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Results 201 - 250 of 869
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Savabieasfahani Mozhgan - - 2006
Increased occurrence of reproductive disorders has raised concerns regarding the impact of endocrine-disrupting chemicals on reproductive health, especially when such exposure occurs during fetal life. Prenatal testosterone (T) treatment leads to growth retardation, postnatal hypergonadotropism, compromised estradiol-positive feedback, polycystic ovaries, and infertility in the adult. Prenatal dihydrotestosterone treatment failed to ...
Tan Clifford - - 2006
BACKGROUND: Panadol Extend is a modified-release paracetamol formulation in which each 665 mg tablet contains 69% slow-release and 31% immediate-release paracetamol. There are no data on Panadol Extend pharmacokinetics in overdose. It is unknown whether the paracetamol treatment nomogram can be used to make decisions regarding the toxicity of this ...
Valderrábano J - - 2006
A study was made of the effect of body fat stored by ewes in early pregnancy on the subsequent immune response to gastrointestinal parasites around parturition. Pregnant ewes were given access to a lucerne pelleted diet either ad libitum (H) or at approximately 0.70 of their maintenance requirements (L) from ...
Zhang Qi - - 2006
This study was designed to determine the regulatory effect of glucocorticoid and estradiol on expression of ovine intrauterine membrane-associated prostaglandin E(2) synthase 1 (mPTGES1) in late gestation and at labor. For gestational and labor groups, 16 pregnant ewes from 95-147 d gestational age (dGA) and four pregnant ewes at spontaneous ...
Sloman Katherine A - - 2006
The physiological and behavioural responses of two size groups of oscar (Astronotus ocellatus) to hypoxia were studied. The physiological responses were tested by measuring M(O(2)) during decreasing environmental oxygen tensions. Larger oscars were better able to maintain oxygen consumption during a decrease in P(O(2)), regulating routine M(O(2)) to a significantly ...
Val-Laillet David - - 2006
The present study investigated the rewarding effects of nonnutritive sucking on the development of a filial preference. Two experiments were conducted to test whether nonnutritive visceral and oral stimuli have reinforcing properties independent from each other or act in synergy. Lambs could interact freely with their dam but were deprived ...
Kenyon P R - - 2006
AIM: To determine the effects of liveweight (LW) and duration of teasing with vasectomised rams prior to breeding on both the mating performance and pregnancy rate of ewe hoggets. METHODS: Five hundred and forty-six (1/2) Romney x (1/4) Texel x (1/4) Finnish Landrace ewe hoggets were weighed and randomly assigned ...
Ledezma-Torres R A - - 2006
The purpose of the present investigation was to generate pregnancy associated glycoprotein (PAG)-profiles throughout pregnancy in a heterogenous sample of sheep using a radioimmunoassay with a heterologous antibody (anti-caPAG(55+59), #708) and utilize them for the purpose of pregnancy detection. From 2 weeks after the introduction of males into the breeding ...
Song Gwonhwa - - 2006
Cystatin C (CST3) is a secreted inhibitor of lysosomal cysteine proteases cathepsins B (CTSB) and CTSL, which are abundant in the ovine endometrium and conceptus. In mice, cathepsins and cystatins play important roles in implantation and placentation. This study determined effects of the estrous cycle, pregnancy, progesterone (P4), and interferon-tau ...
Liu Xinyu - - 2006
In the ewe, a rise in circulating concentrations of FSH preceding follicular wave emergence begins in the presence of growing follicles from a previous wave. We hypothesized that prostaglandin F(2alpha) (PGF(2alpha)) given at the time of an endogenous FSH peak in cyclic ewes would result in synchronous ovulation of follicles ...
Al-Gubory K H - - 2006
Ovine placental lactogen (oPL) is produced by the conceptus trophectoderm and is secreted into both the maternal and fetal circulations. The present study was designed to examine in vivo the luteotropic effect of recombinant oPL (roPL), as determined by monitoring progesterone concentration and cycle length (experiment 1), and the antioxidative ...
Costine Beth A - - 2007
During maternal recognition of pregnancy, the conceptus stimulates endometrial secretion of PGF2alpha and PGE2. However, PGF2alpha is less effective in causing luteal regression in pregnant than in non-pregnant ewes. Experiments were conducted to elucidate mechanisms for reduced luteal sensitivity to PGF2alpha during maternal recognition of pregnancy. Corpora lutea (CL) were ...
