. Geeze, in the South Island of NZ I'd reckon that half the mares would still be struggling to hit a proper cycle & it doesn't stop them producing early winners.[/QUOTE]

So true. From what I hear thoroughbred studs seem to shut off serving around November here and thus most foals are on the ground early. I don't really know how they manage it. I guess it must be something to do with limited service numbers via live service or something.
At NRS only about 60 % of the foals are on the ground by 1 Dec. Dec tends to be the busiest foaling time at NRS... indicating how many mares are served in January.
That's in a early year. We were foaling upwards of 50 mares in January. When I started I was told that January foals always had problems and it would be a busy month nursing sick foals and diificult deliveries. I guess the numbers of problematic ones are not really higher but they can be more intense. I put it down to the mare more than anything. with serving to come after that most seasons. even after the stallions had gone back north.
I have a filly foaled 18 Feb. now 2, well grown and showing as much promise as any.