); nitrogen deposition rate was highest with addition of Gly and small peptide; Compared with the test groupâ… , the last three groups reduced a little, but nitrogen deposition rate had no significant difference(P>0.05);(5)The serum total protein in test groups increased significantly(P<0.05) compared with the control group; The serum albumin in test groupâ… reduced ignificantly(P<0.05) compared with the control group; The serum albumin increased significantly(P<0.05) with the addition of Gly.(6) With the level of CP reducing, the serum uric acid leve reduced significantly(P<0.05).In all treatments, the level of the serum uric acid in test groupâ… was the lowest.With the level of CP reducing, the serum triglycerides increased,The group of Gly had the highest serum triglyceride.In the last three groups the group of lacking Arg had the highest serum triglyceride.When the CP of the diets reduced by 4%, the level of the serum IGF-1 had no significant difference(P>0.05); the level of the serum IGF-1 was higher than the experimentâ… when added the Gly and small peptide .There was no significant difference(P>0.05)in the last three groups.(7) With the level of the dietary CP reducing , the pectoral filtration rate reduced, but the crureus filtration rate had no significant difference(P>0.05). With the level of the diteary CP reducing , he crureus drip loss reduced significantly(P<0.05), the pectoral shearing force reduced significantly,too(P<0.05). |
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