The metabolizable energy and standardized ileal digestibility of amino acids in dry extruded-expelled soybean meal in comparison with solvent-extracted soybean meal fed to broiler chickens

Dear Sirs, thank you for this paper. However, there are many pieces of information missing that make it difficult to make correct conclusions. First is a gross analysis of the two soya products, in particular the oil content, with its direct impact on AME evaluation. Next is an indication of either the anti-nutrient (trypsin inhibitor) levels in the two materials; or a measure of potential heat-damage (over processing) in the solvent extracted product. We have found direct correlations between these two processing indicators and the SID factors for amino acids, that are not related to CHO component of the soya (although I agree that better characterisation of this fraction is important). MPS

Dear Sirs: Very interesting work. I agree with Mr. Smith that a more detailed characterization of both the DESBM and Solvent SBM would be of interest. We work in the DESBM business, and have some plants producing expellers with more than 8 % oil, whereas some are below 5 % using smaller presses with ring configuration, instead of bars. Also, some work with hight temperatures in the extruders (more than 145-150 degrees C) to ensure proper deactivation and produce a darker product, overcooked, and with low PDI. Same applies to SBMs, some plants overcook the meal to maximize solvent recovery, affecting the digestibility.