Fermentation of soya-bean meal with Aspergillus usami improves phosphorus availability in chicks

The present study examined the effect of the fermentation of soya-bean meal with Aspergillus usami on phosphorus availability in chicks. Thirty 1-week-old male Leghorn-type chicks were divided into three groups and fed following each diet for 4 weeks: 1) a diet containing soya-bean meal (SBM diet; total phosphorus, 5.5 g kg−1 dry matter; nonphytate-phosphorus, 2.0 g kg−1 dry matter), 2) a diet containing soya-bean meal supplying inorganic phosphorus (SBM + P diet; total phosphorus, 7.7 g kg−1 dry matter; nonphytate-phosphorus 4.2 g kg−1 dry matter), or 3) a diet containing the fermented soya-bean meal (FSBM diet; total phosphorus, 5.6 g kg−1 dry matter; nonphytate-phosphorus, 3.6 g kg−1 dry matter). Body weight gain was significantly higher in the chicks fed the FSBM diet and the SBM + P diet than in those fed the SBM diet during the 4-week feeding trial. The 5-week-old chicks were killed and the left femur was collected at the end of the feeding period. Body weight gain, femoral dry weight, ash, calcium and phosphorus contents, as well as ash density, were significantly greater in the chicks fed the FSBM and SBM + P diets than in those fed the SBM diet. Body weight gain and femoral parameters did not differ between the chicks fed the FSBM diet and those fed the SBM + P diet. It was concluded that fermentation improved phosphorus availability of soya-bean meal in chicks and that dietary supplementation of inorganic phosphorus was not necessary for chicks fed FSBM.