De novo fatty acid synthesis and balance of fatty acids of pigs fed different fat sources

A matter of body weight and sex type: Pig carcass chemical composition and pork quality

This study compares minced carcass chemical composition and meat quality of castrated (CM), immunocastrated (IM) and entire male (EM), and female (FE) pigs at 70, 100 and 120 kg target body weights (TBW) (n = 80; 20 per sex). Sex affected fat, protein, and moisture content of the minced carcasses. Carcass fatty acid (FA) composition was affected by sex, with higher saturated and monounsaturated FA content in CM than in FE, IM and EM, and higher polyunsaturated FA in CM than in EM, with FE and IM in between. Except for intramuscular fat, which was higher in CM than in FE and EM, no significant differences between sexes were found in meat quality. TBW affected carcass chemical composition and some meat quality traits. An interaction between sex and TBW was found with IM approaching EM or CM depending on TBW.

Effects of Dietary Pork Fat Cooked Using Different Methods on Glucose and Lipid Metabolism, Liver Inflammation and Gut Microbiota in Rats

Cooking may affect the nutritional value of pork fat, and, nowadays, people have been paying an increasing amount of attention to the method of cooking. In this study, the effects of dietary pork fat cooked using different methods on body metabolism and intestinal microbes were studied in rats. Fat was extracted from pork belly meat cooked using three methods: braising (braising cooking method, BCM), stewing (SCM) and deep fat frying (DCM). The three types of pork fat were added to animal feed, and the effects of each on body weight, glucose and lipid metabolism, liver inflammation and intestinal microbes in rats were compared with the effects of soybean oil-treated feed (SO) and a blank control (BC). Rats in all three groups fed with cooked pork fat exhibited significant increases in body weight compared with the controls across the experimental feeding period. Furthermore, all three types of pork fat led to significant changes in the serum concentrations of triglycerides (TG) and total cholesterol (TC) relative to the controls, with the greatest increases in TG and TC in the BCM and DCM groups, respectively. All three types of pork fat led to significant decreases in serum high-density lipoprotein cholesterol concentrations relative to the controls, with the lowest concentration in the SCM group. All three types of pork fat also led to significant increases in low-density lipoprotein cholesterol concentrations relative to the controls, with the smallest increase in the DCM group. Rats in the SCM group had the highest level of liver fat deposition, followed by those in the BCM, DCM, SO and BC groups. Compared with the controls, the three groups fed with different types of cooked pork fat had significantly lower hepatic expression of nuclear transcription factor kappa B (NF-κB). The expression levels of NF-κB in the DCM and SO groups were significantly lower than those in the other groups. The abundance of Proteobacteria species in the intestines of rats was significantly lower in the BC group than in the other groups fed with cooked pork fat, and the abundance of Bacteroidetes species was significantly lower in the BCM, SCM and DCM groups than in the BC and SO groups. From the changes in the abundance of Firmicutes and Bacteroides, pork fat in the three cooking methods has a certain potential to promote the production of body obesity.

Effects of Dietary Perilla Cake Supplementation in Growing Pig on Productive Performance, Meat Quality, and Fatty Acid Profiles

The objective of this study was to determine the effect of perilla cake (PC) supplementation in a growing pig diet on overall growing performance, meat quality, and fatty acid profile. A total of 24 barrow grower crossbred pigs (Large White × Landrace) × Duroc with an initial average body weight of 26.33 kg were fed with a basal diet supplemented with PC at 0%, 5%, and 10% in (PC0, PC5, and PC10, respectively) for 12 weeks. At the end of the experimental period, pigs were slaughtered to determine carcass traits and meat quality. Back fat, abdominal fat, and longissimus dorsi (LD) muscle were collected to investigate fatty acid composition. The results show that the average daily gain (ADG) in the PC10 significantly increased. However, PC supplementation did not influence carcass traits and meat quality except the color as described by lightness (L*). Dietary PC supplementation significantly increased the α-linolenic acid (ALA, C18:3 cis-9, 12, 15), whereas n6/n3 ratio decreased significantly in all tissues investigated. Thus, it can be concluded that the supplementation of PC in growing pig diet is a potential way to increase the fatty acid composition to that required for healthier meat.

