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Results 301 - 350 of 847
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Santiago-Moreno J - - 2001
Embryos from five anesthetized mouflons (Ovis gmelini musimon), superovulated with FSH-o (Ovagen) were transferred into preselected Spanish Merino sheep (Ovis aries). Myorelaxation was complete in four of five donor mouflons. The status of the uterus of potential recipients was evaluated by transrectal ultrasonography, and those ewes with fluid in the ...
Thomas L - - 2001
This study examined the pattern of circulating leptin in age-matched sheep during adolescent pregnancy, and its relationship with maternal dietary intake, body composition and tissue expression of the leptin gene. Overfeeding the adolescent pregnant ewe results in rapid maternal growth at the expense of the placenta, leading to growth restriction ...
Gray C A - - 2001
Endometrial glands secrete molecules hypothesized to support conceptus growth and development. In sheep, endometrial gland morphogenesis occurs postnatally and can be epigenetically ablated by neonatal progestin exposure. The resulting stable adult uterine gland knockout (UGKO) phenotype was used here to test the hypothesis that endometrial glands are required for successful ...
El-Sherif M M.A. - - 2001
A study based on 12 pregnant and six dry Barki ewes was carried out to examine the changes in blood constituents during pregnancy and lactation periods. The blood parameters were blood hemoglobin, packed cell volume percent (PCV%), mean corpuscular hemoglobin concentration (MCHC), glucose, aspartate aminotransaminase (AST or GOT), alanine aminotransaminase ...
Lucidi P - - 2001
Ram effect, defined as shortening of seasonal anestrus in ewes by exposure to the ram, is now well recognized but the underlying mechanisms are still unclear. Little information also exists whether the ram is able to influence the estrus cycle and ovulation. Three experiments were conducted to investigate endocrine response, ...
Stellflug J N - - 2001
Three groups of ewe lambs born in May (experiment 1; n=211) or April (experiment 2; n=174) were used to evaluate the effects of selection line and induction of estrus on pregnancy rate. Experiment 1 was a single factor experiment with induction of estrus as the main effect. In early December, ...
van Cappellen van Walsum A M - - 2001
In fetal lambs, severe hypoxia (SH) will lead to brain damage. Mild hypoxia (MH) is thought to be relatively safe for the fetal brain because compensating mechanisms are activated. We questioned whether MH, leading to mild acidosis, induces changes in cerebral metabolism. Metabolites in cerebrospinal fluid (CSF) samples, as analyzed ...
Avdi M - - 2001
The present study was designed to study follicular growth and its interactions with the corpus luteum of pregnancy in sheep during early, middle and late pregnancy and during postpartum anestrus. Ewes with 1 or 2 corpora lutea in one ovary were selected from a larger group of Serres ewes. All ...
Tuo W - - 2001
Scrapie is a naturally occurring prion (PrP) disease causing a fatal neurodegenerative disorder in sheep and goats. Previous studies suggest that scrapie is transmitted naturally through exposure to the scrapie agent in wasted placentas of infected ewes. This study determined the distribution and biochemical properties of PrP cellular (PrP-C) and ...
Knights M - - 2001
The objectives were to evaluate, in anestrous ewes, the effectiveness of a CIDR-G device (0.3 g progesterone) administered for 5 d to induce estrus; and FSH (Folltropin; 55 mg NIH-FSH-P1 equivalent) in saline:propylene glycol (1:4) 24 h before insert removal (Day 0), to increase ovulation rate and prolificacy. Ewes of ...
Stellflug J N - - 2001
The difficulty of cervical penetration severely limits the use of transcervical AI (TAI) in sheep, and trauma from cervical manipulation (CM) may reduce fertility after TAI. We investigated the effects of cervical dilation using exogenous oxytocin (OT) to facilitate TAI and its effects on reproductive variables after laparoscopic AI (LAI). ...
Paek B W - - 2001
OBJECTIVE: Long-term access to the fetal circulation has the potential to open up new perspectives in the treatment of numerous fetal anomalies. The purpose of this study was to investigate the safety of long-term catheterization of fetal placental vessels. METHODS: A midline laparotomy was performed in 4 time-mated pregnant ewes ...
