Submitted to: Veterinary Clinics of North America
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/13/2017
Publication Date: 8/12/2017
Citation: Baldwin, R.L., Connor, E.E. 2017. Rumen function and development. Veterinary Clinics of North America: Food Animal Practice. https://doi.org/10.1016/j.cvfa.2017.06.001.
Technical Abstract: The ruminal epithelium is uniquely placed to impact the net utilization of nutrients of the whole body. The symbiosis between the microbiome inhabiting the lumen and the host is largely dependent upon the provision of a constant supply of nutrients from roughage that would otherwise be unusable to the mammalian digestive system. Physically, a barrier to the contents of the lumen, the rumen epithelium serves an obvious protective function, which when compromised, results in disease states discussed in detail in later chapters. Interestingly, the ruminal epithelium is a stratified squamous epithelium which is typically associated with protective functions rather than absorption. As such, ruminal epithelium is unlike other gastrointestinal tissue barriers. Metabolically, the ruminal lining serves a critical role in mitigating the diffusion of end products of fermented feedstuffs into circulation. In fact, the metabolic contributions of the ruminal epithelium have received a great deal of research attention as the impact of the tissue on production efficiency is undeniable. Moreover, the process and regulation of the developing rumen epithelium has received a great deal of research interest. This is due to the fact that the tissue is incompletely developed at birth and requires the establishment of a viable ruminal fermentation for complete development by weaning. This developmental process has been viewed with interest not only from the health and well being aspect of rearing replacement heifers and production animals, but also as a unique model system for the investigation of nutrient gene interactions occurring naturally. This chapter seeks to describe the basic structure and metabolic characteristics of the epithelial lining of the rumen, and discuss the importance of the differentiation of the tissue during normal development production practice.