妊娠早期饲粮添加不同水平N-氨甲酰谷氨酸改善母羊产羔性能的研究

旨在研究妊娠早期饲喂不同水平N-氨甲酰谷氨酸(N-carbamylglutamate,NCG)对母羊产羔性能及相关血液指标的影响.选用2～3胎次湖羊160只,随机分为4组,每组40只母羊,自配种当天(记为妊娠第0天)开始,分别饲喂基础饲粮(对照组)、基础饲粮+0.05％NCG、基础饲粮+0.08％NCG、基础饲粮+0....     

N-氨甲酰谷氨酸的研究进展

N-乙酰谷氨酸的类似物,N-氨甲酰谷氨酸(N-Carbamylglutamate,NCG)是L-谷氨酸上的氨基被氨基甲酰化后的产物,能激活动物体内氨甲酰磷酸合成酶-Ⅰ (Carbamyl Phosphate Synthetase 1,CPS-Ⅰ)和二氢吡咯-5-羧酸合成酶(pyrroline-5-carboxylate synthetase,P5CS),促进动物内源精氨酸的生成.精氨酸是一种重要的功能性氨基酸,在动物细胞信息传递和营养代谢中起重要作用,但其受价格高且与赖氨酸、色氨酸和组氨酸有拮抗作用而未能作为饲料添加剂在动物生产中大量推广使用.作为精氨酸内源合成激活剂,NCG化学合成方便,价格仅为精氨酸的10％,因此越来越受到人们的关注.文中主要介绍NCG在动物生产中作用机理、应用状况与展望.     

妊娠后期日粮中添加不同水平N-氨甲酰谷氨酸对母猪繁殖性能的影响

本试验研究了日粮中添加不同水平N-氨甲酰谷氨酸(N-carbamylglutamate,NCG)对妊娠后期母猪繁殖性能的影响,并对其作用机理进行初步探讨.选用妊娠80 d的长大母猪32头,随机分成4组(对照组和试验组1、2、3),每组8个重复.对照组饲喂基础日粮,试验组在基础日粮中分别添加0.04％、0.08％、0.12％ NCG.母猪妊娠第110天采血分离血浆用于测定血浆游离氨基酸、NO、NOS、激素含量和血液生化指标.结果表明,母猪妊娠后期日粮中添加0.08％NCG比空白对照组窝产活仔数提高11.75％(10.75 vs.9.62,0.05＜P＜0.1),窝产活仔总质量提高13.23％(16.52 kg vs.14.59 kg,P＜0.05),窝产死胎数降低57.14％(0.75 vs.1.75,P＜0.05),降低了血浆尿素氮含量(P＜0.05),同时提高了血浆精氨酸、NO、生长激素、锌离子浓度(P＜0.05).日粮中添加0.04％和0.12％ NCG也改善了母猪部分繁殖性能.上述结果表明,母猪妊娠后期日粮中添加NCG提高了母猪的繁殖性能,其作用机制可能是NCG有效提高了母猪内源精氨酸的合成,改善了母猪子宫内环境和胎猪营养供给,保证了胎猪的存活和生长.     

N-氨甲酰谷氨酸在养猪生产中的应用

N-氨甲酰谷氨酸(N-carbamylglutamate,NCG)是一种新型的猪用饲料添加剂,在饲料中按一定比例添加可显著提高猪的繁殖性能和生产性能。N-氨甲酰谷氨酸(NCG)主要通过促进精氨酸的内源合成,提高母猪窝产仔数和初生重,增强公猪的繁殖力,促进仔猪的生长和发育。作者将NCG在养猪生产中的应用进行了综述,以期为提高养猪生产效率提供参考依据。     

