Ovarian parameters and fertility of dairy cows selected for one QTL located on BTA3
ABSTRACT Recently, one Quantitative Trait Locus (QTL) of female fertility located on Bos Taurus chromosome 3 (BTA3), QTL-F-Fert-BTA3, has been identified in Holstein breed. It is implied in the success rate after the first AI (AI1) in cow. The failure of pregnancy can be due to several factors involved in the different steps of the reproductive process. The aim of our study was to finely phenotype heifers and primiparous cows selected for their haplotype at the QTL-F-Fert-BTA3. We specifically studied the ovarian follicular dynamic and several fertility parameters. Females carrying the favourable haplotype "fertil+" or unfavourable haplotype "fertil-" were monitored by transrectal ultrasonography during their cycle before the first AI (AI1). Follicular dynamic was similar between the two groups. However, the length of the estrus cycle was shorter in heifers than in primiparous cows and two-wave cycles were shorter than three-wave cycles, regardless of the age and the haplotype. The concentration of plasma anti-Müllerian hormone was correlated with the number of small antral follicles. It was higher in heifers than in primiparous cows, independently of their haplotype. The success rate at the AI1 was significantly higher in "fertil+" than in "fertil-" primiparous cows, 35 d after the AI1 (70% vs 39%). In both haplotypes, pregnancy failure occurred mainly before 21 d after AI1. The commencement of luteal activity after calving was significantly earlier in "fertil+" than in "fertil-" primiparous cows. Calving-AI1 and calving-calving intervals were similar between "fertil+" and "fertil-" primiparous cows. Taken together, "fertil+" and "fertil-" primiparous cows present a difference in the success rate after AI1 that is not explained by variations of ovarian dynamics.
- SourceAvailable from: Svetlana Uzbekova
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- "Dairy " Fertilþ " and " FertilÀ " cows were housed at the experimental herd of the INRA local experimental unit (Nouzilly, France) and rationed similarly. Physiological parameters such as growth, puberty, ovarian dynamics, energy balance, milk quality, and nutrition behavior have been reported for the local herd of 44 " Fertilþ " and " FertilÀ " female cows including 16 cows used in the present study, during the first lactation period  . Plasma anti-Müllerian hormone (AMH) concentrations were measured before the first lactation in these cows . "
ABSTRACT: Prim’Holstein heifers selected for “Fertil-” homozygous haplotype of QTL-F-Fert-BTA3 showed a higher rate of early pregnancy failure and slower embryo development after in vitro maturation (IVM) suggesting lower oocyte quality. We aimed to ascertain intrafollicular factors related to lower oocyte quality in “Fertil-” cows. Analysis of individual oocytes showed meiotic progression delay in “Fertil-” as compared to “Fertil+” dairy cows after in vivo and in vitro maturation (p<0.05). Expression of several genes localized to QTL-F-Fert-BTA3 or related to meiosis and MAPK pathway were analyzed in individual metaphase-II oocytes by real-time PCR. Energy metabolism, apoptosis, extracellular matrix and QTL’s genes were analyzed in surrounding CC. In vivo, significant decrease in prostaglandin synthase PTGES1 and PTGS2 expression coupled with lower PTGS2 protein abundance in cumulus cells (CC) and reduced expression of MOS in enclosed metaphase-II oocytes from “Fertil-” cows was observed. IVM strongly deregulated gene expression in CC and in oocytes as compared to in vivo; nevertheless, differential expression of several genes including MOS was observed between the two haplotypes. During IVM, PTGS2 activity inhibitor NS398 (50μM) led to lower expression of FASN (fatty acid synthase) in CC and of MOS in treated metaphase-II oocytes. By immunofluorescence, MOS protein was localized to a midbody-like contractile ring separating the polar body from the ooplasm, suggesting a role in the terminal stage of oocyte maturation. Our results suggest that factors involved in prostaglandin synthesis and lipid metabolism in CC could impair oocyte maturation and might be involved in the reduced fertility of “Fertil-” cows.Theriogenology 01/2013; DOI:10.1016/j.theriogenology.2013.11.013 · 1.85 Impact Factor
