A total of 202 cattle manure (CM), 165 poultry manure (PM), and 174 pig slurry (PS) samples were collected in France and Reunion Island' major livestock regions. Samples were analyzed for their dry matter (DM), total Nitrogen (N) and ammonium (NNH4) contents. After homogenization of the spectral responses (standardization, removal of interference due to sample holding devices) of the three NIR spectrometers, NIR models were shown to valuably characterize the agronomic potential of fresh manures. As an example, the standard error of the NIR model for N of PM fresh samples, was only twice to three-folds those reported for models developed with finely homogenized (ground, dried) samples. Even done on a small set, direct "on farm" characterization of PM with a portable apparatus after a rough homogenization of the samples showed promising performance. This can represent a valuable alternative to expensive and time-consuming reference methods in the laboratory.