Apparent digestibility of crude fibre in ponies fed either a low or high-protein diet.

The research study explores the impact of low and high-protein intake on the apparent crude fibre digestibility in ponies. The study indicates that varying protein intake levels did not significantly influence crude fibre digestion, and it also suggests that a low-protein diet impacts the balance between faecal and urinary nitrogen.

Research Design and Procedure

• The researchers conducted the study on four adult ponies. They experimented with two different diets for these ponies in a cross-over design to analyze the impact of protein levels on crude fibre digestibility.
• Both high-protein and low-protein diets were composed of grass hay and concentrates. The low-protein diet consisted of 1.5 grams of digestible crude protein per kg of body weight daily, while the high-protein diet comprised 3.6 grams.
• Both diets provided the same daily crude fibre intake – 2.4g per kg of body weight.

Results

• No significant difference was seen in the apparent crude fibre digestibility between the two dietary groups. On a low-protein diet, the digestibility was recorded to be 42.9%, while a high protein diet showed 38.1% digestibility.
• The low-protein diet led to a significant rise in the ratio of faecal to urinary nitrogen.

Interpretation

• The researchers suggested that despite a lower protein intake, an efficient mechanism seems to be in place during the digestion process. Enough urea was transferred from the bloodstream into the intestine, which released enough ammonia in the hindgut to support microbial growth and keep up the fibre fermentation process.
• This implies that in terms of fibre digestion, changing protein intake from a sufficient level to a borderline deficient level does not adversely affect the ponies. The body compensates for low protein by adjusting the nitrogen balance in excreta and retaining necessary ingredients for fibre digestion.