Non antibiotic strategies to modify the microbial population of dairy cattle: impacts on milk production, animal health, and food safety

In the United States, the dairy industry includes approximately 9 million cattle that produce on average 19,000 pounds of milk a year, and comprise 50% of the ground beef supply.  Cattle are ruminant animals that depend on a symbiotic relationship with the microbial population of their gastrointestinal tract to convert forage and grain to high quality meat and milk. The gastrointestinal microbial population of dairy cattle is extremely dense and diverse, and is a complex natural ecosystem that can be utilized to improve animal production efficiency, sustainability, animal and human health, as well as food safety.  For example, a decreased ruminal microbiome diversity and increased lactate utilizing bacterial populations in beef and dairy cattle have been linked with increased milk production efficiency.  While antibiotics have been used for many years to shift microbial populations to increase production efficiency, the mode of action of antibiotics on the gastrointestinal microbiome and host animal physiology (both positive and negative) remain largely unknown and unreplaceable.  Non-antibiotic strategies have been devised to modify the microbial population of dairy cattle on the farm.  A large number of approaches, including management practices, dietary changes, organic acid inclusion, probiotic and prebiotic feed additives, and vaccination have been widely used worldwide in the dairy industry to enhance milk production and feed efficiency, as well as to improve animal health.  Many of these strategies rely upon harnessing the natural competitive nature of bacteria and specific microbial ecological factors to eliminate pathogens that negatively impact animal production, health, or food safety which may have unintended consequences of which we need to be aware. In this presentation we explore the ecology behind the efficacy of alternatives to antibiotics and how they may impact dairy production efficiency and can be used to improve both human and animal health.
 
Keywords: antibiotic alternatives, prebiotics, organic acids, microbiome, animal efficiency.

Abstract presented at the 3rd International Symposium on Alternatives to Antibiotics 2019.