【作者】 孙志洪；

【导师】 姚军虎； 谭支良；

【作者基本信息】 西北农林科技大学 ， 动物营养与饲料科学， 2004， 硕士

【摘要】 选用 3 只浏阳生长黑山羊（10.00±0.15kg），安装瘤胃瘘管，十二指肠近端瘘管和回肠末端瘘管，饲喂玉米、豆粕和玉米秸秆为基础的日粮。采用 Cr2O3 为食糜标记物，瘤胃投放，测定山羊十二指肠和回肠食糜中氨基酸流通量，计算各种氨基酸在山羊小肠消化率，依据肌肉氨基酸模式计算限制性氨基酸的灌注量。试验表明，生长山羊在实用日粮条件下需灌注的第一、第二和第三限制性氨基酸的量分别是：Met，0.77g/d；Lys，0.91g/d；Leu，0.58g/d。 在此基础上，12 头浏阳生长黑山羊（10.00±0.23kg）按随机区组设计接受氨基酸混合液（对照组）以及分别减去 3 种氨基酸（Met、Lys 和 Leu）的灌注液（处理组），对照组灌注混合氨基酸使进入山羊十二指肠的各种氨基酸（日粮氨基酸+灌注氨基酸）达到山羊肌肉中氨基酸模式，试验组按“递减法”灌注从对照组中减少相同比例（21%）某一种氨基酸的成分。试验结果表明：减 Met 组 IGF-I 的血清浓度极显著低于对照组（P<0.01），减 Lys 组与减 Leu组血清 IGF-I 浓度均显著低于对照组(P<0.05)，三处理组间血清 IGF-I 浓度差异不显著（P>.05）。减 Met 组与减 Lys 组血清 Insulin、GH 和 IgA均显著低于对照组(P<0.05)，三处理组间及减 Leu组和对照组间血清 Insulin、GH 和 IgA浓度差异不显著(P>0.05)。减 Met 组和减 Lys 组血清 IgM 低于对照组(P<0.05)和减 Leu组（P<0.05），减 Met 组和减 Lys 组间及减 Leu 组和对照组间血清 IGM 差异不显著(P>0.05)。3 处理组间血清 IgG 浓度差异不显著(P>0.05)。减 Met 组 PUN 显著高于对照组(P<0.05)，三处理组间、减 Lys 组和对照组间及减 Leu组和对照组间 PUN 差异不显著(P>0.05)。 3 处理组间血清 TP 差异不显著(P>0.05)。减 Met 组 IGF-I mRNA 表达水平极显著低于对照组 (p<0.01)，显著低于减 Leu组(p<0.05)，减 Lys 组 IGF-I mRNA 表达水平显著低于对照组(p<0.05)，减 Met 组和 Lys 组间、减 Lys 组和减 Leu组间及减 Leu组和对照组间 IGF-I mRNA表达水平无显著差异(P>0.05)。减 Met 组骨骼肌 DNA浓度低于对照组(P<0.01)和减 Leu组(P<0.05)，减 Lys 组骨骼肌 DNA浓度低于对照组(P<0.05)，减Lys 组骨骼肌 DNA 浓度和减 Leu组、对照组差异不显著（P>0.05），减 Leu和对照组间骨骼肌 DNA浓度差异不显著（P>0.05）。减 Met 组与减 Lys 组空肠粘膜 DNA浓度低于对照组(P<0.05)，3 处理组间空肠粘膜 DNA 浓度差异不显著（P>.05）、减 Leu 组和对照组空肠粘膜 DNA浓度差异不显著（P>0.05）。减 Ｍｅｔ 组与减 Ｌｙｓ 组骨骼肌 ＲＮＡ 浓度低于对照组（Ｐ＜０．０５），３ 处理组间骨骼肌 ＲＮＡ 浓度差异不显著（P>0.05），减 Leu组和对照组骨骼肌 RNA 浓度差异不显著（P>0.05）。减 Met 组空肠粘膜 RNA 浓度低于对照组(P<0.01)，减 Lys 组空肠粘膜 RNA 浓度低于对照组(P<0.05)，3 处理组间空肠粘膜 RNA<WP=6>浓度差异不显著（P>.05），减 Leu组和对照组空肠粘膜 RNA浓度差异不显著（P>0.05）。 本研究表明，限制性氨基酸从分子水平如 IGF-I 的基因表达、从组织器官水平如肠粘膜和骨骼肌细胞的分裂增生、从蛋白水平 PUN、从免疫水平如 IgA、从激素水平 GH、Insulin 上影响动物机体的生长。更多还原

