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Results 351 - 400 of 869
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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 ...
Weems Y S - - 1999
Ninety-day pregnant ewes were either laparotomized, ovaries left in situ or bilaterally ovariectomized, and a jugular venous catheter and an inferior vena cava catheter via the saphenous vein were installed. Seven days later, placenta slices were collected and incubated in vitro for 4 h. Secretions of progesterone, PGE, estradiol-17beta and ...
Weems Y S - - 1999
Ewes were lutectomized and treatments were started 72 h later. Pregnant ewes were treated with vehicle; prostaglandin F2alpha (PGF2alpha); cortisol (C); trilostane (TR), a 3beta-hydroxy-steroid dehydrogenase inhibitor; PGF2alpha + C; TR + PGF2alpha; TR + C, or TR + PGF2 + C. TR, TR + PGF2alpha, TR + C, and ...
Regnault T R - - 1999
Pregnant ewes were exposed chronically to thermoneutral (TN; 20+/-2 degrees C, 30% relative humidity; n=8) or hyperthermic (HT; 40+/-2 degrees C 12 h/day, 35+/-2 degrees C 12 h/day, 30% relative humidity, n=6) environments between days 37 and 93 of pregnancy. Ewes were killed following 56 days of exposure to either ...
Dwyer C M - - 1999
The onset of maternal behaviour in sheep is controlled by levels of oestrogen and progesterone in gestation and the release of oxytocin during delivery. Factor analysis was used to investigate the relationships between maternal behaviour, offspring behaviour, and maternal ovarian hormone levels during gestation in sheep. Ewes gave birth to ...
Sewalem A - - 1999
The present study compares embryonic mortality between lines selected for different production traits, assesses the effects of inbreeding of the hen and embryo on embryonic mortality, and estimates genetic parameters of embryonic mortality. The experiment covered 10 generations of selection for increased egg number (EN), egg weight (EW), egg mass ...
Hensley, Erika L.
Experiments were conducted to determine the effects of a treatment used to dilate the cervix for transcervical AI and embryo transfer on pregnancy or fertilization rates in sheep. Experiment 1 was conducted as a 2 x 2 factorial, with the main effects of estradiol-17b (E2) and oxytocin (OT). On d ...
Osgerby J C - - 1999
Insulin-like growth factors (IGFs) are thought to be important regulators of embryonic and fetal development. The half life, distribution and action of IGFs are modulated by a family of IGF-binding proteins (IGFBP). This study investigated the pattern of IGFBP-1 expression in the ovine uterus during the oestrous cycle and early ...
Wallace J M - - 1999
The aim was to investigate whether placental growth and hence pregnancy outcome could be altered by switching adolescent dams from a high to a moderate nutrient intake, and vice-versa, at the end of the first trimester. Embryos recovered from adult ewes inseminated by a single sire were transferred in singleton ...
al-Gubory K H - - 1999
To study the role, if any, of luteal factors in the control of prolactin secretion during the last two thirds of pregnancy in the ewe, we examined: a) the effect of RU 486 administration on prolactin secretion on days 97, 112 and 131 of pregnancy in five intact ewes and ...
Roesch D M - - 1999
The suppression of plasma adrenocorticotropic hormone by very low levels of cortisol is reduced in pregnant adrenalectomized ewes, suggesting that pregnancy reduces the efficacy of the high-affinity corticosteroid receptor. This study was designed to determine the effects of pregnancy on the availability, immunoreactivity, and affinity of both corticosteroid receptors: the ...
Kutty C I - - 1999
A palpation technique using both hands was developed by the author and used for examination of internal reproductive organs, pregnancy diagnosis, and assessment of approximate stages of gestation in small ruminants. The study was conducted in 4 stages on 87 female goats and 30 slaughterhouse source ewes First, 20 doelings ...
Grilló M J - - 1999
Forty yearling Brucella-free ewes were inoculated with Brucella ovis by the conjunctival route in mid or late first pregnancy. Only a few ewes excreted B ovis during pregnancy and gave birth to stillborn lambs, but most of them excreted the organism at lambing or during lactation. One of the 11 ...
Shinozuka N - - 1999
OBJECTIVES: This study examined the effects of increased myometrial contracture frequency from 96 to 131 days' gestation on ovine fetal oxygen transport and physiologic response to acute hypoxemia. STUDY DESIGN: Ten pregnant ewes received either saline solution (control, n = 5) or long-term administration of oxytocin (600 microU. kg-1. min-1) ...
