日粮中添加NCG对妊娠前期鄂尔多斯细毛羊子宫内膜层及胎儿发育的影响

为了研究日粮中添加N-氨甲酰谷氨酸(NCG)对妊娠前期鄂尔多斯细毛羊子宫内膜层及胎儿发育的影响,试验选择受孕鄂尔多斯细毛羊母羊40只,随机分为3组:NCG1组饲喂基础日粮+0.30 g NCG/d(n=13),NCG2组饲喂基础日粮+0.40 g NCG/d(n=13),对照组饲喂基础日粮(n=14),开展妊娠期0 d至90 d的饲喂试验。结果表明:妊娠期第90 d,NCG1组胎儿肺脏重显著高于对照组,NCG2组胎儿肝脏重显著高于对照组(P0.05);妊娠期第17天,NCG1组母羊子宫内膜OPN基因表达量显著高于NCG2组(P0.05)和对照组(P0.01),NCG2组母羊子宫内膜Integrinαvβ3基因表达量显著高于对照组(P0.05);妊娠期第90 d,NCG2组和NCG1组胎儿肾脂肪BMP7(P0.05)和UCP-1基因表达量显著高于对照组(P0.01),而NCG1组(P0.01)胎儿肾脂肪PGC-1α基因表达量显著低于对照组,NCG2组(P0.01)胎儿肾脂肪PRDM16基因表达量显著低于对照组。在本试验条件下,妊娠前期日粮中添加NCG有效促进了鄂尔多斯细毛羊妊娠识别、早期胚胎定植和子宫内膜层发育,保障了胎儿早期程序化健康生长。     

精氨酸对妊娠后期鄂尔多斯细毛羊胎儿生长发育的影响研究

旨在通过对鄂尔多斯细毛羊母羊颈静脉灌注L-精氨酸,研究其对鄂尔多斯细毛羊母羊妊娠后期（90-140d）胎儿生长与发育的影响。试验选择22只母羊,在90 d开始灌注115μmol L-Arg-HCl/kg体重（Arg1组）、155μmol L-Arg-HCl/kg体重（Arg2组）和生理盐水（对照组）,3次/d。妊娠第115天和第140天,进行实验母羊孕体检查,并记录胎儿体重、器官重量和体尺长度,收集母体及胎儿血浆测定血浆氨基酸浓度。结果表明,母羊妊娠第140天,Arg2组较Arg1组和对照组显著增加了胎儿心脏和肝脏重量（P〈0.05）。母羊妊娠第115天和第140天,灌注L-精氨酸显著增加母体血浆精氨酸和鸟氨酸浓度（P≤0.01）,增加胎儿血浆生糖氨基酸（苏氨酸、甲硫氨酸、苯丙氨酸和赖氨酸）浓度（P≤0.05）。     

瘤胃保护性精氨酸及N-氨甲酰谷氨酸对细毛羊肠道黏膜蛋白质合成率的影响

本试验旨在探讨不同水平瘤胃保护性精氨酸(Arg)及N-氨甲酰谷氨酸(NCG)对细毛羊肠黏膜蛋白质合成率的影响。选用15只体况良好,平均体重为(25.00±3.39)kg的5月龄半同胞羯鄂尔多斯细毛羊断奶羔羊随机分成5组,分别为基础饲粮组(1组,对照组)、基础饲粮+0.15 g/d NCG组(2组)、基础饲粮+0.20 g/d NCG组(3组)、基础饲粮+1.50 g/d Arg组(4组)、基础饲粮+2.00 g/d Arg组(5组)。进行45 d饲喂以后,试验羊空腹12 h后一次性大剂量灌注L-苯丙氨酸,90 min后采集十二指肠和空肠黏膜,检测小肠黏膜蛋白质合成率。结果表明:试验组的十二指肠与空肠黏膜的蛋白质合成率显著高于对照组(P<0.05)。在各试验组中,3组、4组、5组同1组相比提高幅度较大,其中4组显著高于其他试验组(P<0.05),而3组和5组间差异不显著(P>0.05)。结果提示,添加不同水平的瘤胃保护性Arg及NCG对肠道黏膜蛋白质合成率具有提高作用,分别以1.50 g/d Arg和0.20 g/d NCG 2个剂量较好。     

