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Results 451 - 500 of 847
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Dwyer C M - - 1996
To distinguish between ewe and lamb breed effects on prenatal growth, ease of parturition and early lamb behaviour, an embryo-transfer study was carried out using a hill breed (Scottish Blackface; liveweight: 54.25 +/- 1.03 kg, mean +/- s.e.m.) and a lowland breed (Suffolk; 80.33 +/- 1.52 kg) to obtain the ...
Lakritz J - - 1995
The purpose of this study is to describe a developmental defect of the caudal cervical and cranial thoracic vertebrae in 11 purebred Colombia lambs. The lambs were either affected at birth, or developed the condition within the first 18 days of age. Cervicothoracic kyphosis, with a compensatory cervical lordosis and ...
Ueda T - - 1995
Effects of prenatal corticosteroid on the properties of surfactant have not previously been evaluated. A single ultrasound-guided fetal injection with 0.5 mg/kg betamethasone 48 h before delivery of preterm lambs at 134- to 135-days gestation improved oxygenation, lowered the ventilatory pressures required to maintain arterial PCO2 between 30 and 40 ...
Bunge R - - 1995
Two- and three-year-old F1 crossbred ewes produced from Suffolk and Targhee dams and sires of the prolific wool breeds of Finnsheep, Combo-6, and Booroola Merino and the hair breeds of St. Croix and Barbados were pasture-mated to Dorset rams over a 4-yr period at the Dixon Springs Agricultural Center in ...
Deprest J A - - 1995
OBJECTIVE: Our purpose was to evaluate the feasibility of intrauterine endoscopic fetal surgery in a fetal lamb model by creating a urinary tract obstruction. STUDY DESIGN: Lower urinary tract obstruction was created by ligation of the urethra and urachus in 21 fetal lambs, eight at 95 to 105 days' gestation ...
Windsor D P - - 1995
The experiments described examined the effects of a number of factors on the level of uterine insemination achieved in Merino ewes by a transcervical insemination technique (Guelph system for transcervical artificial insemination; GST-AI). Cervical penetration rate is an important limitation to the use of such methods in Merinos. Simulated insemination ...
Broad K D - - 1995
In the multiparous ewe, intracerebroventricular (i.c.v.) infusions of corticotrophin releasing factor (CRF) act centrally to facilitate the induction of maternal behaviour if administered with vaginocervical stimulation. Changes in CRF mRNA expression in the brains of multiparous ewes were therefore examined as a function of late pregnancy, parturition and lactation using ...
Willard J M - - 1995
Ovine pregnancy-specific protein B (oPSPB) was isolated from sheep placentas. Antiserum to oPSPB was developed in rabbits. A quantitative RIA was developed and used to assay the serum concentrations of oPSPB during and after pregnancy in ewes bearing single or twin fetuses. Suffolk and Panama ewes, kept with rams equipped ...
Sargison N D - - 1995
A naturally occurring outbreak of sheep scab in a flock of 202 ewes during mid-pregnancy resulted in exudation from the scab lesions and hypoalbuminaemia lasting for two to 10 weeks in the severely affected ewes. The serum albumin concentration at the time of diagnosis and two weeks after treatment with ...
Boulton M I - - 1995
The aim of this study was to investigate the role of FSH in the control of ovulation rate by the Booroola gene. Three Booroola genotypes (FecBFecB, FecBFec+ and Fec+Fec+) of the F2 population, from a cross between Booroola Merino and Scottish Blackface, and two Booroola genotypes (FecBFec+ and Fec+Fec+; 25% ...
Wallace J M - - 1995
We examined the key events underlying maternal recognition of pregnancy and the prevention of luteolysis in early postpartum ewes by synchronously transferring single expanded blastocysts recovered from control ewes on day 11 of pregnancy into the uterus of either postpartum recipients that had been induced to ovulate 28 days after ...
Bauer M K - - 1995
Nutrition is a major determinant of the somatotropic axis during postnatal life. However, little is known about the response of the fetal somatotropic axis to nutritional limitation. From day 100 of gestation (term = 147 days), singleton-bearing ewes were fed either ad libitum (control; n = 6) or 25% of ...
