The successful incorporation of unfamiliar ingredients into swine diets is often limited by the availability of information on their nutrient content. Since the energy content of swine diets represents the largest and most expensive portion of the diet, knowledge of the digestible energy (DE) content of alternative ingredients can provide feed formulators with insight into the nutritional value of these feeds and promote greater use of these non-traditional ingredients in swine rations. The direct determination of the DE content of swine feeds typically involves either the total collection of feces or the use of a digestibility marker. These techniques are time consuming, expensive and require a large quantity of feed. These problems can largely be overcome by using the mobile nylon bag technique (MNBT). In this method, small samples of finely ground feed are sewn into nylon bags and placed into a small beaker containing hydrochloric acid and pepsin to simulate gastric digestion. After a short incubation period, the nylon bags are removed from the beaker and inserted into the digestive tract of a pig through duodenal cannulae. The amount of material remaining in the nylon bag, after passage through the digestive tract is then used to calculate nutrient digestibility. A modified protocol for the MNBT has recently been developed at the University of Saskatchewan. This new protocol has been used to determine the DE content of 39 ingredients with potential to be used in swine rations. The MNBT has several advantages compared with conventional digestibility methods in that many feeds can be tested in a relatively short duration of time with significantly fewer animals being used, only small amounts of feed are required and the test allows for energy measurements in feedstuffs that would not normally be fed to pigs as a single ingredient. Use of the MNBT to accurately determine the energy content of alternative feed ingredients could allow swine nutritionists to establish a hierarchy between available feeds on an objective basis and to ensure that any rations formulated using those ingredients meet the energy requirements of the animal. The overall results of this study indicate that the MNBT has great potential for use in determining the digestible energy content of swine feeds. For the most part, values obtained in the present experiment compared favourably with previously published values. Where differences were obtained, variation in chemical content provided a reasonable explanation for the discrepancy. This in combination with that fact that we have previously compared our modified MNBT with conventional digestibility methods and obtained similar results leads us to believe that the MNBT is a useful tool in determining DE values for swine.