Prevention of acidosis and laminitis associated with grain feeding in horses.

This research investigates the link between the consumption of large amounts of carbohydrates in the form of starch or sugars by horses, and its resulting condition, laminitis. The study’s principal focus is how acidosis in the gut links to an overload of carbohydrates and the development of laminitis, and how to control this process using a formulation of the feed additive virginiamycin for horses.

Understanding Laminitis and Acidosis

• The research defines laminitis as a common and debilitating condition in horses that is known to result from the consumption of large quantities of rapidly fermentable carbohydrates, such as starch or sugar.
• These carbohydrates can catalyze rapid fermentation and result in acidic conditions, particularly in the cecum and colon. This, in turn, leads to gastro-intestinal acidosis, characterized by an accumulation of lactic acid and reduced concentration of volatile fatty acids.
• Interestingly, the build-up of acid does not occur uniformly in all animals given an equal amount of grain. This variability is reflective of the uneven development of laminitis.

The Potential Role of Feed Additives

• The research underscores that it is possible to control the accumulation of lactic acid through the use of antimicrobial feed additives. These are active against gram-positive bacteria such as Streptococcus bovis and Lactobacillus species, principally responsible for lactic acid production at low pH.
• One such additive is virginiamycin. Other studies have proven its efficacy in controlling lactic acid build-up.
• In this research, a formulation of virginiamycin for horses has been developed. Notable for its particulate nature, it remains active in the hindgut and retains itself in the cecum.

Experiment Aim and Methodology

• The aim of the research experiment is to investigate how the virginiamycin formulation can control laminitis in horses that have free access to a high-grain diet.
• It implicitly hopes to provide indirect evidence that preventing gut acidosis (via controlling lactic acid accumulation) can prevent or mitigate laminitis in horses.