节律性日粮对鄂尔多斯细毛羊泌乳性能和血液指标的影响

研究节律性日粮对鄂尔多斯细毛羊母羊泌乳中后期泌乳量、乳成分和血液指标及羔羊生长发育的影响。选择体况良好,平均体重为(39.34±2.58)kg的泌乳中后期鄂尔多斯细毛羊母羊30只,随机分为3组,每组10只,分别为对照组、高-低蛋白组和低-高蛋白组,进行为期60 d的节律性蛋白日粮饲喂试验。结果表明,泌乳期60 d高-低蛋白组试验母羊和90日龄高-低蛋白组羔羊的平均体重显著高于对照组(P0.05),整个试验期高-低蛋白组试验母羊和羔羊的平均日增重均显著高于对照组(P0.05);泌乳期45 d高-低蛋白组试验母羊乳脂肪含量显著高于对照组(P0.05),泌乳期60 d高-低蛋白组试验母羊的平均泌乳量和乳蛋白含量显著高于对照组(P0.05);泌乳期60 d和90 d高-低蛋白组试验母羊血液中葡萄糖浓度显著高于低-高蛋白组和对照组(P0.05)、总蛋白的浓度显著高于对照组(P0.05),泌乳期60 d高-低蛋白组试验母羊血液中胰高血糖素浓度显著高于低-高蛋白组和对照组(P0.05)。在本试验条件下,节律性饲喂不同蛋白浓度日粮不仅可以有效提高细毛羊泌乳中后期母羊体重、日增重、泌乳量、乳脂肪和乳蛋白的含量,而且促进羔羊的快速生长和发育,泌乳中后期鄂尔多斯细毛羊更适合高-低蛋白节律性饲喂方式。     

妊娠早期饲粮中添加N-氨甲酰谷氨酸对母羊早期胚胎存活及相关血液指标的影响

本试验旨在研究妊娠早期饲粮中添加N-氨甲酰谷氨酸（NCG）对母羊胚胎存活及相关血液指标的影响,并对其作用机制进行初步探讨。选择发情正常、健康状况良好的湖羊50只,随机分为2组（对照组和NCG试验组）,每组25只母羊,自配种当天开始给母羊分别饲喂基础饲粮（对照组）和基础饲粮+0.11%NCG（NCG组）,饲喂期38 d。测定妊娠第19和38天母羊血浆游离氨基酸、总一氧化氮合酶（TNOS）、内皮型一氧化氮合酶（eNOS）、诱导型一氧化氮合酶（iNOS）、一氧化氮（NO）、雌二醇、孕酮的浓度;38 d时每组各屠宰7只妊娠母羊,测定妊娠母羊的黄体数和活胎儿数等指标。结果显示,与对照组相比,妊娠第38天时,NCG组每只母羊总胎儿数增加了79.72%（P<0.05）,活胎儿数增加了79.72%（P<0.05）,胎儿形成指数增加了0.26（P<0.05）,胎水体积增加了72.89%（P<0.05）,活胎儿总重提高了71.13% （P<0.05）;NCG组妊娠第19天的甘氨酸、蛋氨酸、赖氨酸、精氨酸、NO、iNOS、eNOS和孕酮的浓度显著高于对照组（P<0.05）,NCG组妊娠第19天的瓜氨酸和脯氨酸极显著高于对照组（P<0.01）;NCG组妊娠第38天的精氨酸、脯氨酸和NO显著高于对照组（P<0.05）,NCG组妊娠第38天的iNOS和eNOS的浓度极显著高于对照组（P<0.01）。由此,妊娠早期饲粮中添加NCG提高了胚胎和胎儿的存活,增加了妊娠母羊第38天的总胎儿数和活胎儿数,改善了母羊的繁殖性能,其作用机制可能是NCG促进了母羊内源性精氨酸的合成,提高了母羊血浆精氨酸、NO和孕酮含量,改善了子宫内环境和营养供给,使之有利于胚胎着床和妊娠维持。     

