Time required for adaptation of protein metabolism

Authors: Zanton, Geoffrey

Submitted to: Journal of Dairy Science
Publication Type: Abstract Only
Publication Acceptance Date: 3/24/2015
Publication Date: 7/13/2015
Citation: Zanton, G.I. 2015. Time required for adaptation of protein metabolism [abstract]. Journal of Dairy Science. 98(suppl 2):312.

Interpretive Summary:

Technical Abstract: Animals that can appropriately adjust to varying environmental and nutritional conditions possess a survival advantage. Maintaining homeostasis and homeorhesis in response to changing nutritional conditions requires flexibility in nutrient partitioning and efficiencies. This is especially the case for protein metabolism, since there is no dedicated pool of amino acids held in reserve for times of changing dietary protein availability. Research on the adaptation in protein metabolism to changing dietary conditions could have potential implications for experimental design and on basic and applied animal nutrition. However, experiments directly evaluating the metabolic characteristics and appropriate timing of dietary adaptation are very limited. This is especially true when compared to the number of experiments that have evaluated a response to a nutritional change after the period of adaptation is presumed to be complete, although rarely verified. Factors that affect the adaptive responses in protein metabolism in the ruminant are multiple and likely interact with each other. However, the time required for adaptation appears to mostly depend on factors such as the duration and level of the previous nutritional condition, the difference from the current nutritional condition, the timing of these dietary changes with respect to the physiological state of the animal, the priority of the metabolic demand, and the productive state of the animal (i.e., maintaining, growing, or lactating or combinations thereof). As a consequence of these varied factors, from an experimental perspective, the time required for adaptation may depend on the response variables, productive state of the animal, and the treatments under investigation. Existing literature will be reviewed to highlight time-related adaptive responses to diet changes on protein digestion, post-absorptive metabolism, and production and to emphasize areas where this understanding is incomplete.