精氨酸对胎鼠宫内生长迟缓的影响

通过探讨日粮添加精氨酸（Arg）对胎鼠宫内生长迟缓的影响,为Arg应用在动物生产上提供理论基础。试验将120只雌性小白鼠随机分为6组：0．0％Arg组、0．25％Arg组（基础日粮添加0．25％Arg,下同）、0．5％Arg组、0．75％Arg组、1．0％Arg组、1．5％Arg组,试验期间各组自由采食和饮水。每组随机抽取10只孕鼠进行眼球摘除采血,颈椎脱臼处死孕鼠,剖腹取胎鼠、胎盘和子宫,分别称重,记录胎鼠数、胎儿宫内发育迟缓（IUGR）数、死胎数（含吸收胎数）、胎鼠重、子宫重和相应的胎盘重。结果：（1）所添加的Arg浓度对孕鼠无毒性作用;（2）与对照组相比,日粮添加0．5％Arg可降低死胎率达54．70％（P〈0．05）,从而极显著提高胎鼠数（P〈0．01）;（3）日粮中添加0．5％ArgIUGR率比对照组降低了约64．9％（P〈0．05）。结论：日粮添加精氨酸可以降低死胎率和IUGR率,提高胎鼠数和胎鼠重。     

施马伦堡病毒感染

施马伦堡病是由施马伦堡病毒(schmallenberg virus,SBV)引起的一种新发现的吸血昆虫传播的动物疾病。该病可引起成年牛发热、腹泻、奶牛产奶量下降,怀孕牛羊感染可引起胎儿畸形、流产或死胎。目前荷兰、比利时、德国西部、法国北部和英国东南部有疫情报道,已有国家严禁从上述出现施马伦堡病毒疫情的国家进口相关动物产品。本文汇总了最新的疫情研究进展,介绍了该病的病原、流行病学和预防控制措施。     

Glucose homeostasis and metabolic adaptation in the pregnant and lactating sheep are affected by the level of nutrition previously provided during her late fetal life

This study investigated whether undernutrition (UN) during late fetal life can programme the subsequent adult life adaptation of glucose homeostasis and metabolism during pregnancy and lactation. Twenty-four primiparous experimental ewes were used. Twelve had been exposed to a prenatal NORM level of nutrition (maternal diet 15 MJ ME/d) and 12 to a LOW level of nutrition (maternal diet 7 MJ ME/d) during the last 6 weeks pre-partum. The experimental ewes were subjected to two intravenous glucose tolerance tests (IGTT) in late gestation (one prior to (G-IGTT) and one by the end of a feed restriction period (RG-IGTT)), and a third around peak lactation (L-IGTT). LOW had lower basal insulin concentrations during lactation, and significantly decreased absolute insulin secretion during the L-IGTT in spite of similar glucose tolerance, indicating increased insulin sensitivity in LOW during lactation. There was no effect of prenatal UN on glucose tolerance during G-IGTT, however, during RG-IGTT LOW was more glucose intolerant and apparently more insulin resistant compared to NORM. In conclusion, UN during late fetal life in sheep impairs subsequent pancreatic insulin secretory capacity during adult life, and reduces plasticity of down-regulation of insulin secretion in response to a metabolic challenge. Furthermore, prenatal UN appears to programme mechanisms, which in young adult females can shift the insulin hypersensitivity observed during early lactation into an insulin resistance observed during late gestation and feed restriction. Early postnatal UN caused by lowered milk intake in early postnatal life may have contributed to these phenomena.     

Electrocardiographic confirmation of a twin pregnancy in a mare at 8 months of gestation

A 15-year-old Warmblood mare, at 8 months of gestation, was presented to the Ghent University Faculty of Veterinary Medicine for evaluation of suspected stage one labor. Transrectal ultrasonography revealed no clear signs of placentitis or stage one labor. The combined thickness of uterus and placenta was 11 mm and the cervix was closed. Twin pregnancy was suspected by transabdominal ultrasonography but could not be confirmed with certainty. An electrocardiogram (ECG) was recorded from the mare's abdominal wall to register a fetal ECG. To confirm twin pregnancy, registration of both fetal ECGs simultaneously on the same ECG trace was attempted. Twelve different electrode configurations were used. In 11 recordings, one fetal ECG was visible. Only one specific right-sided electrode configuration showed both fetal ECGs at the same time, which confirmed twin pregnancy. Although electrocardiographic diagnosis of a twin pregnancy in a mare is possible, this case highlights the need for multiple electrode configurations and the high likelihood of false negatives.     

