The Scots, competitive at the start, were eventually ripped apart by Test players Grant Elliott and captain BJ Watling, both of whom scored centuries in an imposing 347 for six. Scotland were bowled out for 148 in reply with 16.3 overs to spare.
Bradburn said: "We are a better side than we showed out there today. It was evident that we are lacking the quality of cricket that we came up against today and it's a short, sharp reminder of where we need to be to compete at this level.
"Having said that, I thought that for 35 overs we could be pretty pleased. We used the conditions well, bowled quite smart and fielded well.
"When we had them five wickets down I thought we could have kept them to about 270, which would have been par, but we didn't respond well to the pressure in the last 15 overs."
Bradburn, who guides Scotland to the World Cup early next year, where their first game is against the full New Zealand side, was forced to reflect that the Kiwis' second-string had an enviable depth of talent.
"I know the quality they have and I suppose a few months ago I would have been pleased with a performance like that," he said. "It has been nice to meet up with a few old friends but my focus is firmly on Scotland and getting the team prepared for the World Cup. The two sides were a long way apart today - they played extremely well - but we have to learn from it and bounce back in Sunday's game."
The sides reconvene in Ayr tomorrow before the series concludes in Edinburgh on Thursday. The Scots went into the first encounter without a clutch of first-choice players but it is doubtful that, even had they been at full strength, they would have lived with the star-studded tourists, most of whom have full cap experience.
The astonishing late onslaught from Elliott and Watling was not just impressive for the rate at which runs were accumulated but also for the way the pair preserved their wickets. Having come together at 139-5 they put on 185 for the sixth wicket in just 19 overs.
Scotland were in touch with the run-rate and, at the half-way stage in their innings, were even ahead of their rivals at the equivalent stage. The difference was that Bradburn's side had lost seven wickets and lacked anyone with the firepower of Elliott and Watling. There was some resistance from Richie Berrington, whose sixth-wicket stand with Michael Leask offered real promise until the Stoneywood-Dyce player was superbly caught on the boundary by Ish Sodhi for 21.
Berrington went on to top-score with 41, including five fours and the only six of the Scotland innings, before he became the last of Scott Kuggeleijn's three victims. David Murphy then kept the Kiwis waiting for their victory with 31 not out.
Earlier, there was little hint of the carnage to follow as Scotland's bowlers made an encouraging start after Matt Machan had won his first toss and elected to insert the tourists.
Anton Devcich had reached 17 at a run-a-ball when Ali Evans found the outside edge and Murphy took the catch. Hamish Rutherford, who spent a season at Ayr seven years ago, miscued a delivery from Safyaan Sharif and further inroads were made when Majid Haq bowled Dean Brownlie for 40 and Evans trapped Daryl Mitchell in front.
Colin de Grandhomme, the former West of Scotland professional, hit a swashbuckling 32 but when Haq removed him, hopes were high that Scotland could keep the total within manageable proportions. These were dashed as Elliott and Watling launched a brutal counter-attack.
Elliott moved smoothly through the gears, and accelerated after reaching 50 but his clean hitting was eclipsed by Watling, whose second 50 came from only 13 deliveries. He finished unbeaten on 119 from 71 balls, including seven maximums.