The first week of the new handicapping system –  under which non-feature races must contain a horse weighted at the minimum of 53kg in an attempt to induce an 8kg spread – has caused chaos for jockey managers with weight-restricted riders who are booked weeks in advance for mounts.

A number of benchmark races at Canterbury on Saturday featured the weights being dropped so the new minimum of 53kg could be met, meaning jockeys who can't ride at such a light weight have been forced to renege on longstanding commitments.

The AJA has sought a meeting with Racing NSW over the festive period to air their concerns and Fairfax Media spoke to several jockeys on Wednesday who were privately aggrieved at the new system, which could see heavier riders giving up close to 25 per cent of their earnings through lost bookings.

But of more concern are fears jockeys whose opportunities may now dry up will starve themselves to lower their minimum riding weights to tailor the new system.

"We've insisted a meeting with Racing NSW to discuss the full ramifications of the system and the meeting needs to take place as an absolute priority because the health and wellbeing of NSW's riders is being put at risk due to the decisions and policies that have been put in place now," the AJA said in a statement provided to Fairfax Media.

Some of Sydney's top riders – including the country's most celebrated – Hugh Bowman, Melbourne Cup-winning hoop Blake Shinn, Godolphin's retained rider James Doyle and premiership hopeful Josh Parr – face the prospect of sitting in the jockeys' room on a more regular basis given they don't ride light weights.

Racing NSW rubber stamped the handicapping changes only three days before Christmas, arguing a greater spread in weights would increase field sizes and eradicate instances of horses carrying big weights above 60kg under compressed scales. It is due to be reviewed after six months.

But the changes have already rankled the jockeys.

"There's still plenty of rides for the heavier jockeys and I don't think they're going to be as affected as they think they're going to be," Racing NSW chief executive Peter V'landys said. "There is no doubt that the spread of weights has improved field sizes and made racing in the metropolitan area a lot more competitive.

"We did a survey of the jockeys before we introduced it about going to a 53kg minimum and I met with some of them and they were keen to experiment with the 53kg. Naturally some people are going to be impacted, but we've got to act in the best interests of the industry as a whole when we do these things."

The $150,000 Canterbury Classic features nine declared starters – excluding emergencies – carrying 53kg while in other key Magic Millions lead-up races preferred jockeys have lost rides due to the changing weight scale.

Stewards have given Christian Reith permission to ride Le Cordon Bleu 1kg over his allotted weight of 53kg in the Canterbury Classic given there are so few featherweight jockeys in Sydney this weekend.

"It's been very frustrating for everyone," said leading jockey manager Bryan Haskins, whose roster includes Bowman and Shinn. "If it doesn't appear to work it is usually not working.

"You've got to think of the owners too and they are excited when they're told Hugh Bowman is going to ride their horse and then come acceptance time they're screaming for a 53kg jockey because the weights have been lowered."

Sydney's leading trainer Chris Waller has long argued the previous handicapping system was forcing horses to carry too much weight, which at least has been alleviated under the recent changes.

"The concept is right because I'm just dead against horses carrying big weights, but we've now got to be very careful of what jockeys we book," he said.

"We're ringing an owner telling them they've got Hugh Bowman or Blake Shinn or Tye Angland to ride – it might even be a 54kg rider – but when the weights come out we've found they've dropped. We need to find that happy medium.

"We shouldn't be afraid to try things and I commend them for that, but at this stage it's very hard booking jockeys."

Added Peter Snowden: "I just can't understand how we can be changing weights at acceptance time. All hell broke loose on Tuesday when we realised what was going to happen and we lost four riders on our horses for the Canterbury meeting and we've had to get new jockeys.

"I'm all for reducing the topweights, but we shouldn't be reducing the minimum to 53kg and we're going to end up with a situation where instead of booking jockeys two or three weeks in advance to get your rider of preference we'll be doing them on a Tuesday and Wednesday morning."