Viérin M - - 2001
The aims of the study were: (1) to test the influence of pregnancy on responses of ewes to several fear-eliciting situations, (2) to compare the first and latest stages of pregnancy, and (3) to investigate possible correlations between fear reactions and progesterone levels. Fear reactions of nonpregnant (NP; N=22) and ...
Gray C A - - 2001
Endometrial glands are present in all mammalian uteri and produce secretions that are hypothesized to support conceptus (i.e., embryo/fetus and placental membranes) survival and development. In sheep, endometrial gland morphogenesis occurs postnatally and can be epigenetically ablated by chronic neonatal exposure to a progestin from birth, thereby producing an adult ...
Buxton D - - 2001
Neospora caninum is an important cause of fetal loss in cattle but has also infrequently been shown to cause disease in sheep and goats. Experimental infection of pregnant sheep with N. caninum causes clinical and pathological changes very similar to those of neosporosis in cattle. An experiment in sheep was ...
Fthenakis G C - - 2001
In each of two experiments, the reproductive performance of ewes naturally infested with sarcoptic mange and of uninfested ewes was assessed in in-season natural breeding conditions (experiment I) or in out-of-season controlled breeding conditions (experiment II). A statistically significant difference was observed in the total lambs born per ewe (infested ...
Sormunen-Cristian R - - 2001
A comparison of conserving timothy/meadow fescue/meadow grass as silage or hay was conducted with Finnish Landrace ewes. Intake of hay (H), silage (S) and hay/silage (HS), and the performance of 30 Finnish Landrace ewes carrying twins, triplets and quadruplets and suckling either twin or triplet lambs was measured during the ...
King K J - - 2001
BACKGROUND: The liability to overwhelming infection of children lacking a spleen either as a result of its congenital absence or because of splenectomy, has been frequently documented. Although there have been numerous studies of the consequences of experimental splenectomy in postnatal animals, this is the first study of the effects ...
Butler J E - - 2000
Since the actual combinatorial diversity in the V(H) repertoire in fetal piglets represents <1% of the potential in mice and humans, we wondered whether 1) complementarity-determining region 3 (CDR3) diversity was also restricted; 2) CDR3 diversity changed with fetal age; and 3) to what extent CDR3 contributed to the preimmune ...
Van Saun R J - - 2000
A high prevalence of metabolic disease was evident in a large flock of sheep early in the lambing season. Pregnancy toxemia and secondary hypocalcemia were diagnosed on the basis of history, physical examination findings, and results of serum biochemical analyses. To decrease costs to the owner, pooled serum samples were ...
Paek B W - - 2000
OBJECTIVE: The purpose of our study was to determine whether prenatal repair of myelomeningocele prevents or reverses hindbrain herniation in the sheep model. STUDY DESIGN: A myelomeningocele was surgically created in fetal sheep. One group was repaired later in utero; the others were delivered without repair. After delivery, lambs were ...
Kitagawa H - - 2000
BACKGROUND: If creating an obstructive uropathy early in glomerulogenesis produces MCDK (Multicystic Dysplastic Kidney), then a very early obstruction may produce Potter's Syndrome (PS) with oligohydramnios. METHODS: Fetal lambs at 50 days' gestation underwent urethral and urachal ligation using fine SILASTIC (Dow Corning, Midland, MI) tubing and were delivered by ...
Ozaki T - - 2000
OBJECTIVE: The aim of this study was to investigate functional development of small arteries from the skeletal circulation of fetal sheep and to determine whether maternal undernutrition affects responses to vasoconstrictive and vasodilatory agonists in arteries from the late-gestation fetus. STUDY DESIGN: We investigated vasoconstrictive and vasodilatory responses of isolated ...
Bawa E K - - 2000
Three groups of pregnant Yankasa ewes, made up of six ewes in each group were assigned at random to first, second and third trimester of pregnancy studies. The ewes were experimentally infected with T. vivax to study the effects of the infection on pregnancy and the results of Novidium Chemotherapy. ...
Whitley N C - - 2000
Eighty-four nulliparous ewes were used to examine the effect of short-term insulin treatment on feed intake and reproductive performance. Following estrus synchronization, ewes were observed for estrus (= Day 0) and were penned individually beginning on Day 7. Ewes were fed twice daily and feed intake was recorded. On Days ...
