From optimized intestinal functions to excellent performance of poultry

Thanks to our excellent speakers Prof. Dr. Richard Ducatelle from Ghent University and Dr. Juha Apajalahti from Research Centre Alimetrics the webinar organized on the 20th of April has proved a success.

We’ve learnt a lot about the essential role of the small intestine in absorption of nutrients from our valued speakers. These functions crucial to the profitability of the poultry production are often disturbed by inflammation due to a variety of causes, including coccidiosis and even heat stress. Using modern research methods we can study those functions and develop modern feed ingredients to improve intestinal functions. Progres® – the only product to apply the power of natural resin acids in animal feeding – sets a benchmark for such innovations. We would like to thank also our audience for engaging actively with the topics presented!

In the chicken gastrointestinal tract, absorption of nutrients mostly takes place in the duodenum and jejunum through transcellular, receptor mediated active uptake mechanisms. Since bacterial cells are largely composed of the same building blocks as eukaryotic cells, both can be expected to compete for the same macro- and micronutrients, including trace elements.

This is the fundamental reason why the microbiome of the jejunum and even more so of the duodenum is of a remarkably low density and low metabolic activity. Any expansion of the small intestinal microbiota will trigger a vigorous inflammatory response of the host mucosa through activation of Toll-like receptors. Such expansion of microbiota can be due to overeating. Pathogenic microorganisms are yet another cause of intestinal inflammation.

The modern broiler has been selected for high feed intake and at the same time, this animal has become more susceptible to the inflammation triggering action of facultative and obligate pathogens entering the gastrointestinal tract. Inflammation is associated with a shift in the metabolism of the intestinal epithelial cell, characterized by reduced mitochondrial respiration. This metabolic state reduces the uptake of nutrients, leading to performance losses. It is associated with tight junction leakage, which in turn leads to bacterial translocation from the intestinal lumen across the epithelium into the portal vein and from there to the liver. In severe cases, the liver may react with an acute phase response, further contributing to the catabolic processes.

Activation of matrix metalloproteinases in the propria mucosae underneath the intestinal epithelium aggravates the damage by destabilizing the tissue integrity. Any interventions aiming at breaking this vicious circle will help the birds to restore the equilibrium in the intestinal ecosystem and to benefit more from the nutrients. Resin acids extracted from pine tree rosin have been shown to inhibit matrix metalloproteinase activity, thereby interrupting the vicious circle of small intestinal inflammation.

The main goal of diet amendment with an additive is to improve feed conversion efficiency and health of production animals. Such end points are measured in all performance trials. However, it has become increasingly common to also analyse the effect of diet modification on parameters expressing microbiota, immune system, and the digestive physiology of the host. Motivation to such research can come from many different things. Besides the obvious scientific curiosity, the data on product mode-of-action can be invaluable for the development of next-generation products and the troubleshooting situations where the product fails to work for an unknown reason. Trials based on feeding and weighing are essential but not enough in the present competitive business environment.

Depending on the category of the additive, the mode-of-action can be easily resolved, or it can be highly complex involving interplay between the additive, intestinal microbiota, and multiple functions of the host. In many cases, the dynamics is too complex to be studied in live animals alone. Analysis of samples originating from an animal trial provide a snapshot image which seldom brings forth the kinetics of several partial processes ongoing concurrently. Therefore, it is necessary to use ex vivo or in vitro experimental approaches to be able to reveal different partial processes involved. The gained knowledge promotes attempts to reconstruct the mode-of-action in the animal superorganism. Typical partial processes in the gastrointestinal tract of any warm-blooded animal are the utilisation of dietary nutrients by the intestinal microbiota and their concomitant uptake by the host. Also, intestinal bacteria produce a range of metabolites which serve as substrates for other bacteria in the intestinal habitat or become absorbed by the microvilli in the intestinal brush border.

Feed additives can have effect on bacterial growth and metabolism. Consequently, they indirectly affect the assortment of compounds which regulate various host functions or serve as substrates for the catabolic or anabolic reactions of the host. The character of a feed additive determines its fate in different tissues of the host and the routes of its potential disposal from the body.