Genetic and non-genetic parameters related to embryo production in superovulated Large White (LW) gilts.

The aim of this study was to identify genetic and non genetic factors which might affect results of embryo production of Large White (LW) cyclic gilts from data collected in one herd during 6 years. Donors (n=1060) were synchronized with a progestogen treatment and luteolysis was induced 13-15 days later by 2 injections of cloprostenol. To stimulate follicular development 800IU eCG was then injected 24h later, followed by 500IU hCG 48h later.

Selection of impubertal gilts by ultrasonography optimizes their oestrus, ovulatory and fertility responses following puberty induction by PG600.

In a group of gilts, occurrence of puberty is spread over several weeks. The optimal time to apply puberty induction is therefore difficult to define, as treatment of puberal gilts is meaningless. Changes in uterine aspect around puberty can be detected by ultrasonography.

Post-insemination level of feeding does not influence embryonic survival and growth in highly prolific gilts.

This study was designed to investigate the influence of a high level of feeding during early gestation on embryonic survival and variability of embryonic development in hyperprolific LW gilts. During the 7 days after the first insemination, gilts were fed either 4 or 2kg daily of a gestation diet (groups High, n=15, and Control, n=13, respectively). Gilts were slaughtered at 27.

Induction and synchronization of ovulations of nulliparous and multiparous sows with an injection of gonadotropin-releasing hormone agonist (Receptal).

The objective of this study was to determine if administration of a set dose (10 microg) of a gonadotropin-releasing hormone agonist, buserelin (Receptal; Rc), at set times after altrenogest (Regumate; RU) treatment or after weaning was able to induce and synchronize ovulation in female swine (gilts and sows). The pubertal (n=187) gilts were allocated to four groups, all synchronized with RU. Group 1 (RU) was inseminated twice at detected estrus, Group 2 (RU+Rc120) and Group 4 (RU+Rc104) received 10 microg Rc at 120 or 104 h after the end of RU treatment, respectively, and Group 3 (RU+eCG+Rc104) was treated with 800 IU equine chorionic gonadotropin (eCG) at 24h and Rc 104 h after the end of RU treatment, respectively.

Development of OPS vitrified pig blastocysts: effects of size of the collected blastocysts, cryoprotectant concentration used for vitrification and number of blastocysts transferred.

Unhatched blastocysts from Large White hyperprolific gilts (n=103) were identified, measured and vitrified using the Open Pulled Straw (OPS) technique to evaluate the effects of the collected blastocyst size and cryoprotectant concentrations used for vitrification, and the number of embryos transferred per recipient. Vitrified/warmed blastocyst viability was estimated in vitro, as the percentage of embryos developing after 72h, and in vivo, on pregnancy Day 30. In the in vitro study, we compared the use of three cryoprotectant concentrations (16.

The effectiveness of the stereomicroscopic evaluation of embryo quality in vitrified-warmed porcine blastocysts: an ultrastructural and cell death study.

The objective of this study was to analyze the validity of the stereomicroscopic evaluation of vitrified-warmed (V-W) porcine blastocysts. Unhatched blastocysts were obtained from Large-white gilts (n=10). Blastocysts (n=156) were vitrified using the Open Pulled Straw technology.

[Cryopreservation and transfer of pig in vivo embryos: State of the art].

The present review article describes the development of porcine cryopreservation and transfer of embryos and the sanitary regulations related to these technologies. Rapid progress has been made during the last decade in cryopreservation by using vitrification which involves a very rapid cooling rate. Currently, this technology is suitable for morulae and blastocysts and to date, more than 300 piglets are born after surgical transfers of vitrified embryos.

Piglets born after non-surgical deep intrauterine transfer of vitrified blastocysts in gilts.

The aims of this study were: (1) to evaluate the effect of the number of previous estrus of recipient gilts on effectiveness of intrauterine insertion of a flexible catheter designed for non-surgical deep intrauterine catheterization during diestrus in pigs; and (2) to determine the farrowing rate and the litter size after non-surgical deep intrauterine embryo transfer (ET) of porcine blastocysts vitrified by the open pulled straw (OPS) method. In experiment 1, 27 large white hyperprolific gilts (LWh) with 2-6 previous estrus were used. Intrauterine insertions of the flexible catheter were carried out at day 5.

Ultrastructure and cell death of in vivo derived and vitrified porcine blastocysts.

