Execute multiple curl cmds with sleep and send output to file

First off, I am, in no way a Unix/Linux expert, so please bear with me. Also, I sure hope I've selected the proper topics for this question...

I need to run a few thousand curl cmds but I'm having difficulties figuring out how to go about doing this.

1. The curl is an XPOST (e.g. JSON)
For example:
curl -XPOST -H 'name1: value1' -H 'name2: value2' -H "Content-type: application/json" -d '{ "name3": [{"blah1": "blah1","aaa1": "blah2"}]}' 'http://domain.com'
curl -XPOST -H 'name1: value1' -H 'name2: value2' -H "Content-type: application/json" -d '{ "name3": [{"blah2": "blah2","aaa2": "blah2"}]}' 'http://domain.com'
curl -XPOST -H 'name1: value1' -H 'name2: value2' -H "Content-type: application/json" -d '{ "name3": [{"blah3": "blah3","aaa3": "blah2"}]}' 'http://domain.com'

The thing is I need to run this in a script so that there is a delay between each one. Also, once 1 curl is run, I get back a result which I'd like to save.

I thought I could just load all of the curl cmds in a text file and run something like:

while read line; do $line; sleep 5; done < input_curl.txt >> output_curl.txt

The resulting curl response would be something like:
{"name2":"value2","resultname1":resultvalue1,"resultvalue2":"resultname2","resultname3": etc etc...

My thought was that I'd be able to run each curl, line by line, then have it sleep for 5 seconds, and then run the next one. And, the curl result would be writen to output_curl.txt. Of course, that doesn't work.

Any help would be greatly appreciated.

Thanks,
Larry