Petratos S - - 2000
Prenatally, neuroactive steroids that modulate GABAergic activity may be synthesized de novo within the fetal brain. We have examined changes in immunoreactivity staining for the steroidogenic enzymes cholesterol P450 side-chain cleavage (P450scc), and 5alpha-reductase type-2 in the cerebellum of late gestation (130-145 days gestation) fetal sheep and newborn lambs (1-4 ...
Deprest J A - - 2000
OBJECTIVE: To evaluate effects of in-utero endoluminal balloon tracheal occlusion (TO) as suggested for the treatment of Congenital Diaphragmatic Hernia (CDH) on the higher airways of a fetal lamb model. STUDY DESIGN: Fetuses from time-dated pregnant ewes underwent at 94 days (term=145 days) in-utero tracheal occlusion. In study animals an ...
Booth K K - - 2000
Twenty-five pregnant Dorsett ewes were randomly divided into three groups to test if ewes use their vomeronasal organs for offspring recognition during nursing. One group of eight ewes (procaine) were made anosmic by irrigation of the nasal olfactory apparatus with a zinc sulphate procaine solution. The second group of nine ...
Houdijk J G - - 2000
Within the overall hypothesis that the periparturient relaxation of immunity (PPRI) to gastrointestinal parasites has a nutritional basis, we studied whether an increased intake of metabolizable protein (MP) could affect the expression of immunity to Teladorsagia (Ostertagia) circumcincta of twin-bearing and -rearing Greyface ewes. Two sets of iso-energetic diets were ...
McDougall J J - - 2000
The adrenoceptor profile of blood vessels supplying the medial collateral ligament (MCL) of virgin and primagravid (day 29 of pregnancy) rabbit knees was examined. Topical bolus administration of the alpha1-adrenoceptor agonists methoxamine and phenylephrine, and the alpha2-adrenoceptor agonist clonidine, to exposed knee joints resulted in a dose-dependent vasoconstriction of ligamentous ...
Heasman L - - 2000
We investigated the influence of restricted maternal nutrition between 28 and 77 days gestation on survival and thermoregulatory adaptation following Caesarean section delivery near to term. This study was designed to examine the hypothesis that adaptation after birth would be compromised in those lambs born to nutrient restricted ewes. We ...
Brand TS - - 2000
The primary selection objective in the South African Mutton Merino is meat production, while wool plays a secondary role. The Merino, on the other hand is selected for wool production. Respectively 20 and 23 of each genetic different type of ewes were used in a 15-week indoor study to quantify ...
Takahashi Y - - 2000
Nonselective cyclooxygenase (COX) inhibitors are potent tocolytic agents; however, they also have adverse fetal effects such as constriction of the fetal ductus arteriosus. Recently, selective COX-2 inhibitors have been used in the management of preterm labor in the hope of avoiding fetal complications. However, both COX-1 and -2 are expressed ...
Freking B A - - 2000
Effects of Dorset, Finnsheep, Romanov, Texel, and Montadale breeds for performance as sires were estimated in the initial phase of a comprehensive evaluation of these breeds as contributors to sheep crossbreeding systems. Objectives were to evaluate the effects of ram breed, ewe breed, season of mating, and two-way interactions. Rams ...
Gadd T S - - 2000
The insulin-like growth factor (IGF) system plays an important role in the regulation of uterine function and placental growth. However, there is little information regarding the localization and regulation of IGF binding protein-5 (IGFBP-5) in the reproductive tract. The distribution of this IGFBP was therefore investigated using in situ hybridization ...
Vincent J N - - 2000
Crossbred ewes (1/2 Dorset, 1/4 Rambouillet, and 1/4 Finnsheep) from a flock being selected for spring fertility, defined as ability to lamb following ram exposure in May and June in Virginia (37 degrees N latitude), were used to study the duration of the seasonal anestrus. In the first 3 yr ...
Revell D K - - 2000
Previous studies have shown that shearing pregnant ewes at mid- or late-pregnancy is associated with an increase in lamb birth weight. The present study was designed to investigate metabolic responses that may underlie this response. Single- and twin-bearing ewes were either unshorn or shorn at mid-pregnancy (Day 69 of pregnancy; ...
