Effect of sex, dietary glycerol or dietary fat during late fattening, on fatty acid composition and positional distribution of fatty acids within the triglyceride in pigs

Abstract

The effect of sex, source of saturated fat (lard v. palm oil) and glycerol inclusion in the fattening diet on composition and fatty acid positional distribution in the triglyceride molecule was studied in pigs from 78 to 110 kg BW. Average daily gain and carcass characteristics, including ham and loin weight, were not affected by dietary treatment but sex affected backfat depth ( P < 0.01). A significant interaction between sex and glycerol inclusion was observed; dietary glycerol increased lean content in gilts but not in barrows ( P < 0.05 for the interaction). Individual and total saturated fatty acid (SFA) concentrations were greater in barrows than in gilts. In contrast, the concentration of total polyunsaturated fatty acids (PUFA) and of C18:2n-6, C18:3n-3, C20:3n-9 and C20:4n-6 in the intramuscular fat (IMF) was higher ( P < 0.05) in gilts than in barrows. Sex did not affect total monounsaturated fatty acids (MUFA) concentration in the IMF. The proportion of SFA in the subcutaneous fat (SF) was higher in barrows than in gilts ( P < 0.001). Within the individual SFA, sex affected only the concentrations of C14:0 and C16:0 ( P < 0.001). Dietary fat did not affect total SFA or PUFA concentrations of the IMF but the subcutaneous total MUFA concentration tended to be higher ( P = 0.079) in pigs fed lard than in pigs fed palm oil. Dietary glycerol increased total MUFA and C18:1n-9 concentration in the IMF and increased total MUFA and decreased C18:2n-6, C18:3n-3 and total PUFA concentrations in the SF. The data indicate that altering the fatty acid composition of the triglyceride molecule at the 2-position, by dietary intervention during the fattening phase, is very limited.

Piglet birthweight and sex affect growth performance and fatty acid composition in fatty pigs

“…A sex-related effect on the FA profile has been reported in many studies (Segura et al 2015a;Daza et al 2016;Egea et al 2016). Differences between males and females were similar in SCF, IMF and the PL fraction of the liver.…”

Effect of sex and dietary treatment on the composition and rheological properties of dry-cured ham subcutaneous fat

“…This finding supports the theory that there is a limited possibility of altering FA composition at the sn-2 location of the TAG by dietary intervention during the fattening phase (Segura et al 2015a). This is a matter of interest, because it is believed that SFA in the sn-2 position have a more detrimental health effect than those located in the external sn-1,3 location (Berry 2009), thus negatively affecting pork consumer acceptability.…”

“…Innis et al (1997) provided diets differing in total FA composition and distribution within the TAG, they studied the liver lipids of piglets and reported a limited effect of dietary treatment, and therefore suggested metabolic regulation of FA composition in sn-2 position. Segura et al (2015a) also found a limited effect of either sex or dietary treatment on the FAs located in the internal sn-2 position of pig SF. Gastric and pancreatic lipases hydrolyze FA from the external positions of the TAG.…”

Free-Range Feeding Alters Fatty Acid Composition at the sn-2 Position of Triglycerides and Subcutaneous Fat Physicochemical Properties in Heavy Pigs

“…5 EXT: IB × DR pigs free-range reared and exclusively fed on acorns and grass according to the traditional feeding system. 6 SFA (saturated fatty acids) = C14:0 + C15:0 + C16:0 + C17:0 + C18:0 + C20:0, 7 MUFA (monounsaturated fatty acids) = C16:1n-7 + C17:1 + C18:1n-9 + C10:1n-9, 8 PUFA (polyunsaturated fatty acids) = C18:2n-6 + C18:3n-3 + C20:3n-6 + C20:4n-6, 9 UI (unsaturation index) = [(C16:1n-7 + C17:1 + C19:1n-9 + C20:1n-9) + 2 × C18:2n-6 + 3 × (C18:3n-3 + C20:3n-6) + 4 × C20:4n-6], 10 Σn-6/Σn-3 = (C18:2n-6 + C20:3n-6 + C20:4n-6)/C18:3n-3.…”

“…Studies aimed to control the FA distribution by dietary intervention in pigs are scarce and evidence that the FA composition in the internal sn-2 position is highly regulated and resistant to dietary manipulation [7,9], thus maintaining a narrow range of variation. Accordingly, previous studies in pigs evaluated the effects, such as dietary glycerol or saturated diets, that resulted in limited modifications at the sn-2 position in the TAG [10]. Other dietary supplementations, such as the use of compounds that reduce the ∆ 9 -desaturase enzyme activity, have been related to an increase in the proportion of saturated FA at the sn-1,3 position [9].…”