Determination and Prediction of Standardized Mineral Availabilities in Different Sources of Soybean Meals for Broilers

This study was conducted to estimate the standardized mineral availabilities (SMAs) of 10 soybean meals (SBMs) fed to broilers, and prediction models were developed and validated based on chemical properties. A total of 308 broilers (22 d of age), having similar initial body weights, were assigned at random to 11 dietary groups, with 7 replicate cages per group and 4 broilers per cage. On d 26, the broilers were given 4 h access to either a mineral-free diet or 10 test SBM-formulated diets. Fecal collection then proceeded for 52 h for SMA measurement. SMA-prediction models were established via stepwise regression using data from 9 SBMs, with the remaining SBM randomly used to validate the models’ accuracy. Soybean meal source influenced (p < 0.02) SMAs in broilers. Manganese (Mn) exhibited the lowest standardized availability (SA) at 30.4%, whereas calcium (Ca) showed the highest SA at 66.2%. Six prediction models for SAs of potassium (K), Ca, phosphorus (P), zinc (Zn), Mn, and copper (Cu) in SBMs for broilers were developed from the chemical properties, exhibiting R2 values spanning 0.487 to 0.964 (p < 0.04). The prediction model for standardized Ca availability provided the best goodness-of-fit (R2 = 0.964, p < 0.001). By contrast, this model for standardized Cu availability performed the worst (R2 = 0.487, p = 0.037). Except for Zn and Mn, the predicted SAs for Ca, P, K, and Cu were generally consistent with the measured values. Taken together, the constructed prediction models in our work can serve as a reliable tool for quickly predicting the SAs of Ca, P, K, and Cu in SBMs for broilers.