Quantitative expression and immunohistochemical detection of glucose transporters, GLUT1 and GLUT3 in the rabbit placenta during successful pregnancy

Glucose is essential for the development of the fetus. We address here the quantitative expression and immunohistochemical localization of glucose transporter (GLUT1 and GLUT3) in the rabbit placenta during successful pregnancy. Blood glucose level showed a significant decrease at the gestation period in comparison with non-pregnancy. Maternal serum glucose was gradually increased according to fetal development. Quantitative RT-PCR results showed that expression of GLUT1 was significantly increased from day 13 to day 18, while GLUT3 mRNA level was significantly decreased during the same periods. Western blot analysis demonstrated that GLUT1 protein did not change significantly in the placenta during pregnancy when compared to non-pregnant uteri. Immunohistochemistry indicated that distribution of GLUT1 was observed mainly to the surface of the outer trophoblasts, whereas GLUT3 mainly localized to the basal site of the inner trophoblasts and fetal blood vessels. These results suggest that glucose is transported through GLUT1 from the maternal blood stream for use as a placental fuel and for further transport through GLUT3 to the fetal circulation, thus signifying the distinct anatomical localization of GLUT1 and GLUT3 in the rabbit placenta during successful pregnancy.     

Expression and localization of NO synthase isoenzymes (iNOS and eNOS) in development of the rabbit placenta

Nitric oxide synthase (NOS) is a key regulator of angiogenesis and embryogenesis in the mammalian reproductive process. Here, we attempted to clarify the expression and localization of inducible and endothelial NOS (iNOS and eNOS) in the developing rabbit placenta. Real-time RT-PCR analysis indicated that iNOS mRNA was significantly upregulated till the complete development of the placenta (d18), and then significantly decreased at the end of fetal growth stage (d28) during successful pregnancy. The eNOS mRNA was also enhanced in the pregnant uteri and gradually decreased near the term of pregnancy. Western blot analysis also showed elevation of the iNOS and eNOS protein levels during the course of successful pregnancy till the functional maturation of the placenta (d18). Immunohistochemical study revealed distinct localizations of iNOS along the radial arteries and eNOS at the spiral arteries and arterial sinuses in the developing placenta. This may reflect that iNOS and eNOS participate in pregnancy success through placentation-specific vascular formation and by supporting adequate blood circulation in the rabbit placenta.     

山羊妊娠早期胎儿胎盘血管形成及相关基因的表达

旨在探究大足黑山羊妊娠早期胎儿胎盘血管发育、分布和血管生成相关因子表达状况,并对血管生成相关因子表达之间和血管发育进行相关性分析。本研究随机选取15只8月龄、体格相近、身体健康的国家级畜禽遗传资源—大足黑山羊青年母羊,经同一种公羊自然交配后(以末次配种当天记为0 d),经剖腹产手术采集妊娠第20、25和30天的胎儿和胎儿胎盘以及经屠宰采集妊娠第45和60天的胎儿和胎儿胎盘作为研究对象,通过免疫组化法评估胎盘血管发育和分布情况,采用qRT-PCR技术检测主要血管生成相关基因的mRNA表达水平,分析血管生成相关基因之间以及与胎盘血管发育分布的相关性。结果显示,胎儿体重和体长随着妊娠的进行逐渐增加,且血管内皮细胞阳性率处于较高水平(>26%)。山羊胎儿胎盘毛细血管总面积/组织区域面积(CAD)逐渐升高;毛细血管总数/单位组织区域面积(CND)在妊娠25~30 d增加,30~60 d降低,毛细血管总面积/毛细血管根数(APC)呈相反趋势;毛细血管总周长/单位组织区域面积(CSD)无显著变化。妊娠早期胎儿胎盘VEGFA的表达量随着妊娠的进行逐渐升高,且与血管分布存在一定的相关性,其受体FLT1和KDR表达量呈先增高后降低的趋势,分别在30和45 d达到峰值。血管生成相关基因ANGPT1/2及其受体TEK和FGF2及其受体FGFR2的表达均在妊娠30 d时较高。综上表明,在妊娠30 d前,胎儿胎盘主要通过毛细血管形成分支促进血管面积的增加;而在30~60 d,主要通过单位血管的增粗促进血管面积的增加,并且血管生成相关基因的表达在妊娠30 d时较高,这可能和子叶开始形成有关。山羊妊娠早期胎儿胎盘中VEGFA可能通过其受体结合与其他血管生成因子共同作用调控胎儿胎盘血管形成。     

