Hyper prolific sows have a high nutritional demand during lactation to produce sufficient milk for their large litters. To meet those requirements, it is common practice to include high levels of soybean meal (SBM) in lactation diets. Which, considering the amino acid profile of SBM is a good source of protein at a reasonable cost. However, SBM cannot be digested and absorbed very rapidly in the gastrointestinal tract due to the presence of anti-nutritional factors (ANF’s), like trypsin inhibitors. As most lactation diets are supplemented with synthetic amino acids the incorporation of slowly digestible protein sources causes an asynchrony in release of amino acids into the blood stream. Enzyme-treated soybean meal (ESBM) is a protein source in which ANF’s are removed and it has been found to be a fast digestible protein source (Bible et al., 2023). It is therefore expected that the replacement of a proportion of SBM by ESBM will result in improved productivity of lactating sows. To test this hypothesis, 1,078 hyper prolific sows (Danbred) were enrolled on a commercial farm in Denmark. Data were collected from January 2023 through June 2023. Sows were fed their normal lactation diet from January to March (CON). Then, sows were fed a diet containing ESBM. There was a one for one replacement rate of ESBM for SBM meal. The inclusion rate of ESBM was 3%. The replacement increased the total crude protein level of the diet by less than 0.3%. It should also be noted the ESBM was fed during the summer months, which was uncommonly hot for the area. ESBM sows had 0.2 more pigs per litter born alive than CON sows (19.7 vs. 19.5 pigs, respectively). ESBM sows also weaned 0.1 more pigs than CON sows (16.8 vs. 16.7 pigs, respectively). There was a 5% increase in ESBM sows serviced before day 7 compared to CON sows (82 vs. 77%, respectively). Farrowing rate increased by 1.5% when sows were fed ESBM (88.9 vs. 87.4%, respectively). When pigs per sow per year was calculated, there was an increase of 0.6 pigs per sow by feeding ESBM (37.1 vs. 36.5 pigs, respectively). This on-farm experiment resulted in a 3 to 1 return on investment by feeding ESBM.