The suitability of morphometric parameters of fat cell size for the purposes of animal science research. 1. Cellularity of swine subcutaneous adipose tissue influenced by different fattening ages and graded feed levels

The cellularity of subcutaneous adipose tissue of 108 male castrated pigs (German Landrace) was investigated. The tissue was taken bioptically under anesthetic conditions. The outer and the inner layer of backfat were examined separately, fresh unfixed tissue slices floating in Ringer solution were subjected to microscopic measurements of adipocyte diameters. The animals were kept in feeding experiments, 3 and 2 sectors respectively of growing period were examined (40 kg; 66 kg, 88 kg body mass) divided into 6 and 4 feeding levels respectively for 21 days (0.4; 0.6/0.8; 1.0; 1.2; 1.4 MJ metabolic energy per kg body mass0.75 per day). The inner layer of backfat showed bigger fat cells compared to the outer layer. The average fat cell size was greater for the older and heavier than for the younger animals. The gradation of food administration resulted not in a straight parallel rise in fat cell size but in an effective consequence with respect to the distribution frequency of the dates: The higher the food energy level, the more the accumulation of small fat cells from 10 til 30 microns diameter. These cell fractions succeeded in being signified as typical and important closed population. Other authors also had described these particular cells, i.e. "fat cell clusters" and "VSFC" (= very small fat cells) respectively. An external use of the dates for computer simulation programs resulted in success and manifested the independently gained conclusions. The examinations were performed by support of different branches of literature and the results had to be discussed in front of a wide background of known connections.(ABSTRACT TRUNCATED AT 250 WORDS)