Ruminant forestomach

CLA, the acronym for a series of conjugated dienoic isomers of linoleic acid, occurs naturally in many foods, particularly dairy products and other foods derived from ruminant animals (6). Synthetically prepared CLA inhibits chemically-induced mouse epidermal and forestomach neoplasia (7,8) and rat mammary neoplasia (9). Hence, the effect of CLA on carcinogenesis is opposite that of linoleic acid. 

Llamas are so-called pseudo-ruminant animals which have their evolutionary origin in the arid high Andean mountains in South America. They ruminate and are forestomach fermenters. But their forestomachs are not as fully compartmentalized and do not retain feed particles and liquid in the same way as in the true ruminants (Clemens and Stevens, 1980). 

Trans fatty acids present in the diet arise from two origins. The first is from bacterial biohydrogenation in the forestomach of ruminants, which is the source of trans fatty acids present in mutton and beef fats. These are present at a concentration of 2-9% of bovine fat. Trans-11-octadecenoic acid is the main isomer produced although trans-9- and tra s-10-octadecenoic acid are also produced. Thus, trans fatty acids occur in nature and cannot be considered to be foreign substances. 

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