IS SBM REALLY THE KING?
In past Nutricles, we underline regularly the importance of balanced microbiota in order to guarantee gut health for both Swine and Poultry. It is a fragile balance between cellulolytic and proteolytic bacterial population that is maintained by a well balanced diets.
When formulating protein, we are defining a minimum level of crude protein together with 4 or 5 digestible amino-acids. But we are now realizing that this is not sufficient. Keeping only these nutrients may lead us to make wrong arbitration. In theory, we should formulate based on the 11 essentials amino-acids as lysin, methionine, methionine + cysteine, threonine, tryptophan, valine, leucine, isoleucine, arginine, histidine and phenylalanine. If we do not provide the animal the correct digestible level of these acids, the performance will be affected.
In practice, we do not work with phenylalanine, histidine. Some nutritionists do not even look at leucine, isoleucine, valine or arginine. By overlooking these amino-acids, we are taking a risk of not covering the animal requirement.
To secure a sufficient supply, we tend to increase the level of crude protein considering that if we bring an excess of crude protein, we should cover all the 11 amino-acids. But such assumption is coming with three major drawbacks 1 – Crude protein is actually measured by analyzing the quantity of Nitrogen in a diet and multiplying it by 6.25. This is from the assumption that nitrogen is derived from protein containing 16 % nitrogen. But in reality, this ratio varies for each ingredient depending on their mix of amino-acids. It should be 5.7 for soya or 6.0 for rice. Such approximation could create major variation in your real amino-acids supply. 2 – All proteins do not come with the same ratio of amino acids and increase the level of crude protein do not increase the supply of every amino acid by the same ratio. 3 – By pushing for more crude protein, we are not selecting only the digestible portion. At the contrary, in a least cost formulation context, the system will select the cheapest source of crude protein which is most of the time non-digestible. Such imprecisions are responsible of significant loss of performance in Swine and Poultry production and often at the origin of diarrhea in piglets. As we mentioned in several nutricles, non-absorbed peptides and Non-Digestible Proteins (NDP) will be used by the proteolytic bacterial population both in the proximal intestine and the colon as fermentation substrate and produce toxic compounds. Undigested Lysine will be fermented into cadaverine Undigested Histidine will be fermented into histamine Undigested Tyrosine will be fermented into indole and skatole Undigested Methionin & Cysteine will be fermented into Hydrogen Sulfide Histamine has several biological functions including induction of chloride secretion into the gut lumen, which may promote diarrhea. High intestinal concentrations of hydrogen sulfide have been considered detrimental for the host due to its effect on cell respiration and genomic DNA damage.
Protein-derived metabolites formed by other proteolytic bacteria such as clostridia may also induce impaired barrier function through altered mucus composition and tight junctions, thereby favoring the translocation of enterobacteria as secondary opportunists.
In addition to the production of toxic compounds, the proteolytic fermentation triggers the development of proteolytic bacteria that are consider harmful for the host (E.Coli, Streptococcus, Clostridium). These mechanisms are the reasons why we normally cap the proportion of Soybean meal to a maximum of 10% in prestarter diet and 20% only to starter diet. To limit these proteolytic fermentations, we should get more sophisticated in our approach to protein formulation 1 - We should formulate based on as many digestible amino acids as possible including valine, arginine, leucine and isoleucine. The literature gives nowadays precise information about each ingredient composition in digestible amino acids. We know as well quite well the requirement for every animal stage for the 9 most limiting amino-acids. 2 - We should remove any minimum of crude protein and set instead a minimum of DP (Digestible Protein) and maximum level of NDP to limit proteolytic fermentation. By doing so, we will limit the incorporation of natural ingredient and give a priority to synthetic amino-acids who bring no NDP. The part of synthetic amino-acids is normally calculated only based on its cost. But once you starting using NDP nutrient, synthetic amino-acids will be given a priority with a positive impact on gut health.
You need to be cautious on the maximum NDP you will set. We should not ask the formulation software a scenario that he cannot realize. There is not yet synthetic leucine and isoleucine on the market and the software will still need to call for natural ingredients to cover these amino acids and that will come with their portion of NDP.
3 - Protease help to reduce the NDP portion of ingredients. Several proteases are now available for Swine and Poultry with many years of successful records. Do not hesitate to ask us more information on the protease available on your market. 4 - Increase the level of soluble and insoluble dietary fibres in your diet requirement. By doing so, you will feed and promote the development of the cellulolytic bacteria that will compete with the proteolytic flora in the intestine. Several studies (Zentek, 2015 – British Journal of Nutrition) clearly shows that higher level of CP increases the production of ammonium and putrescine while the increase of dietary fibre will bring these toxic compounds levels down.
In the past years, the proteolytic fermentation at the origin of diarrhea and wet feces were controlled by AGP. Since the AGP are under pressure, it is urgent to relook at strategies to control proteolytic fermentations. Such change of strategies will require an upgrade of your ingredients matrix both in term of DP (Digestible Protein), NDP (Non-Digestible Protein) and TDF (Total Dietary Fibre). At Nutrispices, we maintain database of ingredients matrix and we can help you to upgrade your matrix with most common ingredients used Vietnam, Thailand and Myanmar. Do not hesitate to come back to me if you want to collaborate on such project.
If you would like to get more informed, please contact us.