he may not have been interested if he had only just had his bottle.
you can try not giving him the whole bottle, and then doing it... or give it to him between feeds.
I think a lot of babies aren't that keen to start with... it's a bit odd for them when they're just used to drinking milk!
you might wanna try just pureeing some carrot or something to start with, it'll be cheaper than jars if he doesn't want it! Also, to start with they only want small amounts and aren't jars too much for one feed?