re. wild vs domestic dietary animals:
here are some tidbits from crawford & marsh, the driving force, 1989, ch.12
"if an animal is overfed & denied exercise it simply gets fat [excess adipose tissues]. if the process is continued long enough, it loses muscle & depot fat infiltrate the retreating muscle fibers, giving the 'marbled' appearance characteristic of modern intensively fed animals. this infiltrating fat is, like the rest of the storage fat of ruminants, saturated fat ...
"by contrast, under natural or free-living circumstances this cannot happen ... hence analysis of its [wild] meat shows it to be characterized by the type of fatty acids involved in cell function & structure, that is [aa, epa, dha]" (p.222).
"before the enclosures of the 17th century, cattle had mostly been herded in open grass, bushland, & forest. when people began to contain them in fields ... the variety of food that the animals could select for themselves was drastically reduced [alfalfa & clover, which are legumes, within electric fences]" (p.223).
"added to all this was the clever idea of castration, again to make the males quiet & to gain weight faster: but the weight was largely fat -- saturated, storage fat" (p. 224).
"the energy contained in [dietary] storage fat represents about 1.097 times 10 to the power of 14 joules a day, or enough to keep an oil-fired 1200 mw station in operation for a year. translated into candle power [candle = sat fat], the present animal production in the uk provides enough white storage fat for all families to throw away their electric light bulbs. we now eat the candles" (p. 225)
the following is from their table 5:
"comparison of proportion of lean meat & nutrients in the carcasses of wild [w] & domestic [d] beef animals"
lean meat w = 75% d = 50%
protein & nutrients w = 15% d = 10%
(water removed)
storage fat w = 4% d = 25%
[sat fat]
"what is termed lean meat in butchers' carcasses is not lean meat at all. the tissue is infiltrated with veins of [storage] fat, which can account for anything up to 20% of its weight. in wild animals there is virtually no visible fat between the muscle fibers. the only fats present [in wild] are structural lipids [aa, epa, dha] used for building the cells. any surplus fat the [wild] animals have is stored around the interior organs such as the kidneys & the heart" (p.227).