Changes in adipose cells of Longissimus dorsi muscle in Iberian pigs raised under extensive conditions

Abstract

Twenty-four Iberian castrated male pigs were used to characterize and evaluate the effect of the duration of "Montanera" in the adipocytes size and its relation with the backfat thickness and intramuscular fat. The animals were fed under extensive conditions during 30, 60 and 90 days in the "Dehesa" before slaughtered. Carcass weight, percentage of intramuscular fat, thickness of backfat and its three layers and adipocytes size of the intramuscular fat were obtained. The group which expended 90 days on fattening obtained the highest adipocytes, with an area higher by a 50% than those that only expended 30 days. The differences in diameter and perimeter adipocyte were not as marked as area. A significant positive correlation between the diameter, area and perimeter of adipocyte with the backfat thickness were found. The fat cells in Iberian pig hypertrophy during the "montanera stage", being this increase significant from month to month in this period of fattening. Also, this adipocyte increase is correlated with the animal weight. The correlation between adipocyte size and inner layer of backfat shows that the inner layer obtained in live pig by ultrasound techniques could be a good marker of fat infiltration in pigs fattening in "montanera" system.

Ibérico (Iberian) Pig

“…In the context of the evaluation of growth performance, it is of interest to point out the extreme values recorded as it can be assumed that the maximum figures obtained for each growing phase correspond to Iberian pig's growth potential determined in ad libitum or close to ad libitum feeding conditions (i.e. 524 g/day in growing stage [50], 800 g/day in overall fattening stage [51,52] and 1018 g/day from 128 kg onwards [65]).…”

“…The back fat thickness values measured in all considered studies spanned from 35 to 90 mm on the withers (in average 85 mm in studies with final body weight above 100 kg [55,62,85]), from 10 to 90 mm at the level of the last rib (in average 58 mm in studies with final LW above 100 kg [25, 29-31, 34, 35, 37-44, 46, 51, 52, 55, 64, 65, 68, 69, 76, 77, 82, 85, 86]) and from 48 to 65 mm when measured above gluteus medius muscle (in average 56 mm in studies final body weight above 100 kg [68,76]). Similarly, muscularity measured as loin eye area span from 13 to 29 cm 2 (in average 23 cm 2 in studies with final LW above 100 kg [30,31,34,35,65,76,82]) and muscle thickness measured at the cranial edge of gluteus medius muscle from 11 to 60 mm (in average 40 mm in studies with final body weight above 100 kg [68,76]). Percentage of lean meat content is not reported in the literature as this is not commonly estimated on Iberian pig carcass composition studies, which are focused mainly in the premium cuts obtained from these animals (hams, shoulders and loins).…”

Muscle transcriptome analysis identifies genes involved in ciliogenesis and the molecular cascade associated with intramuscular fat content in Large White heavy pigs

“…For these specific productions, Semimembranosus muscle (SM) composition is of primary importance, since it affects the sensory and nutritional quality of high-quality dry-cured hams. The pig genetic types used for this high economic-value production are characterized by higher live weight and slaughter age, characteristics that can influence the maturation stage of the muscle-interspersed adipocytes [28][29][30].…”

Differences in histomorphology and expression of key lipid regulated genes of four adipose tissues from Tibetan pigs

“…The adipocyte area at 30 days of fattening in Iberian pigs was close to 13,693.49 ± 3,085.12 μm 2 and 26,252.38 ± 8,429.56 μm 2 at 90 days of fattening, with increases in the adipocyte area of backfat as the pigs gained weight. The adipocyte area was also positively correlated with the fattening time of pigs ( Ayuso et al, 2018 ). In female Pietrain × (Large White × Landrace) pigs, the diameter of the subcutaneous adipocytes was 81 ± 4 μm at 210 days of age ( Gardan, Gondret & Louveau, 2006 ).…”