Morphological and molecular signs of injury and cell death and subsequent regeneration following vitrification of porcine blastocysts were evaluated by light (LM) and transmission electron microscopy (TEM) as well as TUNEL/propidium iodide (PI) nuclear staining followed by confocal microscopy (CSM). In vivo derived blastocysts were assigned to one of the following four groups: Controls-(1) fixed immediately after collection (C0h) and (2) after 24 hr culture in vitro (C24h) and vitrified embryos-(3) fixed immediately after vitrification and warming (V0h), and (4) after 24 hr of culture upon warming after vitrification (V24h). Observation by LM and TEM showed that the V0h embryos displayed collapse of the blastocoele cavity (BC) and cell swelling, a general distension or shrinkage of mitochondria and massive increase in the amount of vesicles, vacuoles, and secondary lysosomes (SLs).

In vitro development following one-step dilution of OPS-vitrified porcine blastocysts.

The objective of this experiment was to compare the in vitro survival and hatching rates of OPS-vitrified porcine blastocysts obtained after conventional (three-step dilution) or direct (one-step dilution) warming procedures. Expanded blastocysts were collected by laparotomy from weaned crossbred sows (n=7) on Day 6 of the cycle (D0: onset of estrus). Vitrification was performed as described by Berthelot et al.

Characterization of human CD55 and CD59 transgenic pigs and kidney xenotransplantation in the pig-to-baboon combination.

New transgenic pigs expressing combinations of regulators of complement activation and other molecules are needed to resist xenograft hyperacute rejection (HAR) and to further analyze and treat xenograft rejection. Double transgenic pigs for human CD55 (hCD55) and human CD59 (hCD59) using the promoter of the human elongation factor 1 alpha gene were generated, and their kidneys were transplanted into nonimmunosuppressed baboons. hCD55 and hCD59 were mainly expressed by the endothelial cells, and these cells showed increased resistance to complement-mediated lysis.

Vitrification of porcine embryos at various developmental stages using different ultra-rapid cooling procedures.

In this study, three different vitrification systems (open pulled straw: OPS; superfine open pulled straw: SOPS; and Vit-Master technology using SOPS: Vit-Master-SOPS) were compared in order to investigate the influence of cooling rate on in vitro development of vitrified/warmed porcine morulae, early blastocysts, or expanded blastocysts. Embryos were obtained surgically on Day 6 of the estrous cycle (D0 = onset of estrus) from weaned crossbred sows, classified and pooled according their developmental stage. A subset of embryos from each developmental stage was cultured to evaluate the in vitro development of fresh embryos; the remaining embryos were randomly allocated to each vitrification system.

Transfer of vitrified blastocysts from one or two superovulated Large White Hyperprolific donors to Meishan recipients: reproductive parameters at Day 30 of pregnancy.

The present study was designed to determine the effect of pooling embryos from two donors on the reproductive success of transfer of vitrified/warmed porcine blastocysts. Intact blastocysts were collected from superovulated Large White Hyperprolific gilts (n = 24) on Days 5-5.5 after artificial insemination.

Determination by echography of uterine changes around puberty in gilts and evaluation of a diagnosis of puberty.

Three experiments were carried out to evaluate the use of ultrasonography in assessing the onset of puberty in gilts. In experiment 1, gilts (n = 17) were scanned 3 times per week beginning at 133 and continuing until 187 days of age. The ultrasonic appearance of the uterus was described, quantified and compared with the reproductive status observed at slaughter.

Birth of piglets after OPS vitrification and transfer of compacted morula stage embryos with intact zona pellucida.

In swine, five to six days post-insemination, morulae and blastocysts are collected together after uterine flushing. The purpose of this study was to vitrify zona pellucida-intact morulae with Open Pulled Straw (OPS) technology and obtain piglets after transfer. Morulae (200) were vitrified after a two-step equilibration in ethylene glycol, dimethyl sulfoxide and sucrose in Hepes-buffered TCM199 + 20% NBCS medium (TCM).

Relationship between peri-oestrus progesterone levels and time of ovulation by echography in pigs and influence of the interval between ovulation and artificial insemination (AI) on litter size.

Two methods for the determination of ovulation were compared to one ultrasonography performed 5 times a day. Time of ovulation by echography was 40 +/- 5.8 h (mean +/- SD) after the onset of oestrus.

Piglets born after vitrification of embryos using the open pulled straw method.

Morulae and unhatched blastocysts from Large White hyperprolific (LWh) and Meishan (MS) gilts were selected to test an ultrarapid open pulled straw (OPS) vitrification method with two media. The viability of vitrified/warmed embryos was estimated by the percentage of embryos that developed to the hatched blastocyst stage in vitro or by birth after transfer. In Experiment 1, two cryoprotectant dilution media were compared for cryopreservation of MS and LWh blastocysts: TCM was a standard Hepes-buffered TCM199 + 20% NBCS medium and PBS was a PBS + 20% NBCS medium.

