Microbial Protein Synthesis Effect

The amino acids reaching the small intestine are supplied by the microbial protein produced, the undegraded feed protein, amino acids and peptides from feed which escape degradation, and endogenous secretions. The microbes that are produced in the rumen, and then pass down the digestive tract, may supply 60 to 80 percent of the amino acids absorbed from the small intestine. In a horse, protein, which has not been absorbed by the small intestine, "escapes" to the large intestine. There, bacteria produce microbial protein with a high biological value. Microbial protein is the “nearly perfect” protein in terms of its amino acid profile. Unfortunately, only 15% of these microbial proteins can be used efficiently by the horse. Therefore, an increase in the microbial population would convert to more efficiency.

The efficiency of microbial protein synthesis is a major factor affecting the overall amino acid requirement of ruminants and cecum fermenters, and is influenced by a number of factors including 1) energy source, 2) supply of nutrients such as nitrogen, sulfur, branched chain fatty acids and 3) environmental characteristics such as dilution rate, pH and microbial species present (Hespell and Bryant, 1979). An average efficiency of microbial synthesis of 17 grams of microbial protein per 100 grams of digestible organic matter was determined for many diets, although values were generally higher for sheep and forage based diets than for cattle and concentrate diets (Bergen et al., 1982). Through a continuous-culture experiments conducted by the University of West Virginia, Amaferm showed about a 14% to 30% increase in the amount of microbial protein available for use.

Specific research information can be found by clicking on the links below:

Caton et al.,  1993

Campos-Montiel and Viniegra-Gonzalez,  1995

Beharka and Nagaraja,  1998