Advanced maternal age induces fetal growth restriction through decreased placental inflammatory cytokine expression and immune cell accumulation in mice

Advanced maternal age is a risk factor for female infertility, and placental dysfunction is considered one of the causes of pregnancy complications. We investigated the effects of advanced maternal aging on pregnancy outcomes and placental senescence. Female pregnant mice were separated into three groups: young (3 months old), middle (8–9 months old), and aged (11–13 months old). Although the body weights of young and middle dams gradually increased during pregnancy, the body weight of aged dams only increased slightly. The placental weight and resorption rate were significantly higher, and live fetal weights were reduced in a maternal age-dependent manner. Although mRNA expression of senescence regulatory factors (p16 and p21) increased in the spleen of aged dams, mRNA expression of p16 did not change and that of p21 was reduced in the placenta of aged dams. Using a cytokine array of proteins extracted from placental tissues, the expression of various types of senescence-associated secretory phenotype (SASP) factors was decreased in aged dams compared with young and middle dams. The aged maternal placenta showed reduced immune cell accumulation compared with the young placenta. Our present results suggest that models using pregnant mice older than 8 months are more suitable for verifying older human pregnancies. These findings suggest that general cellular senescence programs may not be included in the placenta and that placental functions, including SASP production and immune cell accumulation, gradually decrease in a maternal age-dependent manner, resulting in a higher rate of pregnancy complications.     

Streptozotocin-induced diabetes increases apoptosis through JNK phosphorylation and Bax activation in rat testes

Diabetic disease is known to suppress male reproductive activity in laboratory animals and humans. The present study was designed to evaluate whether streptozotocin-induced diabetes increases apoptotic cell death in rat testes through activation of the JNK and Bax pathway. Diabetes was induced by a single intravenous injection of streptozotocin (40 mg/kg) and testis samples were collected after 3 months. Compared with controls, body weight and testicular weight were lower in the diabetic group, and the apoptotic index in testicular germ cells was significantly increased. Expression of phospho-JNK and Bax was significantly increased in the diabetic group, and the level of activated caspase-3 was also increased, compared to that of controls. Our findings suggest that streptozotocin-induced diabetes increases apoptotic cell death in rat testes through phosphorylation of JNK and activation of Bax.     

Alteration of the gene and protein levels of insulin-like growth factors in streptozotocin-induced diabetic male rats

Insulin-like growth factor (IGFs: IGF-I and IGF-II) systems have been reported to be associated with the onset of diabetic mellitus. Therefore, we investigated the effect of diabetes on regulation of the IGF system in the liver, kidneys and heart, which are important organs in the pathogenesis of diabetes. The experimental groups were subdivided into three groups: 1) controls, 2) streptozotocin (STZ)-induced untreated diabetic group, and 3) an insulin-treated group (plus diabetic rats). In the present study, starting on the second day after STZ treatment, the diabetic group exhibited hyperglycemia, polyuria, and polydipsia, which are characteristic of diabetes melittus. Serum levels of IGF-I were decreased, but those of IGF-II were increased in the diabetic group compared with the controls. The expression levels of IGF-I and IGF-II protein in the livers of the diabetic group had a similar pattern to the serum. In addition, the expression levels of liver IGF-I mRNA and IGF-II mRNA were decreased in the diabetic groups. In the heart, IGF-I levels were decreased, but IGF-II levels were increased in the untreated diabetic groups, which was consistent with the expression levels of their mRNA. However, both the IGF-I and IGF-II levels in the kidneys were increased in the untreated diabetic groups, but the mRNA levels were decreased. Insulin treatment ameliorated the changes of IGF system in the serum, liver, kidneys, and heart. In conclusion, diabetes induced alteration of the IGF system tissue-specifically, and this was blocked by insulin treatment.     