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- "All these females were selected for their homozygous haplotype " fertilϩ " or " fertilϪ " at one QTL-F-Fert-BTA3. Like their mothers, this first generation of heifers was phenotyped for growth, puberty and ovarian dynamics according to the methods described in Coyral-Castel, et al. . We used eight heifers (4 " fertilϩ " and 4 " fertilϪ " ) from this generation for the ovarian stimulation and OPU experiments. "
ABSTRACT: We have previously shown that Holstein cows selected for their homozygous favorable ("fertil+") or unfavorable ("fertil-") haplotype at one quantitative trait loci (QTL) of female fertility located on chromosome 3 (QTL-F-Fert-BTA3) had a different success rate 35 and 90 days after the first artificial insemination. To determine whether the lower fertility in "fertil-" animals could be related to oocyte quality, we analyzed the embryo development rate in vitro and the oocyte meiotic maturation in vivo in "fertil+" and "fertil-" heifers. In vitro maturation and fertilization of immature oocytes recovered by ovum pick-up from "fertil+" and "fertil-" heifers resulted in similar cleavage and blastocyst rates in the two haplotypes. However the percentage of expanded blastocysts and the number of cells per blastocyst were significantly higher in "fertil+". Oocytes from presumptive preovulatory follicles were analyzed after ovarian stimulation. A similar rate of immature (from prophase to metaphase-I) and mature oocytes (metaphase-II) was obtained in the two haplotypes, whereas a significantly higher percentage of oocytes from metaphase-I to metaphase-II was observed in "fertil+" compared to "fertil-" heifers. Since cumulus cells (CCs) could reflect the developmental competence of oocytes, we analyzed the expression of seven genes included in the QTL-F-Fert-BTA3 using real-time PCR in bovine CCs after in vivo or in vitro maturation, as a model of higher and lower competence, respectively. Transcript levels of TAGLN2, EEF1A1 and PIGM were higher in CCs after in vitro maturation (IVM) compared to in vivo maturation, whereas no difference was observed for IFI16, KIRREL, SPTA1 and PEX19 expression. The expression levels of all these genes in in preovulatory CCs were not significantly different between "fertil+" and "fertil-" heifers. In conclusion, the lower fertility of "fertil-" females could be partially due to a lowest quality of the oocytes and consequently of preimplantation embryo development.Theriogenology 03/2012; 77(9):1822-33.e1. DOI:10.1016/j.theriogenology.2011.12.028 · 1.85 Impact Factor
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ABSTRACT: High between-animal variability in the number of embryos produced by multiple ovulation and embryo transfer (MOET) and ovum pick-up and in vitro production (OPU-IVP) methods remains a major limit to the development of embryo biotechnologies in cattle. The measurement of anti-Müllerian hormone (AMH) endocrine concentrations in cows can help to predict their follicular and ovulatory responses to gonadotrophin treatment. The present study aimed to provide practical information for a simple prognostic method based on AMH measurement in Holstein cows. Accurate AMH concentrations could be measured with ELISA in blood or plasma. In cows undergoing repeated OPU protocols over 1 year, the AMH concentrations measured in plasma samples collected before each gonadotrophin treatment were found to be highly repeatable and were tightly correlated with follicular responses. From data obtained at both an experimental station and farm settings, it was possible to propose AMH cut-off values to identify low-responding cows. Gonadotrophin-stimulated cows producing fewer than 15 large follicles at oestrus and fewer than 10 embryos in MOET protocols could be discarded efficiently with plasma AMH concentrations below 87 and 74 pg mL(-1), respectively. In conclusion, we propose a prognostic method based on a single AMH measurement to improve the results of embryo biotechnologies.Reproduction Fertility and Development 09/2012; 24(7):932-44. DOI:10.1071/RD11290 · 2.58 Impact Factor