玉米S-腺苷甲硫氨酸合成酶基因家族成员在盐胁迫条件下的差异表达   总被引：3，自引：1，他引：2  

朱晶莹  王寒玉  张晏萌  余爱丽 《核农学报》2011,25(3):427-431,493

S-腺苷甲硫氨酸合成酶(SAMS)是植物代谢过程中的一个关键酶,催化甲基供体和化合物前体S-腺苷甲硫氨酸的合成.为研究S-腺苷甲硫氨酸合成酶基因在盐胁迫条件下的响应和功能,以玉米甘油醛-3-磷酸脱氢酶(GAPDH)基因为内参基因,通过半定量RT-PCR法分析玉米SAMS基因在盐胁迫条件下的表达模式.结果表明,玉米SAM...  相似文献   

Effect of coated and non-coated fatty acid supplementation on broiler chickens experimentally infected with Campylobacter jejuni     

Molatová Z  Skřivanová E  Baré J  Houf K  Bruggeman G  Marounek M 《Journal of animal physiology and animal nutrition》2011,95(6):701-706

The aim of this study was to examine whether and to what extent the supplementation of feed with a coated or non-coated mixture of fatty acids (caprylic and capric acid) affects broiler chickens experimentally infected with Campylobacter jejuni. The study was carried out using 48 chickens divided into four experimental groups. Throughout the whole rearing period (1-42 days), the chickens were fed a diet supplemented with 0.25% caprylic and capric acid (1:1), coated or non-coated. At the age of 14 and 28 days, chickens were orally challenged with C. jejuni. At regular time intervals post-inoculation, the shedding of C. jejuni was assayed using quantitative real-time PCR. Both supplements significantly decreased faecal C. jejuni counts by 1.2-4.1 log(10) CFU/g 4 days post-inoculation; after this time period, the effect of medium-chain fatty acids (MCFA) was less pronounced or absent. Campylobacter jejuni counts in excreta samples were significantly lower in chickens fed coated MCFA than in those fed non-coated MCFA. No effect of MCFA on feed intake or growth of chickens was observed. In conclusion, (i) MCFA are active against C. jejuni and (ii) the encapsulation enhanced the efficacy of the acids. These results allow the recommendation of using MCFA as feed additives in chickens, preferably 2-3 days before slaughter.  相似文献   

基质与控释肥配比对大丽花穴盘苗的影响   总被引：1，自引：0，他引：1  

魏元秀  李丽  马丽  陈宝成  张民 《北方园艺》2011,(20):162-165

以大丽花及花卉专用包膜控释肥为试材,研究了包膜控释肥以及基质与肥料配比对大丽花穴盘苗生长发育的影响.结果表明:采用合适的包膜控释肥施用量和适宜的基质与肥料配比对大丽花穴盘苗生长具有显著的促进作用.采用珍珠岩与蛭石按体积比1∶1配成的基质,当基质与控释期为4个月的包膜控释肥的配比(重量比)为3∶1(处理M3F1)时,大丽花出苗成活率最高,苗期的叶绿素含量、叶面积也显著高于其它处理.从施肥后基质浸出液在苗期pH、电导率以及速效磷和速效钾含量的变化来看,处理M3F1均处于花卉苗生长的较适宜范围.  相似文献   

蛋氨酸对动物生长发育及毛发生长调控作用的研究进展     

王文楠  孙亚波  刘海英  朱延旭  杨桂芹  王耀民 《中国饲料》2019,(5):4-7

蛋氨酸(Met)是动物生长必需氨基酸中唯一含硫氨基酸,其可参与机体内众多代谢途径,为动物提供甲基,合成动物生长所需要的蛋白质和生物活性物质,是动物生长和毛发生长的第一限制性氨基酸。日粮中必须添加适量的蛋氨酸才能满足动物生长需要,对毛皮动物,蛋氨酸还会影响毛发的生长和品质,所以蛋氨酸又被称为"生命性氨基酸"。本文综述了蛋氨酸在动物生长发育及毛发生长中的调控作用,以期为蛋氨酸在畜牧生产中的科学应用提供参考。  相似文献   

