Measurement of the nutrient and energy contents of feedstuffs: Is the adoption of the latest approaches to analysis overdue?

An inspiring article, Dr. Pesti; I often wonder how to integrate the new concepts regarding soluble and insoluble fiber—and the relationship between them—into the context of more precise energy valuation.
Likewise, the correlations between metabolizable energy, net energy, and daily amino acid deposition during animal growth should help identify efficiency gains related to thermal comfort.

Great article but it is essential to report in the Armidale method the recommended analytical method for starch analysis. The traditional Ewers method reveals a lot of artefact values especially in non-cereal grains. The measured starch content will impact a lot of other calculated nutrients, including energy

Same for digestible or real protein and also for EE (ClH) and “sugars” vs. sucrose.
Kees, see you in Warsaw!!!

It might be a Conference place.

Great discussion. However, I always wonder how long will take to move from total starch to an analysis of amylose and amylopectin of a specific starch? So, starch is an important indication of the caloric potential of an ingredient. However, we still have many question to be addressed (amylose:amylopectin; how retrograde types of starch can affect the final energy?; how much we can affect the energy availability of the starch under high temperature to dry it; or, how a non corrected use of expander and/or pelleting can affect its energy?)

Dear Gene! Still, this is something that bothers me. Starch is a such complex molecule, with so many variants, even made just by glucose, that is not easy to fully consider its energy value. We need to find better ways to express the energy that comes from it.

Is corn main sow for industrial starch, food, feed or ethanol? Then its different properties and yields, so its marketing price.
A few will chosse non GMO varieties to feed animals, other white corn for tortillas, and country imports could go by lower price withour any qualityies.

Dear Gene! This is an important gap on our formulation side. One calorie in broiler diets can cost from 0,08 to 0,18 US$ (more or less, depending the year and the country). But, I know that this issue it is not fixed due to the complexity of the "simple" starch composition and the post harvesting consequences that can happen when it is bad treated. I would be happy enough if we can have at least amylose and amylopectin analysis. That will help a lot on the efficient use of amylase. Sometimes, we formulate diets to breeders, to achieve an specific energy consumption (feed restricted) and the hens get fat or below the weight. My general assumption is that the energy of the diet (corn, main energy source) does not match with the energy assumption. Broilers can eat more or less to overcome differences (ad libitum feeding). But, with breeders, no. This is the reason that I always recommend (on breeders) checking weekly breeders body weight and energy consumption (protein and lysine, too). If the breeders are not gaining weight, we overestimated the real corn energy. If the breeders are gaining weight, we underestimated the real corn energy. And in this discussion we are not bringing the non starch polysaccharides (hahahaha.)

Dear Gene, the equations from the works of Dr. Sakomura and her coworkers are fantastic. We have been using them, very much. However, the discussion always come from the energy values that we stablish to different ingredient sources, mainly corn. When we follow theoretical weekly energy consumption and relate it to the weight of the hens we can see if we are under or overestimating their energy values. But I know, this subject can go on and on, for ever. This is the reason that I say that nutrient and energy requirements of breeders are based on science data with a good amount of "state of art", too. Closer we are on average breeders body weight and their weight variability more precise we will be with our nutrition proposals.

As mentioned before in the FORUM the microbioma of the digestive tract varies with age of the animal so the use of starch for microbial growth and then with less availability to the animal, but with a change of properties as microbial protein. If you follow this pathway the changes are enormous and endless changes.

Dear Gene, Antonio and other colleagues,
Thank you for the session and excellent discussions.
Gene,
I wish many of the young scientists see these communications to develop new research projects.
I miss the old days where you and Dr. Britton used to take the prominent front seats in the Informal Nutrition Symposium ready to hep straighten the misconceptions.
Best wishes,
Mamduh

Yes, Dear Sifri. Fantastic time in our professional lives.

Good to hear from Mamduh, my old running buddy.
Paul Cotter