Abdominal fat

In most domesticated species, deposits of abdominal fat can be divided between peritoneal and inguinal regions; the exception is the duck, in which subcutaneous fat deposits, required for thermal insulation, comprise the largest single depot and are a special development in this species. The fat of the peritoneum is located within the abdominal cavity and extends ventrally over the visceral mass, being attached to the peritoneal membranes lining the abdominal wall. Inguinal fat lies along the interior femoral and tibiotarsal region and extends from the sartorious muscle to approximately two-thirds the length of the tibiotarsus. Consistency and appearance of fat in terms of its chemical and physical nature can vary between species, reflecting not only genetic traits but also diet. For example, abdominal deposits of fat in horses and certain Channel Island breeds of cattle are yellow while those of sheep are hard and white and those of pigs soft and greyish in colour. Body temperature is important, with fat being almost semi-fluid compared with that at cooler temperatures. Brown adipose tissue is not found in abdominal fat stores.