TY - JOUR
T1 - Repeatability of Pig True Ileal Amino Acid Digestibility Coefficients
T2 - Among and Within Laboratories
AU - Hodgkinson, Suzanne M.
AU - Stroebinger, Natascha
AU - Montoya, Carlos A.
AU - Stein, Hans
AU - de Vries, Sonja
AU - van der Wielen, Nikkie
AU - Hendriks, Wouter
AU - Moughan, Paul J.
N1 - As shown in Tables 2\u20134, there was no statistically significant difference in the true ileal AA digestibility values between laboratories for any food other than wheat bread (objective 1). The coefficients of variation based on variance estimates between laboratories were low for the AAs used to calculate DIAAS, ranging from 2.8% for isoleucine to 13.6% for tryptophan. There are many interlaboratory testing programs that evaluate differences between laboratories for AA analysis (only AA analysis, not including an animal study), and from these studies, typical CVs range from 4% to 20% [18]. Thus, the interlaboratory CVs found in the present study fall within the lowest part of this range and can thus be considered as acceptable, supporting the robustness of the standardized method to determine true ileal AA digestibility. The variability between the laboratories (indicated by pooled SEM) can also be considered to be low, with the highest variability found for bovine collagen [0.072 and 0.060 for the mean of indispensable amino acids (IAAs) and overall mean digestibility]. The pooled SEM values were lowest for whey protein isolate (WPI) and pigeon peas (0.011, 0.018 for the mean of IAAs for WPI and pigeon peas, respectively, and 0.011 and 0.017 for overall mean of AAs for WPI and pigeon peas, respectively). It should be noted that as WPI, pigeon peas, and sorghum were tested in 11 (sorghum for 1 laboratory) or 12 pigs (all other laboratories and foods) in each laboratory, this would likely decrease the pooled SEM values compared with foods tested in 6 animals per laboratory.In conclusion, true ileal AA digestibility values determined in the growing pig for the same foods in different laboratories (interlaboratory variation) do not vary greatly. When a single food was evaluated a second time in the same laboratory, very little variation among digestibility values was found. These results support the robustness of the standardized protocol using the growing pig model to determine true ileal AA digestibility for the calculation of DIAAS for application in the adult human.Project Proteos, funded by a consortium of food companies and food sectors, coordinated by Global Dairy Platform, Chicago, USA.
PY - 2025/5
Y1 - 2025/5
N2 - Background: When determining true ileal amino acid (AA) digestibility values in the growing pig to calculate digestible indispensable AA score, there are aspects of the protocol, both genetic and environmental, that vary between laboratories. Objectives: This study aimed to determine true ileal AA digestibility in 9 foods in each of 3 laboratories (Australasia, Europe, and North America) to determine interlaboratory variability. In each laboratory, 3 foods were also evaluated twice to determine intralaboratory variation. Methods: Each laboratory followed a standardized protocol to determine true ileal AA digestibility for each food. Growing pigs received each food for 7 d and digesta were collected via a cannula at the terminal ileum on days 6 and 7. True ileal AA digestibility coefficients were determined for each food at each laboratory to evaluate interlaboratory variability. Three foods were evaluated twice in different cohorts of pigs at each laboratory (intralaboratory variation). Results: There was no statistically significant effect (P > 0.05) of the laboratory on the true ileal AA digestibility coefficients for 8 of the foods. Differences in AA digestibility were found for wheat bread. The mean coefficient of variation (CV) between laboratories for digestibility of the indispensable AAs was 5.0% with an overall mean for all AAs of 5.5%. For intralaboratory variability, there were no statistically significant differences (P > 0.05) in AA digestibility for any food with mean CVs for each AA within each of the 3 laboratories for the indispensable AAs of 1.3%, 1.1%, and 0.9%. Conclusions: True ileal AA digestibility values determined in the growing pig for the same foods in different laboratories (interlaboratory variation) do not vary greatly. When a single food was evaluated a second time in the same laboratory, little variation among digestibility values was found.
AB - Background: When determining true ileal amino acid (AA) digestibility values in the growing pig to calculate digestible indispensable AA score, there are aspects of the protocol, both genetic and environmental, that vary between laboratories. Objectives: This study aimed to determine true ileal AA digestibility in 9 foods in each of 3 laboratories (Australasia, Europe, and North America) to determine interlaboratory variability. In each laboratory, 3 foods were also evaluated twice to determine intralaboratory variation. Methods: Each laboratory followed a standardized protocol to determine true ileal AA digestibility for each food. Growing pigs received each food for 7 d and digesta were collected via a cannula at the terminal ileum on days 6 and 7. True ileal AA digestibility coefficients were determined for each food at each laboratory to evaluate interlaboratory variability. Three foods were evaluated twice in different cohorts of pigs at each laboratory (intralaboratory variation). Results: There was no statistically significant effect (P > 0.05) of the laboratory on the true ileal AA digestibility coefficients for 8 of the foods. Differences in AA digestibility were found for wheat bread. The mean coefficient of variation (CV) between laboratories for digestibility of the indispensable AAs was 5.0% with an overall mean for all AAs of 5.5%. For intralaboratory variability, there were no statistically significant differences (P > 0.05) in AA digestibility for any food with mean CVs for each AA within each of the 3 laboratories for the indispensable AAs of 1.3%, 1.1%, and 0.9%. Conclusions: True ileal AA digestibility values determined in the growing pig for the same foods in different laboratories (interlaboratory variation) do not vary greatly. When a single food was evaluated a second time in the same laboratory, little variation among digestibility values was found.
KW - AAs
KW - DIAAS
KW - pig
KW - protein quality
KW - true ileal AA digestibility
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UR - http://www.scopus.com/inward/citedby.url?scp=105002143373&partnerID=8YFLogxK
U2 - 10.1016/j.tjnut.2025.03.013
DO - 10.1016/j.tjnut.2025.03.013
M3 - Article
C2 - 40107455
AN - SCOPUS:105002143373
SN - 0022-3166
VL - 155
SP - 1398
EP - 1407
JO - Journal of Nutrition
JF - Journal of Nutrition
IS - 5
ER -