152 Overview of probiotic supplementation and opportunities to improve cow-calf production

Abstract The growing concern of increased antimicrobial resistance and their adverse effects on host microbiota and health has led to the investigation of new alternatives to achieve pathogen control and promote host health. By definition, probiotics (also known as direct fed microbials; DFM) are live microorganisms that confer a health benefit to the host when administered in adequate amounts. Probiotics supplementation has been an effective management practice to improve health and performance of the livestock through the inhibition of pathogens and improvement of feed digestion. Several modes of action provide explanations for the improved health and reduced morbidity in livestock, including: direct inhibition of pathogen growth via production of anti-bacterial factors and competition for dietary ingredients (growth substrates); intestine protection by activating mucus production, which acts as reservoir of antibodies, mucins, and antimicrobial peptides, and as a selective barrier for trapping pathogens and other unwanted substances; competition against pathogens for binding sites; support for optimal intestinal barrier integrity; biofilm formation; and reduction in inflammation by modulating the release of immunoglobulins and pro- and anti-inflammatory cytokines. Moreover, probiotics support the production of a cascade of enzymes that improve digestibility of starch, fat, protein, and fiber in the gastrointestinal tract. Combined, the aforementioned modes of action and improved digestibility explain the increased livestock health and performance following probiotic supplementation reported in several species. Spore forming bacteria have been the primary microorganisms used as probiotics due to their stability and viability after processing, storage, and manipulation. This presentation will summarize ongoing and published data on probiotic supplementation to improve cow-calf production, including studies evaluating probiotic supplementation to optimize post-weaning growth and reproduction of developing Bos indicus-influenced beef heifers. Moreover, the presentation will include the potential effects of probiotic supplementation on nutritional management of beef cows during gestation and early lactation, with emphasis on the future offspring growth performance and immune response. It has also been observed that neonatal gut colonization is crucial for the developing gut and naïve immune system and has long-term health effects. Thus, partial data on microbiome and metabolome of beef cows and their calves will also be shared in this presentation.