Table 6.

Welfare issues and minimization strategies.

Procedure	Animal welfare issue	Minimization strategy for the con
Ovarian stimulation	Ovarian stimulation increases the number of available follicles, helping in this way to maximize the collection of oocytes per anesthesia and reducing the number of interventions as much as possible. Con: Injections can be stressful for the animals. Ovarian stimulation may accelerate the progression of certain existing genital tract pathologies.	Exclusion of animals with severe genital tract pathologies from the OPU program.
Full anesthesia	Full anesthesia removes the necessity for mechanically restraining the animals during the procedure—with all the associated risks of injury. Con: May cause severe complications such as aspiration, respiratory depression, hypoxemia, hypertension, pulmonary shunting and ventilation/perfusion mismatch.	Specifically designed ethorphine-free protocol already tested on 500+ animals. The protocols employ four different drugs in order to lessen their individual dosages. For each drug with the exception of ketamine hydrochloridre a specific antidote is available to immediately reverse the effects. Preliminary ultrasound screening may remove possibility of unnecessary use of anesthesia. Ovarian stimulation, maximizing the number of oocyte recovery for each intervention.
Transrectal ultrasound-guided oocyte recovery	Con: Non sterility of the procedure, with the risk of infection.	Cleaning and disinfection of the rectum prior the procedure adopting operative standards from human medicine. Ovarian stimulation, maximizing oocyte recovery for every intervention.