PUBLISHED BY SOYBEAN GROWERS FOR THE FEED INDUSTRY APRIL 2007
   
 
Amino Acid Bioavailability
An International Committee on Terminology to Report Amino Acid Bioavailability and Digestibility issued a report on the terminology used to describe the bioavailability and ileal digestibility of amino acids in swine feed ingredients. The Committee developed a detailed technical review of the advantages and disadvantages for various amino acid digestibility measurements. Briefly, apparent ileal digestibility (AID) is calculated by comparing total ileal outflow of amino acids (sum of endogenous losses and undigested dietary amino acids) to dietary amino acid intake. One disadvantage of AID values for the various feed ingredients is that they are not additive in formulating feeds. This disadvantage is partially corrected for in standardized ileal digestibility (SID) by accounting for endogenous losses of amino acids. While correcting AID values for both endogenous losses and specific losses caused by the ingredient’s characteristics (type of fiber and antinutritional factors) results in the true ileal digestibility (TID). Agreement on terminology and improving measurements to better define the quality of various feed ingredients is important in formulating swine rations. The Committee suggested that SID values should be used for formulating swine feeds until the more accurate TID values become available.

So how does this relate to soybean meal use? In the paper, the Committee provides a table that reported various ileal digestibility values for selected protein supplements that have use in swine rations.
  Canola Meal Sunflower Meal Soybean Meal (*) Soybean Meal
Lysine        
AID 70.5% 68.6% 56.3% 87.3%
SID 72.1 71.1 57.5 92.0
TID 78.4 85.0 67.1 96.6
Threonine
AID 63.6 68.5 54.1 75.2
SID 65.8 72.8 56.1 88.0
TID 74.6 85.0 68.6 101.0

(*) This is a soybean meal sample with a high residue trypsin inhibitor activity.
 


These data clearly demonstrate the relatively high quality of soybean meal, regardless of ileal digestibility measurement, when compared to other oil seed meals that can be used in swine rations. These data also show that improperly processed soybean meal can be easily identified using ileal digestibility values. One can predict that growth studies will reflect the quality differences between the two soybean meals. The Committee encouraged the use of SID values in formulating swine rations since they are available and reflective of the protein quality of feed ingredients. Improvements, or refinements, in feed formulation will continue to show the value of soybean meal in highly productive swine rations.

Stein, H.H., and co-workers. 2007. Invited review: Amino acid bioavailability and digestibility in pig feed ingredients: Terminology and application. J. Animal Sci. 85: (172-180).

Soybean Meal-Indian Major Carp
The effects of varying the level (20, 30 and 40%) of soybean meal on the growth and survival of Indian major carp were the objective of an experiment involving ten fish per tank and four tanks per treatment. The results of the 90-day study showed that the best growth, protein efficiency ratio, feed conversion and fish survival were obtained from the test diet that contained 35.4% protein and 40% soybean meal inclusion level. The researchers concluded that soybean meal is readily available, acceptable and a cost-effective protein source for formulating feeds for Indian major carps.

Jose, S., and co-workers. 2006. Effect of soybean meal-based diets on the growth and survival rate of the Indian major carp, Cirrhinus mrigala (Ham.). Aquaculture Nutr. 12(4): 275.279.
 
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