Fat clogging, fat cell count and fat cell size in swine in relation to age and feeding intensity

Growth dependent changes of fat gain, the number of fat cells in the cutlet muscle and the size of the fat cells in the bacon of the back were studied in dependence on feeding intensity with a total of 145 male castrates of the genotype (L X E) XSF. Between their 5th and 32nd weeks of life the animals were butchered at intervals of 3 weeks and the parameters were determined. The gain of fat and the intramuscular fat content were highest in the high-level variant (daily weight gain 720 g) and lowest in the low-level variant (daily weight gain 530 g). The diameter of the fat cells in the middle layer of the bacon of the back increased up to an age of 26 weeks and then remained constant. Differences between the feeding groups were registered; the animals of the high-level group had the biggest fat cells from the 14th week onwards. A nutrition-caused difference between the number of fat cells per mm2 of the cutlet muscle could not be found. The calculated total number of fat cells in the cutlet muscle increased due to growth up to an age of 26 weeks. The results provided basic knowledge of fat gain and influences on it in pigs and they indicate possibilities of making statements on fat retention determining the microstructure of the fat tissue of the living animal by means of biopsy.