Using Reproductive Technologies

Whenever a female animal is used for more than one mating (MaxUse>1), this implies some form of reproductive boosting.

MateSel supports two female reproduction options:

• MOET (In-vivo fertilisation, Multiple Ovulation and Embryo Transfer)
• IVF/JIVET

Under the “Female Candidate Usage Settings” tab in MateSel, you have the option to elect which reproductive technology you are using:

Under MOET, all progeny from any one female have the same sire. Under IVF/JIVET, it is possible for all progeny to have a different sire (although they could conceivably all have the same sire, e.g. when that results in the lowest progeny inbreeding values and there is a high weighting on that).

Set female MaxUse numbers to 2 or more, this being the maximum number of planned pregnancies in recipient females for the donor females concerned. You can set these figures globally in Group Configuration or set them for individual females in the main data file. You might also set values for female MinUse, so that you have a standard value of range of number of planned pregnancies (or recipients) per female.

Note that the total number of matings input to MateSel (when not grouping) or reported by MateSel (when grouping) is the total number of planned pregnancies. So, an insemination into a female involving eight predicted embryo transfers is in fact eight matings, not one.

Take account of this when setting the target number of matings. Target number of matings can be grerater than the number of candidates to drive MOET and IVF/JIVET. Under IVF, you can reduce or avoid the incidence of duplicate matings. But note that duplicate matings can be nominated by MateSel for good reasons!

Note

When using MOET, MaxUse and MinUse constraints for males operate differently. An insemination into a super-ovulated female is taken in the code as a single use. However, the contribution of this to the reported Use value for that male is the number of matings (planned recipient pregnancies) for that female, such that the declared MaxUse for that male can be “legally” exceeded. Moreover, MustUse and MinUse constraints can be violated for males under MOET. These things are a consequence of how MOETing works: Matings are allocated to a female as for IVF/JIVET, but then, before evaluating the solution, the first allocated sire replaces all the other allocated sires for that female, and this is done after usage constraints have been applied.

The MOETing switch operates across the whole dataset – it applies to all females with MaxUse>1, either all IVF or all MOET. There could be a need to let this operate at the Group level – so that for example one Group of females are to be available as IVF donors, and a different Group in the same analysis are to be available as MOET females. We have never had such a request, but we may provide such functionality if sufficient demand arises.