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+0.11% NCG，40 d后均饲喂基础饲粮。测定母羊产羔性能和妊娠第0、20、40天母羊血浆中游离氨基酸、总一氧化氮合酶（TNOS）、诱导型一氧化氮合酶（iNOS）、一氧化氮（NO）、生长激素、雌二醇、孕酮、尿素和氨浓度。结果显示，0.08%和0.11% NCG组产羔性能显著提高，两组的窝产羔数和窝产活羔数较对照组显著增加（P<0.05），但活羔初生个体重显著降低（P<0.05）；各NCG组妊娠第40天NO浓度显著升高（P<0.05），0.11% NCG组妊娠第40天iNOS浓度和妊娠第20天孕酮浓度较对照组显著升高（P<0.05）；0.08%和0.11% NCG组妊娠第20天氨浓度显著低于对照组和0.05% NCG组（P<0.05），0.11% NCG组妊娠第40天氨浓度显著低于对照组（P<0.05）。综上，妊娠早期母羊饲粮添加NCG可提高母羊体循环iNOS、NO和孕酮浓度，改善胎盘营养与妊娠维持状态；降低血浆氨浓度，提高胎儿发育环境安全性，改善母羊产羔性能，提高母羊窝产羔数和窝产活羔数。     

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+0.11%NCG,40 d后均饲喂基础饲粮。测定母羊产羔性能和妊娠第0、20、40天母羊血浆中游离氨基酸、总一氧化氮合酶(TNOS)、诱导型一氧化氮合酶(iNOS)、一氧化氮(NO)、生长激素、雌二醇、孕酮、尿素和氨浓度。结果显示,0.08%和0.11%NCG组产羔性能显著提高,两组的窝产羔数和窝产活羔数较对照组显著增加(P0.05),但活羔初生个体重显著降低(P0.05);各NCG组妊娠第40天NO浓度显著升高(P0.05),0.11%NCG组妊娠第40天iNOS浓度和妊娠第20天孕酮浓度较对照组显著升高(P0.05);0.08%和0.11%NCG组妊娠第20天氨浓度显著低于对照组和0.05%NCG组(P0.05),0.11%NCG组妊娠第40天氨浓度显著低于对照组(P0.05)。综上,妊娠早期母羊饲粮添加NCG可提高母羊体循环iNOS、NO和孕酮浓度,改善胎盘营养与妊娠维持状态;降低血浆氨浓度,提高胎儿发育环境安全性,改善母羊产羔性能,提高母羊窝产羔数和窝产活羔数。     

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...     

泌乳期日粮添加N-氨甲酰谷氨酸对经产母猪和哺乳仔猪的影响

本试验旨在研究泌乳期日粮添加N-氨甲酰谷氨酸(NCG)对经产母猪泌乳性能、血浆部分氨基酸和免疫指标及仔猪生长性能的影响。试验选取28头健康二元杂交母猪(3~4胎),随机分为2组,每组14头,每头母猪为1个重复。从产前12 d开始分别饲喂基础日粮(对照组)和0.08%NCG日粮(NCG组)至产后第22天(仔猪断奶)。统计哺乳仔猪的生长指标,并采集母猪分娩后第10天静脉血液样品以测定血浆部分氨基酸浓度和血液生化指标。结果表明:与对照组相比,NCG组哺乳期仔猪日增重、断奶个体重和断奶窝重分别提高40 g、0.93 kg和11.14 kg(P0.05),断奶窝仔数差异不显著(P0.05),母猪的泌乳量显著增加(P0.05);NCG组母猪产后第10天血浆精氨酸和脯氨酸浓度均显著提高(P0.05),鸟氨酸、赖氨酸、组氨酸浓度和血氨浓度差异不显著(P0.05),血浆尿素氮浓度显著减低(P0.05);NCG组母猪血清Ig M、Ig G水平和白蛋白浓度显著升高(P0.05),总蛋白浓度差异不显著(P0.05)。结果提示,日粮添加NCG可提高泌乳母猪的泌乳性能及血浆精氨酸和脯氨酸水平,降低母猪血浆尿素氮的浓度,改善母猪的免疫机能,并提高哺乳仔猪的生长性能。     

