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Ruminant Nutrition Symposium II

By: Dr. Emily Taylor

Awardee Talk: Midwest Cattle Feeding Over the Past 40 Years – Dr. Daniel Loy, Iowa State University

The Ruminant Nutrition Symposium II began with Dr. Daniel Loy reviewing the past forty years of the cattle industry in the Midwest. The industry consistently deals with change; technology advancements (adoption), black swan events (reaction), and disruptive technologies. He described two disruptive technologies that have significantly affected cattle feeding – The convergence of microcomputer technology with the development of growth models based on the California Net Energy System, and the development of the ethanol industry and widespread availability of corn co-products. These microcomputers gave rise to new tools, including feeding program performance and cost projections, ration analysis programs, and feedlot tracking and performance monitoring. The ethanol industry offered many new feedstuffs that have higher energy than the grain being processed. These feedstuffs are now widely used across the Midwest. Dr. Loy suggested new disruptors will continue – precision technology, smart sensors, artificial intelligence, automation of feed milling and delivery, traceability and genomics, or a new byproduct stream for cattle to upcycle. There will likely be a new disrupter within our careers, and we have to learn to navigate what is coming.

From Phlogiston to Chromatin Structure: The Deepening Our Understanding of Animal Energy Use – Dr. Kristen Johnson, Washington State University

Dr. Johnson described the many breakthroughs that have occurred in our understanding of metabolism. For example, the development of the calorimeter that led to the creation of energy partitioning systems and the advancement in analyses used to determine the chemical composition of feeds that allowed nutrition to become quantitative and qualitative. Within thirty minutes, Dr. Johnson reviewed a timeline starting with Plato and Aristotle’s early fundamentals of the four elements through the genome-level breakthroughs of today. The expression of regulatory proteins, gene networks, and DNA level deletions and mutations has opened the door to a greater understanding of animal physiology and behavior. Future opportunities, nutrigenomics, gene editing, intestinal microbiome, and epigenetics aim to deepen our knowledge about genomics and nutrition to make our goal of providing all animals with the appropriate nutritional needs for health, productivity, and wellbeing.

A Century and a Half of Nitrogen and Protein Metabolism in Ruminants – Dr. Gerald Huntington, North Carolina State University

Dr. Gerald Huntington began his presentation reviewing the discovery of nitrogen balancing, energy and protein metabolic interactions, and the role of urea in ruminant metabolism. The use of surgically altered animals, isotopically labeled molecules, and standardized laboratory analyses drove the quantitative knowledge of ingestion, ruminal degradability of dietary protein, digestion, absorption, and metabolism of N-containing compounds. Today, research teams have created empirical and mechanistic models for estimate rates and daily amounts of ruminal degradability of dietary protein, ammonia production, urea recycling, microbial protein synthesis, post ruminal protein digestion, metabolic fecal nitrogen, and amino acid absorption and metabolism. These models predict metabolizable amino acids for maintenance, reproduction, postnatal growth, and lactation. Dr. Huntington described future challenges the industry may face. For example, climate changes and heat stress, world food supply vs. environment, Emphasis on extensive production and grazing animals, and efficiency. It is our job to measure the efficiency with adaptability for future challenges.

Mineral Metabolism – Dr. Jerry Spears, North Carolina State University

Dr. Spears began his discussion on progress made over the years in mineral metabolism for ruminants. He identified the 15 minerals classified as essential and reviewed them individually based on their mode of action and deficiency signs within the animal. He continued to discuss the discovery of trace mineral antagonists, which resulted in the development of trace mineral sources for improved bioavailability, including organic trace minerals and hydroxy chloride. Trace minerals have been identified as having an effect on different aspects of the immune system and potentially may aid in disease resistance. Ultimately, the knowledge of mineral nutrition and metabolism has significantly increased in the past 100 years, but still, many questions need to be answered.

Anomalies of Carbohydrate Digestion and Metabolism by Ruminants – Dr. Fredric Owens, Oklahoma State University

The majority of dietary energy for the ruminant is carbohydrates derived from either plant cell walls, fresh conserved forages, or starch of grains and concentrates. Dr. Owens began his presentation by discussing the ruminants' ability to utilize non-protein N and nutrient-dense foods like byproducts and how they are a key ecological advantage over non-ruminants. He continued to discuss discrepancies within the literature, suggesting more research is needed better to identify carbohydrate digestion and metabolism within the ruminant animal.