Kühholzer B - - 1999
This study was performed to investigate the developmental potential of microinjected embryos recovered from superovulated prepuberal lambs. Fifty-nine mixed-bred lambs (about 3 mo old) were superovulated either with 18 mg FSH-P with (Group FSH/+S) or without (Group FSH/-S) progestagen treatment, or with 10 mL Ovagene following progestagen treatment (Group OVA/+S). ...
Yazdi M H - - 1999
Variance and covariance components for birth weight (BWT), as a lamb trait, and litter size measured on ewes in the first, second, and third parities (LS1 through LS3) were estimated using a Bayesian application of the Gibbs sampler. Data came from Baluchi sheep born between 1966 and 1989 at the ...
Merimsky O - - 1999
Ewing's sarcoma of the pelvic bones was diagnosed in a 21-year childbearing woman, raising major medical and ethical problems. The diagnostic and therapeutic approaches during the sixth month of gestation were tailored in order to cure the patient and avoid unnecessary toxicity to the fetus. Ancillary tests included ultrasound and ...
Vos E A - - 1999
The usefulness of fecal estrone (E1) measurement as a tool for pregnancy diagnosis was investigated. Concentrations of E1 were measured in feces from pregnant and nonpregnant sows by a direct ELISA without extraction. Highly significant differences in E1 concentrations were found in feces from nonpregnant and pregnant sows (P = ...
Andres S - - 1999
The present study evaluates blood GSHPx activity in 18 sheep flocks at range, to identify those seasons with the highest risk of selenium deficiency. Samples were taken from 1108 15-day-old lambs during the two usual lambing periods in this geographical area (autumn-winter and spring-summer). The overall mean values in the ...
Ferreira G - - 1999
Institut National de Recherche Agronomique/Centre National de la Recherche Scientifique Within 4 hr after parturition, ewes learn to recognize the odor of their lamb. Whether scopolamine, a muscarinic antagonist, interferes with lamb odor retention was studied. After 4 hr of mother-young contact, ewes were separated from their lambs for 3 ...
Mitchell L M - - 1999
The objective of this study was to determine the relative importance of seasonal changes in ovulation rate, fertilization rate and embryo survival as the cause of reduced lambing rates in ewes mated in February compared with those mated in November. The study was conducted at 57 degrees N using mature ...
Al-Gubory K H - - 1999
In sheep, there have been few and conflicting data regarding the necessity of the corpus luteum (CL) for the maintenance of pregnancy. The aims of the present study were to examine the effect of luteectomy on and after Day 50 of pregnancy on maternal plasma progesterone concentrations and the progression ...
Timmerman M - - 1998
Uterine and umbilical uptakes of alanine (Ala) were measured in 10 ewes before (control) and during intravenous infusion of Ala, which increased maternal arterial Ala concentration from 115 +/- 14 to 629 +/- 78 microM (P < 0.001). In 8 of these ewes, placental Ala fluxes were traced by constant ...
Freetly H C - - 1998
Our objective for this study was to determine the pattern of nutrient flux across the portal-drained viscera (PDV) and liver in ewes with varying numbers of fetuses. Catheters were placed in the hepatic portal vein, a branch of the hepatic vein, a mesenteric vein, and the abdominal aorta of ewes. ...
McDougall J J - - 1998
The ligaments of weight-bearing joints are known to become mechanically inferior during pregnancy, and it has been postulated that this may be due to changes in tissue perfusion. Calcitonin gene-related peptide (CGRP) and epinephrine exert a tonic influence on the vasculature of the medial collateral ligament (MCL), and the present ...
Nuvor S V - - 1998
In this paper, the Eimeria oocyst output of two groups, pregnant ewes (group 1) and non-pregnant controls (group 2), which were followed from September 1993 to August 1994, is described. In both groups of animals the level of oocyst output was high during the minor rainy season. However, during the ...
Heasman L - - 1998
We investigated the influence of restricted maternal nutrition between 28 and 77 d of gestation on placental weight and appearance, and on fetal weight and conformation. Single-bearing ewes were fed either twice [i.e. controls (n = 19)] or half [i.e. nutrient-restricted (n = 28)] their energy requirements from 28 to ...
Al-Gubory K H - - 1998
Ewes of the Préalpes-du-Sud breed (n = 112) were mated with fertile rams and were used to investigate the effect of the presence of vasectomized rams during pregnancy on reproductive outcomes. Ewes in the control group (n = 56) were isolated from rams during the whole period of pregnancy, whereas ...
Carter A M - - 1998
OBJECTIVE: To calibrate a reflectance pulse oximeter developed at the Division of Perinatal Physiology, University Hospital of Zurich, for monitoring of oxygen saturations below 70%. METHODS: Oxygen saturation measured noninvasively with the reflectance pulse oximeter in fetal sheep was compared with oxygen saturation of arterial blood samples measured by a ...
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