N-氨甲酰谷氨酸和精氨酸对京海黄鸡肉仔鸡生长性能和血液指标的影响

本试验旨在探讨N-氨甲酰谷氨酸(N-carbamylglutamate,NCG)和精氨酸(Arg)对京海黄鸡肉仔鸡生长性能、血清生化参数及游离氨基酸含量的影响。选用1日龄体重相近的京海黄鸡肉仔鸡600只,随机分为5组,每组6个重复,每个重复20只。对照组饲喂基础日粮,试验Ⅰ、Ⅱ、Ⅲ、Ⅳ组饲喂在基础日粮中分别添加0.05%、0.10%、0.15% NCG及0.10% Arg的试验日粮。试验期28 d。结果表明,与对照组相比,添加0.05%、0.10%、0.15% NCG及0.10% Arg组平均日增重(ADG)升高,添加0.10% NCG组料重比(F/G)显著降低(P<0.05);添加0.10% NCG组血清中血氨(AMM)、尿酸(UA)和低密度脂蛋白(LDL)含量相对于其他各组显著降低(P<0.05),添加0.15% NCG组血清中一氧化氮(NO)、一氧化氮合成酶(NOS)和碱性磷酸酶(ALP)含量显著高于对照组(P<0.05);与对照组相比,添加0.10%、0.15% NCG组和添加0.10% Arg组血清中Arg含量显著升高(P<0.05)。综上所述,日粮中添加NCG有助于提高京海黄鸡肉仔鸡血清中Arg和脯氨酸(Pro)的含量,改善血液指标,提高肉仔鸡的生长性能,其中NCG添加水平为0.10%时效果较好。     

鸡胚发育过程中胚胎液中几种游离氨基酸的动态变化

本实验旨在研究鸡胚发育过程中尿囊液和羊水中天冬氨酸、谷氨酸、精氨酸和亮氨酸浓度的动态变化。选用72枚6胚龄的三黄鸡鸡胚,按重量相近原则分为6组,每组12个重复,分别在孵化第7、8、11、13、14、18天采集尿囊液和羊水,并利用高效液相色谱法分析其氨基酸浓度。结果表明:尿囊液中,除8胚龄外,其他各胚龄精氨酸浓度均高于另外3种氨基酸(P<0.05),13胚龄精氨酸浓度显著低于其他胚龄(P<0.05),而18胚龄显则著高于其他胚龄(P<0.05)。羊水中,各胚龄精氨酸浓度均高于其他3种氨基酸;除11胚龄外,13胚龄精氨酸浓度显著高于其他胚龄(P<0.05);7胚龄天门冬氨酸浓度显著高于13、14、18胚龄(P<0.05);但18胚龄谷氨酸及亮氨酸浓度则显著升高(P<0.05)。以上结果说明,在尿囊液及羊水中,所测4种氨基酸浓度变化不尽相同,但总体精氨酸含量最丰富,这可能与鸡胚发育的营养与代谢有关。     

乌蒙半细毛羊“锌缺乏症”的研究

试验旨在研究乌蒙半细毛羊"锌缺乏症"的病因。在赫章县兴发养殖场选取20只锌（Zn）缺乏的乌蒙半细毛羊作为试验组,在威宁县凉水沟种羊场选取20只健康的乌蒙半细毛羊作为对照组。采用电感耦合等离子体原子发射光谱法分析土壤、牧草和动物血液及肝脏中微量元素的含量,应用全自动血细胞分析仪测定血液参数,应用全自动生化分析仪测定血清生理生化指标。结果发现,试验牧场土壤及牧草中锌含量均极显著低于对照牧场（P<0.01）;试验组乌蒙半细毛羊血液和肝脏中Zn含量极显著低于对照组（P<0.01）,两组间其他元素含量均无显著差异（P>0.05）;试验组乌蒙半细毛羊血液中红细胞数（RBC）、淋巴细胞（LY）和中性粒细胞（NE）均极显著低于对照组（P<0.01）;血清中超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH-Px）和过氧化氢酶（CAT）、乳酸脱氢酶（LDH）、碱性磷酸酶（AKP）活性均极显著低于对照组（P<0.01）,丙二醛（MDA）含量极显著高于对照组（P<0.01）,而两组间血红蛋白（Hb）、红细胞压积（PCV）、白细胞数（WBC）、血清尿素氮（BUN）含量和谷草转氨酶（AST）、谷丙转氨酶（ALT）、谷氨酰转肽酶（γ-GT）活性均无显著差异（P>0.05）。综上所述,乌蒙半细毛羊"锌缺乏症"主要由土壤和牧草锌含量过低引起,且在日粮中添加适量的硫酸锌可以防治乌蒙半细毛羊"锌缺乏症"的发生。     

Biochemical Profile of Amniotic and Allantoic Fluid During Different Gestational Phases in Mares

