The contribution of fat mobilization to the regulation of fat deposition in growing Large White and Piétrain pigs

Nutritional Influences on Skatole Formation and Skatole Metabolism in the Pig

Skatole is a tryptophan (TRP) metabolite with fecal odor. Together with the testicular steroid androstenone it is regarded as a main determinant of boar taint, even if elevated concentrations of skatole occur occasionally in gilts and barrows. Skatole concentrations in adipose tissue result from a complex process, which includes the availability of TRP and the presence of specialized bacteria in the gut in need of TRP for energy production, as well as absorption, transport and accumulation of skatole in adipose tissue. Several steps of this process are influenced by diet and specific feed compounds. In the present paper the current knowledge about physiological mechanisms of skatole dynamics is summarized. Additionally mechanisms are discussed, by which effective feeding strategies and feed additives exert their influence in the prevention of high skatole concentrations in adipose pig tissue. It was concluded that the most effective measures are those which influence several steps of skatole formation. Despite the numerous studies carried out in the field of skatole physiology, interesting aspects still need clarification, such as the effect of adipose tissue turnover. Reliable control of skatole accretion in fat of boars is one of the main prerequisites for pork production with entire males.

Effect of diet saturation on growth performance, carcass characteristics and fat quality of heavy pigs

Twenty-four castrated male (Duroc × Large Withe × Landrace) with an average weight of 69.4 kg were randomly distributed and located in individual cages and given the experimental diets. Diets were provided ad libitum and were formulated containing three levels of palm oil and hydropalm (hydrogenated palm stearine): 4% and 0% (low saturation), 2% and 2% (moderate saturation) and 0% and 4% (high saturation). Pigs were slaughtered at a local slaughterhouse with an average weight of 129.1 kg. The dietary treatment had no significant influence on growth performances and carcass characteristics. The diet saturation led to an increase of C18:0 and ΣSFA (saturated fatty acids) proportions and to a reduction of C18:1 n-9, C18:2 n-6 and ΣPUFA (polyunsaturated fatty acids) proportions and in subcutaneous backfat outer and inner layers. The dietary treatment affected significantly the melting point of subcutaneous backfat outer layer but had no significant influence on the melting point of the subcutaneous backfat inner layer. However, a linear effect of C18:0 proportion of subcutaneous backfat outer and inner layers on the melting point was observed. Dietary treatment had no significant effect on the main fatty acids pattern of intramuscular neutral and polar lipids from Longissimus dorsi muscle. In neutral lipids of liver a dietary influence (p < 0.05), but not a clear dose--response relationship, was observed for C16:0, C18:1 n-9, ΣSFA and ΣPUFA fatty acids, whereas in polar lipids the dietary treatment had no significant effect on the main fatty acids proportions. No effect of diet saturation was found on rheological properties of fat except for the hardness. The hardness was higher in the pigs that received the diet with 0% of palm oil and 4% hydropalm than in those given the diet with 4% of palm oil and 0% hydropalm.

Dietary vitamin A concentration alters fatty acid composition in pigs

This experiment was conducted to study the effect of vitamin A concentration in the diet on fatty acid composition in pigs. One-hundred and twenty eight Duroc × (Large White × Landrace) castrated male pigs were used. Pigs were randomly distributed and located in cages of four pigs each to the following treatment: vitamin A-enriched diet (100,000IU/kg) (n=16) and control diet with a basal level (7500IU/kg) (n=16). The pigs were slaughtered at an average weight of 125.9kg. No effect of diet vitamin A level on performance, carcass traits and intramuscular fat percentage was observed. The retinol concentration in subcutaneous backfat and retinol and retinol palmitate contents in liver were higher in the pigs that were given the vitamin A enriched diet than in those receiving the control diet. However the vitamin A supplementation did not increase the retinol content in the muscle. Pigs receiving the vitamin A enriched diet showed a higher C16:0 and ∑SFA proportions in the outer layer and C18:0 and ∑SFA proportions in the inner layer. Moreover, the diet rich in vitamin A led to a reduction of C18:1 n-9 and ∑MUFA proportions in subcutaneous backfat inner layer. Dietary vitamin A concentration had not influence on main fatty acids composition of intramuscular lipids. Dietary vitamin A enrichment lead to a higher C16:0, ∑SFA concentration in liver lipids.