Abstract: This experiment used the mobile nylon bag technique (MNBT) to determine dry matter and energy digestibility in traditional feeds as well as non-traditional feeds in order to calculate digestible energy (DE) values for use in ration formulation programs for swine. A total of 23 ingredients were tested in this experiment including six animal protein sources (blood meal, fish meal, meat meal, spray dried animal plasma, spray dried red blood cells and shrimp head flour), six oilseeds (extruded full-fat soybean, raw sunflower seeds, roasted sunflower seeds, caraway seeds, raw flaxseeds, and micronized flaxseeds), three oilseed meals (cottonseed meal, soybean meal, and borage meal), five wheat or wheat by-products (wheat, wheat distillers grains, wheat mill run, wheat bran, and dried wheat thin stillage) and three miscellaneous feeds (beet pulp, barley malt and milk-fat product). Nylon bags containing one gram of feed were placed in a 1000 mL beaker containing 500 mL of a solution made up of deionized water, 0.01 N HCl and one gram of purified activated pepsin powder and incubated for 4 h at 37?C. The bags were then inserted into the duodenum of one of five pigs through simple T-cannulae. Eight bags were administered to each pig daily. The bags were inserted into the duodenal cannulae during feeding time with four bags being inserted in the morning and four bags being inserted during the afternoon meal. With each feeding, two bags were introduced 15 minutes apart. Between five and ten nylon bags were prepared for each feed and the experiment was conducted over a seven-day period. Overall, the MNBT produced similar results to previously published DE values for 11 out of the 17 ingredients for which previous measurements have been made. For the six feeds where there was a significant discrepancy between the MNBT and previously published values, variation in chemical content provided a reasonable explanation for the discrepancy. For untreated flaxseed, caraway seed, barley malt and beet pulp, the author believes that previously published values are too high for feedstuffs containing such high neutral detergent fibre contents. In the present experiment, the MNBT generated a DE value of 4253 kcal/kg for untreated flaxseed, 1763 kcal/kg for caraway seed, 1800 kcal/kg for barley malt and 1905 kcal/kg for beet pulp, For raw sunflower seed, genetic selection has increased the ether extract content of the seed and therefore the DE value obtained here (3830 kcal/kg) is thought to more closely reflect the DE content of sunflower seeds currently being grown. Only for meat meal, did the MNBT produce a suspect result (3433 kcal/kg), which cannot be readily explained. For the remaining six feeds, there are no previously published values with which to compare the DE values determined with the MNBT. Based on their chemical analysis and the generated DE values, shrimp head flour (3473 kcal/kg), dried wheat stillage (4291 kcal/kg), roasted sunflower seed (3903 kcal/kg), micronized flaxseed (4155 kcal/kg), and milk fat product (8004 kcal/kg) all appear to have some potential for use as ingredients in swine rations. In contrast, borage meal (1562 kcal/kg) does not appear to be a useful ingredient. The overall results of this experiment indicate that the MNBT has considerable potential for use in determining the digestible energy content of swine feeds. 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.
Shiyan Qiao and P.A. Thacker , 2004. Digestible Energy Content of Traditional and Non-Traditional Feeds for Swine Determined Using the Mobile Nylon Bag Technique . Journal of Animal and Veterinary Advances, 3: 371-377.