The influence of supplemental alpha-galactosidase and phytase in a vegetable ration for dogs on the digestibility of organic components and phytate phosphorus

The dry feeds contain a higher amount of vegetable ingredients and conseque ntly more alpha-galactosides, which are known to cause flatulence in dogs, and more phytates. Because mammals do nor produce endogenous phytase, the p hosphorus source in the phytate molecule is not available. In addition, phy tates can form complexes with several divalent cations. In this experiment alpha-galactosidase (AG), phytase (PT) or both were added to a nearly compl ete vegetable ration. The digestibility coefficients were determined by usi ng the total collection of faeces method. The AG significantly increased th e digestibility coefficients of dry matter, organic matter, crude protein, and N-free extract. As expected, the PT significantly increased the digesti bility coefficient of phosphorus. Fresh faecal samples were taken to determ ine the content of dry matter, pH, organic acids, biogenic amines and inosi tol phosphates (IP). The AG significantly reduced the content of propionic and lactic acid. The PT induced a significant reduction of the hexa-inosito l-phosphates without any influence on the content of the lower inositol pho sphates.