Digestive tract of ruminant

Plant lipids generally have an even number of carbon FAs, while animal lipids include odd-numbered carbon chain FAs, and, in some cases, branched chain FAs formed by bacterial activity in the digestive tract of ruminant mammals [5,41]. Branched FAs can also be formed in low amounts from other kind of lipids as a result of microbial activity after burial. 

Propionic (propanoic) acid-producing bacteria are numerous in the digestive tract of ruminants. Within the rumen some bacteria digest cellulose to form glucose, which is then converted to lactate and other products. The propionic acid bacteria can convert either glucose or lactate into propionic and acetic acids which are absorbed into the bloodstream of the host. Usually some succinic acid is also formed. 

Recall that the original development of eukaryotic creatures may have started with a symbiotic relationship between two prokaryotes and that symbiosis between algae and nonphotosynthetic organisms may have led to development of higher plants. Associations between species are still important today. For example, the bacteria in the protozoa of the digestive tract of ruminant animals are essential to production of meat. Our own bodies play host to bacteria, fungi,... 

Although forests are obvious as sources of gas, it is the microorganisms that are especially important in generating atmospheric trace gases. Methane, which we have already discussed, is generated by reactions in anaerobic systems. Damp soils, as found in marshes or rice paddies, are important micro-biologically dominated environments, as are the digestive tracts of ruminants such as cattle. 

Formaldehyde treatment this process is used to protect certain nutrients (in particular proteins, amino acids and fatty acids) from the action of microorganisms during the passage through the upper part of the digestive tract of ruminants. While several rumen protection processes exist, formaldehyde treatment, which has been used in France since the 1980 s, is the only one represented in the tables. 

Ruminants have a higher requirement for the element than non-ruminants because some of the element is wasted in microbial synthesis of organic compounds with no physiological activity in the host s tissues. Furthermore, vitamin B12 is poorly absorbed from the digestive tract of ruminants, the availability in some cases being as low as 0.03.The ruminant has an additional requirement for the vitamin because of its involvement in the metabolism of propionic acid (see p. 202), an important acid absorbed from the rumen. 

Bloat (tympany) Dysfunction of the digestive tract of ruminants characterized by intraruminal pressure buildup due to the accumulation of fermented gases. As a result, there is a distention of the left side of the abdomen and accumulation of toxic metabolites that can kill the animal. 

The important tapeworms inhabiting the digestive tract of animals are Moniezia expansa, M. benedeni and Thysaniezia giardi (ruminants), Anoplocephala perfoliata, A. magna, and Par anoplocephala mamillana (horses), Dipylidium caninum,... 

Methane Is commonly found In nature wherever bacteria decompose organic matter In the absence of oxygen, as In marshes, swamps, or the muddy sediment of lakes—hence. Its common name, marsh gas. In China, methane has been collected from the mud at the bottom of swamps for use In domestic cooking and lighting. Methane Is similarly formed from bacteria In the digestive tracts of certain ruminant animals, such as cows. 

Cellulose differs from amylose principally in the stereochemistry of the acetal linkages, which are a in amylose but P in cellulose. a-Amylase is specific for al 4 bonds and is not able to hydrolyse pi 4 bonds. An alternative enzyme, termed cellulase, is required. Animals do not possess cellulase enzymes, and thus cannot digest wood and vegetable fibres that are predominantly composed of cellulose. Ruminants, such as cattle, are equipped to carry out cellulose hydrolysis, though this is dependent upon cellulase-producing bacteria in their digestive tracts. 

Humans and other mammals lack the /3-glucosidase enzyme needed to hydrolyze cellulose, so they cannot use it directly for food. Several groups of bacteria and protozoa can hydrolyze cellulose, however. Termites and ruminants maintain colonies of these bacteria in their digestive tracts. When a cow eats hay, these bacteria convert about 20% to 30% of the cellulose to digestible carbohydrates. 

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