Fresh and preserved green fodder modify effects of urinary acidifiers on urine pH of horses.

The research article is a study investigating how different diets, with or without acidifiers, affect the urine and blood pH levels of horses. The highlight of the study finding is that diets consisting of green fodder did not lead to significant decrease in pH levels when acidifiers were added, as opposed to diets that consisted of straw.

Explanation of the Research Methodology

• The research utilized four ponies with varying body weights and subjected them to six different diets in a cross-over experimental design, structured to maintain body weight.
• The diets were composed of different main compounds, including fresh grass, alfalfa hay, grass cobs, grass silage, straw, and extruded straw, with the last two being supplemented with and without acidifiers.
• The feeding of these diets spanned between 2 to 10 days, after which urine pH was measured. In the case of fresh grass, alfalfa hay, straw, and extruded straw, blood pH, blood base excess, bicarbonate, and mineral balance were also determined.

Key Research Findings

• Diets consisting of straw or extruded straw led to a significant drop in the urine pH when acidifiers were included with the pH decreasing from 7.8 to approximately 5.2.
• However, diets premised on fresh or preserved green fodder did not demonstrate a similar trend, instead the pH did not decrease below 7 when acidifiers were added.
• Blood pH was similarly affected. Acidifiers showed minimal effect on the pre-prandial blood pH only in the straw diet, but post-prandial blood pH declined significantly in all diets augmented with acidifiers.
• Blood bicarbonate and base excess parameters mirrored the diet and acidifier effects.
• The researchers found no systematic impact on faecal and renal mineral excretion and apparent mineral digestibility by the diet or acidifiers, except for chloride. Inorganic chloride salt demonstrated better digestibility than chloride from the feed.
• The only stabilisation of acid-base balance was observed with green plant material, suggesting the potential role of chlorophyll and its metabolites in the effect of green fodder on acid base balance.