Future of Amino Acid Evaluation in Poultry Nutrition
Published:October 31, 2014
Summary
INTRODUCTION Supply of the right amount of nutritionally adequate feed ingredients to the animal is key for efficient production of animal products. Attaining the goal of supplying the right amount of nutritionally adequate feed ingredients calls for careful evaluation and good understanding of the bioavailability of nutrients and energy in each feed ingredient formulated into a mixed diet. Cr...
A very clear and effective summary of different descriptions of amino acid digestibility.
As a team, Evonik personnel are intimately involved in amino acid nutrition, and I have a few questions / points.
1. You comment "...Digestibility of AA represents portion of total dietary AA that is enzymatically hydrolyzed, fermented by digestive tract microbes and absorbed from gastrointestinal lumen..." I assume you would subtract those AAs lost to microbial fermentation; they are effectively removed from host animal utilisation 2. Are you completely happy that Rooster assays accurately measure AA digestibility in young broiler? We have big reservations. 3. Table 2. Our estimates of AA digestibility in Canola / Rapeseed meal are considerable lower than those shown in Table 2 (for Soya, close agreement). Field experience tells us that Rapeseed meal is a less effective amino acid source. 4. Table 3. Very interesting comparison of heat damaged DDGS digestibilities. Any comment on mechanism of reduced digestibility, in particular for Methionine? 5. Kluth and Rodehutscord (2006); you comment on a lack of difference in digestibility of soya and rape for both broiler and turkey. Again, this is unexpected...
Nice article. Couple of comments:
1. Apparent ileal digestibility (AID) is quite useful when assessed in commercial conditions because all endogenous losses show up with the reduced AID values. These are all losses that may need to be replaced, depending on the economics of the situation. So, since endogenous losses that only show up in your commercial environment (i.e., site-specific basal endogenous losses from stress, illness, heat, and so on) are very important for production, they need to be considered for formulation. A simple way to think about this is that, if you are witnessing elevated gut mucin sloughing in your operation, then you need to replace the amino acids in gut mucins in the diet.
2. Related to my comments in #1, do ducks how lower basal endogenous losses than broilers? If so, why would this be?
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