Transcriptomics, proteomics, microbiomics, metabolomics ... If you have read any scientific articles lately, chances are you have heard of one of these cutting-edge approaches. The development of technologies such as DNA microarrays, next-generation sequencing and advanced mass spectrometry have allowed for broad application in animal nutrition research.

The increased use of comprehensive analysis approaches, or omics, in animal nutrition is the result of recent advancements in the technology behind them and the bioinformatics methods for analysis. These methods allow for a molecular look into how nutrition can influence an animal.

In its truest sense, the science of animal nutrition is driven by the need to interpret the interaction of nutrients and health, production and well-being. Because nutrition has a continuous, life-long impact, it can be one of the most important influences on animal health and production, allowing for optimal formulation of diets and feeding strategies to meet an animal’s needs.

By integrating omics into nutrition research approaches, we can begin to revolutionize how we think of diet formulation or ruminant nutrition. These tools enable us to understand the molecular reasons for specific outcomes or effects of nutrients.

While previous dairy nutrition research has established the basic guidelines for feeding for performance and health, omics approaches provide many new opportunities for optimization of nutrition and understanding the functionality of dietary components.

While traditional nutrition studies or “feed and weigh” studies can give us a good deal of information on nutrition, these technologies take dairy nutrition to the next step. Shifts in the molecular markers that omics approaches measure help us start to understand nutrition on a more precise level.

Omics takes a systems biology approach to nutrition and asks how nutrition impacts gene expression (transcriptomics), protein abundance (proteomics), metabolite products (metabolomics) and the host prokaryotic environment (microbiomics).

Transcriptomics relates changes in gene expression to shifts in nutrition, leading to the field of nutrigenomics. These changes allow for the rapid evaluation of nutritional strategies and a complete profile of how biological functions and signaling pathways shift with diet changes.

Proteomics is a second method of measure for products of nutrient-gene interactions. Together transcriptomics and proteomics provide the opportunity to identify biomarkers of nutrition molecules that can be used to identify nutritional status.

Metabolomics allows for the profiling of metabolic responses to diets and measures the products of transcriptional and protein changes. While the area of metabolomics is still in its infancy with regard to dairy nutrition, it has the potential to provide a better understanding of nutrition and its relationship with gene function.

Microbiomics, or the use of high-throughput sequencing to identify prokaryotic species, has greatly expanded our ability to detect and quantify microbial species in a population compared to culture techniques.

Microbiomics provides us the ability to understand what a healthy microbiome is, identify shifts during changes in production status or disease state and gives us greater insight into how different diets can affect the population.

Previously, culture methods were used to evaluate bacterial shifts, but these methods were limited and could not detect all populations in a system. Profiling the entire microbial population, or microbiome, is essential for answering three key questions: What microbes are present, what is their function, and how can diet influence them?

Understanding the impact of diet on the microbiome can have implications from animal health to environmental impact. In addition, defining these relationships can allow for both rumen and gut microbiome manipulation through diet to provide benefits to the cow.

A better understanding of the regulation of genes and gene products by nutrients can provide new insight into how and why nutrients work. For example, previous trace mineral work has identified a link among selenium status, source and reproduction.

Because of its role in antioxidant systems, reproductive disorders during selenium deficiency were typically concluded to be the result of abnormal levels of oxidative stress.

Using nutrigenomics, researchers discovered that selenium supplementation could regulate the expression of genes involved in protein translation and energy production, both indirect but important components of fertility in females.

In males, researchers discovered that selenium played an essential role in regulating the expression of genes responsible for maintaining the structure of the seminiferous tubules.

This molecular information can help decipher the specifics behind nutrition and potentially provide the tools for precision or targeted diets. For example, researchers have used transcriptomics to determine what gene functions are up-regulated, or turned on, in the mammary tissue of cows with high milk yield compared to those with low milk yield.

Using metabolomics, another set of researchers aimed to elucidate the mechanisms of milk production affected by forage quality. They determined that forage quality affected key metabolic pathways, such as amino acid metabolism, which could be contributing to differences in production.

These types of studies can help provide molecular understanding behind production differences and indicate potential opportunities for nutritional mitigation of these differences.

Together, omics sciences can help fill the gap between genetic makeup and phenotype, revolutionizing dairy nutrition.  PD