Evaluation of a second uterine flushing on embryo recovery in Nelore cows

Abstract

The objective of the present study was to evaluate the effect of a second uterine flushing on number of recovered embryos. Cyclic Nelore cows (n= ) were used as donors. Animals were kept under grazing conditions in a farm at Mamborê, Paraná state. Cows were submitted to two sessions of multiple ovulation 80 days apart. At a random stage of estrus cycle (Day 0) donors received an intravaginal device with 1.9 g of progesterone (CIDR; Pfizer; Brasil). Twenty four hours later (Day 1) cows were injected with 2.5 mg/ IM of Estradiol Benzoate (Estrogin, Farmavet, Brasil). Between Day 5 and Day 9, donors received decreasing doses of 250 UI of FSH (Pluset; Calier, Brasil). On Days 7 and cows received 25 mg/ IM of dinoprost (Lutalyse, Pfizer, Brasil) and progesterone implants were removed 12 hs later. Artificial insemination was performed 12 and 24 hours after estrus detection. The first embryo recovery was performed 7 days after AI with the Foley catheter positioned in the uterine body. A total of 1.000 mL of PBS (Embriocare, Cultilab, Brasil) was used in a closed system of uterine flushing, with a 70 µm filter. Recovered uterine fluid was evaluated under a stereomicroscope (SMZ 654, Nikon, Japan) and embryos were classified accord to IETS (1998). Twenty four hours later, the second uterine flushing was performed following the same procedure. Results were analyzed by t-Student test (p < 0,0 ). After 12 superovulation procedures, we obtained a total of 131 ova/embryo, being 91.4% (120/131) from the first uterine flushing and 8.4% (11/131) from the second one. We conclude that the second uterine flushing provided a small improvement on the number of recovered embryos. The feasibility of this method is restricted to special conditions, when the value of the embryos supports the additional work.