施马伦堡病毒感染

施马伦堡病是由施马伦堡病毒（schmallenberg virus,SBV）引起的一种新发现的吸血昆虫传播的动物疾病。该病可引起成年牛发热、腹泻、奶牛产奶量下降,怀孕牛羊感染可引起胎儿畸形、流产或死胎。目前荷兰、比利时、德国西部、法国北部和英国东南部有疫情报道,已有国家严禁从上述出现施马伦堡病毒疫情的国家进口相关动物产品。本文汇总了最新的疫情研究进展,介绍了该病的病原、流行病学和预防控制措施。     

不同剂量精氨酸对孕鼠子宫肥大细胞的影响

为探索不同剂量精氨酸(Arg)对孕鼠子宫肥大细胞(MC)的影响,本试验将40只小鼠随机分为对照组、0.25%Arg组、0.5%Arg组和1.0%Arg组,妊娠16d时处死孕鼠,计数胎鼠;取孕鼠子宫组织经Carnoy′s液固定,甲苯胺蓝染色,观察并计数MC。结果显示:0.5%Arg组的MC较对照组显著减少(P0.05),1.0%Arg组的MC较对照组极显著减少(P0.01),0.25%Arg组的MC较对照组无统计学意义,0.5%Arg组的胎鼠数极显著高于对照组和1.0%Arg组(P0.01)。说明日粮中添加适量的Arg对胎儿生长有促进作用。     

Fibrinonecrotic Placentitis and Abortion Associated With Pantoea agglomerans Infection in a Mare

Pantoea agglomerans, family Enterobacteriaceae, is a Gram-negative bacterium that may be isolated from soil and from plants. This bacterium has been associated with disease in plants, humans, and rarely in domestic animal species. We describe here a case of fibrinonecrotic placentitis and equine abortion associated with P. agglomerans infection in southern Brazil. A fetus with 10 months of gestation and its placenta were evaluated. Gross lesions were observed in the cervical star extending to the body of the chorioallantois and consisted of a focally extensive, transmural, severely thickened yellow area. Histologically, this area in the chorioallantois was effaced by severe necrosis, associated with marked inflammatory infiltrate of neutrophils and abundant deposition of fibrin and cellular debris. Aggregates of bacterial rods were noted intermixed with inflammation areas. No significant lesions were observed in the remaining organs inspected. Tissue samples of the lung, placenta, and stomach contents were cultured, and microbiological tests revealed the growth of P. agglomerans in all evaluated samples. The present study reaffirms the participation of P. agglomerans as a cause of bacterial placentitis and abortion in horses.     

Accuracy of early fetal sex determination by ultrasonic assessment in goats

The objective of this study was to determine the accuracy of early fetal sex determination by ultrasonic assessment of the relative location of the genital tubercle (GT) in goats at different stages of pregnancy as well as by the identification of fetal external genitalia. Pregnant animals were divided into three experimental groups (EI: n=21, EII: n=28, EIII: n=33). In EI, fetuses (n=27) were transrectally monitored daily from days 40 to 60 of pregnancy with a linear transducer (6.0 and 8.0MHz). In EII, fetuses (n=40) were examined once between days 45 and 70 of pregnancy by transrectal ultrasonography. In EIII fetuses (n=52) between days 100 and 120 of pregnancy, were submitted to a single transabdominal ultrasonography using a convex transducer (5.0 and 7.5MHz). Regardless of fetal sex diagnosis, 15/15 (EI), 13/16 (EII) and 9/14 (EIII) of single pregnancies and 10/12 (EI), 20/24 (EII) and 21/38 (EIII) of twin pregnancies were correctly identified. The accuracy of sex identification among EI (92.6%), EII (82.5%) and EIII (57.7%) was not statistically different (P>0.05). Identification of the GT in male fetuses was possible from day 45 onward. Changes in the GT position were not observed between days 53 and 60 of pregnancy. Accuracy of fetal sexing under field conditions is high in goats when ultrasound imaging is properly timed during pregnancy and when it is performed with proper equipment by experienced operators.     

