I upgraded to 1.4.2 and no longer have this issue, even with a high latency connection of 550ms. This can probably be closed.
I'd like to echo that I would consider this one of the worst flaws of Minecraft. Chunk errors have been around for a long time in various forms. Dinnerbone did some work to make it better in 1.3, but they still occur frequently. I think everyone has gotten used to them at this point, and yes there are workarounds, but it's still super annoying.
It seems like it should be handled better though. My latency isn't that high, ~200ms. That's not great, but it seems like it would be pretty common.
I know that you can do it, and have always been able to feed animals multiple times. I guess I was pointing out that it's unexpected and would be more helpful if it prevented me from wasting wheat on them.
Jon brings up a good point. If it heals them like it does with dogs, then this is understandable behavior.