【作者】 胡良卫；

【导师】 李吕木；

【作者基本信息】 安徽农业大学 ， 动物营养与饲料科学， 2007， 硕士

【摘要】 蛋氨酸是动物的必需氨基酸之一,同时也是反刍动物的限制性氨基酸,在动物体内除合成体蛋白外,还可参与多种转甲基的反应生成许多含甲基的生理活性物质。对于单胃动物而言,提高日粮蛋氨酸供给可满足其对蛋氨酸的需要。然而,反刍动物由于瘤胃微生物的作用,通过日粮直接增加蛋氨酸的供给量并不能显著改善到达小肠的蛋氨酸量。而离子载体能够抑制瘤胃微生物的蛋白质脱氨反应,从而减少蛋白质在瘤胃内被降解,但离子载体能否抑制氨基酸的脱氨降解尚未见报道。因而探讨其对蛋氨酸的影响,对于研究蛋氨酸的瘤胃代谢和进一步科学使用离子载体均具有十分重要的意义。试验一:拉沙里菌素对瘤胃蛋氨酸代谢的影响。用三只装有永久性瘤胃瘘管的萨能母山羊为试验动物,试验分为4期,每期6天,每期为一个处理。对照组:基础日粮;处理1:基础日粮+15g蛋氨酸;处理2:基础日粮+15g蛋氨酸+0.15g拉沙里菌素;处理3:基础日粮+15g蛋氨酸+0.20g拉沙里菌素。每期的最后一天为血样和瘤胃液的采样日,采样日的采样时间点为3个,即当日早晨饲喂前(0小时)、饲喂后2小时和5小时。血样和瘤胃液经处理后,测定样本中游离蛋氨酸(FM)的含量和有关酶的活性。结果表明,0小时,在血清中,0.15g拉沙里菌素组GOT活性极显著低于仅添加15g蛋氨酸组(P＜0.01);在瘤胃液中,0.20g拉沙里菌素组GGT活性显著低于仅添加15g蛋氨酸组(P＜0.05),0.15g拉沙里菌素组GOT活性显著低于仅添加15g蛋氨酸组(P＜0.05),0.20g拉沙里菌素组GOT活性极显著低于仅添加15g蛋氨酸组(P＜0.01)。2小时,在血清中,0.15g拉沙里菌素组GGT活性极显著低于仅添加15g蛋氨酸组(P＜0.01);在瘤胃液中,0.20g拉沙里菌素组GGT、GOT和GPT活性极显著低于仅添加15g蛋氨酸组(P＜0.01),0.15g拉沙里菌素组的GOT、GPT活性显著低于仅添加15g蛋氨酸组(P＜0.05),0.15g拉沙里菌素组、0.20g拉沙里菌素组的RFFM水平较仅添加15g蛋氨酸组分别高出36.4%、36.6%。5小时,在血清中,0.15g拉沙里菌素组GGT活性显著低于仅添加15g蛋氨酸组(P＜0.05);在瘤胃液中,0.15g拉沙里菌素组和0.20g拉沙里菌素组的GPT活性均极显著低于仅添加15g蛋氨酸组(P＜0.01),仅添加15g蛋氨酸组的RFFM水平显著低于0.15g拉沙里菌素组(P＜0.05)和0.20g拉沙里菌素组(P＜0.05),而0.20g拉沙里菌素组的RFFM水平又比0.15g拉沙里菌素组高出10.6%。结果提示,拉沙里菌素对血清中的γ-谷氨酰转移酶和谷草转氨酶的活性以及瘤胃液中的γ-谷氨酰转移酶、谷草转氨酶和谷丙转氨酶的活性有抑制作用,拉沙里菌素可增加蛋氨酸的瘤胃稳定性,并且添加0.20g拉沙里菌素的作用效果优于添加0.15g。试验二:瘤胃稳定剂对肉牛生产性能的影响研究。挑选9头夏洛来小公牛(315kg±24.5kg)随机分成3组(即对照组、试验1组和试验2组),采用单因子随机区组设计研究瘤胃蛋氨酸稳定剂对肉牛生产性能的影响。每组3个重复,每个重复1头试牛。试验1组添加0.13%瘤胃稳定剂+0.15%蛋氨酸,试验2组添加0.13%瘤胃稳定剂+0.20%蛋氨酸,对照组添加0.15%蛋氨酸。其中预试期10天,正试期75天,正试期分为三个阶段,每个阶段25天。结果表明,在第三阶段,添加0.13%瘤胃稳定剂+0.15%蛋氨酸组和添加0.13%瘤胃稳定剂+0.20%蛋氨酸组的饲料转化率分别提高0.1%、4.3%,日增重分别提高5.6%、10.5%;添加0.13%瘤胃稳定剂+0.20%蛋氨酸组较添加0.13%瘤胃稳定剂+0.15%蛋氨酸组和仅添加0.15%蛋氨酸组饲料转化率分别提高9.3%和28.5%,日增重分别提高10.5%和40.0%:添加0.13%瘤胃稳定剂+0.15%蛋氨酸组较仅添加0.15%蛋氨酸组饲料转化率提高21.2%,日增重提高26.7%。结果提示,瘤胃稳定剂对促进肉牛的日增重和提高其饲料转化率有一定的效果,这种效果与其作用时间和日粮的蛋氨酸水平有关。更多还原

