Improvement in embryo recovery using double uterine flushing

Abstract

The objective of the present study was to evaluate the effects of double uterine flushing on the recovery of embryos/ova in cattle. Two hundred and ten embryo recovery procedures were conducted using a double uterine flushing method, and the results were compared with 432 conventional single-flushing procedures. Cyclic Limousin ( n = 403) and Guzera ( n = 239) donor cows received an intravaginal progesterone releasing device and 2 mg of estradiol benzoate on Day 0. Between Days 5 and 9, donors received decreasing doses of FSH, which ranged from 200 to 300 IU ( Bos indicus) and 300 to 500 IU ( Bos taurus). On the afternoon of Day 7, donors received an injection of 500 μg cloprostenol and progesterone implants were removed 12 h later (morning of Day 8). Artificial insemination was performed between 14 and 26 h after first detection of behavioral estrus. Cows were randomly assigned to have embryos recovered by a double-flushing method ( n = 210) or the conventional single-flushing procedure ( n = 432). For the double-flushing procedure, after first flushing the whole uterus with 1 L of Dubelco’s Phosphate Buffered Saline (DPBS), a Foley catheter was positioned in the uterine body to permit refilling of the uterus with fresh DPBS (80–150 mL). The catheter was closed with the plunger of a disposable 5 mL syringe, and the donors were allowed to rest in a holding area for 30 min. Thereafter, a second flush was performed to recover the solution remaining in the uterus. Animals from the control group were subjected to a single uterine flush. From 210 double-flushing procedures, 1409 viable embryos were recovered. In comparison, from 432 cows receiving the single-flushing procedure, 1993 embryos were recovered. Double flushing increased ( P < 0.05) the number of embryos recovered per procedure compared to single flushing (6.7 ± 0.4 versus 4.6 ± 0.2, respectively; mean ± S.E.M.). When double flushing was performed, average recovered embryos/ova increased ( P < 0.05) from 8.3 ± 0.4 to 12.7 ± 0.7 in Limousin and from 7.9 to 11.5 in Guzera. Also, utilization of double flushing increased ( P < 0.05) the number of viable embryos from 4.7 ± 0.3 to 6.9 ± 0.5 in Limousin and from 4.5 ± 0.4 to 6.4 ± 0.7 in Guzera. Mean total embryos/ova was similar ( P > 0.05) between the control group and after the first uterine flushing in the double-flushing group; therefore, both flushings were conducted efficiently. In conclusion, double uterine flushing increased embryo recovery in cattle.