Determination of apparent and standardized ileal digestibility of amino acids in corn HP-DDG fed to growing pigs

Abstract

The corn-based ethanol production industry provides co-products with potential value as animal feed. However, the nutritional value of these co-products should be adequately determined for their sustainable implementation in swine diets. Therefore, a study was conducted to determine the concentration of amino acids (AA), apparent ileal digestible amino acids (AID), standardized ileal digestible amino acids (SID), and crude protein (CP) in corn distillers dried grains with high protein content (corn HP-DDG) for pigs. Six growing pigs (initial body weight: 46.30 ± 2.14 kg) were surgically fitted with a T-cannula at the distal ileum and allotted to a duplicate 2 × 3 incomplete Latin Square Design. Diets containing corn HP-DDG as the only AA source and a nitrogen-free diet (NFD) were formulated. Corn HP-DDG was used as a test ingredient to replace 40% of the starch in NFD, and titanium dioxide (0.5%) was added as an indigestible marker to both diets. Pigs were fed between 08:00 and 18:00 h during five days of adaptation and a sequence of two days of ileal digesta collection. On an as-fed basis, the chemical composition of corn HP-DDG was 40.41% CP, 1.39% lysine, 1.57% methionine + cysteine, 1.61% threonine, 0.23% tryptophan, and 2.15% valine. The AID and SID values of corn HP-DDG were 74.04% and 80.87% for CP; 76.32% and 79.15% for lysine; 84.75% and 86.52% for methionine + cysteine; 71.97% and 78.30% for threonine; 83.86% and 92.44% for tryptophan; and 76.34% and 80.47% for valine, respectively. In conclusion, the SID CP and AA in corn HP-DDG were within the previously published values, and the determined SID coefficients should be used to formulate accurate diets for pigs.