Fat firmness of subcutaneous adipose tissue in intensively reared lambs

The aim of the work was to study the relationship between subcutaneous adipose tissue development and the fat firmness score attained in the carcass. For this purpose, 48 Lacaune male lambs were fed a concentrate from 23.5±0.2 to 41.4±0.2 kg live weight (63±0.7 to 122±3.2 days of age, respectively). After slaughter, the lamb carcasses were classified according to fat firmness (1: very firm to 5: very soft/oily). Subcutaneous adipose cell was measured and their overall distribution determined. Results showed that the adipose cells of the studied lambs exhibited a bimodal distribution, suggesting that a fast postnatal hyperplasic or cell proliferation process had been initiated in the subcutaneous adipocytes. In addition, the size of the small adipocyte peak was inversely correlated with the firmness of the fat (40.5, 37.7 and 30.9% of total adipocytes for groups of lambs with a firmness score of 4–5, 3 and 1–2, respectively). In this way, the average adipocyte cell diameter of the lambs with firmness scores of 4–5 (71.8±0.55 m) was less than that for the lambs with scores of 3 (73.9±0.46 m), and in turn, the diameter of this latter group was smaller than that of lambs with scores of 1–2 (77.6 ± 0.59 m). This work indicates the existence of a relationship between the intensity of the hyperplastic process undergone in the lamb subcutaneous adipose tissue and its fat firmness. © 2003 Elsevier B.V. All rights reserved