Nutritional value of low-phytate barley evaluated in rats

The nutritional effects of two barley mutant lines with an altered phosphor us (P) profile and phytate content (13 and 43% of total P, respectively) we re studied. Because grain quantities were limited, rats served as a model f or the pig in a feeding trail. Four groups of five Wistar rats (weighing 65 g) were fed the low-phytate lines, the mother variety and a mixture of bar ley varieties. All diets were supplemented with vitamins and minerals excep t for P, calcium, zinc and copper. The apparent digestibility of P was impr oved by up to 13% in the mutant lines. Although all diets were very similar in their zinc content, only rats fed the mutant lines had a net absorption and a positive zinc balance, indicating the improved availability of this mineral. Rats appear to be a suitable model for P utilization in pigs and c an thus provide plant breeders with a mineral bioavailability assay for use at an early stage.