As explained by this answer, adding trackers to torrents may speed up their download, as well as allow you to share the files with more peers.
Is there some way by which I can automatically add a list of trackers to every torrent I add on my client (which is uTorrent), besides the ones embedded in the .torrent file?
Or do I need to do this manually for each torrent?
Don’t. Do NOT AT ALL.
Unless someone else has already added the tracker, you won’t find anyone. And if they’ve just added the tracker, guess what, you’ll already see them on the tracker that came with it.
If you’re really sure there’s peers out there you’re not seeing, then turn on DHT. It’s that simple.
Just adding trackers however not only doesn’t ‘speed anything up’ (trackers have NOTHING to do with speed, just like the number of phone books you have to look a phone number up doesn’t make a conversation any faster) you’re sending out more traffic, which means you’ve less to use for transfers.
You’re also adding bandwidth and load to trackers, for no gain, so you’re actually harming trackers.
Still think it’s a good idea? (if you want to see the maths just from TPB putting 4 tracker on every torrent, I did it here. With 50M peers, it works out about 20Tb of useless duplicated data PER TRACKER, PER MONTH.