Comparison of the metabolic and antioxidant effects of diltiazem and vitamin E on streptozotocin-diabetic rats

In this study, solitary and combined effects of vitamin E and the calcium-channel blocker diltiazem were investigated in streptozotocin (STZ)-induced diabetic rats. Thirty male Wistar albino rats, weighing approximately 200 g were used. Diabetes mellitus was induced by a single intravenous injection of STZ at a dose of 65 mg/kg body weight. Five experimental groups were established as STZ-diabetic, STZ-diabetic + vitamin E, STZ-diabetic + diltiazem and STZ-diabetic + vitamin E + diltiazem. Vitamin E was injected intraperitoneally three times a week at a dose of 500 mg/kg body weight. Diltiazem was given orally every day at a dose of 25 mg/kg body weight. At the end of the study (10 weeks) blood glucose levels of diabetic rats, which had received vitamin E and diltiazem, had significantly decreased when compared with untreated diabetic rats (P < 0.02). Similarly, HbA1c levels had significantly decreased in diabetic rats which had received vitamin E (P < 0.05), diltiazem (P < 0.01) and vitamin E + diltiazem (P < 0.02) when compared with untreated diabetic rats. Liver glutathione levels of diabetic rats, which had received vitamin E (P < 0.01) and vitamin E + diltiazem (P < 0.05) had significantly increased when compared with untreated diabetic rats. Liver lipid peroxide levels had significantly decreased in diabetic rats, which had received vitamin E (P < 0.001) and diltiazem (P < 0.01). With respect to their metabolic and antioxidant effects, vitamin E proved superior to diltiazem.     

Expression and possible role of 20alpha-hydroxysteroid dehydrogenase in the placenta of the goat

20Alpha-hydroxysteroid dehydrogenase (20alpha-HSD) catalyzes the conversion of progesterone to its inactive form 20alpha-dihydroprogesterone (20alpha-OHP). 20Alpha-HSD is expressed in the murine placenta, suggesting a role, yet unidentified, played by this enzyme during the course of pregnancy. To elucidate the possible roles of 20alpha-HSD during pregnancy, 20alpha-HSD gene expression in the placenta was examined by Northern blot analysis, and progestin (progesterone and 20alpha-OHP) concentrations in the maternal and fetal sera and the amniotic fluid were measured by radioimmunoassay in pregnant Shiba goats. The expression of 20alpha-HSD mRNA was observed in the placenta and the intercaruncular part of the uterus during mid to late pregnancy. Analysis by in situ hybridization revealed that 20alpha-HSD mRNA was mainly localized in the endometrial epithelium of the caruncle side of the placenta. Considerable enzyme activity of 20alpha-HSD was also detected in the cytosolic fraction of the placenta and intercaruncular part of the uterus. Although concentrations of progesterone and 20alpha-OHP in the maternal serum showed similar profiles, progesterone levels in the fetal serum stayed extremely low throughout the pregnancy. The 20alpha-OHP concentration in the fetal serum was always higher than that in the maternal serum. In the amniotic fluid, the concentrations of both progesterone and 20alpha-OHP remained at very low levels throughout the pregnancy. These results support the notion that 20alpha-HSD protects the fetus from the cytotoxic effects of progesterone, and thereby maintains the normal development of the fetus.     

Expression of inhibins, activins, insulin-like growth factor-I and steroidogenic enzymes in the equine placenta

In this study, the expression patterns of inhibins, activins, insulin-like growth factor-I (IGF-I) and steroidogenic enzymes in equine placentae recovered during the latter two-thirds of gestation were examined. Concentrations of inhibin A and inhibin pro-alphaC in endometrial and fetal placental tissue homogenates were very low during the period examined, whereas these tissues contained high concentrations of activin A. In both maternal endometrial and fetal placental tissues, activin A levels decreased as pregnancy progressed. Expression of inhibin alpha-subunit was not observed in the placenta using either immunohistochemistry or in situ hybridization. Inhibin/activin betaA-subunit and its mRNA were confined to maternal endometrial glands, whereas immunopositive betaB-subunit was not detected in either endometrial glands or microcotyledons. Cytochrome P450 side chain cleavage enzyme was detected by immunohistochemistry in both endometrial glands and microcotyledons, whereas cytochrome P450 17alpha-hydroxylase/lyase was absent in these tissues. Immunopositive signals for 3beta-hydroxysteroid dehydrogenase and cytochrome P450 aromatase were localized in microcotyledons but not in endometrial glands. Immunohistochemistry revealed that IGF-I was highly expressed in microcotyledons around Day 130, and decreased as pregnancy progressed. Changes in the expression of IGF-I were correlated with the number of PCNA positive cells in the placenta. The present study demonstrated the presence and localized the site of expression of activin, IGF-I and steroidogenic enzymes in equine placental tissues during the latter two-thirds of gestation; the results suggest that activin and IGF-I may be involved in the regulation of placental development.     

