Better birds: Improving poultry performance through nutrigenomics

By: Kristen M. Brennan, Ph.D.

When you hear the word “nutrigenomics,” your first reaction may be “What in the world is that?” Nutrigenomics is an up-and-coming research field that aims to understand how nutrition can influence an animal’s genome and what that means for animal health and production. It isn’t genetic engineering or modification, but rather a way of measuring changes in the activity of genes that result from changes in an animal’s diet. This field of research opens many doors that were previously closed in classic animal nutrition and allows us to better understand how “you are what you eat,” or rather, your chickens are what you feed them.

What is nutrigenomics?

Before we can talk about nutrigenomics, let’s do a quick review of molecular biology. Each animal has what’s called a genome that contains all of the genetic material, or DNA, of an animal and provides the basic blueprint for life. These carefully drawn out plans provide the blueprint for that animal’s life. However, outside influences, such as nutrition, can have a strong impact on the expression of this genetic information, or essentially how that blueprint is read.

Over the last decade, genomes have begun to be sequenced. This means that we know the approximate makeup of an animal’s entire genome. Identifying the genome sequences opened the door for cutting-edge research approaches to understand the molecular mechanisms behind everyday life. Even more importantly, we can now use genomic technologies to understand how each of the genes in that genomic sequence responds to outside influences and how this relates to the health and disease of an animal. The genomic sequence is very stable, so changes in function and activity come from up-regulating (“turning on”) or down-regulating (“turning off”) individual genes to produce (or decrease) products called transcripts in response to a stimulus like nutrition.  These transcripts code for the proteins that make up structures and functions in the cells, so the result is that changes occur in physiological processes like energy production or immune response.

Nutrigenomics is the field of research we use to study these changes in gene activities that occur because of changes in the animal’s diet. This information can help us better understand how nutrition influences animal health and production by giving us insights into what is going on within the cell in response to changes in the diet. We can measure the response in animal tissue using a technology called DNA microarrays. These tools are the basis of nutrigenomics studies and allow researchers to profile the activity of all the genes on a genome at once. The information gathered from nutrigenomics studies can provide us with a better understanding of nutrition by giving us clues to how nutrients work, why different forms of nutrients have different effects and how such nutrients can be optimized for health and production.

How can we use nutrigenomics to further poultry nutrition?

Current research can paint us a picture of how nutrigenomics is being applied to poultry nutrition. For example, recent work at Alltech has helped decipher why different forms of nutrients in the diet, such asBioplex®organic minerals versus inorganic forms of minerals, can have very different effects on animal health. Before nutrigenomics, analyses like animal growth and tissue nutrient content gave us only part of the picture. But now, we can understand why changes occur.

Mineral matters

We know that Bioplex minerals support increased tissue levels. Through nutrigenomics, we identified changes in important transport proteins in the intestine that lead to increased mineral uptake into tissues when Bioplex zinc is used in poultry diets. In a similar fashion, we used nutrigenomics to understand whySel-Plex® has a greater effect on reproduction than inorganic selenium. Traditional poultry nutrition studies were only able to reach the conclusion that it was due to selenium’s role in antioxidant defenses. However, nutrigenomics data confirmed this and, more importantly, indicated that selenium in the form of Sel-Plex could alter genes involved in energy production and reproductive signaling in the oviduct. In males, it made a clear impact on genes involved in tissue structure and function.

Early birds

Another area in which nutrigenomics is leading to a new understanding of the importance of nutrition is nutritional programming. This concept is the idea that nutrition, especially early in life, can have lasting imprints on an animal’s entire life. By understanding the gene expression patterns that are targeted by early life nutrition, we can begin to determine how this programming occurs and use it to our advantage in poultry production. For example, nutrigenomics studies have shown that changing the trace mineral content in the post-hatch diet can have long-term effects on genes in the gastrointestinal tract that are important for nutrient transport and for intestinal tissue structure. These genes remain changed in the adult bird weeks after the post-hatch period.

In the future, the information that nutrigenomics provides us could change the way we feed birds and make poultry nutrition a more precise field. Molecular findings can add to our understanding of how nutrition influences animal production and health and how we can use nutrition to get the best out of our animals. Nutrigenomics provides a way to know preciously what nutrients, timing of nutrients or combinations of nutrients are optimal. Through this information, we can not only streamline nutrition, but improve performance, efficiency and health.