N-氨甲酰谷氨酸对奶牛超排效果及血液指标的影响

本研究旨在探讨饲喂N-氨甲酰谷氨酸（NCG）对奶牛超数排卵效果及血液生化指标的影响。选取荷斯坦育成牛16头,随机分为2组,每组8头,对照组饲喂基础饲粮,试验组在基础饲粮的基础上饲喂20 g/（d·头）的NCG,采用连续4 d递减注射FSH法测定NCG饲喂时间对供体牛超排效果的影响,分别在3次超排处理的第0、5、9天采集尾根静脉血测定激素指标及血清生化指标。结果表明,①NCG饲喂20 d时（第1次超排）,试验组头均回收胚数、可用胚数、退化胚数、未受精卵数与对照组相比差异均不显著（P>0.05）;NCG饲喂50 d时（第2次超排）,试验组头均回收胚数显著高于对照组（P<0.05）;NCG饲喂80 d时（第3次超排）,试验组头均可用胚数显著高于对照组（P<0.05）;综合考虑3次超排效果,试验组头均回收胚数显著高于对照组（P<0.05）。②NCG饲喂时间对供体牛血清中促卵泡素、促黄体素、孕酮、雌二醇的浓度均无显著影响（P>0.05）,说明NCG饲喂时间对奶牛生殖激素的分泌无影响或为次要影响因素,超排效果的变化与生殖激素变化无明显的关联作用。③NCG饲喂时间对供体牛血清中谷草转氨酶的浓度无显著影响（P>0.05）;在NCG饲喂13 d时,试验组供体牛血清中葡萄糖浓度显著高于对照组（P<0.05）;在NCG饲喂34 d时,试验组供体牛血清中尿素氮浓度显著低于对照组（P<0.05）;在NCG饲喂43和69 d时,试验组供体牛血清中一氧化氮浓度显著高于对照组（P<0.05）。综合考虑,在重复3次超排时,每头供体牛每天饲喂20 g NCG,可提高3次连续超排的回收胚数4.98枚及可用胚数1.8枚,进而降低胚胎的生产成本。     

N-氨甲酰谷氨酸缓解猪肠道氧化应激的研究进展

肠道是机体内外环境的交汇点,易受外界环境变化诱导产生活性氧自由基,严重时造成机体氧化还原系统失衡,从而诱发肠道氧化应激。N-氨甲酰谷氨酸(NCG)是N-乙酰谷氨酸(NAG)的结构类似物,可以促进肠道内源精氨酸的合成。近些年研究发现,NCG在缓解猪肠道氧化应激和维持肠道健康方面发挥重要作用。本文综述了NCG缓解猪肠道氧化应激的作用机制,也为NCG在缓解生猪氧化应激上的应用提供参考。     

日粮中添加N-氨甲酰谷氨酸(NCG)对断奶仔猪生长的影响

试验旨在探讨仔猪在断奶后2周内日粮中添加精氨酸内源合成激活剂:N-氨甲酰谷氨酸(NCG)对精氨酸内源合成、肠道形态以及生长性能的影响。试验选取23±3日龄健康断奶阉公猪(杜×长×大)180头,并按体重、窝别等随机分为3个处理,处理1:对照组,饲喂基础日粮;处理2:精氨酸组,基础日粮添加1%L-精氨酸,处理3:NCG组,基础日粮添加0.05%NCG;每个处理6个重复(圈),每圈10头。试验末每圈选取1头仔猪采血并屠宰取空肠中段,测定血浆精氨酸浓度、血浆生长激素浓度以及空肠形态。经过试验,得出以下结论,断奶仔猪日粮中添加N-氨甲酰谷氨酸(NCG)可以改善断奶仔猪的生长,并不是通过提高采食量来实现的,而是通过增加内源精氨酸合成,提高血浆生长激素水平,以及恢复小肠形态等方面作用,最终促进断奶仔猪生长。     