Ascorbic acid concentration in plasma, in amniotic and allantoic fluids, in the placenta and in 13 tissues of sheep fetuses and newborn lambs]

At each 8 on an average 92 (body weight 615 +/- 49 g) and 120 days (b.w. 1.8 +/- 0.40 kg) old fetuses as well as at 6 newborn lambs (b.w. 2.8 +/- 0.65 kg) the concentration of ascorbic acid in the plasma, in the amniotic- and allantois-fluid, in the fetal and maternal part of the placenta and in 13 tissues was analyzed. The highest concentration in the plasma (73 +/- 11 micrograms/ml) was determined in the newborns. The concentration in the amniotic-fluid decreased and that in the allantoic-fluid, the adrenals and the fetal part of the placenta increased in the course of growth. In the cerebrum, the cerebellum, the brain stem, the lungs, the heart, the kidneys, the M. longissimus and the M. semimembranosus the concentration diminished during the fetal growth. In the liver, the spleen and the pancreas the concentration was similar. The function of the ascorbic acid during the fetal development is discussed. The results are compared with those at human, pig and calf fetuses. In analyzing the ascorbic concentration in fetal body fluids of ungulates the high concentration of fructose as an influence-factor in the usual applied methods has to be considered.     

饲粮添加脯氨酸对妊娠环江香猪体成分的影响

本试验旨在研究饲粮添加脯氨酸对妊娠环江香猪体成分的影响。选取32头妊娠15 d的环江香猪,随机分为2组,每组8个重复,每个重复2头猪。2组试验猪分别饲喂在基础饲粮中添加0.77%L-丙氨酸(等氮对照组)和1.00%L-脯氨酸(脯氨酸组)的饲粮。分别于妊娠第45和70天时,每个重复选择1头母猪屠宰,测定其体成分。结果表明:与等氮对照组相比,妊娠第45天时脯氨酸组环江香猪的脂肪率显著降低(P0.05),皮肤率呈增加趋势(0.05≤P0.10);妊娠第70天时脯氨酸组的脂肪率显著增加(P0.05),皮肤率呈降低趋势(0.05≤P0.10),背最长肌中脯氨酸的含量显著增加(P0.05),精氨酸和丙氨酸的含量呈增加趋势(0.05≤P0.10)。与妊娠第45天时相比,妊娠第70天时脯氨酸组的脂肪率显著增加(P0.05),瘦肉率与皮肤率显著降低(P0.05)。由此可见,饲粮添加脯氨酸可增加妊娠环江香猪机体脂肪和精氨酸的沉积量,妊娠中期的机体脂肪沉积量比妊娠前期有所增加,从而有利于胎儿的生长发育。     

妊娠后期限饲蒙古绵羊对其胎盘生长发育及胎盘块类型的影响

本试验旨在研究妊娠后期限饲蒙古绵羊对其胎盘生长发育及胎盘块类型分布的影响。选择健康蒙古绵羊42只(经同期发情且受孕),于妊娠90 d选择6只母羊进行屠宰,其余按体重随机分配到3个组:0.175 MJ/(kgW0.75.d)(RG1:n=14)、0.33 MJ/(kgW0.75.d)(RG2:n=12)和自由采食组0.67 MJ/(kgW0.75.d)(CG:n=10),进行不同能量水平饲养至妊娠140 d,再选择6只母羊进行屠宰。结果表明:妊娠后期限饲母羊严重影响了RG1组(P<0.01)、RG2组(P<0.05)的胎盘重及胎儿重(P<0.01);RG1组A类型胎盘块重量(P<0.01)、数量(P<0.01)与RG2组A类型胎盘块数量(P<0.05)显著低于CG组;RG1组B类型胎盘块重量(P<0.05)、数量(P<0.01)与RG2组B类型胎盘块数量(P<0.05)显著高于CG组;随着母体营养水平的降低,C、D类型胎盘块出现的几率增加,且C、D类型胎盘块血管数量显著高于A、B类型胎盘块血管数量(P<0.05)。这说明妊娠后期限饲蒙古绵羊影响了胎盘的生长发育,使得胎盘块数量、重量、类型和血管数量等发生了明显改变。     

Effects of isulin-like growth factor-I on maternal and fetal plasma amino acid levels in pregnant rats

Pregnant rats were subcutaneously administered with recombinant human insulin-like growth factor-I (rhIGF-I) in doses of 0 (control), 1, 2, and 4 microg/g body weight per day from day 18 to 21 of pregnancy. On day 21 of pregnancy, maternal and fetal plasma samples were collected and those amino acid levels were measured. The ratios of fetal/maternal plasma amino acids, especially leucine, isoleucine, tryptophan, phenylalanine and tyrosine, increased in 2 microg rhIGF-I treated group. Both total fetal weight and total placental weight were also higher than those in the control group. These results suggested that IGF-I enhanced fetal growth by, as one of its possible mechanisms, promoting placental amino acid supplies from the mother to fetuses.     

