Variability in feed quality between populations of Acacia saligna (Labill.) H. Wendl. (Mimosoideae)—implications for domestication

Due to its favorable agronomic traits, Acacia saligna has the potential to be used as a perennial forage crop in the agricultural regions of southern Australia. The feed quality of populations from across the natural range of A. saligna was examined using in vitro and spectroscopic methods. The mean feed quality of A. saligna was found to be low in comparison to other forage species commonly used in southern Australia, this was due primarily to low dry matter digestibility (DMD) and high protein precipitable tannin (PPT) levels. The content of crude protein (CP) and fibre were both moderate, and the content of essential minerals was found to meet the basic requirements for sheep, with the exception of phosphorus. There was a significant level of variation in fodder quality between the sampled populations. The feed qualities of some populations were found to approach or exceed what is desirable for a livestock feed. The results showed that A. saligna has the potential to produce feed of an acceptable quality. Further development of the species as a crop requires the detailed characterisation of the variation. Some of the variation in feed quality was correlated with genetic variation in the species, and was poorly correlated with known environmental variation. It may therefore be genetically controlled, suggesting that the feed quality of A. saligna could be improved through selection and breeding.