Hunter J G - - 1995
The objective of this study was to evaluate the physiologic consequences of a pneumoperitoneum (pneumo) to the midterm fetus in a pregnant sheep model. The performance of laparoscopic cholecystectomy (LC) during pregnancy is controversial. The primary concern regarding the safety of LC during pregnancy is the physiologic consequences of the ...
Santos A C - - 1995
BACKGROUND: Ropivacaine is a new amide local anesthetic, having therapeutic properties similar to those of bupivacaine but with a wider margin of safety. Bupivacaine is probably the most commonly used drug in obstetric epidural analgesia, even though laboratory studies have suggested that pregnancy increases the cardiotoxicity of bupivacaine but not ...
Bassett J M - - 1995
The mean (+/- sd) packed cell volume (PCV) of the lambs in a flock mated by 'out-of-season' breeding methods and housed throughout the last six weeks of pregnancy and the whole of the suckling period declined to 23.3 +/- 3.34 per cent when the lambs were a month old, but ...
Panter K E - - 1995
Selenium fed to open cycling ewes in the form of sodium selenate or Astragalus bisulcatus (a selenium accumulator plant) at 24 or 29 ppm selenium, respectively, in alfalfa hay pellets did not alter the estrous cycle length, estrus behavior, progesterone or estrogen profiles, pregnancy rate or outcome of parturition (P ...
Desta B - - 1995
Experiments were designed to investigate the mechanism underlying the endothelium-dependent relaxation to trandolaprilat, a converting enzyme inhibitor, in canine coronary arteries previously exposed to bradykinin. Rings suspended in organ chambers were exposed to bradykinin for 3 min and washed repeatedly for 150 min. Trandolaprilat caused relaxations [IC50(-log M)8.59] in rings ...
Sterning M - - 1995
The pregnancy rate and the subsequent litter size were studied in 332 Swedish Yorkshire primiparous sows, fed according to a commercial Swedish feeding regime during lactation. The sows were weighed and backfat depth was recorded at the first farrowing, at weaning, and at mating. Oestrous detection was performed once daily ...
McMillen I C - - 1995
We have investigated whether the maternal melatonin rhythm provides the fetus with either a circadian or seasonal 'signal' during development. Our findings provide evidence that melatonin can generate and entrain the early evening peak in the daily rhythm of fetal breathing movements. In contrast, daily variations in maternal and fetal ...
Lévy F - - 1995
The respective roles of the main and accessory olfactory systems in the development of maternal behavior and selective suckling were investigated in parturient primiparous and multiparous ewes. Vomeronasal nerve section before parturition did not disturb either maternal behavior or maternal selectivity at suckling. By contrast, anosmia induced by zinc sulphate ...
Houghton D C - - 1995
We have investigated the effect of surgical disconnection of the fetal hypothalamus and pituitary (HPD) on generation of the daily rhythm in fetal plasma melatonin and PRL concentrations under long and short photoperiods. Fetal HPD or a sham operation was carried out at around 110 days gestation. Ewes carrying either ...
Jabbar G - - 1994
Two commercially available progestogen products for cattle, melengestrol acetate (MGA) and norgestomet (SMB), were evaluated for their ability to induce synchronized estrus in anovulatory ewes. Seasonally anestrous ewes (n = 232) were randomly assigned to one of seven treatments: 1) control (C); 2) MGA only (OMGA; .3 mg of MGA/d); ...
Guillery E N - - 1994
We have studied maturational changes in the kinetics of the proximal tubule Na+/H+ antiporter. Microvillus membrane vesicles were prepared from renal cortex of fetal and newborn lambs. Amiloride-sensitive uptake of 22Na+ by these vesicles was measured and Woolf-Augustinsson-Hofstee plots were used to determine the Michaelis constant (Km) and rate of ...
Prozesky L - - 1994
Previously published results of dosing trials, involving 82 ewes, revealed that 66% of the offspring of dams exposed to cultures of Diplodia maydis in the second trimester of pregnancy and 87% of lambs of ewes exposed in the third trimester, were born dead or died soon afterwards. Spongiform degeneration of ...
Buckrell B C - - 1994
A transcervical technique (the Guelph System for transcervical AI) was used to inseminate 2060 ewes on 65 farms (average 31 ewes, range 5 to 107) in Ontario, Canada, from October 1990 to September 1992, using previously frozen semen. Estrus was synchronized using progestagen pessaries and PMSG with median inseminations done ...
