Reproductive performance parameters

The estrus rate (ER) is defined as the proportion of animals that were in estrus per 100 animals included. All animals in estrus were inseminated. The farrowing rate (FR) is defined as the proportion of animals that farrowed per 100 inseminations. The farrowing efficiency index (FEI) is defined as the proportion of animals that farrowed per 100 animals included and is therefore an innovative parameter taking into account both ER and FR in only one figure. It is calculated as the number of farrowings divided by the number of gilts and sows enrolled post-weaning or post-synchronization. Only animals inseminated within 7 d pw (n = 484) are taken into account, since animals coming into estrus later than 7 d pw (n = 26) are considered as subfertile [30].