Adequate nutrition is imperative to a good embryo transfer program. The term flushing refers to a rising gain in nutrition or energy level more specifically over a period of time. If your donor and recipient animals are on a maintenance diet; 60 days prior to programming a rise in feed up to 2 or 2.5 pounds per head per day would be adequate (depending on the quality of feed/hay). Once the IVF program is completed donors can be placed on the selected diet of owner’s choice. It is our recommendation that recipients are maintained on the diet until pregnancy detection.
Donors in “show shape” or in a body condition score (BCS) of 4 or 5 (BCS range is 1-5) are overweight. This is an issue when placing them into an IVF program. It is recommended that these donors gradually lose weight by decreasing their ration over a period of 60-90 days prior to flush date and be in a BCS of 3 at time of synchronization.
Justification: This rising plane of nutrition can help stimulate a population of follicles on the ovaries of the donor to be more responsive to FSH stimulation. For recipient females this can result in a higher quality corpus lutuem at transfer, thus resulting in higher pregnancy rates.
Obese animals typically do not respond to stimulation as well, have shorter estrus receptivity periods, and have longer recoveries, and higher chance of complications from the aspiration procedure. Therefore, bringing obese donors down to pasture shape or “working clothes” or BCS 3-3.5 is recommended.