Levy D M - - 1994
Gastric emptying was studied indirectly by paracetamol absorption in 20 patients at 8-12 weeks' gestation and also in 20 non-pregnant controls. Subjects received paracetamol 1.5 g in a tablet with 50 ml of water and remained semi-recumbent for 2 h while venous blood samples were obtained at 15-min intervals. The ...
Assad R S - - 1994
Epicardial fetal pacing via thoracotomy has the potential of being a safer and more reliable procedure to treat congenital complete heart block (CHB) associated with fetal hydrops refractory to medical therapy. To assess the acute electrophysiological characteristics of two ventricular epicardial leads, a new experimental model of fetal heart block ...
Nijland R - - 1994
In the fetus, the arterial oxygen saturation (SaO2) in the ascending aorta is higher than in the descending aorta. We questioned whether this difference over the ductus arteriosus (delta SaO2) would change during hypoxaemia. Therefore, six chronically instrumented fetal lambs (119-126 days of gestation) were studied, by changing the inspired ...
Dickinson J E - - 1994
OBJECTIVE: We hypothesized that maternally administered methamphetamine would alter fetal sympathoadrenal activity. STUDY DESIGN: Six chronically catheterized near-term pregnant ewes received an intravenous bolus injection of methamphetamine (1.25 mg/kg). Maternal and fetal arterial blood gas values, glucose, insulin, lactate, and catecholamines were measured in the control period and at 15, ...
Joseph S A - - 1994
Monoamine concentrations were measured in cisternal cerebrospinal fluid (CSF) of unanesthetized fetal (115-135 days gestation) and newborn (2-34 days old) sheep. Norepinephrine (NE) and 3,4-dihydroxyphenylacetic acid (DOPAC) concentrations decreased with gestational age; NE CSF concentrations were significantly higher in the newborn (336.4 +/- 61.7 pg/ml; n = 5) compared with ...
Cendron M - - 1994
The functional effects of bladder outlet obstruction in the developing urinary tract are well recognized in patients born with posterior urethral valves, in whom a spectrum of bladder dysfunction has been described. To better understand the changes occurring in the partially obstructed developing lower urinary tract, a fetal lamb model ...
Gaucherand P - - 1994
OBJECTIVE: To investigate the reliability of our animal model and study the fetal response to placental ischemia. STUDY DESIGN: Eight monofetal pregnant ewes were fitted with appliances in conformity with a previously defined operating protocol which we have developed. Microspheres at different concentrations were injected through the fetal face of ...
Faucher D J - - 1994
Arginine vasopressin (AVP) is a peptide hormone which is found in neurons within the paraventricular (PVN) and the supraoptic (SON) nuclei of the hypothalamus. In fetal sheep, this neuropeptide is involved in maturational processes and adaptive responses to 'stress'. This study examined the effect of age on the total number ...
West T R - - 1994
The purposes of this study were to determine the effects of BW in growing lambs on rates of palmitate esterification (PE) and activity of glycerophosphate acyltransferase (GPAT) in subcutaneous and intermuscular adipose tissue in vitro and to determine the relationship between these in vitro measurements and carcass lipid accretion. At ...
Fowden A L - - 1994
Prostaglandins (PGs) are produced by a variety of uteroplacental tissues during pregnancy and are released into the fetal fluid sacs and both the uterine and umbilical circulations. Uterine PG output increases towards term and is enhanced by maternal undernutrition in pregnant ewes and mares. In both species, withdrawal of food ...
Windsor D P - - 1994
We compared conventional methods for laparoscopic and cervical artificial insemination (AI) to a transcervical AI procedure (Guelph System for Transcervical AI; GST-AI) for use with frozen semen in Merino ewes. The GST-AI procedure was performed by an experienced operator in Experiment 1 (771 ewes) and by 2 inexperienced operators in ...
Wallace J M - - 1994
Overfeeding during early pregnancy in ewes compromises pregnancy establishment and/or embryo survival. To determine whether high feed intakes after ovulation alter the secretory dialogue between the conceptus and the endometrium, 24 embryos (8-16-cell) from ewes fed maintenance rations were synchronously transferred in singleton on Day 3 of the cycle (oestrus, ...
