Effects Of Different Amino Acid Patterns On Immune Function And Production Performance In Hy-Line Brown Hens

This experiment by reducing the level of dietary protein,and change some essential amino acid content and the proportion of different amino acid pattern of Hyline brown layers of young chicken immune function,growth performance and production performance of laying hens,egg quality and feed utilization rate.give the result as follows:(1)Three hundred six-week-old Hy-line variety brown layers were randomly divided into 5 groups.There were 4 repetitions for each group;15 layers for each repetition.Based on NRC(1994)Standard,we designed 5 amino acid patterns including Patterns1,2,3,4 and 5.Thereinto,Pattern 1 was the contrast group.About 0.6% crude protein was reduced to adjust addition levels of some essential amino acids,forming Patterns 2,3,4 and 5.After that,the work discussed the influence of different amino acid patterns on productivity and immunity of 6-18 weeks old layers.Result showed that Patterns 2,3,4 and 5 had better daily weight gain,feed conversion efficiency and 18-week-old body weight than Pattern 1 in varies degrees.Pattern 5 was the best.Immune function index analysis showed that Patterns 2,3,4 and 5 had higher chicken thymus index,spleen index,bursal index,serum Newcastle disease antibody titer,Lym transformation rate and lgG level than Pattern 1.Thereinto,Pattern 5 reached a significant difference in thymus index,bursa index,Newcastle disease antibody titer,Lym transformation rate and lgG level(P<0.05).Pattern 2 reached a significant difference in serum Newcastle disease antibody titer and lgG level(P<0.05).(2)The experiment was conducted to investigate the effects of the different amino acid patterns on apparent digestibility of Ash,CP,EE,CF of the later period of laying hens,and to estimate the optimal required amino acid pattern for the later period of laying hens.Two hundred and forty Hy-Line Brown laying hens aged at 60 weeks in good health were randomly divided into 6 groups with namely the control group(Mode1),Mode 2,Mode 3,Mode 4,Mode 5 and Mode 6,respectively.Both apparent digestibility of crude protein(CP)of pattern 2,3,4,6 and apparent digestibility of ether extract(EE)of pattern 6 were significantly higher(P<0.05)than that of pattern5.For apparent digestibility of amino acid,Ser and Met of pattern 2,Tyr and Met of pattern 3,Met of pattern 4 were all significantly higher(P<0.05)than that of pattern 5.The results showed that the apparent digestibility of all kinds of amino acids in model2 were higher.Compared with the control group,the model 2 most amino acids table view digestibility have been varying degrees of increase,the East Tianmen aspartic acid increased by 2%,the tyrosine increased by 9.8%,histidine increased 6.4% and glycine increased 0.9%.(3)The results showed that: Compared with the group 5,the egg weight of Group 3 and 4 significantly increased 23.4%(P<0.05)and 25.3%(P<0.05),respectively.Laying rate of Group 2,3 and 4 significantly improved 16.1%(P<0.05),19.7%(P<0.05)and 27.3%(P<0.05),respectively,compared with the control group.And the material egg ratio of Group 3,4 compared to the group 5 dramatically decreased 21.4%(P<0.05)and 22.4%(P<0.05),respectively.The amino acid pattern had no significant effect on daily feed intake of laying hens and egg secondary rate(P> 0.05).Different amino acid patterns significantly affected egg quality.The group 4 of the highest level of eggshell color model,group 1 was the lowest,but no significant differences among the groups(P>0.05);There were no significant difference of egg shape index(P>0.05);eggshell strength in group 2 group was the highest,compared with group 1,group 3,group 4,group 5,group 6 was 17.59% higher(P> 0.05),1.13%(P>0.05),19.47%(P>0.05),15.17%(P>0.05),14.87%(P>0.05);Protein height in group 1 was the highest,compared with group 2,group 3,group 4,group 5 and group6 high 7.91%(P>0.05),6.43%(P>0.05),7.06%(P>0.05),34.48%(P<0.05)and28.17%(P<0.05);Haugh unit in group 4 was the highest,compared with group 1,group 2,group 3,group 5 and group 6 high 3.29%(P>0.05),8.08%(P>0.05),0.1%(P>0.05),17.4%(P>0.05)and 13.47%(P>0.05);Egg yolk color analysis table That group 5 egg yolk color of the highest level,compared with group 1,group 2,group 3,group 4 and group 6 high 14.12%(P>0.05),8.15%(P>0.05),4.93%(P>0.05),7.66%(P>0.05)and 2.93%(P>0.05).