妊娠后期饲粮中添加N-氨甲酰谷氨酸对伊犁母马血浆参数及新生马驹体重、体尺指标的影响

本试验旨在研究妊娠后期饲粮中添加N-氨甲酰谷氨酸(NCG)对伊犁母马血液参数及新生马驹体重、体尺指标的影响。按照体重、年龄、预产期相近的原则选择30匹妊娠后期[(280±15) d]伊犁母马,随机分为2组,每组15匹,其中对照组饲喂基础饲粮,NCG组在基础饲粮中添加0.17%的NCG。饲喂期共计52 d,其中预试期7 d,正试期45 d,分别于试验的第0、21、45天采集母马血液样品,分离血浆用于血浆参数的测定。结果显示：与对照组相比,NCG组新生马驹的初生重、体高显著提高(P<0.05),胸围、管围极显著提高(P<0.01)。NCG组母马分娩后的妊娠率与对照组相比提高了19.99%(P>0.05)。与对照组相比,在试验第21天,NCG组母马血浆中总一氧化氮合成酶(TNOS)、内皮型一氧化氮合成酶(eNOS)、诱导型一氧化氮合成酶(iNOS)活性差异不显著(P>0.05),一氧化氮(NO)含量极显著提高(P<0.01);在试验第45天,NCG组母马血浆中TNOS、iNOS、eNOS活性极显著降低(P<0.01)。与对照组相比,在试验第0、21天,NC...     

母猪妊娠中后期饲粮中添加N-氨甲酰谷氨酸复配产品对其生产性能的影响

为验证妊娠后期母猪饲粮中添加N-氨甲酰谷氨酸（NCG）为主的复配产品对其繁殖性能的影响,2010年12月至2011年2月,选择45头长白或者大白母猪参与试验。按照胎次、品种和妊娠天数均衡的原则将这些母猪随机分配到2个不同饲粮处理中,对照组母猪22头,饲喂猪场的常规玉米-豆粕-小麦麸型基础饲粮;试验组母猪23头,在饲喂基础饲粮的基础上每头每天额外添加3 g NCG复配物,从妊娠中后期（怀孕第55~65天）开始饲喂,直至母猪分娩。参与试验的母猪饲养于发酵床饲养舍中,每栏饲养2～3头母猪。每天上午和下午各饲喂1次,对于NCG复配物组母猪,下午添加完基础饲粮后根据栏中母猪头数额外补加一定数量的NCG复配物,搅拌均匀任其采食。预产期前1周左右将母猪转移产房饲养。母猪分娩后24 h内对仔猪进行个体称重,记录活仔窝重、窝产仔数、窝产活仔数和弱仔数。以母猪个体为单位利用SAS的GLM程序对生产性能指标进行分析。试验结果表明,妊娠第55~65天开始在母猪饲粮中添加NCG复配物有效改善母猪的窝产性能,试验组母猪活仔初生窝重更高、窝产仔数和窝产活仔数更多,仔猪头均重更大,同时也发现NCG复配物组母猪的弱仔率和死胎率有所降低;除此之外,在发酵床饲养体系中使用NCG复配物可能还有改善母猪机体健康降低死淘率的作用。     

精氨酸及N-氨甲酰谷氨酸对断奶羔羊肠道免疫力的影响

研究旨在观察不同水平瘤胃保护性精氨酸及N-氨甲酰谷氨酸(NCG)对断奶羔羊肠道免疫能力的影响.选用15只体况良好,体重为25.00 kg±3.39 kg的5月龄半同胞鄂尔多斯断奶羯羔羊随机分为5组.分别为对照组(1组)、瘤胃保护性精氨酸Arg-1.5组(2组)、瘤胃保护性精氨酸Arg-2组(3组)、瘤胃保护性N-氨甲酰谷氨酸NCG-0.15组(4组)、瘤胃保护性N-氨甲酰谷氨酸NCG-0.20组(5组).在45 d试验期以后,每组分别选取一只试验羊,空腹12h后,用戊巴比妥钠麻醉后进行屠杀,迅速屠宰后,采取肠粘膜样品来检测小肠的白细胞介素-2(IL-2)、分泌型免疫球蛋白A(SIgA)、一氧化氮(NO)和一氧化氮酶(TNOS与iNOS)的含量.结果表明,各处理组的IL-2浓度和SIgA浓度与对照组相比差异均显著(P＜0.05);对于NO,TNOS和iNOS只有NCG-0.15组与对照组无显著性差异(P＞0.05),但含量比对照组较高.其他处理组与1组均差异显著(P＜0.05).综合得出NCG-0.20,Arg-2.0与Arg-1.5对肠道免疫力的影响较大,其中Arg-1.5影响最大(P＜0.05).结果提示,日粮添加瘤胃保护性精氨酸及N-氨甲酰谷氨酸对肠道免疫力有提高作用.     