Stern M - - 1993
Sequential surgical procedures in cleft lip/palate (CL/P) patients result in scar formation that is believed to be associated with midface growth retardation. By use of a previously developed fetal lamb model, wound healing characteristics were investigated after in utero CL repair. It is hypothesized that scarless healing after fetal CL ...
Hall J A - - 1993
This study was conducted to determine the effects of the corpus luteum (CL) of pregnancy and(or) the previously gravid uterine horn (g-UH) on the incidence and site of ovulation and the duration of luteal function in postpartum (PP) ewes. Ewes were laparotomized at d 60 to 80 of gestation and ...
Schrick F N - - 1993
The development of ovarian follicular and luteal structures during the estrous cycle and early pregnancy in ewes was examined. Ewes were treated with prostaglandin F2 alpha to induce estrus; they were placed with either two fertile or two vasectomized rams and observed for estrus twice daily. Beginning at estrus (Day ...
Leonard C - - 1993
The prevalence of enzootic abortion of ewes in Scotland was estimated over a period of five years. Between 1987 and 1991, 30.7 per cent of all flocks with breeding ewes in Scotland submitted ovine abortion material, and of these flocks 28 per cent showed evidence of the infection, giving a ...
Schrick F N - - 1993
Transrectal ultrasonography was used in ewes to determine the earliest day at which pregnancy could be detected, the number of embryos present, and the pattern of growth of the embryos. Twenty-one ewes were placed with 2 fertile rams and 20 ewes with 2 vasectomized rams. All ewes were treated to ...
Majeed A F - - 1993
We describe criteria for choosing Cesarean section to treat dystocia, and identify factors that appeared to influence the success of Cesarean section in Iraqi Awassi ewes under clinical condition. The study was conducted on 276 ewes presented for dystocia during the lambing seasons from 1985 to 1990. Out of 130 ...
Bretzlaff K N - - 1993
Hydrometra was diagnosed in 41 of 1,411 (2.9%) Rambouillet and crossbred Rambouillet-Booroola Merino range ewes that were being examined with ultrasonography for pregnancy. Most diagnoses of hydrometra (40 of 41) were made at a second examination of 581 of the 1,411 ewes 40 days after the first examination (6.9%). Some ...
Ward S J - - 1993
The onset and duration of ovarian activity was assessed in 19 March-born, pure bred Friesland ewe lambs. Blood samples were collected for progesterone assay from 6 August-27 March when the lambs were 5-12 months of age. From 23 January a harnessed vasectomised ram was introduced. Colour marks on the rumps ...
Narkewicz M R - - 1993
Fetal glucose production has been observed in the chronically hypoglycemic, hypoinsulinemic (HH) fetal lamb. The purpose of this study was to test the hypothesis that induction of hepatic gluconeogenic enzymes occurs in this condition. The activities of both mitochondrial and cytosolic phosphoenolpyruvate carboxykinase (PEPCK), fructose-1,6-diphosphatase, and glucose-6-phosphatase, three key enzymes ...
Buxton D - - 1993
Experimentally induced toxoplasmosis in pregnant ewes was treated with a combination of sulphamezathine and pyrimethamine. Fifteen untreated ewes gave birth to 14 live and six dead lambs whereas all the 15 lambs born to the 12 treated ewes were viable. The placental lesions were less severe, the gestation period was ...
Braw-Tal R - - 1993
Plasma immunoreactive inhibin (i-inhibin) was measured in Assaf and Booroola-Assaf (1/2 Booroola-1/2 Assaf) ewe lambs between the ages of 2 and 15 weeks and correlated with plasma FSH. I-inhibin concentrations were similar in both genotypes and was maximal at 2 weeks of life and decreased thereafter. These levels (mean +/- ...
García A - - 1993
Nonbred and pregnant ewes were examined ultrasonographically at intervals of 4 to 6 days on Days 17 to 34 after estrus. Each ewe was diagnosed as pregnant or nonpregnant, and a score for degree of certainty in the diagnosis was recorded. The goal of the study was to define criteria ...
Ruffing N A - - 1993
Chimeric sheep-goat pregnancies were established in 24 ewes and 29 does by transferring 251 embryos, prepared by the blastomere-aggregation technique, to 52 ewes and 61 does. Fifteen does experienced early pregnancy failure; however, term offspring were delivered by 24 ewes (17 lambs, 3 kids, 6 chimeras) and 14 does (6 ...
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