Effects of the mycotoxin metabolite de-epoxy-deoxynivalenol (DOM-1) on embryo development and sperm motility in cattle.

Contamination of animal feed with Fusarium spp results in accumulation of mycotoxins including deoxynivalenol. In animals, deoxynivalenol is metabolized to de-epoxy deoxynivalenol (DOM-1), which is generally considered to be a non-toxic metabolite; however, recent studies demonstrated that DOM-1 can reduce steroid production and induce apoptosis in the bovine ovary. The objectives of this study were to assess the effects of DOM-1 on applied aspects of reproductive function in cattle, specifically sperm function and embryo development in vitro and follicle growth and superovulatory responses in vivo. The effect of naturally contaminated feed on superovulatory responses was assessed; a dose of 6 ppm deoxynivalenol increased blood DOM-1 concentrations to 20 ng/ml, but this did not alter the number of viable embryos recovered on day 7. However, intrafollicular injection of DOM-1 (100 ng/ml) directly into the growing dominant follicle resulted in cessation of follicular growth over the subsequent 3 days. Treatment with DOM-1 reduced motility of bull spermatozoa over a 10-h period in vitro. Addition of DOM-1 to oocytes in vitro during IVM did not alter rates of cumulus expansion and nuclear maturation, but treatment during IVF reduced the rate of blastocyst formation. These data illustrate that DOM-1 is more biologically active than previously thought and negatively impacted reproductive outcomes in cattle.

Effect of superovulation on uterine and serum biochemical parameters and its potential association with transferable embryos in Holstein dairy cows.

The objective of this study was to determine the effects of superovulation (SOV) on serum and uterine biochemical parameters, uterine bacteriology and cytology and number of transferable embryos (TE). Dairy cows were placed on a Presynch/CIDR Synch protocol. The SOV group was superovulated, induced in estrus, and inseminated, whereas the control group was induced in estrus and inseminated without SOV. Uterine bacteriology and cytology and uterine and serum biochemical parameters were measured at day 7 of the estrous cycle to start the SOV protocol, as well as on the day of embryo recovery (DER). The SOV group produced 7.5 ± 6.7 oocytes/embryos, of which 3.4 ± 4.7 were TE. Serum urea and E2 and uterine Glu, CK, LDH, TP, P4 and PGFM in the control group and serum P4 and PGFM and uterine LDH and PGFM in the SOV group were significantly higher (p < 0.01) at DER than day 7. At DER, uterine urea, LDH, PGFM and TP and serum urea, LDH, PGFM, and P4 concentrations were higher (p < 0.01) in the SOV group than the control. There was no significant variation in uterine bacteriology or cytology. Overall, these results infer that SOV affects both serum profile and uterine secretions, and that these changes may influence the number of TE.

Effect of synchronization of follicle-wave emergence with estradiol and progesterone and superstimulation with follicle-stimulating hormone on milk estrogen concentrations in dairy cattle.

Very little is known about the effects of hormonal synchronization of follicle waves and superovulation on the estrogen content of a cow's milk. The objective of this study was to determine the effect in dairy cows of synchronization with estradiol-17ß (E2) and progesterone (P4) on milk E2 concentrations and to compare these levels with those achieved during superstimulation for 4 d with porcine follicle-stimulating hormone (FSH). The milk E2 concentrations were raised significantly above pretreatment levels (P < 0.05) for 2 d after synchronization, the mean peak being 40.2 ± 18.5 (standard error) pg/mL and the pretreatment mean 1.5 ± 0.5 pg/mL. The mean peak E2 concentration during ovarian stimulation was 4.4 ± 0.7 pg/mL. The mean E2 concentration was significantly higher (P < 0.05) after synchronization than during superstimulation for the 1st milking after synchronization but not subsequent milkings. The milk estrone concentrations were above pretreatment levels for 1 d after synchronization and were not different from those observed during superstimulation.

Il y a peu d'information sur l'effet de la synchronisation hormonale de la vague folliculaire et de la surovulation sur la quantité d'oestrogène dans le lait de la vache. L'objectif de cette étude était de déterminer l'effet de la synchronisation avec le 17ß-estradiol (E2) et la progestérone (P4) sur les concentrations de E2 dans le lait et de les comparer avec celles mesurées après stimulation avec la hormone folliculostimulante (FSH). Des vaches laitières ont été synchronisées avec E2 et P4 et surstimulées pendant 4 jours avec la FSH porcine. Le protocole de synchronisation a augmenté significativement (P < 0,05) les concentrations E2 dans le lait par rapport aux niveaux du prétraitement pendant les 2 jours suivant la synchronisation (concentrations maximales de 40,2 ± 18,5 pg/mL contre 1,5 ± 0,5 pg/mL prétraitement). Ces concentrations étaient significativement plus élevées (P < 0,05) que celles observées pendant la surstimulation (4,4 ± 0,7 pg/mL) pour la 1ère traite après la synchronisation. Les concentrations de l'estrone dans le lait étaient plus élevées que celles du prétraitement pour 1 jour après synchronisation, et elles n'étaient pas différentes des niveaux observés pendant la surstimulation.(Traduit par les auteurs).