Fermentation Anaerobic Digestion

Fermentation is defined as the process of substrate degradation in the absence of oxygen. The best known (to humans) fermentations involve the production of beer, wine, or vinegar (acetate), which is also an important end-product of ruminal and intestinal fermentations. Nearly all feed protein and carbohydrates can be degraded by bacteria via ruminal fermentation to produce volatile fatty acids (VFA) and microbial cells (Fig. 1). The VFA are absorbed by the host animal and provide the animal with a source of carbon and energy for maintenance and productive functions. The most important VFA to the animal are acetate (vinegar), propionate, and butyrate. Microbial cells (bodies) are washed out of the rumen along with the small feed particles and are also digested, providing the ruminant animal with an excellent source of high-quality protein (especially essential amino acids), as well as B vitamins as a by-product of fermentation. Thus, the ruminant provides the microorganisms a hospitable environment and food in exchange for the microorganisms providing nutrients derived from a low-quality feed to the animal truly, a mutualistic relationship.

Feedstuff's (Forage, Grain)

Feedstuff's (Forage, Grain)

Fig. 1 Activity of the rumen.

Although the ruminal fermentation is generally beneficial to the animal, in some cases, the end-products of the ruminal fermentation can be detrimental to the animal, or even to the environment. Some bacteria ferment specific amino acids (tryptophan) and produce 3-methylindole, which can be inhaled by the animal, resulting in asphyxiation (bovine emphysema). Other problems that can be traced to production of harmful end-products of the rumen fermentation include bloat (swelling of the rumen caused by gas production) and lactic acidosis (accumulation of strong acid in the rumen, which damages the tissues of the rumen and inhibits the beneficial fermentation). Some of the ammonia produced from ruminal protein fermentation is not utilized by the animal, but is excreted in the urine and directly impacts the environment (environmental nitrogen pollution). Methane is a powerful greenhouse gas produced by ruminal microorganisms that is eructated (belched) by all ruminant animals.

Atkins Low Carb Diet Recipes

Atkins Low Carb Diet Recipes

The Atkins Diet is here. Dr Atkins is known for his great low carb diets. Excluding, Dr Atkins carb counter and Dr Atkins New Diet Revolution.

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