Freking B A - - 2006
A resource population of ewes derived from Dorset and Romanov grandparents was generated over 5 yr to provide genotypic and phenotypic data to estimate effects of each callipyge genotype on component traits of reproduction. Effects on ovulation rate were estimated from data recorded by examination of ovaries from serially slaughtered ...
Ali A - - 2006
This study was undertaken to describe the development of individual follicles and corpora lutea (CL) in Ossimi ewe lambs at different seasons of the year in the subtropics. Seven ewe lambs underwent daily ultrasonographic examination for 20 interovulatory periods (IOP) during spring, winter and autumn. Ovarian follicles >or=2 mm and ...
Harmeyer J - - 2006
The impact of pregnancy on ketone body disposal during a hyperketonaemic clamp was examined by tracer isotope dilution techniques in seven 12 h fasted sheep in three reproductive states, in the dry non-gestating period, late in gestation and during early lactation. After a sampling period of 60 min under basal ...
Karen Aly - - 2006
The aim of the present study was to evaluate and, compare the accuracy of transabdominal ultrasonographic (US) and the progesterone (P4-RIA) and ovine pregnancy-associated glycoprotein (ovPAG-RIA) tests for the discrimination between single and multiple pregnancy in sheep. One hundred pregnant AwassixMerino ewes were scanned by transabdominal ultrasonography (3.5 MHz linear-array ...
Spencer Thomas E - - 2006
Endometrial gland development is a postnatal event in the ovine uterus that can be inhibited epigenetically by chronic exposure of ewe lambs to a synthetic progestin after birth. The uterus of neonatally progestinized ewes lack endometrial glands and display a uterine gland knockout (UGKO) phenotype. Progestin ablation of endometrial gland ...
Scott Jennifer L - - 2006
Leucocyte changes after insemination may affect conceptus implantation, but information regarding leucocyte populations in the ruminant reproductive tract is limited. The present study investigated changes in leucocyte populations and distribution in the ovine reproductive tract following oestrus and insemination. Fifteen ewes were mated with a ram for 1 h and ...
Bazer Fuller W - - 2006
Interferon (IFN)tau, a Type I IFN produced by the conceptus trophectoderm, is the pregnancy recognition signal in ruminants that prevents development of the endometrial luteolytic mechanism. In addition, IFNtau acts in a paracrine manner on the ovine endometrium to induce or increase expression of type I IFN-stimulated genes (ISGs). Initially, ...
Parraguez Víctor H - - 2006
Fetal growth and newborn weight from ovine gestations at high altitudes (HA) are greater in ewes that live at HA for several generations than in those native to low altitudes (LA) exposed to HA only during pregnancy. Because the placenta is a key regulator of fetal growth, the present study ...
Casas E - - 2005
Objectives were to estimate effects of sire breed (Dorset, Finnsheep, Romanov, Texel, and Montadale), dam breed [Composite III (CIII) and northwestern whiteface (WF)], mating season (March and May), and their interactions on reproductive traits of mature F1 ewes in spring mating seasons. A total of 1,099 F1 ewes produced 1,754 ...
Kleemann David O - - 2006
Wide variation in reproductive performance of commercial Merino flocks in south central Australia is the result of genetic and environmental influences that are both amenable to change through decisions of management. Relationships of reproductive traits (estrus, ovulation, fertility, fecundity, lamb survival, and lambs weaned) with variables that graziers can change ...
Kenyon P R - - 2005
AIMS: To determine if sward height grazed by ewes in mid- to late-pregnancy affects subsequent indices of colostrum intake by twin and triplet lambs, and the extent of the variation in colostrums intake between twin and triplet litter-mates. METHODS: Blood samples were collected from 75 twin and 46 triplet litters, ...
Kenyon P R - - 2005
AIM: To determine whether short-term progesterone supplementation post mating or shearing of ewes in early pregnancy affected either the proportion of ewes that lambed or that had multiple lambs, or the birthweight of lambs. METHODS: Romney ewes (n=457) were synchronised in oestrus using controlled internal drug-releasing (CIDR) devices containing progesterone, ...
Kenyon P R - - 2005
AIM: To determine the effects of liveweight (LW) and use of teaser rams prior to mating on both the mating performance and pregnancy rate of ewe hoggets. METHODS: Romney hoggets (n=841) were weighed and randomly assigned to one of two treatment groups; either exposed to seven harnessed, vasectomised (teaser) rams ...