Effect of progesterone supplementation on pregnancy and embryo survival in ewes

Two hundred eighteen ewes were used in experiments 1) to develop a progesterone supplementation regimen capable of sustaining serum concentrations of progesterone at about 2.0 ng/ml for a period of 50 d (Exp. 1) and 2) to determine the effects of progesterone supplementation (d 6 to 50 after mating) on pregnancy and embryo survival rates in mated ewes (Exp. 2). In ovariectomized ewes in Exp. 1, s.c. administration of four cylindrical (9.5 x 60 mm) silastic implants, containing 20% (1.1 g) progesterone by weight, sustained mean serum concentrations of progesterone of 1.9 +/- .07 ng/ml compared with 1.03 +/- .05 ng/ml in ewes bearing two implants. In Exp. 2 each ewe (n = 159) was mated to two fertile rams at a spontaneous estrus (d 0) during mid-breeding season. Mean ovulation rate, determined on a subgroup of 46 ewes, was 1.45 +/- .05. On d 6, ewes were assigned randomly to control (two implants containing no progesterone) or progesterone-treated (four implants similar to those used in Exp. 1) groups. From d 7 to 50 after mating, progesterone concentrations in serum were greater (P less than .001) in progesterone-treated (four implants similar to those used in Exp. 1) groups. From d 7 to 50 after mating, progesterone concentrations in serum were greater (P less than .001) in progesterone-treated (3.50 +/- .06) than in control (2.65 +/- .05) ewes. Pregnancy rates (86% and 83%) and calculated embryo survival rates (77% and 78%) were similar (P greater than .05) for the control and progesterone-treated groups, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)     

Dietary N-carbamylglutamate or L-arginine improves fetal intestinal amino acid profiles during intrauterine growth restriction in undernourished ewes

Our previous studies demonstrated that prenatal in utero growth restriction impairs postnatal intestinal function.Thus,improving postpartal intestinal absorption capacity and growth by manipulating the maternal diet prepartum is of importance.This work was conducted to determine whether supplementation of N-carbamylglutamate(NCG)or rumen-protected L-arginine(RP-Arg)increased fetal intestinal amino acid(AA)profiles in intrauterine growth retardation(IUGR)fetuses.On d 35 of gestation,Hu ewes(n=32)carrying twin fetuses were randomized into 4 groups(8 ewes and 16 fetuses in each group),where diets were as follows:100%of nutrient requirements recommended by National Research Council(NRC,2007)(CON);50%of nutrient requirements recommended by NRC(2007)(RES);RES+RPArg(20 g/d),(RES+ARG);and RES+NCG(5 g/d),(RES+NCG).On d 110 of gestation,both fetal and maternal tissues were collected and weighed.Compared with RES,solute carrier family 1,member 5(SLC1A5)was upregulated(P<0.05)within fetal jejunum,duodenum and ileum when supplementing NCG and RP-Arg.Relative to RES,RP-Arg or NCG supplementation to RES resulted in upregulation(P<0.05)of peptide transporter 1 protein abundance within the fetal ileum.NCG or RP-Arg supplementation to RES also upregulated phosphorylated mechanistic target of rapamycin(pmTOR)-to-mTOR ratio in the fetal ileum induced by IUGR(P<0.05).As a result,during IUGR,supplementation of Arg or NCG affected intestinal AA profiles in the fetus in part through controlling mTOR signal transduction as well as AA and peptide transport.Future studies should be conducted to understand the role(if any)of the placenta on the improvement of growth and AA profiles independent of the fetal intestine.This would help demonstrate the relative contribution of intestinal uptake in fetal life.     

