It is possible to add an object in LWJGL without using translation function (glTranslatef) ? and if it is possible does this improve somehow performance ?
glTranslatef doesn't add objects in LWJGL but translates OpenGL's built-in modelViewProjection matrix. Based on the fact that you're using
glTranslatef I would say that you're using legacy OpenGL where this is the only way of matrix translations and these calls are not hardware accelerated.
Possibly the best way to improve your performance is to switch to modern OpenGL, bring your own math library with your own matrices (LWJGL's utility library provides you with these but you can look for other libraries if you want to) and start using shaders.
glTranslate is deprecated and slow, so you shouldn't use that function anyway and rather use the matrix operations, like
Matrix4f.translate(modelPos, modelMatrix, modelMatrix);
to transform your models.
and feed a complete Model-View-Projection matrix to the shader as described in the link above. Another way to gain a little more performance would also be to use Uniform Buffers instead, but I'm not sure if lwjgl does support that, yet.