Wallace Jacqueline M - - 2005
Overnourishing the singleton-bearing adolescent sheep throughout pregnancy promotes maternal tissue synthesis at the expense of the nutrient requirements of the gravid uterus. Consequently, the growth of the placenta is impaired and results in the premature delivery of low-birth-weight lambs relative to moderately fed adolescents of equivalent age. To establish if ...
Abecia J A - - 2006
To determine the ovarian response to the ram effect after treatment with melatonin, on 8 March, 71 Rasa Aragonesa ewes were randomly assigned to either the treatment group and given an 18mg melatonin implant or the untreated group. On 19 April (day 0), rams were introduced into the flock. Melatonin ...
Loi Pasqualino - - 2006
We report on cloning experiments designed to explore the causes of peri- and post-natal mortality of cloned lambs. A total of 93 blastocysts obtained by nuclear transfer of somatic cells (granulosa cells) were transferred into 41 recipient ewes, and pregnancies were monitored by ultrasound scanning. In vitro derived, fertilized embryos ...
Grazul-Bilska Anna T - - 2006
The objectives of this study were to: (1) evaluate the pregnancy rates after transfer of embryos produced in the presence or absence of epidermal growth factor (EGF) during in vitro maturation, and (2) compare several variables of the gravid uterus on day 140 after fertilization in single, twin and triplet ...
Gaskins C T - - 2005
Breeding ewes to lamb at 1 yr of age can improve profitability for some production systems. The first objective of this study was to evaluate the effect of age and weight at breeding and total postweaning weight gain on reproductive performance of ewe lambs. The second objective was to compare ...
Bordes Agnes - - 2005
BACKGROUND: The aim of this study was to evaluate the long-term outcome of autotransplantation of vitrified warmed hemi-ovaries into ewes. METHODS: Six hemi-ovaries from six ewes aged 6 to 12 months were vitrified. After dissection of the medulla, the hemi-ovarian cortex was stored at -196 degrees C in liquid nitrogen. ...
Bispham J - - 2005
Maternal nutrient restriction at specific stages of gestation has differential effects on fetal development such that the offspring are programmed to be at increased risk of a range of adult diseases, including obesity. We investigated the effect of maternal nutritional manipulation through gestation on fetal adipose tissue deposition in conjunction ...
Kleemann David O - - 2005
High levels of reproductive loss have been reported in commercial Merino flocks (n=68) from the cereal/livestock and high rainfall zones in South Australia (Kleemann DO, Walker SK. Fertility in South Australian commercial Merino flocks: sources of reproductive wastage. Theriogenology 2005;63:2075-88). Relationships between reproductive traits (estrus, ovulation, fertility, fecundity, lamb survival) ...
Reix Philippe - - 2005
This study was aimed at validating the use of a custom-made wireless pulse oximeter in freely moving lambs, using radiotelemetry transmission. First, measurements obtained simultaneously using the new, wireless oximeter and a standard commercially-available pulse oximeter (Nonin 8500) were compared in five lambs during 5min episodes of normoxia, hypoxia and ...
Luther Justin S - - 2005
The objective of the current study was to determine the effects of hormonal treatments on ovarian follicular development and oocyte quality in anestrous ewes. Multiparous crossbred (RambouilletxTarghee) ewes were given melatonin implants (MEL) and/or controlled internal drug release (CIDR) devices in conjunction with follicle stimulating hormone (FSH) during anestrus (March-May). ...
Kleemann David O - - 2005
To identify reasons for low fertility in the Merino in South Australia, we defined the extent and sources of reproductive wastage in flocks of maiden (n=14) and mature age (n=54) Merino ewes managed on 43 properties over 4 year. In a second study, reproductive wastage was examined in a very ...
Meurisse M - - 2005
The influence of estrus, pregnancy, parturition, and maternal experience on the expression of estrogen receptor-alpha (ERalpha) was investigated in hypothalamic and limbic regions of the sheep brain, using immunocytochemistry. Four days before parturition, previous maternal experience was associated with a higher density of ERalpha-labeled neurons in the paraventricular and supraoptic ...