【Abstract】 Methionine is one of animal essential amino acids,and ruminant restriction amino acid.Except synthesizing protein,participating many transfer-methylic reactions and producing many containing methylic physiological active materials.About mono-stomach animal,to increase methionine amount in diet can satisfy its methionine requirement. However,due to ruminal microorganism degradation,to increase methionine amount in ruminant diet can’t satisfy its methionine requirement.And ionophore can inhibit microorganism deamination of protein in rumen,which decreases protein degradated in rumen.However,it hasn’t been reported whether ionophore can inhabit amino acids’ deamination or not.So objective of this thesis to study on inhibiting effect of ionophore on ruminal metabolism of methionine,to increase methionine by-pass amount and come true a new method of rumen protection.In Exp.1 effect of ionophore on methionine metabolism of runen.3 goats fitted with fistula in the rumen.Experiment included 4 periods.Every period which was a treatment was 6 days.The treatments in the experiment were based diet plus 0(Control group,CG),15g Met(Treatment 1,T1),15g Met and 0.15g lasalocid(Treatment 2,T2),15g Met and 0.20g lasalocid(Treatment 3,T3).Sampling time was at 0 hour(feeding before morning),2 hours(feeding after morning),and 5 hours(feeding after morning)in the last day of every period.The content of free methionine(FM)and related enzymatic active in samples treated were determined.In 0 hour GOT active in serum sample of T2 was significantly lower than that of T1(P＜0.01);GGT active in rumen fluid sample of T3 was significantly lower than that of T1(P＜0.05),GOT active in rumen fluid sample of T2 was significantly lower than that of T1(P＜0.05),and GOT active in rumen fluid sample of T1 was significantly higher than that of T3(P＜0.01).In 2 hours,GGT active in serum sample of T2 was significantly lower than that of T1(P＜0.01);GGT、GOT and GPT actives in rumen fluid sample of T3 was significantly lower than that of T1(P＜0.01),GOT and GPT actives in rumen fluid sample of T2 was significantly lower than that of T1(P＜0.05),the content of RFFM in rumen fluid sample of T2 and T3 was increased by 36.4%and 36.6% Compared T1.In 5 hours,GGT active in serum sample of T2 was lower than that of T1 (P＜0.05);GPT active in rumen fluid sample of T2 and T3 was lower than that of T1 (P＜0.01),the content of RFFM in rumen fluid sample of T2 and T3 was higher than that of T1(P＜0.05),the content of RFFM in rumen fluid sample of T3 was increased by 10.6% Compared T2.We concluded that lasalocid had invariably effective in inhibiting GGT and GOT actives in serum and rumen fluid and GPT active in rumen fluid,lasalocid can increase ruminal stability of methionine,and effective of T3 was better than that of T2.In Exp.2 effect of rumen stabilizing agent on beef cattle performance.This experiment adopting single factor random blocks design,9 Charolais steers (315kg±24.5kg)were randomly divided into three groups(control group,CG;test 1 group, T1;test 2 group,T2),three repeats in every group,one steer in every repeats.The test groups in the experiment were based diet plus 0.15%Met(Control group,CG),0.13% Rumen stabilizing agent(RSA)and 0.15%Met(Treatment 1,T1),0.13%RSA and 0.20% Met(Treatment 2,T2).Pretesting time was ten days;the experiment was divided into three phases,twenty-five of every phase.The results showed that Feed efficiency(FE)and daily gain(DG)of T1 and T2 in the third phase 0.1%,4.3%and 5.6%,10.5%,respectively. FE of T2 in the third phase was higher than that of T1 and CG for 9.3%and 28.5%, respectively.DG of T2 in the third phase was higher than that of T1 and CG for 10.5%and 40.0%,respectively.DG of T1 was higher than that of CG for 26.7%.FE of T1 was higher than that of CG for 21.2%.Thus,we concluded that RSA had invariably effective in promoting DG and FE of beef cattle,which had related with action time and the quantity of Met in diet.更多还原