Metabolic and Microbial Transitions: A New Frontier in Understanding Left Displacement Abomasum

Abstract

Metabolic and microbial shifts are a new and growing area of knowledge in the pathogenesis and progression of Left Displaced Abomasum (LDA) in dairy cattle. It is one of the most frequently occurring metabolic and digestive diseases of high-producing dairy cows especially during the transition period around parturition. LDA has traditionally been linked to negative energy balance, hypocalcemia, ketosis and decreased feed intake. However, recent research has shown that changes in the rumen and gut microbial communities as well as substantial metabolic changes are important in the pathogenesis. Physiological changes during the transition period are extreme, to accommodate the demands of lactation and energy, and result in a disruption of carbohydrate, lipid and protein metabolism. These disturbances can change the rumen environment and microbial population, causing decreased motility and an increase in gas accumulations, thus increasing the susceptibility of the abomasum to displacement. Recent molecular methods, such as metagenomics and metabolomics, have allowed the study of microbial diversity and metabolic markers linked to LDA. Dysbiosis, the alteration of the bacteria, has been associated with digestion problems and inflammatory reactions, especially the reduction of fiber-digesting bacteria and rise of opportunistic bacteria. These metabolomic and microbial shifts offer novel opportunities for early diagnosis, prevention, and therapeutic interventions. Management of nutrition, supplementation with probiotics, and monitoring of dairy cow metabolism could be used to decrease the occurrence of LDA and enhance dairy cow health and productivity. The aim of this review is to summarise existing knowledge related to metabolic disturbances and microbial dysbiosis, and their co-interactions in the aetiology and management of LDA in dairy cattle.