I am currently reading The Heart of Haiku by Jane Hirshfield. In it, many examples of haikus translated from Japanese are given. However, in their English form, they lack the rhythm and meter of Haiku. Does this take away from their meaning? If so, in what way? In music, songs' lyrics are often translated loosely to maintain the melody and rhythm. Does an equivalent process occur for music?
Douglas Hofstadter wrote a wonderful meditation on translation, the book Le Ton Beau de Marot. It contains literally scores of translations of the same poem from French into English. Each translation preserves some aspects of the original: meter, rhyme, various aspects of tone, wordplay, vowels, consonants. Some are close, some are loose. Some are whimsical, some are serious.
Each of them is the same poem; each of them is different from all others.
There is no way to capture everything about a poem in translation. You can't even read the same poem twice: the "translation" from the page into your head will always vary a little. A great poem, I'd say, is one that will vary more between readings, making it evergreen.
I don't think it's fair to say that translation "takes away" from the meaning of the poem. There was never any single "meaning" for it to detract from. A translation adds to it, creating a new poem which is somehow conceptually related, but the original remains right where it was.
A poem -- indeed, any text -- is a dialogue between its author and its reader. The "meaning" of that dialogue is the change it produces in the reader. The author never really knows the reader's state to start with, and can't point to a unique transformation that they can be certain will take place. The author may have a variety of hopes for it, and the totality of those hopes are expressed in the text as you see it. Change a single letter and you get a different thing. Substitute a word for its "synonym" and you still get a different thing. That's why Tom Robbins had a character declare, “There are no such things as synonyms!"
So in every translation, something is lost, and something is gained. That "something" could be anything, any aspect of language. You can hope to arrive at a similar effect that a native reader would have had upon reading the original, but even that native reader won't have a single "meaning" for the poem. So how close you come to achieving that effect is itself a new dialogue.
Oh yes. But it should not stop you reading in translation!
Tang Dynasty Poetry, for instance, has an additional layer of meaning based on the ideograms used. Reading in translation removes this dimension.
Rhythm can be used to impart meaning, but in my experience this is fairly rare.
Many of these elements will be described in commentary on the poems in the translated works, so my advice is, where possible, look for translations with the most annotation, and, where possible, read multiple translations.