The Herald spoke to a dozen jockeys and most self-test regularly and have obeyed the rules, knowing that if they go to the track they will have to test again anyway.
But with positive cases, close contact rules and some not willing to risk infecting others when feeling unwell even after testing negative, the jockey ranks are thin.
"We know of some jockeys who have had Covid and we have no reason to believe they aren't reporting it and standing down so we are confident our protocols are working," says New Zealand Thoroughbred Racing chief executive Bernard Saundry.
"But we aren't going to disclose other people's personal medical conditions. If the jockeys want to discuss that publicly that is their right but we are testing every jockey at every meeting and there isn't a lot else we can do."
Saundry says splitting this weekend's two major meetings helps trainers engage the jockeys at a level they want, and knows this weekend may not be a one-off.
"If the situation arises where we have to keep meetings separate to have enough jockeys available then we will do that.
"That could mean one meeting per Saturday in the North Island for even a couple of weeks but we will monitor numbers and keep people informed."
Trentham is now the only thoroughbred meeting in the country on Saturday but it is top class, with the $400,000 New Zealand Oaks, a star-studded $260,000 Levin Classic and the $80,000 Cuddle Stakes.
Self Obsession has opened the $2.30 final field favourite for the Oaks after drawing barrier eight while stablemate Imperatriz is the $2.40 favourite for the Levin Classic, with both to be ridden by Michael McNab.