The effect of rumen bolus containing vitamins and minerals on superovulatory outcome and embryo quality in cows

In this study, it was aimed to reveal the effect of giving vitamin A, β-carotene, vitamin E, Selenium and Zinc before the superovulation (SOV) protocol with slow-dissolving rumen boluses on the SOV response, number and quality of embryos. In the study, 22 healthy Holstein breed primiparous cows were randomly selected between 150-318 lactation days. Donors were randomly divided into two groups: Group Bolus (GB) (n=11) and Group Control (GB) (n=11). 21 days before the superovulation protocol to GB; While the control group was given a bolus containing vitamin A, β-carotene, vitamin E, selenium and zinc, no treatment was applied. To evaluate vitamin and trace mineral levels, blood samples were taken 21 days before SOV (pre-SOV) and on the day of embryo flushing (post-SOV). Analyzes were carried out by inductively coupled plasma-mass spectrometry and HPLC. There was no statistical difference between vitamin and trace mineral blood levels between GB and GC before and after SOV (p>0,05). While retinol and β-carotene increased after SOV in each group (p<0,05), Se GB decreased (P<0,05). At the end of the study, an average of 21,18±2 follicles were counted on the day of estrus, and an average of 18,91±2,07 follicles were counted (p>0,05). The average number of ovulated follicles was determined to be 17,45±2,57 in GB and 17±2,37 in GC (p>0,05). A total of 161 (mean 14,64±1,85) corpus luteum (CL) were detected in GB, and a total of 155 CL (mean 14,09±1,67) were detected in GC (p>0,05). A total of 115 embryos were produced in GB and 86 embryos in GK (p>0,05). Of the collected embryos, 103 in GB and 65 in GK were of transferable quality (p>0,05). 12 non-transferable embryos were produced in GB and 21 non-transferable embryos in GK (p>0,05). A correlation was detected between the number of follicles on the day of estrus and transferable embryos in GB (r=0,64), and a correlation between the number of follicles on the day of estrus and non-transferable embryos in GB (r=0,75). There is a correlation between the number of ovulated follicles and the number of CL (r = 0,82) and the number of transferable embryos (r = 0,71) in GB, and between the number of ovulated follicles and non-transferable embryos in GK (r = 0,76) was detected. Additionally, a correlation was determined between the number of CLs in GB and the number of transferable embryos (r = 0,85) and the total number of embryos (r = 0,87). It was observed that bolus administration containing vitamins and trace minerals in the diet did not cause significant increases in blood levels and did not cause a significant change in the number of follicles and CLs and therefore the number of embryos developing after SOV. Since individual differences are very important in superovulation and embryo production, selecting donors by taking these factors (historical SOV data) into consideration may be a better way to increase success.