Sandrine Freret

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We have previously characterized 2 haplotypes (Fertil+ and Fertil-) of Holstein dairy cows differing in 1 female fertility quantitative trait locus (QTL) located on chromosome 3 (QTL-Fert-F-BTA3) between positions 9.8 and 13.5 cM. This QTL is composed of 124 genes, some of them being involved in metabolism or reproduction. Primiparous Fertil+ and Fertil-(More)
Improvement of reproduction in dairy cows has become a major challenge in dairy production. We have recently shown that dairy cows carrying the 'fertil-' haplotype for one quantitative trait locus (QTL), affecting female fertility and located on the bovine chromosome 3, had a significantly lower conception rate after the first artificial insemination than(More)
Prim'Holstein heifers selected for the "Fertil-" homozygous haplotype of QTL-Female-Fert ility-BTA3 showed a greater rate of early pregnancy failure and slower embryo development after IVM suggesting lower oocyte quality than those selected for "Fertile+". We aimed to ascertain intrafollicular factors related to lower oocyte quality in "Fertil-" cows.(More)
Currently Mycobacterium avium subsp. paratuberculosis (MAP) infection is diagnosed through indirect tests based on the immune response induced by the infection. The antigens commonly used in IFN-γ release assays (IGRA) are purified protein derivative tuberculins (PPD). However, PPDs, lack both specificity (Sp) and sensitivity (Se) in the early phase of(More)
The objective of this study was to determine whether fish oil supplement has an effect on adipose tissue lipid profiles and gene expression in postpartum dairy cows. Holstein cows were supplemented with either long-chain n-3 polyunsaturated fatty acid (PUFA; protected fish oil) or control PUFA (n-6; toasted soybeans) for 2mo after calving (n=23 per diet).(More)
In sheep, the 'ram effect' induces out-of-season fertility and good nutrition increases prolificacy. This experiment determined if fatness or short-term nutritional supplementation modified the response to the 'ram effect'. A group of 48 Île-de-France ewes were fed diets that produced groups with body-condition scores (BCS) of >3.0 and <2.0. Within each BCS(More)
The dynamics between Mycobacterium avium subspecies paratuberculosis (MAP) infection and the immune response of goats naturally exposed to MAP were studied in a herd where the clinical expression of paratuberculosis had been observed. Four generations of goats were observed over a 33-month period: mothers of three different generations (G1, G2, G3) and(More)
The objective of this study was to determine the effect of a rumen-protected fish oil supplement on the production and reproduction variables in postpartum dairy cows. Holstein cows (n=46) were given a basal total mixed diet plus one PUFA supplement: n-3 (n-3; protected fish oil; 1% dry matter intake (DMI); n=23) or control (n-6; toasted soybeans; 1.8% DMI;(More)
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(More)
The first ovulation induced by male effect in sheep during seasonal anoestrus usually results in the development of a short cycle that can be avoided by progesterone priming before ram introduction. In elucidating the involvement of the hypothalamic-pituitary-gonadal axis in the occurrence of short cycles, the effects of progesterone and the time of(More)