Fetal fluids have different vital functions that sustain both pregnancy and normal parturition. The biochemical composition of amniotic fluid during gestation is not well established; thus the purpose of the present study was to determine the biochemical profile of both amniotic and allantoic fluids from mares during initial, mid, and latter third phases of pregnancy. Samples were collected after slaughter, using allantocentesis and amniocentesis. Sixty samples of fetal fluids were analyzed. Alkaline phosphatase (AP), glucose, total protein (TP), urea, creatinine, Ca, chloride (Cl), Na, and K concentrations were measured using commercially available kits. The AP concentration in amniotic fluid was higher than that in allantoic fluid during the three gestational phases (P < .05). There were no differences between glucose mean values of allantoic and those of amniotic fluids (P < .05). However, glucose values were higher in the allantoic fluid in the last trimester of pregnancy. TP was higher in the amniotic fluid than in allantoic fluid (P < .05). Urea values varied among the phases; however, there were no differences between the amniotic and allantoic fluid values (P > .05). Creatinine values were higher in allantoic fluid (P < .05). Na and Cl concentrations were higher in amniotic fluid (P < .05). However, Ca and K concentrations were higher in the allantoic fluid.     

Effects of Different Types of N-carbamylglutamate on the Growth Performance,Serum Biochemical Indexes and Fat Distribution of Tan Sheep

The objective of the present experiment was to determine the effect of different types of N-carbamoylglutamate on growth performance,serum biochemical indexes and fat distribution of Tan sheep. Sixty male Tan lambs with average weight of (20.14±0.31)kg and similar age were randomly assigned three groups with five replications per group and 4 lambs per replication. The lambs in control group were fed basal diet, while lambs in test groups were fed diets containing 0.1% NCG and 0.1% RP-NCG,respectively. The results showed that:① Comparing with control group,the ADG was significantly improved (P<0.05) and F/G was significantly decreased (P<0.05) when 0.1% NCG or 0.1% RP-NCG were supplemented,while there was no significant difference between two experimental groups (P>0.05).② Dietary supplemented with 0.1% NCG or 0.1% RP-NCG significantly decreased the serum urea nitrogen (P<0.05),but there were no significant differences in serum total protein,creatinine content and creatine kinase activity (P>0.05).③ The ration of meat weight to carcass weight of two experimental groups was significantly improved (P<0.05).As 0.1% NCG or 0.1% RP-NCG were supplemented in the diets, the content of subcutaneous fat and GR value were significantly decreased (P<0.05),and the content of intramuscular fat (IMF) was significantly increased (P<0.05).In conclusion,dietary supplemented with 0.1% NCG or 0.1% RP-NCG could improve the growth performance and slaughter performance while there was no significant difference between NCG and RP-NCG.     

Metabolomic Profile of Allantoic and Amniotic Fluid in Late-term Gestational Mares Characterized by 1H-nuclear Magnetic Resonance Spectroscopy

The amniotic and allantoic fluid compartments in the mare serve essential roles throughout pregnancy and parturition. Although the global metabolomic profile of amniotic fluid in women has been extensively characterized, current data for equine fetal fluids are limited. Therefore, the goal of this study was to characterize the global metabolomic profile of equine allantoic and amniotic fluid through nuclear magnetic resonance spectroscopy. Fetal fluids were collected between 270 and 295 days of gestation from 12 pregnancies through ultrasound-guided transabdominal puncture. A total of 24 samples (n = 10 allantoic fluid; n = 9 amniotic fluid; n = 5 admixed fluid) were analyzed by one-dimensional proton (¹H) and two-dimensional (¹H-¹³ C) nuclear magnetic resonance spectroscopy. Metabolites were integrated and compared between fluid types using a Kruskal–Wallis test at P < .05 significance. A total of 28 distinct metabolites were found in allantoic and admixed fluid, whereas 23 metabolites were identified in amniotic fluid. Allantoic fluid contained significant elevations (P < .05) in the metabolites betaine, creatine, creatinine, citrate, histidine, nitrophenol, tryptophan, π-methylhistidine, and unknown metabolite #1 compared with amniotic fluid, whereas amniotic fluid contained statistically increased concentrations of the metabolite lactate compared with allantoic fluid (P = .003).     

