Nutritional value of a genetically improved high-lysine, high-oil corn foryoung pigs

Two experiments were conducted to compare the nutritional adequacy of a gen etically improved high-lysine, high-oil corn (HLHOC;.408% lysine, 6.21% fat , as-fed basis) and a high-oil corn (HOC; .289% lysine, 5.97% fat, as-fed b asis) for young growing pigs. Experiment 1 used four non-littermate barrows (initially 20.0 kg BW) fitted with ileal T-cannulas in a crossover-designe d digestion study. The .75% total lysine diets contained 8.5% casein and an equal amount of lysine (.25%) from the test corn. Apparent ileal digestibi lities of amino acids, GE, DM, and CP were similar (P >.10) between diets. Apparent ileal lysine digestibilities were 65 and 71% for the HOC and HLHOC , respectively, assuming the lysine in casein to be 100% digestible. Experi ment 2 used 100 barrows reared in a segregated early-weaning environment (i nitially 8.3 kg BW and 27 d of age) to evaluate five corn-soybean meal-base d diets in a 2 x 2 factorial arrangement with main effects being corn type and dietary lysine (.80 or 1.15% digestible lysine). The fifth diet consist ed of the .80% digestible lysine HDC diet supplemented with .23% additional L-lysine . HCl (.975% digestible lysine) to verify that lysine was the lim iting amino acid in the low-lysine diets. Increasing digestible lysine from .80 to 1.15% increased (P <.001) ADG and gain/feed (G/F) regardless of cor n variety. Combined ADG and G/F were .347 kg and .641 and .443 kg and .790 for the .80 and 1.15% digestible lysine diets, respectively. Within lysine level, corn type did not affect ADG, ADFI, or G/F (P >.10). The results of these studies indicate that the lysine in HLHOC is as available as the lysi ne in HOC and that HLHOC can be used successfully in swine diets.