精氨酸和维拉帕米对缓解胎鼠宫内发育迟缓的影响

本研究在日粮中添加精氨酸(L-Arg)和钙阻滞剂维拉帕米,旨在探讨L-Arg通过钙信号对小鼠宫内发育迟缓(IUGR)的影响。将160只雌性小白鼠随机分为4组,对照组饲喂基础日粮,L-Arg组、钙阻滞剂组、L-Arg+维拉帕米组分别在基础日粮中添加0.5%L-Arg、8 mg/kg维拉帕米、0.5%L-Arg+8 mg/kg维拉帕米。在妊娠第10、12、14、16天颈部放血处死母鼠,剖腹取胎鼠、子宫和胎盘等样品,测定相关指标,取14 d母鼠子宫固定于Carnoy’s和多聚甲醛中,分别用作肥大细胞(MC)、HE和免疫组化染色。结果表明:Arg组胎鼠数量、胎鼠体重等IUGR指标显著高于对照组(P0.05),维拉帕米组显著或极显著低于Arg组(P0.05或P0.01);L-Arg组子宫MC数显著低于对照组(P0.05),极显著低于维拉帕米组(P0.01);Arg组子宫巨噬细胞数较对照组显著增多(P0.05),维拉帕米组较对照组显著减少(P0.05),Arg组与维拉帕米组差异极显著(P0.01);L-Arg组子宫微血管(MVD)数较对照组显著增多(P0.05),较维拉帕米组显著减少(P0.05)。综上,L-Arg通过调控MC释放介质来提高母鼠的繁殖能力,维拉帕米能阻止Arg该作用,表明L-Arg通过钙信号发挥生物学作用,是其缓解IUGR的机理之一。     

Time-dependent changes of calbindin D-28K and parvalbumin immunoreactivity in the hippocampus of rats with streptozotocin-induced type 1 diabetes

The hippocampus is affected by various stimuli that include hyperglycemia, depression, and ischemia. Calcium-binding proteins (CaBPs) have protective roles in the response to such stimuli. However, little is known about the expression of CaBPs under diabetic conditions. This study was conducted to examine alterations in the physiological parameters with type 1 diabetes induced with streptozotocin (STZ) as well as time-dependent changes in the expression of two CaBPs changes of were being evaluated. Rats treated with STZ (70 mg/kg) had high blood glucose levels (>21.4 mmol/L) along with increased food intake and water consumption volumes compared to the sham controls. In contrast, body weight of the animals treated with STZ was significantly reduced compared to the sham group. CB-specific immunoreactivity was generally increased in the hippocampal CA1 region and granule cell layer of the dentate gyrus (DG) 2 weeks after STZ treatment, but decreased thereafter in these regions. In contrast, the number of PV-immunoreactive neurons and fibers was unchanged in the hippocampus and DG 2 weeks after STZ treatment. However, this number subsequently decreased over time. These results suggest that CB and PV expression is lowest 3 weeks after STZ administration, and these deficits lead to disturbances in calcium homeostasis.     

日粮中添加NCG对妊娠前期鄂尔多斯细毛羊血液、尿囊液和羊水中氨基酸浓度的影响

为了研究日粮中添加NCG(N-氨甲酰谷氨酸)对妊娠前期鄂尔多斯细毛羊血液、尿囊液和羊水中氨基酸浓度的影响,试验选择年龄、胎次和体况相近、平均体重为50.62±0.52 kg的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 N...     