Free amino-acid concentrations in the equine placenta: relationship to maternal and fetal plasma concentrations

Free amino-acid concentrations were measured in maternal venous and fetal umbilical vein plasma, and in the allantochorion, of Thoroughbred mares at term. Concentrations in maternal and fetal plasma were similar to those reported previously in equids. The concentrations of free amino-acids in the allantochorion were higher than those in the maternal and fetal plasmas and were characterised by high levels of the nonessential amino-acids as observed in other species. Fourteen of the 20 amino-acids measured had similar allantochorion/umbilical vein concentration ratios suggesting that simple gradient diffusion might play a part in their transfer from the placenta to the fetus.     

Dietary rumen-protected L-arginine or N-carbamylglutamate attenuated fetal hepatic inflammation in undernourished ewes suffering from intrauterine growth restriction

This study aimed to explore whether dietary rumen-protected L-arginine (RP-Arg) or N-carbamylglutamate (NCG) supplementation to feed-restricted pregnant ewes counteracts fetal hepatic inflammation and innate immune dysfunction associated with intrauterine growth retardation (IUGR) in ovine fetuses. On d 35 of pregnancy, twin-bearing Hu ewes (n = 32) were randomly assigned to 4 treatment groups (8 ewes and 16 fetuses per group) and fed diets containing 100% of the NRC requirements (CON), 50% of the NRC requirements (RES), RES + RP-Arg (20 g/d) (RESA), or RES + NCG (5 g/d) (RESN). At 08:00 on d 110 of gestation, fetal blood and liver tissue samples were collected. The levels of triglyceride, free fatty acid, cholesterol and β-hydroxybutyrate in the fetal blood of RESA and RESN groups were lower (P < 0.05) than those of the RES group, but were higher (P < 0.05) than those of the CON group. The interleukin (IL)-6 and IL-1 levels in fetal blood and liver tissue as well as the myeloid differentiation primary response 88 (MyD88), transforming growth factor β (TGFβ), and nuclear factor kappa B (NF-κB) mRNA levels in the fetal liver were decreased (P < 0.05) by the NCG or RP-Arg supplementation compared to the RES treatment. Similarly, the toll-like receptor (TLR)-4, MyD88, TGFβ, and p-c-Jun N-terminal kinase (JNK) protein levels in the fetal liver were reduced (P < 0.05) in the NCG and RP-Arg -supplemented groups compared to the RES group. These results showed that dietary supplementation of RP-Arg or NCG to underfed pregnant ewes could protect against IUGR fetal hepatic inflammation via improving lipid metabolism, down-regulating the TLR-4 and the inflammatory JNK and NF-κB signaling pathways, and decreasing cytokine production in ovine fetal blood and liver tissue.     

In utero exposure to the anti-androgen flutamide influences connexin 43 and β-catenin expression in porcine fetal gonads

Recent reports have indicated a role of cell-to-cell interactions during gonadal development and functions. Numerous reports indicate that fetal hormonal disruption induces abnormalities in the developing reproductive system and, therefore, may interfere with reproductive functions later in adult life. Hence, this study investigated the effect of androgen deficiency during late prenatal periods on the gap junction-associated connexin 43 (Cx43) and the adherens junction-associated β-catenin expression in the fetal porcine gonads. Thus, pregnant gilts were injected with anti-androgen flutamide (for 7 d, 50 mg/kg BW per day) or corn oil (control groups) starting at 83 (GD90) or 101 (GD108) gestational day. On GD90 and GD108 the fetuses were excised and fetal gonads were obtained. To assess Cx43 and β-catenin expression real-time PCR and immunohistochemistry were performed. In fetal testes, Cx43 was localized between Leydig cells, whereas β-catenin was observed mainly within the seminiferous tubules. In fetal ovaries, Cx43 was detected between interstitial cells and between granulosa cells of forming follicles, whereas β-catenin was found within egg nests, in oocytes' membrane, and in granulosa cells of forming follicles. Immunohistochemistry showed decreased Cx43 and β-catenin expression in fetal gonads from flutamide-treated pigs compared with respective controls. However, the ovaries from animals treated with flutamide on GD108 showed increased Cx43 expression. The changes of Cx43 and β-catenin expression after prenatal flutamide treatment were confirmed at the mRNA level. These findings suggest that androgen deficiency during late gestation may lead to disturbed intercellular interactions in fetal porcine testes affecting testicular functions, as well as impaired follicular formation in fetal ovaries. Our results further signify the role of androgens in the regulation of cell-to-cell interactions within fetal porcine gonads.     

