Dairy producers and dairy nutritionists understand the importance of proper vitamin and mineral nutrition during both the dry period and the transition period. However, they often underestimate the role that key antioxidant nutrients play in immune function and their long term impact on uterine and udder health.
The main objective of this study was to determine if a grain-based SARA challenge causes translocation of LPS from the gut into peripheral circulation. This was achieved by measuring plasma LPS using a high-sensitivity assay and by monitoring LBP levels in peripheral plasma and milk.
Ken Nordlund, DVM — University of Wisconsin-Madison
In field investigations of suspected ruminal acidosis problems, we have found it practical to perform rumenocentesis on two groups of cows.
Ruminal acidosis is the consequence of feeding high grain diets to ruminant animals, which are adapted to digest and metabolize predominantly forage diets. Feeding diets that are progressively higher in grain tends to increase milk production, even in diets containing up to 75% concentrates.
Subacute ruminal acidosis (SARA) is defined as periods of moderately depressed ruminal pH (between 5.2 and 5.6) that are between acute and chronic in duration (Cooper and Klopfenstein, 1996). The most consistent and immediate clinical sign of SARA is depressed feed intake, evidently because excess organic acids disrupt rumen function (Cooper et al., 1995, 1996) and cause malaise (Provenza et al., 1994).
A major challenge to the current feeding systems of dairy cattle is how to reconcile feeding of large amounts of cereal grains that support high milk production with the high incidence of metabolic disorders.
Dairy cows fed for maximum milk production are at risk of experiencing ruminal acidosis, as recently reviewed by Krause and Oetzel (2006). In high-producing dairy cows, ruminal pH fluctuates over the course of the day as the processes of eating, rumination, ruminal digestion, and VFA absorption occur.
Cows that are fed a diet that will lead to SARA will initially respond much the same as they would in the early stages of ruminal fermentation. Once the major portion of the diet is consumed however, cows that were offered BUFFER-LYX® appeared to handle the increased acid load much better because BUFFER-LYX® minimized the time cows spend below a pH of 5.5. In fact, when compared to cows that did not receive BUFFER-LYX®, they moved to a higher pH more quickly. The pH of cows that were fed a diet conducive to SARA and not offered BUFFER-LYX® stayed below 5.5 for a considerably longer time. When diets or feeding conditions that can lead to acidosis occur, supplementing with BUFFER-LYX® appears to help cows recover from SARA and keep fermentation within a more desirable range.