El-Haddad M A - - 2000
OBJECTIVE: Human and ovine fetuses demonstrate an enhanced rate of spontaneous and angiotensin II-stimulated swallowing. Angiotensin II and nitric oxide synthase have been localized to thirst centers in the brain. This study was performed to determine whether central nitric oxide contributes to the regulation of angiotensin II-induced fetal swallowing. STUDY ...
Bartlewski P M - - 2000
Transrectal ultrasonography of ovaries was performed in 11 ewes from Days 10 to 26 and on Day 30 of pregnancy to record the number, size, and position of ovarian follicles > or = 3 mm in diameter and corpora lutea (CL). Transrectal and/or transabdominal ultrasonography of the uterus was performed ...
Allison Gray C - - 2000
Ovine endometrial gland development is a postnatal event that can be inhibited epigenetically by chronic exposure of ewe lambs to a synthetic progestin from birth to puberty. As adults, these neonatally progestin-treated ewes lack endometrial glands and display a uterine gland knockout (UGKO) phenotype that is useful as a model ...
Heasman L - - 2000
The present study was designed to determine whether altered placental size, as a consequence of maternal nutrient restriction in sheep between 28 and 77 days gestation, is associated with a modified relationship between fetal weight or dimensions and plasma insulin-like growth factor (IGF) I concentration or abundance of hepatic IGF-I ...
Greenwood P L - - 2000
This study investigated associations between fetal and placental weights from 85 to 130 days gestation in 49 fetuses from 21 ewes of a prolific genotype used as an experimental model of intrauterine growth retardation. The proportion of variation in fetal weight explained by placental weight increased from zero at 85 ...
Quinlivan J A - - 2000
AIMS: A single course of prenatal corticosteroid reduces the mortality and morbidity of preterm birth. Repeated courses of prenatal corticosteroids are widely prescribed despite a lack of safety data. Repeated corticosteroids delay myelination in the ovine central nervous system at the time of preterm delivery but with catch-up at term. ...
Graeme K A - - 1999
A previous study reported that the co-infusion of IV sodium thiosulfate (STS) with sodium nitroprusside (SNP) to near-term gravid ewes prevented both maternal and fetal cyanide toxicity. We questioned whether maternally administered STS crossed the ovine placenta to enhance fetal transulfuration of cyanide, or whether the fetus was dependent on ...
Di T - - 1999
OBJECTIVE: To determine whether pregnancy increases cytosolic phospholipase A2 (cPLA2) expression in uterine artery (UA) endothelial cells and vascular smooth-muscle (VSM) cells, and whether ovarian steroids mediate this effect. METHODS: Uterine arteries and omental arteries (systemic control) were isolated from pregnant (120-130 days' gestation) ewes and from nonpregnant ewes synchronized ...
Smolich J J - - 1999
To study the effect of fetal hypoxemia on perinatal norepinephrine and epinephrine total body kinetics, 13 near-term fetal lambs were instrumented with vascular catheters under general anesthesia. One week later, norepinephrine and epinephrine kinetics were measured in normoxemic (n = 7) or spontaneously hypoxemic fetuses (n = 6) with isotope ...
Abecia J A - - 1999
Two groups of ewes were fed to provide 1.70 x (high energy group; n = 15) or 0.56 x (low energy group; n = 15) energy requirements for maintenance of liveweight from 14 d before a synchronized mating in November until slaughter at 9 or 15 d after mating. We ...
Kitagawa H - - 1999
BACKGROUND/PURPOSE: The type of renal dysplasia resulting from obstructive uropathy depends on the completeness of the obstruction and its timing with respect to the stage of glomerulogenesis at the time of the obstruction. The authors created a successful obstructive uropathy model in the female fetal lamb to demonstrate the differing ...
Bispham J - - 1999
We investigated the influence of maternal dexamethasone treatment and ambient temperature on prolactin receptor (PRLR) abundance in brown adipose tissue (BAT) and hepatic tissue from foetuses and 6-h-old lambs delivered by caesarean section. Lambs were either delivered into a warm (30 degrees C; WD) or cool (15 degrees C; CD) ...
Ptak G - - 1999
The production of offspring involving available technologies like ovum pick-up, in vitro embryo production and cryopreservation has not been fully described in the sheep. We tested the overall efficiency of these procedures on 20 Sarda dairy ewes that were twice stimulated for recovery of follicular oocytes. In total, 415 oocytes ...
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