17 research outputs found

    Ovarian characteristics and in vitro nuclear and cytoplasmic oocyte maturation in Duroc and Landrace pigs

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    Differences in total number of piglets born per litter are observed between the Norwegian Duroc (ND) sire and Norwegian Landrace (NL) dam line. The aim of this study was to evaluate ovarian characteristics, and in vitro nuclear and cytoplasmic oocyte maturation in both breeds. One day after weaning, follicular phase ovaries were collected. Ovary length and weight were measured and the number of follicles (< 3 mm and 3–8 mm) was counted. Cumulus-oocyte complexes (COCs) were collected and matured for 48 hr. To assess cumulus expansion, COC area was analysed at 0 and 20 hr. Nuclear maturation and cortical granule (CG) distribution were analysed at 20 and 48 hr, and total glutathione (GSH) was measured at 48 hr to further elucidate cytoplasmic maturation. In first parity sows, a smaller ovary length and fewer 3 to 8 mm follicles were observed in ND compared to NL. For all sows, ND COCs covered a significantly smaller area at 0 hr, but a higher cumulus expansion ratio was observed at 20 hr compared to NL (364 ± 46% versus. 278 ± 27%, p < 0.001). At 20 hr, more ND oocytes exhibited advanced stages of nuclear maturation, while more NL oocytes showed advanced stages of CG distribution. Nuclear maturation to MII stage at 48 hr did not differ between ND and NL oocytes (90.1% and 87.7%, respectively). Moreover, no significant differences were observed for GSH content or CG distribution after maturation. In conclusion, differences with regard to ovarian characteristics as well as to cumulus expansion, and nuclear and cytoplasmic oocyte maturation at 20 hr were observed between the breeds. Further studies are required to determine if this subsequently affects in vitro fertilization and embryo development.publishedVersio

    Effects of feeding naturally contaminated deoxynivalenol diets to sows during late gestation and lactation in a high-yield specific pathogen-free herd

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    Abstract Background The most prevalent Fusarium mycotoxin in grains is deoxynivalenol (DON). Contamination of swine feed with DON can result in reduced consumption and poor growth performance. Gestating and lactating sows need sufficient feed intake for fetus development during late gestation and milk production and body maintenance during lactation. Therefore, there is considerable concern in modern piglet production about the effects of DON contamination in sow feed. Most previous studies in sows have been done under experimental conditions, with DON levels ≥2.8 mg/kg feed. The aim of the current field trial was to investigate the effects of feeding grains that are naturally contaminated with more realistic levels of DON on sows during late gestation and lactation. Methods In a commercial, high-yield specific pathogen-free piglet production unit, 45 Norwegian Landrace × Yorkshire sows were fed three diets from 93 ± 1 days of gestation until weaning of the piglets, and average daily feed intake (ADFI), body weight (BW), production and reproduction performance, as well as sow blood parameters were recorded. Diets were made from naturally contaminated oats, with three concentration levels: 1) control (DON < 0.2 mg/kg), 2) DON level 1 (1.4 mg DON/kg), and 3) DON level 2 (1.7 mg DON/kg). Results Sows that were fed DON level 1 and 2 diets showed a 4–10% reduction in feed consumption during lactation, compared with sows in the control group. However, the DON-contaminated diets did not significantly affect sow BW or backfat thickness. Similarly, there were neither effects on production or reproduction performance, nor on blood parameters in the sows. The effects on skin temperature were variable. Conclusion Naturally contaminated diets with realistic, moderately increased DON levels, fed during late gestation and lactation in a modern high-yield piglet production farm, had limited effects on sow health and production

    Cervical immune activation during the luteal phase may compromise subsequent trans-cervical ram sperm transport

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    International audienceWorldwide, cervical artificial insemination using frozen–thawed semen yields low pregnancy rates. The only exception to this is in Norway, where vaginal insemination with frozen–thawed semen yields pregnancy rates in excess of 60% and which has been attributed to the specific ewe breed used. Our previous work demonstrated differences in cervical gene expression at the follicular phase of the estrous cycle in ewe breeds with known differences in pregnancy rates. In this study, we characterized the cervical transcriptome of the same ewe breeds [Suffolk, Belclare, Fur, and Norwegian White Sheep (NWS)] during the luteal phase, as an optimal environment at the luteal phase could better prepare the cervix for sperm migration through the cervix at the subsequent follicular phase. High-quality RNA extracted from postmortem cervical tissue was analyzed by RNA sequencing. After stringent filtering, 1051, 1924, and 611 differentially expressed genes (DEGs) were detected in the low-fertility Suffolk breed compared with Belclare, Fur, and NWS, respectively. Gene ontology analysis identified increased humoral adaptive immune response pathways in Suffolk. Increased expression of multiple immune genes supports the presence of an active immune response in the cervix of Suffolk ewes, which differentiates them significantly from the other three ewe breeds. Inflammatory pathways were upregulated in the Suffolk, resulting in higher expression of the potent pro-inflammatory cytokines. Therefore, higher levels of pro-inflammatory cytokines indicate unresolved inflammation in the cervix of the low-fertility Suffolk breed that could contribute to reduced cervical sperm transport in the next follicular phase
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