Hypoglycemic Effect of Soluble Epoxide Hydrolase Inhibitors on Diabetic Mice

In order to study the hypoglycemic effect of soluble epoxide hydrolase inhibitors (sEHI) on diabetic mice,the diabetic mice model were successfully induced by high-fat diet and streptozotocin (STZ). The diabetic mice (C57BL/6J) were randomly divided into three groups,including normal control group,diabetic control group and sEHI group,the mice in three groups were fed high-fat diet+1 mg/kg sEHI (t-AUCB),high-fat diet+same volume normal saline,normal diet+same volume normal saline,respectively,and intervention last for 4 weeks. During the experiment,the body weight,blood glucose were recorded,and performed oral glucose tolerance test was conducted. After the experiment,indicators of serum lipids,liver peroxidation and pathological analysis of pancreatic tissue were measured. The results showed that compared with diabetic control group,the fasting blood glucose of mice in sEHI group was significantly reduced (P<0.05),and their glucose tolerance was improved. And the TC (P<0.05),TG (P<0.05) and LDL (P>0.05) in sEHI group were decreased,while the LDL/TC was significantly increased (P<0.05).The SOD and CAT activity in liver of diabetic mice treated with sEHI were significantly increased (P<0.05) and MDA activity was significantly decreased (P<0.05).Based on mouse pancreatic tissue sections,we speculated that sEHI had ability to repair activity on damaged islet tissue. In conclusion,the sEHI could reduce the blood glucose level and the free radical damage,inhibit lipid peroxidation,repair of damaged islet tissue in mice.     

可溶性环氧化物水解酶抑制剂的降血糖功效研究

为探究可溶性环氧化物水解酶抑制剂（soluble epoxide hydrolase inhibitors,sEHI）的降血糖功效,试验以高脂饲料与链脲佐菌素（streptozotocin,STZ）联合诱导的Ⅱ型糖尿病小鼠为研究对象,将C57BL/6J小鼠随机分为：正常对照组、糖尿病模型组和sEHI组,sEHI组饲喂高脂饲料,每日灌胃sEHI （t-AUCB）1 mg/kg,连续灌胃4周;糖尿病模型组饲喂高脂饲料,每日灌胃同等计量的生理盐水;正常对照组饲喂普通饲料,每日灌胃同等体积的生理盐水。期间各组小鼠均自由采食及饮水,记录小鼠体重、血糖并进行口服葡萄糖耐量试验。试验结束后,测定血清血脂指标、肝脏过氧化指标并对小鼠胰岛组织进行病理学分析。结果显示,与糖尿病模型组相比,采用sEHI干预后糖尿病小鼠的空腹血糖显著降低（P<0.05）,而葡萄糖耐量水平升高;小鼠血清总胆固醇（TC）、甘油三酯（TG）、低密度脂蛋白（LDL）水平明显降低,其中TC、TG水平与糖尿病模型组相比差异显著（P<0.05）,而高密度脂蛋白与胆固醇比值（HDL/TC）水平则显著升高（P<0.05）;与糖尿病模型组相比,sEHI干预组小鼠肝脏的超氧化物歧化酶（SOD）、过氧化氢酶（CAT）活性显著提高（P<0.05）,丙二醛（MDA）活性显著降低（P<0.05）;小鼠的胰岛组织切片分析结果表明,sEHI对小鼠胰岛组织有明显的修复作用。综上所述,sEHI具有降血糖、减轻自由基损伤、抑制脂质过氧化、修复受损胰岛组织的作用。     

饲粮中添加发酵苜蓿对母猪繁殖性能和母猪、仔猪抗氧化能力的影响

本试验旨在研究饲粮中添加发酵苜蓿对母猪繁殖性能和母猪、仔猪抗氧化能力的影响。选用80头体况和预产期接近的“长×大”妊娠初产母猪,随机分为4组(对照组、试验Ⅰ组、试验Ⅱ组和试验Ⅲ组),分别饲喂添加0、5%、10%和15%发酵苜蓿的饲粮,每组5个重复,每个重复4头。试验从母猪妊娠开始到哺乳期结束。结果表明：1)与对照组相比,试验Ⅱ组的成活率、健仔数和健仔率显著升高(P<0.05),死胎数、弱仔数和产程显著降低(P<0.05);各试验组的宫内发育迟缓(IUGR)发生率显著降低(P<0.05)。2)与对照组相比,试验Ⅰ组母猪哺乳期平均日采食量显著升高(P<0.05),试验Ⅱ组有升高趋势(P=0.064);试验Ⅱ组、试验Ⅲ组妊娠30 d、妊娠60 d和产前背膘厚显著降低(P<0.05)。3)与对照组相比,试验Ⅱ组、试验Ⅲ组的初生窝重、第7天窝重及个体重、第14天窝重及个体重和断奶个体重显著升高(P<0.05);试验Ⅱ组的断奶窝重、窝平均日增重和初生个体重显著升高(P<0.05)。4)与对照组相比,试验Ⅱ组的初生窝重均匀度显著提高(P<0.05);试...     

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....