Propionic acid has been used successfully as mold inhibitor in fermented feeds such as silages and high moisture corn. Calcium propionate, the salt of propionic acid, has similar antifungal properties offering the same efficacy as the acid form once ionized in water. Because of its convenience, calcium propionate has been the product of choice when ensiling forages.
The ruminant pre-stomachs, particularly rumen and reticulum, are quite unique and work in a symbiotic relationship between the microorganisms in its fluid, and the ruminant itself. This allows the host to digest fibrous carbohydrates for which it has not developed specific digestive enzymes.
The young calf, however, has not fully developed this capacity and behaves almost like a single-stomached animal, relying mostly in milk and highly digestible concentrates to grow. Dairy farmers have used different approaches to accelerate the transition to a functioning rumen so that growing ruminants can use less expensive forages in their diets. This of course must be done without negatively affecting development and performance.
Effects of calcium propionate on the digestive system of calves
Feed fermentation in the rumen supplies volatile fatty acids (VFA) which are excretion products from rumen bacteria. These VFA are essential to the development of rumen papillae (ultimately responsible for their absorption) but are also precursors of energy to the host once absorbed. Both propionate and butyrate have been demonstrated to stimulate papillae growth, with the latter also showing an effect in intestinal development and growth.