Effect of feeding allowance level on embryonic survival, IGF-1, insulin, GH, leptin and progesterone secretion in early pregnancy gilts

The present experiment was conducted to evaluate the effects of feeding allowance level on embryonic survival, uterine development and reproductive hormone secretion in early gestation gilts. A total of 54 F1 crosses of Landrace x Large white gilts were randomly allocated to three treatment groups of high (H, 2 x maintenance), medium (M, 1.2 x maintenance) and low (L, 0.6 x maintenance) feeding level after mating. Blood samples and uterine flushings were collected on day 12, 25 and 35 of pregnancy, and embryonic survival rate was estimated. Concentrations of insulin-like growth factor I (IGF)-1, insulin, growth harmone (GH), leptin and progesterone in serum and uterine flushings were determined by enzyme-linked immunosorbent assay. Embryonic survival was affected by dietary treatment; total number of viable embryos and embryo survival of group M were higher than other groups in the early pregnancy (p < 0.05). Greater foetal weight in M gilts was achieved when gestation advanced to day 35 (p < 0.05), though there was no difference on day 25 of pregnancy among treatments. No appreciable differences were observed in the crown-rump length on day 25 and 35 of pregnancy among groups. Greater weight of uterus and products of conception were identified in M gilts compared with group H and L (p = 0.024 and p = 0.005, respectively) on day 25 of pregnancy. The hormone level was greatly affected by feeding allowance level. In serum, concentrations of IGF-1, leptin and insulin tended to be greater in H than in M and L during the early gestation, while concentrations of GH were greater in M and progesterone were the lowest in H. At the same time, feed allowance level affected the concentration of IGF-1, insulin, GH, leptin and progesterone in uterine flushings. These data demonstrated that feed allowance level after mating has important consequence on embryo survival, embryo development and uterine development, possibly mediated by nutrition level inducing changes in concentrations of reproductive hormones and/or intermediary metabolites in early pregnancy.     

配种前营养策略对母猪妊娠早期胚胎成活率的影响

提高母猪妊娠早期胚胎成活率可以增加产仔数，提高经济效益。配种前营养对妊娠早期胚胎成活率具有重要的影响．这种影响的途径与卵泡发育和卵母细胞质量密切相关。本文综述了配种前营养．包括营养水平、能量来源、蛋白质、纤维等对后备母猪和哺乳母猪妊娠早期胚胎成活率的影响。     

实时B型超声扫描在绵羊妊娠监测中的应用

随着超声诊断技术的不断发展，它在兽医领域的应用也越来越广泛。目前，B型超声主要用于对动物妊娠期子宫和胎儿的监测，关于牛、羊、猪、马、犬、等动物都有应用B型超声监测妊娠的大量报道。本文仅就B型超声在绵羊早期妊娠诊断、怀胎数的判断及判断胎龄三方面进行综述。     

妊娠母羊日粮中添加维生素E对羔羊成活率以及体况指标的影响

试验旨在研究妊娠母羊日粮中添加维生素E(VE)对羔羊成活率的影响.选择42只妊娠45d的成年经产小尾寒羊,随机分为2组,每组21只.对照组小尾寒羊饲喂基础日粮,试验组在基础日粮基础上补饲维生素预混料VE粉,对比两组母羊的产羔率和羔羊成活率.预试期1w,正式试验期4 w.结果表明,试验组母羊产羔23只,繁殖率为109.5...