We have two Saddleback gilts bought as weaners who are now about a year old. The original plan was to put them to the boar we have but as they grew up we realised he might well be a bit senior for their first time - being rather a hefty chap. (We bought in a mature sow who has just had a litter by him - the plan was to breed a replacement boar of his bloodline but only two males in the litter, neither of registration standard. We will probably give her another go as soon as this lot are weaned.)
Anyway, back to the gilts. We decided to use AI for their first litters and started to try and track their cycles. By doing measurements and noticing very small changes we reckoned we had one worked out. So semen arrived today and first insemination was administered while she was having her tea. She did not seem to show any inclination to stand in a convincing way but, after one moment of consternation on her part, things seemed to go ok.
My reason for writing is that the second gilt - from the same litter - is proving very hard to work out. We have not been able to detect any changes or signs of coming on heat over the last three months. If anyone has any words of wisdom we would welcome them.