Vonnahme Kimberly A - - 2005
Nitric oxide (NO) production has been shown to increase uterine blood flow and be elevated in ewes carrying multiple fetuses during late gestation. Vascular endothelial growth factor (VEGF) has been reported to increase eNOS expression and NO production in endothelial cell cultures. As angiogenesis and vasodilatation of the uterine and ...
Wu W X - - 2005
In sheep, fetal cortisol stimulates the conversion of progesterone to estradiol in late gestation initiating labor. It is unclear whether an intact fetal hypothalamic-pituitary-adrenal (HPA) axis is required to induce the estradiol-triggered subsequent endocrine changes including enhanced intrauterine prostaglandin (PG) synthesis associated with the onset of labor. We have shown ...
Oliver Mark H - - 2005
Maternal undernutrition during pregnancy can lead to impaired metabolic regulation in postnatal offspring. The extent to which such abnormalities are determined in early gestation, and may already be present in fetal life, is unknown. We studied the effect of periconceptional undernutrition on fetal growth and metabolism in late gestation. Ewes ...
Deligiannis C - - 2005
A novel method for oestrus-ovulation synchronization in sheep followed by fixed time insemination is presented herewith. Mature dry ewes (n = 28) of Karagouniko breed being at an unknown stage of the oestrous cycle, were used during the middle of breeding season. The treatment protocol consisted of an initial administration ...
Naqvi S M K - - 2005
The lambing rate obtained following cervical artificial insemination (AI) with frozen semen in sheep is low mainly due to the inability of frozen-thawed sperm to traverse the tortuous nature of the cervical canal. Although acceptable fertility has been attained by circumventing the cervical barrier through laparoscope aided intrauterine AI, the ...
Paganoni, Beth Louise
Ewes at two sites were fed to be either condition score 2 or 3 by Day 90 of pregnancy and then grazed on various levels of feed-on-offer (FOO) from Day 90 of pregnancy until weaning, to investigate whether nutrition of Merino ewes during pregnancy and lactation affected the muscle, fat ...
E.K. Bawa
The objective of the study was to investigate the results of Novidium (Homidium chloride) (R) chemotherapy on the effects of Trypanosoma. vivax infection on pregnancy and reproduction in Yankasa (YK) and West African Dwarf (WAD) ewes, infected in their first, second and third trimester of pregnancy. Three groups of ewes, ...
Parraguez V Ctor H - - 2005
The present studies assessed the effect of hypobaric hypoxia on fetal lamb growth in high-altitude (HA) and low-altitude (LA) native ewes. Growth patterns of fetal biparietal diameter (BPD), abdominal diameter (AD) and thorax height (TH) were described by consecutive ultrasound measurements throughout the entire pregnancy. Three groups of animals were ...
Ungerfeld R - - 2005
Two experiments were performed to determine the endocrine and ovarian changes in medroxyprogesterone acetate (MAP)-primed ewes after ram introduction. Experiment 1 was performed during the mid-breeding season with 71 ewes primed with an intravaginal MAP sponge for 12 days. While the control (C) ewes (n = 35) were in permanent ...
Ponsky Lee E - - 2004
PURPOSE: We evaluate the feasibility of applying minimally invasive techniques for fetal vesicostomy. We also evaluate whether transuterine fetal vesicostomy can be performed laparoscopically. MATERIALS AND METHODS: A total of 25 pregnant ewes were time dated at approximately 90 days of gestation. With the animals under general anesthesia a low ...
Loose Jan M - - 2004
OBJECTIVE: To determine whether activin A levels reflect oxygen availability in basal and hypoxic conditions in the late pregnant fetus and newborn lamb. DESIGN: In vivo animal experimental study. SETTING: Department of Physiology, Monash University. POPULATION: Chronically catheterised fetal sheep in late gestation. METHODS: Fetal hypoxia was induced at 125 ...
Val-Laillet David - - 2004
The establishment of filial bonding in sheep relies on the success of the first suckling bouts. Previous work has shown that colostrum ingestion facilitates the development of a preference for the mother. We conducted a series of experiments to investigate the influence of quantitative and qualitative factors linked to fluid ...
Ng'ang'a C J - - 2004
An investigation on the occurrence of peri-parturient rise in trichostrongylid nematode egg output in breeding ewes was carried out on a Ranch in the semi-arid area of Kajiado District in Kenya during the period May 1999-April 2000. During the study, 20 ewes randomly selected from the breeding stock and 20 ...
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