How should we evaluate soybean meal quality?

INTRODUCTION

The use of soybean meal in poultry diets can be tested for antinutritional factors, which is easily identified with ureatic activity and protein solubility in KOH analysis. This research aimed to evaluate soybean meal quality measured by ureatic activity and KOH solubility in poultry feed mills.

MATERIAL AND METHODS

For this analysis, 283 samples were obtained from a broiler feed mill located in Goiás, Brazil. Soybean meal samples were categorized by the KOH protein solubility in 5 groups: < 75%; 75-80%; 80-85%; 85-90% and > 90% and 5 other categories regarding ureatic activity: 0; 0.01; 0.011-0.05; 0.051-0.1 and > 0.1. Descriptive statistics was used to evaluate results.

RESULTS

The percentage of samples obtained were classified in 5 categories of protein solubility in KOH (%) and are presented in Table 1. For the categories of Ureatic activity index (Δ pH), the percentual values found for each of the 5 categories evaluated and are presented in Table 2. For protein solubility in KOH, it was observed that 60.41% of the samples analyzed presented levels varying from 75 to 85% of protein solubility in KOH, that could be considered as a secure index to identify any change in soybean meal processing. But, it is necessary to pay attention to the 39.59% of these samples that the results were outside of the safe range. On the other hand, 87.0% of soybean meal samples had an ureatic activity index lower than 0.1 ΔpH, which can be considered adequate for chickens. But it is important to consider that 13.0% of these samples can be classified as low quality samples. Another value that draws attention is 10.25% of samples with ureatic activity value higher than 0.1 Δ pH and protein solubility greater than 85%. Another value that draws attention is 10.25% of samples with ureatic activity value higher than 0.1 Δ pH and protein solubility greater than 85%. This number of samples exceeding 10% means the possibility of reducing the ingredient quality soybean meal and eventual hazards in broiler performance when this ingredient is added to diets.

CONCLUSION

it is important to investigate the possibility of errors in sampling or analysis to ensure effective quality control of the ingredients.