多分もっと簡単な方法あると思うけど、こんな感じで。
<?php
>>> \App\Service::orderBy('created_at', 'desc')->take(30)->get()->map(function($obj){ return $obj->toArray(); });
=> <Illuminate\Database\Eloquent\Collection #00000000407506fc000000004d667cc2> [
[
"id" => 1,
"user_id" => 1,
"name" => "開発中なサービス",
"created_at" => "2015-05-07 17:21:38",
"updated_at" => "2015-05-07 17:21:38"
]
]
>>>
真中部分をコピペでDBSeederにとかとか。