【Abstract】 The study was conducted to test the effects of limiting amino acids on hepatocyteIGF-I mRNA expression and biochemical indexes of growing goat fed with a based cornstover diet.Three Liu-yang Black goats (10.00± 0.15 kg), fitted with ruminal, duodenal andileal cannula and fed a practical diet were used to determine infusive amounts of limitingamino acids in the duodenum which could be satisfied with the ideal amino acid pattern ofmusle. Results showed thatthe infusive amounts of the first, second and third limiting aminoacids in the duodenum were 0.77g/d (Met),0.91g/d (Lys) and 0.58g/d (Leu) respectively. Twelve Liu-yang Black goat (initial weight10.00± 0.23kg), cannulated in duodenum,were randomized to separate into 4 groups, three goats per group. All animals were put intothe metabolic cages respectively and free to fresh water. The four groups are as follows: A(removing 21%Met from the mixture of Met, Lys and Leu), B (removing 21% Lys from themixture of Met, Lys and Leu),C, (removing 21%Leu from the mixture of Met, Lys andLeu)and D, (control group, the mixture of Met, Lys and Leu). The results showed that: IGF-ImRNA expression of removal Met group was significantly lower than that of control group(p<0.01) and that of removal Leu group (p<0.05) and removal Lys group was alsosignificantly lower than that of control group (p<0.05).The DNA content of skeletal musclesof removal Met group was significantly lower than that of control group (p<0.01) and that ofremoval Leu group (p<0.05) and the DNA content of skeletal muscles of removal Lys wassignificantly lower than than that of control group (p<0.05); DNA content of jejunum mucousmembrane of removal Met group and Lys group was significantly lower than that of controlgroup (p<0.05). RNA content of skeletal muscles of removal Met group and Lys group was<WP=8>significantly lower than that of control group (p<0.05); RNA content of jejunum mucousmembrane of removal Met group was significantly lower than that of control group (p<0.01)and RNA content of jejunum mucous membrane of removal Lys group was significantlylower than that of control group (p<0.05). Serum IGA content of removal Met group and Lysgroup was significantly lower than that of control group (0.05); serum IGM content ofremoval Met group was significantly lower than that of control group (0.01) and that ofremoval Leu group(p<0.05). Serum IGF-I content of removal Met group was significantlylower than that of control group (p<0.01);Serum IGF-I content of removal Lys group and Leugroup was significantly lower than that of control group (p<0.05). Serum Insulin content ofremoval Met group and Lys group was significantly lower than that of controlgroup(p<0.05).Serum GH content of removal Met group and Lys group was significantlylower than that of control group(p<0.05). PUN of removal Met group was significantly lowerthan that of control group (p<0.05). There were no differences about serum TP among fourgroups (P>0.05). It could be suggested that limiting amino acids affect the growth of goatfrom different levels,such as molecule level(such as gene expression of hepatocyte IGF-I),tissue level(such as proliferation of jejunum mucous membrane cell and skeletal muscles cell),immunology level(such as the secretion of IgA, IgM), hormone level (such as GH and Insulin)and protein level (such as PUN). Every level and aspect of promoting growth o f aminolimiting acids is influeced and promoted each other. The role of promoting growth of limitingamino acids is fulfilled by such way.更多还原