Intrauterine infusion of high doses of pig trophoblast interferons has no antiluteolytic effect in cyclic gilts.

In the pig species, the preimplanting trophoblast is known to synthesize and secrete high amounts of interferon during early development. Previous experiments in cyclic gilts using total conceptus secretory proteins suggested that porcine trophoblastic interferons, unlike those of ruminants, exert no effect on the luteal cycle. In the present experiment, cyclic Meishan gilts were divided into two groups, cannulated on both uterine horns, and given daily injections of either a placebo or increasing doses of a mixture of recombinant interferon-gamma and interferon-delta, on Days 11-14 of the estrous cycle.

Presence of leukaemia inhibitory factor and interleukin 6 in porcine uterine secretions prior to conceptus attachment.

Leukaemia inhibitory factor (LIF) plays an important role in embryo development and implantation. We detected peak LIF activity in porcine uterine luminal fluids (ULF) at day 12 of gestation and during day 7 and 13 of the oestrous cycle. A radio-receptor competition assay showed the presence of a molecule in ULF specifically binding to human LIF receptor (LIF-R).

Differential expression, during the estrous cycle and pre- and postimplantation conceptus development, of messenger ribonucleic acids encoding components of the pig uterine insulin-like growth factor system.

The temporal patterns of endometrial expression for mRNAs encoding insulin-like growth factor-I (IGF-I), IGF-II, IGF-binding protein-2 (IGFBP-2), and the type I IGF receptor (IGF-IR) were elucidated in cyclic and pregnant pigs. Peak levels of IGF-I mRNAs occurred on day 12 in cyclic and early pregnant gilts, while IGFBP-2 mRNA levels were lowest on day 10. Pregnant gilt endometrium had higher levels of both RNA classes than the corresponding cyclic endometrium.

Oestrus and LH responses to oestradiol during lactational anoestrus in Chinese Meishan and large white sows.

To investigate endocrine mechanisms associated with the occasional occurrence of fertile oestrus during lactation in the high prolific Chinese Meishan (MS) breed, the incidence of oestrus and changes in plasma luteinizing hormone (LH) levels before and after oestradiol benzoate (OB, 15 micrograms/kg body weight) administration on day 22 was compared in 4 MS and 6 Large White (LW) sows. All sows exhibited oestrus in response to OB. Only 1 sow (MS) ovulated in response to OB, became pregnant and farrowed.

Production of two species of interferon by Large White and Meishan pig conceptuses during the peri-attachment period.

Antiviral activities present in uterine flushings from pregnant Large White, Large White 'hyperprolific', and prolific Meishan gilts, between Days 8 and 20 of gestation were compared. Flushings (20 ml) from all gilts between Days 14 and 20 were positive in an in-vitro interferon (IFN) assay using vesicular stomatitis virus as a challenge infection. Highest antiviral activities (of up to 400,000-1,200,000 total Units/flushing) were obtained at Day 16 of gestation, i.

Interferon-gamma gene and protein are spontaneously expressed by the porcine trophectoderm early in gestation.

The nature and the source of the antiviral activity found in the reproductive tract of pregnant gilts early in gestation were analyzed. Two antigenically distinct antiviral activities were found in uterine flushings and in supernatants of conceptus-conditioned culture medium between days 12 and 20 of gestation, using Madin Darby bovine kidney cells and vesicular stomatitis virus as a challenge in the antiviral bioassay. One component was antigenically identified as interferon-gamma (IFN-gamma).

[Pathologic consequences of a severe influenza outbreak (swine virus A/H1N1) under natural conditions in the non-immune sow at the beginning of pregnancy].

Pathological consequences of a severe outbreak of swine influenza (H1N1 virus) in the non immune sow at the beginning of pregnancy, under natural conditions. A sudden acute outbreak of fever, depression, anorexia and coughing in a group of nulliparous sows from a herd that was currently under epidemiological investigation lead to build a particular disposal of observation. The clinical signs were daily recorded including rectal temperature.

Conceptus development in large white and prolific Chinese Meishan pigs.

Large White (LW) and Meishan (MS) gilts were killed on Days 8, 10, 11, 12, 14 and 30 of gestation. Mean diameters (mm) for MS and LW conceptuses, respectively, were: Day 8, 0.45 and 0.