Effects of Dietary N-Carbamylglutamate and Arginine on Growth Performance and Blood Parameters of Jinghai Yellow Broiler Chicks

This study was conducted to investigate the effects of N-carbamylglutamate (NCG) and arginine (Arg) on growth performance, serum biochemical indexes and serum free amino acid content of Jinghai Yellow broiler chicks.A total of 600 1-day-old chicks with similar weight were used and randomly assigned into 5 groups with 6 replicates per group and 20 chicks per replicate.The control group was fed with basal diet, groups Ⅰ to Ⅳ were fed with the basal diets supplemented with 0.05%, 0.10%, 0.15% NCG and 0.10% Arg, respectively.The trial lasted for 28 days.The results showed that compared with control group, the supplementation of 0.05%, 0.10%, 0.15% NCG and 0.10% Arg increased ADG, the supplementation of 0.10% NCG significantly decreased F/G (P<0.05).The supplementation of 0.10% NCG significantly decreased the contents of AMM, UA and LDL in serum compared with other groups (P<0.05), the supplementation of 0.15% NCG significantly increased the contents of NO, NOS and ALP in serum compared with control group (P<0.05).Compared with control group, the supplementation of 0.10%, 0.15% NCG and 0.10% Arg significantly increased the content of Arg in serum (P<0.05).These results indicated that supplementation with NCG could increase the contents of Arg and Pro in serum, improve blood parameters and growth performance of broiler chicks, and the appropriate supplemental level of NGG was 0.10%.     

Anatomy, physiology and pathology of the amniotic and allantoic compartments in the sheep and cow

In both cows and sheep the allantoic fluid is confined to 2 sacs connected by a flattened isthmus, one in the non-pregnant horn and one in the upper part of the pregnant horn. The chorion encloses the amniotic and allantoic compartments, forming the amniochorion and chorioallantois, respectively. In the last third of gestation the compositions of both amniotic and allantoic fluids differ substantially from each other and from those of foetal urine, and maternal and foetal plasma. There is less variation in composition than in volume for a given gestational age. Abnormalities of volume are more common in cows than sheep, and hydrallantois is more common than hydramnois. Data obtained from both physiological experiments and pathological cases suggest that the foetal membranes play an important role in the regulation of composition and volume of foetal fluids. Evidence is presented that the permeability of the membranes to various solutes, as well as their capacity to produce and respond to a number of hormones, can affect the foetal fluid composition and/or volume. Progesterone, oestrogens and prolactin are some of the hormones known to affect foetal fluids. Foetal adrenal insufficiency has been associated with hydramnios implying a lack of hormones from this gland in this disease. The changes in allantoic fluid composition from normal to that closely resembling maternal/foetal extracellular fluid, in hydrallantois, suggests an alteration of membrane function as an aetiology and the continued production of fluid, after removal of the foetus in some cases, favours this hypothesis.     

Urea cycle metabolism: effects of supplemental ornithine or citrulline on performance, tissue amino acid concentrations and enzymatic activity in young pigs fed arginine-deficient diets

Two experiments were conducted with young pigs to determine the efficacy of ornithine (Orn) or citrulline (Cit) as precursors of arginine (Arg). In Exp. 1, pigs were individually fed an Arg-deficient, semipurified diet (.18% Arg) supplemented with .3% Arg or an equimolar quantity of Orn or Cit. Supplemental Arg or Cit increased rate and efficiency of weight gain, but Orn addition was without effect. Free Arg in plasma 3 h post-prandial was increased by addition of either Arg or Cit to the basal diet. Liver Arg was elevated by dietary addition of Arg, Orn or Cit; kidney Arg and Orn were elevated only in pigs receiving supplemental Cit. Arginine or Cit addition to the diet increased Arg concentration in muscle tissue, but muscle Orn was unresponsive to any of the supplements fed. In Exp. 2, pigs were again fed the Arg-deficient, semipurified diet supplemented with .3% Arg or four times an isomolar quantity of ornithine. Arginine addition to the diet increased weight gain and feed efficiency, while Orn supplementation was without effect. Plasma Orn was increased by excess Orn, while plasma Cit was unaffected by supplemental Arg or Orn. Moreover, excess Orn increased free Orn and proline (Pro) in liver, kidney and muscle. Free Cit, however, increased only in liver from feeding excess Orn. In addition, excess Orn decreased both plasma ammonia and free glutamine (Gln) concentration in brain. Arginase activity was roughly 10, 40 and 100 times greater in hepatic tissue than in renal cortex, renal medulla or intestinal mucosa, respectively, while hepatic ornithine transcarbamoylase (OTC) activity was about 15 times greater than the activity present in mucosa tissue. Renal OTC activity was too low to be accurately measured.