Neospora caninum antibodies in commercial fetal bovine serum

The protozoan parasite Neospora caninum is a major cause of abortion in cattle throughout the world. In the process of propagating Neospora in vitro and producing specific antibodies for development of diagnostic assays in the food supply, our laboratory identified the presence of bovine antibodies to N. caninum in fetal bovine sera. The sera were produced commercially and preferentially recommended for tissue culture use and monoclonal antibody production. Seventeen different fetal bovine serum samples of different grades and from four different companies were examined for the presence of total IgG, IgG₁, IgG₂, and IgM specific for N. caninum. All of the tested serum samples recognized N. caninum specific bands on Western blot. Low IgG serum also recognized these antigens but with lower intensity. Antibody response was also evaluated using a commercially available ELISA kit for N. caninum.     

Effects of intrauterine crowding on available uterine space per fetus in rabbits

The aim of this study was to examine the effects of uterine crowding on available uterine space per fetus and fetal development at 18 days of gestation in unilaterally ovariectomized and intact does from the sixth generation of a divergent selection experiment on uterine capacity. Uterine capacity was estimated as litter size in unilaterally ovariectomized (ULO) does. Records from 37 ULO and 26 intact does were used. All does were slaughtered on d 18 of gestation. Ovulation rate per side in ULO does was almost twice as much as intact does (12.41 ova vs. 6.47 ova, P < 0.001). ULO does showed higher intrauterine crowding at implantation than intact does (9.36 implanted embryos/uterine horn vs. 5.31 implanted embryos/uterine horn, P < 0.001) and a lower available uterine space per live fetus (3.60 cm vs. 4.44 cm, P < 0.001). The available uterine space per embryo decreased quadratically with the number of implanted embryos (b₁ = − 2.46 ± 0.18, b₂ = 0.13 ± 0.01), and showed a negative linear regression coefficient with number of dead fetuses (− 0.18 ± 0.08). The available uterine space affects quadratically the development of the maternal placenta, and to a lesser extent is linearly related to the development of the fetus and its fetal placenta. The coefficients of these regressions were higher in ULO does than intact does, due to the higher degree of uterine overcrowding in these females.

Although the fetal position within the uterus did not affect the proportion of dead embryos, the uterine position could affect the survival of fetuses with a lower available uterine space. A poor blood supply had a negative effect on survival of the fetus and its development. Probability of death for fetuses with placenta receiving less than 3 blood vessels was higher than those receiving more than 3 blood vessels in both ULO and intact does (75.61% vs. 7.32%). Probability of survival asymptotically increases with available uterine space, as a result of the greater availability of uterine space which allows more blood vessels to reach each implantation site. The uterine overcrowding of ULO does was therefore associated with less uterine space and blood supply available at each implantation site, which could be related to higher fetal mortality in these females. Blood supply also affects fetal development. The implantation sites receiving less than 3 blood vessels showed lighter placentas (1.31 g vs. 1.41 g, P < 0.05) and fetuses (2.02 g vs. 2.12 g, P < 0.05) than those receiving more than 3 blood vessels in both ULO and intact does. These results suggest that available uterine space is a limitation component of fetal survival, which is related to an adequate vascular supply for nutrient exchange from the maternal to fetal blood streams and an adequate surface area for development of the placenta.     

Babesia crassa n.sp. (Sporozoa,Babesiidae) of domestic sheep in Iran

Summary

A large Babesia sp., isolated from a sheep in Iran, proved to be serologically and morphologically different from B. motasi and B. ovis.

The parasite, designated B. crassa n. sp., is characterized by the frequent occurrence of four organisms in one erythrocyte, which is the result of quadruple division and, in other cases, of two successive binary divisions. Parasites resulting from the first of two successive binary divisions are exceptionally broad. B. crassa appears to be of low pathogenicity for sheep and goats, to which it is also infective. The vector is unknown.