An evaluation of metabolizable energy content of main feed ingredients for growing pigs when adding dietary lysophospholipids

The present study was conducted to test whether the dietary supplementation of lysophospholipids (LPL) affects digestible energy (DE) content of feed ingredients, nutrient digestibility, and growth performance of growing pigs. In Exp. 1, 8 growing pigs were alternatively used for 8 dietary treatments including 4 feed ingredients (corn, soybean meal, distiller's dried grains with solubles, and animal fat), and 2 LPL concentrations (0% and 0.1%) in 6 periods to determine DE and metabolizable energy (ME) content. In Exp. 2, 200 growing pigs were randomly allotted to 4 treatments on the basis of body weight with 2 concentrations of fat (high and low) and 2 concentrations of LPL (0% and 0.1%). The experimental diets were fed for 42 d in 2 phases. In Exp. 1, gross energy (GE) digestibility, feed DE, and ME were increased in animal fat when LPL were added to the diet. In Exp. 2, the pigs fed LPL showed greater (P < .05) digestibility of EE, GE, crude protein (CP), and DM In phase 2. Pigs fed a high-fat diet had greater (P < .05) digestibility of EE, and GE. Gross energy retention was greater (P < .05) in pigs fed the high-fat diet compared with those fed the low-fat diet in phase 2. During phase 1, the average daily gain (ADG) of pigs fed the high-fat diet was greater (P < .05) than that for pigs fed the low-energy diet. During the second phase, ADG was increased in LPL and high-fat diets (P < .05). The overall results showed that pigs fed the LPL or high-fat treatments had greater ADG and feed to gain ratio (F/G). Considering the 2 experiments, it can be concluded that LPL increase the ME of animal fat and improves ADG and F/G in pigs.