过瘤胃蛋氨酸与过瘤胃赖氨酸不同组合对奶牛瘤胃微生物蛋白产量、产奶性能和氮排泄的影响     

丁大伟  高许雷  滕乐帮  吕永艳  孙国强 《动物营养学报》2019,31(6):2716-2726

本试验旨在研究过瘤胃蛋氨酸(RPMet)与过瘤胃赖氨酸(RPLys)不同组合对奶牛微生物蛋白产量、产奶性能和氮排泄的影响。选取年龄、体重、胎次、产奶量、乳成分及泌乳期相近的荷斯坦奶牛40头,随机分为10个组,每组4头。对照组饲喂基础饲粮,试验组添加不同水平的RPMet和RPLys。RPMet设置3个梯度,添加水平分别为22.5(L)、25.0(M)、27.5g/(d·头)(H);RPLys设置3个梯度,添加水平分别为27.5(L)、30.0(M)、32.5g/(d·头)(H),共组成9个不同组合,分别为LL、ML、HL、LM、MM、HM、LH、MH、HH组(第1个字母为RPMet添加水平,第2个字母为RPLys添加水平)。预试期15d,正试期60d。结果表明:1)在瘤胃微生物蛋白产量方面,各试验组与对照组相比均有所提高,其中MM、HM组极显著高于对照组(P<0.01)。2)在产奶量方面,各试验组均极显著高于对照组(P<0.01),其中以MM组最高,提高幅度达18.61%。3)在乳成分方面,各试验组乳脂率与对照组相比均有所提高,LM、HM、MM组极显著高于对照组(P<0.01);各试验组乳蛋白率与对照组相比均有所提高,MM、HL、LM、ML、HH、HM、LH组极显著高于对照组(P<0.01);各试验组乳体细胞数与对照组相比均有所降低,MH、MM、HL、LH、LM组极显著低于对照组(P<0.01)。4)在氮总排泄量方面,各试验组均极显著低于对照组(P<0.01),其中以MM组最低,降低幅度达11.00%。MM组粪氮、尿氮极显著低于对照组(P<0.01),MM、MH、HL组氮表观消化率、氮沉积极显著高于对照组(P<0.01)。综合各项试验指标,以25.0g/(d·头)RPMet+30.0g/(d·头)RPLys为最佳组合。  相似文献   

Gene expression differences in the methionine remethylation and transsulphuration pathways under methionine restriction and recovery with D,L‐methionine or D,L‐HMTBA in meat‐type chickens          下载免费PDF全文

S. E. Aggrey  F. González‐Cerón  R. Rekaya  Y. Mercier 《Journal of animal physiology and animal nutrition》2018,102(1):e468-e475

This study examined the molecular mechanisms of methionine pathways in meat‐type chickens where birds were provided with a diet deficient in methionine from 3 to 5 weeks of age. The birds on the deficient diet were then provided with a diet supplemented with either D,L‐methionine or D,L‐HMTBA from 5 to 7 weeks. The diet of the control birds was supplemented with L‐methionine from hatch till 7 weeks of age. We studied the mRNA expression of methionine adenosyltransferase 1, alpha, methionine adenosyltransferase 1, beta, 5‐methyltetrahydrofolate‐homocysteine methyltransferase, 5‐methyltetrahydrofolate‐homocysteine methyltransferase reductase, betaine‐homocysteine S‐methyltransferase, glycine N‐methyltransferase, S‐adenosyl‐L‐homocysteine hydrolase and cystathionine beta synthase genes in the liver, duodenum, Pectoralis (P.) major and the gastrocnemius muscle at 5 and 7 weeks. Feeding a diet deficient in dietary methionine affected body composition. Birds that were fed a methionine‐deficient diet expressed genes that indicated that remethylation occurred via the one‐carbon pathway in the liver and duodenum; however, in the P. major and the gastrocnemius muscles, gene expression levels suggested that homocysteine received methyl from both folate and betaine for remethylation. Birds who were switched from a methionine deficiency diet to one supplemented with either D,L‐methionine or D,L‐HMTBA showed a downregulation of all the genes studied in the liver. However, depending on the tissue or methionine form, either folate or betaine was elicited for remethylation. Thus, mRNA expressions show that genes in the remethylation and transsulphuration pathways were regulated according to tissue need, and there were some differences in the methionine form.  相似文献   