Effect of feeding pigs with bergamot by-product on fatty acid composition and oxidative stability of meat and salami

This work investigated the effects of feeding ensiled bergamot pulp to pigs on meat and salami quality. Eighteen pigs were assigned to two experimental treatments and fed a cereal-based concentrate diet (control) or the same diet in which ensiled bergamot pulp replaced 15% dry matter of the diet fed (BP). The BP treatment increased α-linolenic acid (+250%; P < 0.05), docosapentaenoic acid (+62%; P < 0.05), docosahexaenoic acid (+43%; P < 0.05) and consequently n-3 PUFA (+15%; P < 0.01) in meat. In salami, the content of α-linolenic acid, total PUFA and n-3 PUFA increased (+320%, +25% and + 258%, respectively) by feeding the BP diet (P < 0.001). The inclusion of bergamot pulp in the diet did not alter the oxidative stability in raw and cooked meat and colour descriptors. In salami, TBARS values were lower after 5 days of storage (P < 0.001) in BP group (1.54 vs 2.96). Finally, dietary supplementation with ensiled bergamot pulp to pigs improved the nutritional value of meat and meat products.

Dietary soybean oil modulates fatty acid composition of pork

This study was conducted to evaluate the impact of soybean oil level on performance and fatty acid profile of backfat and longissimus lumborum muscle of gilts. Forty-eight gilts with an initial weight of 21.75 ± 0.138 kg and final weight of 98.65 ± 2.106 kg were subjected to one of the following six dietary soybean oil inclusions (0.00, 1.086, 2.173, 3.259, 4.345, and 5.432%). Experimental design was completely randomized block with six treatments and four replicates of two animals each. Lipid profile of backfat and longissimus lumborum muscle was analyzed by gas chromatography. Increasing dietary soybean oil levels did not influence final weight, daily weight gain, and feed intake (P > 0.05) but improved feed to gain ratio (P < 0.05). The inclusion of soybean oil modified the lipid profile of backfat and muscle, reduced saturated and monounsaturated fatty acids, and increased polyunsaturated fatty acids concentration, mainly linoleic and α-linolenic acids (P < 0.05). Increasing dietary soybean oil inclusion decreased atherogenic and thrombogenic indexes, and the omega-6:omega-3 ratio of the backfat and longissimus lumborum muscle (P < 0.05). The level of soybean oil in swine diets influenced backfat and longissimus lumborum lipid profile.

Fatty acid composition and N2 solubility in triacylglycerol-rich adipose tissue: the likely importance of intact molecular structure

Diving tetrapods (sea turtles, seabirds and marine mammals) are a biologically diverse group, yet all are under similar constraints: oxygen limitation and increased hydrostatic pressure at depth. Adipose tissue is important in the context of diving because nitrogen gas (N₂) is five times more soluble in fat than in blood, creating a potential N₂ sink in diving animals. Previous research demonstrates that unusual lipid composition [waxes and short-chained fatty acids (FA)] in adipose tissue of some whales leads to increased N₂ solubility. We evaluated the N₂ solubility of adipose tissue from 12 species of diving tetrapods lacking these unusual lipids to explore whether solubility in this tissue can be linked to lipid structure. Across all taxonomic groups, the same eight FA accounted for 70-80% of the entire lipid profile; almost all adipose tissues were dominated by monounsaturated FA (40.2-67.4 mol%). However, even with consistent FA profiles, there was considerable variability in N₂ solubility, ranging from 0.051±0.003 to 0.073±0.004 ml N₂ ml^-1 oil. Interestingly, differences in N₂ solubility could not be attributed to taxonomic group (P=0.06) or FA composition (P>0.10). These results lead to two main conclusions: (1) in triacylglycerol-only adipose tissues, the FA pool itself may not have a strong influence on N₂ solubility; and (2) samples with similar FA profiles can have different N₂ solubility values, suggesting that 3D arrangement of individual FA within a triacylglycerol molecule may have important roles in determining N₂ solubility.

Meat quality from pigs fed tomato processing waste

Sixteen Nero Siciliano pigs were used to investigate the effect of dietary tomato processing waste on meat quality. During 86 days one group (CON, n = 8) received a pelleted conventional diet, while another group (TOM, n = 8) received the same diet in which tomato waste replaced 15% of corn. The dietary treatment did not affect growth performances. The TOM diet reduced intramuscular fat, SFA and MUFA content, while increasing the n-6:n-3 ratio in meat (P < .05). The TOM diet increased the concentration of PUFA, PUFA n-3, PUFA n-6 and the n-6:n-3 ratio (P < .01). The instrumental colour descriptors of backfat were unaffected by diet. The TOM diet increased deposition of retinol in meat (P < .001) but did not affect oxidative stability parameters measured in fresh meat and meat homogenates with pro-oxidant catalysts. Concluding, tomato pomace fed to pigs at higher levels compared to previous reports had no adverse effects on the investigated meat quality traits.

