title: Additivity of apparent and true ileal amino acid digestibilities in soybean meal, sunflower meal, and meat and bone meal for broilers.
abstract: An experiment was conducted to determine the additivity of apparent and true ileal amino acid digestibility values in soybean meal (SBM), sunflower meal (SFM), and meat and bone meal (MBM). A total of 63 individually caged 5-wk-old broilers were assigned to seven groups and given semi-purified diets containing SBM, SFM, MBM, and their combinations. True digestibilities were estimated by using the homoarginine in guanidinated proteins as the marker. Additivity was tested by comparing the differences between the observed digestibilities of ingredient combinations and the predicted values from measurements with individual ingredients. In general, for both apparent and true digestibilities, there were no significant differences (P > 0.05) between the observed and predicted values in ingredient combinations. The only exception was SBM + MBM combination, in which the observed values for apparent digestibilities of aspartic acid, serine, glutamic acid, isoleucine, and tyrosine were significantly higher (P < 0.05) than the predicted values. Overall, the present results indicate that amino acid digestibility values are additive and that digestible amino acid supply in a complete diet can be predicted from amino acid digestibilities of individual ingredients.
authors.affiliation: Department of Animal Science, University of Sydney, Camden, Australia.
authors.forename: K
authors.initials: K
authors.lastname: Angkanaporn
authors.forename: V
authors.initials: V
authors.lastname: Ravindran
authors.forename: W L
authors.initials: WL
authors.lastname: Bryden
mesh_terms: D000596:Amino Acids / Q000032:analysis / Q000378:metabolism*; D000704:Analysis of Variance; D000818:Animals; D001224:Aspartic Acid / Q000032:analysis / Q000378:metabolism; D001688:Biological Products; D002645:Chickens / Q000378:metabolism* / Q000502:physiology; D004063:Digestion / Q000502:physiology*; D005260:Female; D018698:Glutamic Acid / Q000032:analysis / Q000378:metabolism; D006368:Helianthus / Q000737:chemistry / Q000378:metabolism*; D006709:Homoarginine / Q000378:metabolism; D007082:Ileum / Q000378:metabolism* / Q000502:physiology; D007532:Isoleucine / Q000032:analysis / Q000378:metabolism; D008460:Meat / Q000032:analysis / Q000592:standards*; D008903:Minerals / Q000737:chemistry / Q000378:metabolism*; D011237:Predictive Value of Tests; D012694:Serine / Q000032:analysis / Q000378:metabolism; D013025:Glycine max / Q000737:chemistry / Q000378:metabolism*; D014443:Tyrosine / Q000032:analysis / Q000378:metabolism
chemical_list: D000596:Amino Acids; D001688:Biological Products; D008903:Minerals; D007532:Isoleucine; D006709:Homoarginine; D001224:Aspartic Acid; D018698:Glutamic Acid; D014443:Tyrosine; D012694:Serine; C027762:bone meal