Estimation of the standardized ileal digestible lysine requirement and optimal sulphur amino acids to lysine ratio for 30–50 kg pigs     

Trung Thong Ho  John Khun Kyaw Htoo  Thi Binh An Dao  Maria Eloisa Carpena  Nu Anh Thu Le  Chi Cuong Vu  Quang Linh Nguyen 《Journal of animal physiology and animal nutrition》2019,103(1):258-268

Two experiments were conducted to determine the standardized ileal digestible (SID) lysine (Lys) requirement and the ideal SID sulphur amino acids (SAA) to Lys ratio for 30–50 kg crossbred pigs. In experiment 1, a total of 72 crossbred pigs with an average initial body weight (BW) of 28.9 kg were allotted to one of six dietary treatments in a randomized complete block design. Each diet was assigned to six pens containing two pigs each. Six diets were obtained by supplementing graded levels of L‐Lysine?HCl to create six dietary levels of SID Lys (0.70%, 0.80%, 0.90%, 1.00%, 1.10% and 1.20%). Responses of weight gain (ADG) and gain:feed (G:F) to increasing the SID Lys content of the diet fitted well with the curvilinear‐plateau model; whereas, for plasma urea nitrogen (PUN) two‐slope linear broken‐line model was well fitted. The optimal SID Lys requirement for the pigs of this period was 1.10%. Experiment 2 was a dose–response study using SID Met+Cys to Lys ratios of 50%, 55%, 60%, 65%, 70% and 64%. A total of 72 crossbred pigs with initial BW of 32.9 kg were randomly allotted to receive one of the six diets. Diets 1–5 were formulated to contain 1.0% SID Lys to be second limiting in Lys and diet 6 contained 1.11% SID Lys to be adequate in Lys. The average optimal SID SAA:Lys ratio for maximal ADG and G:F and minimal PUN was 65.2% using curvilinear‐plateau and linear broken‐line models.  相似文献   

Effects of L‐methionine on performance,gut morphology and antioxidant status in gut and liver of piglets in relation to DL‐methionine     

Johanna O. Zeitz  Susanne Kaltenbck  Erika Most  Klaus Eder 《Journal of animal physiology and animal nutrition》2019,103(1):242-250

This study investigated the hypothesis that dietary supplementation of L‐methionine (L‐Met) in weaned piglets in relation to DL‐methionine (DL‐Met) results in a higher antioxidant status and lower need for antioxidant enzyme activation in intestinal epithelium and body tissues, and improves gut morphology and gut barrier function as well as performance. A total of 99 early‐weaned 21‐day old piglets were allotted to six groups and fed a semi‐synthetic wheat–barley‐based basal diet supplemented with 0.067%, 0.107% and 0.147% of either DL‐Met (MetAmino; Evonik, Hanau, Germany) or L‐Met (L‐Met100; CJ Europe, Schwalbach am Taunus, Germany) to reach dietary Met concentrations of 0.16%, 0.20% and 0.24%, of which the latter met the requirements for maintenance and growth based on a pre‐experiment. Feed intake and body weights were recorded weekly, and samples of plasma, liver and duodenum and jejunum mucosa were collected after 3 weeks at slaughter. Plasma concentrations of L‐Met were similar, and those of D‐Met and total Met were higher in piglets fed DL‐Met in relation to those fed L‐Met. Feed intake, daily gains and feed:gain ratio, and the relative bio‐efficacy based on gains and feed:gain ratio were similar for both groups. Likewise, villi length, crypt depth, the villi length:crypt depth ratio in duodenum and jejunum and gene expression of tight junction proteins in the jejunum did not differ. Concentrations of antioxidants like glutathione and tocopherol, the total antioxidant capacity, the mRNA abundance or activity of antioxidant enzymes like superoxide dismutase and glutathione peroxidase, concentrations of thiobarbituric acid reactive substances, markers for oxidative damage of lipids and the expression of inflammatory genes were similar in liver and jejunum mucosa. These data indicate that the effects of L‐Met and DL‐Met supplementation are comparable considering both piglet performance and parameters of gut health and function like gut morphology and the intestinal antioxidant status.  相似文献   

