Energy (Volatile Fatty Acids) Effect

Feed is digested by bacteria that attach to the surface of a feed particle to digest it. However, lignin, a naturally occurring plant compound that gives structural strength to forages, is not digested by the bacteria, and creates a barrier between the bacteria and the hemicellulose and cellulose, the carbohydrates in forages used for energy. When the bacteria digest cellulose and hemicellulose, they produce the volatile fatty acids (VFA) acetate, propionate, and butyrate. These VFA are the main products of the digestion of feed by bacteria. These VFA are absorbed into the blood stream and carried to the liver where they are converted to glucose and fat for energy use by the animal. On a forage-based diet, the proportion of VFA would be approximately 65-70% acetate, 15-25% propionate, and 5-10% butyrate. Acetate is used primarily in the production of milkfat and body conditioning. Propionate is converted into glucose and stored as glycogen for use as energy. Therefore, increasing the digestibility of forages results in more energy to the animal. Glinskey et al., reported that 30% of the digestible energy for the horse is obtained from VFA production in the cecum. Amaferm has been shown to increase total VFA production by 19 to 23%, depending on the species.

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

Frumholtz et al.,  1989

Harper et al.,  1996