Effects of dietary amino acid supplementation on measures of whole‐body and muscle protein metabolism in aged horses     

Christine M. Latham  Ashley L. Wagner  Kristine L. Urschel 《Journal of animal physiology and animal nutrition》2019,103(1):283-294

The objective of this study was to examine markers of whole‐body and muscle protein metabolism in aged horses fed a diet typical for North American aged horses, supplemented with amino acids. In a replicated Latin square design, six aged horses (20 ± 1.1 years) were studied while receiving each of three isocaloric, isonitrogenous diets, a control treatment concentrate (CON; 100 mg/kg^?1 BW day^?1 lysine, 84 mg kg^?1 day^?1 threonine, 51 mg kg^?1 day^?1 methionine), LYS/THR (134 mg kg^?1 BW day^?1 lysine, 110 mg kg^?1 BW day^?1 threonine, 52 mg kg^?1 BW day^?1 methionine) and LYS/THR/MET (132 mg kg^?1 BW day^?1 lysine, 112 mg kg^?1 BW day^?1 threonine, 62 mg kg^?1 BW day^?1 methionine). In each 15‐days period, urine and faeces were collected for assessment of nitrogen balance. Blood samples were collected before and after feeding for analysis of plasma urea nitrogen (PUN), glucose, insulin and plasma amino acid concentrations. Skeletal muscle samples were collected for measurement of proteins associated with muscle protein synthesis and degradation, and horses underwent stable isotope infusion procedures for comparison of differences in whole‐body rates of protein synthesis and degradation. There was no effect of treatment on relative abundance of proteins involved in protein synthesis, nitrogen retention or phenylalanine kinetics. PUN concentrations tended to be higher for LYS/THR (p = 0.054) and were higher for LYS/THR/MET (p = 0.0056) than for CON. Atrogin‐1 abundance tended to be higher in the post‐absorptive state for the CON treatment (p = 0.07), indicating that amino acid supplementation resulted in less muscle protein degradation when horses were in the post‐absorptive state. However, lack of differences in nitrogen retention and phenylalanine kinetics indicated that whole‐body protein metabolism was not improved, and higher PUN concentrations in the supplemented diets suggest that the supplemented amino acids may have been catabolized. Amino acid availability was not limiting protein synthesis in the sedentary aged horses in this study when fed the CON diet.  相似文献   

Inclusion of High Methionine Corn in Pullet Diets     

《The Journal of Applied Poultry Research》2008,17(4):440-445

Synthetic methionine (SM) is routinely added to conventional pullet diets to allow for the formulation of balanced diets. Synthetic methionine, however, is not allowed in organic poultry diets. When SM is not used, diets must be formulated to higher CP levels to achieve the required level of methionine. This study compared inclusion of a commonly used organic corn in pullet starter, grower, and developer diets with a new non-genetically modified high methionine (HM) corn. There were no significant differences in BW gain. The average BW for the pullets on the control and HM corn diets was 1,349 and 1,386 g, respectively. Feed was controlled for most of the study; there were no significant differences in feed consumption or feed efficiency. The results of this study, therefore, indicate that this new HM corn variety is a suitable substitute for organically grown conventional corn varieties in organic pullet diets. The inclusion of HM corn eliminates the need for SM in pullet starter, grower, and developer diets fed to floor-reared Bovan Brown pullets.  相似文献