Relationship between pork fatty acid content in selected muscles and carcass tissues

Pork plays a central role in culinary tradition in Central Europe. Most of the studies determine the fatty acid (FA) content separately in muscles and subcutaneous fat. However, it is also important to determine the FA content of meat products, which contain a mixture of muscles and fat. The determination of FA in carcass tissues is difficult and leads to the destruction of the whole carcass. Thus, the aim of this study was to estimate the FA content of carcass meat (muscles with inter- and intramuscular fat, MC), and carcass soft tissues (muscles with inter- and intramuscular fat and subcutaneous fat, SC) based on a single muscle. Fatty acids were analysed using gas chromatography. Thirty crossbred pigs were fed diets differing in their fatty acid content and n-6:n-3 polyunsaturated fatty acid (PUFA) ratio. Samples of Longissimus thoracis et lumborum (LL), Biceps femoris (BF), Semitendinosus (ST), and Semimembranosus (SM) muscles, MC, and SC were taken. Correlation between linolenic, eicosapentaenoic and docosahexaenoic acids contents and n-6:n-3 PUFA in examined muscles and MC ranged from 0.809 (SM) to 0.961 (LL), from 0.708 (LL) to 0.954 (ST), from 0.907 (SM) to 0.941 (ST), respectively (P = 0.000). Correlation between linolenic, eicosapentaenoic and docosahexaenoic acids contents and n-6:n-3 PUFA in examined muscles and SC ranged from 0.773 (SM) to 0.954 (LL), 0.763 (LL) to 0.983 (BF), and from 0.909 (LL) to 0.940 (ST), respectively (P = 0.000). Results allow estimate the FA content of MC and SC based on their content in single muscles.

The Effect of PUFA-Rich Plant Oils and Bioactive Compounds Supplementation in Pig Diet on Color Parameters and Myoglobin Status in Long-Frozen Pork Meat

The study evaluated the effect of pig diet supplementation with rapeseed or linseed oil, and vitamin E or selenium, or both vitamin E and selenium on color parameters and myoglobin content of pork Semimembranosus muscle after long-term freezing storage during nine months. The influence of the type of the bioactive compounds added to pig diet on the content of myoglobin or oxymyoglobin, metmyoglobin and deoksymyoglobin in Semimembranosus m. was also assessed. The results indicate that the presence of oils rich in polyunsaturated fatty acids (PUFA) in pig diet improves the color of pork meat. Supplementation of dietary plant oils or dietary oils with antioxidants tended to increase significantly the concentration of oxymyoglobin and decrease the concentration of metmyoglobin in meat compared to the control group. The highest content of oxymyoglobin was observed in meat obtained from pigs fed diets with linseed oil. The best color scores (highest a* parameter) was noted for rapeseed oil group (with no addition of antioxidants). In conclusion, the addition of antioxidants to pigs’ forage supplemented with PUFA-rich oils is not recommended in order to improve color of long-term frozen pork.

Effects of the ratio of unsaturated fatty acid to saturated fatty acid on the growth performance, carcass and meat quality of finishing pigs

The effects on finishing pigs (80–100 kg BW) fed diets supplemented with oil sources containing different ratios of unsaturated to saturated fatty acids (UFA:SFA ratio) were evaluated in 15 barrows and 15 gilts (Duroc × Large White × Landrace). Three experimental diets were evaluated using a randomized complete block design, with broken rice, soybean meal and rice bran as the main feedstuffs in the control diet. Diets 2 and 3 consisted of the control diet supplemented with 3% oil, with UFA:SFA ratios of 2.5:1 and 5:1, respectively. Overall, there was no significant difference (P > 0.05) found in the average daily gain (ADG) of the pigs fed the treatment diets; however, the pigs fed the control diet and diet 3 had better (P < 0.05) feed conversion ratios (FCR) than the pigs fed diet 2. The pigs fed diets 2 and 3, which were supplemented with oil at UFA:SFA ratios of 2.5:1 and 5:1, had greater (P < 0.05) average daily feed intakes (ADFI) than the pigs in the control group. Additionally, it was found that the gender of the pigs had an effect (P < 0.05) on the FCR. Interaction effects between the experimental diets and the gender of the pigs (P < 0.05) were found in the ADFI and FCR. There were no significance differences (P > 0.05) among the treatment groups with regard to the carcass quality of the pigs; however, it was found that the gilts had greater (P < 0.01) loin eye areas than the barrows fed diets 2 and 3 and the loin eye area of pig fed diet 2 was the largest (P < 0.05). In the case of the meat quality parameters, it was clearly found that the pigs fed the control diet had a greater (P < 0.05) lightness (L^∗) in the meat colour, and the lowest cooking loss was found in the pigs fed the diet supplemented with fat containing the UFA:SFA ratio of 5:1. Overall, the dietary treatment did not significantly affect the drip loss, thawing loss and shear force of the pork. In conclusion, the supplementation of oil with UFA:SFA ratios of 2.5:1 and 5:1 has the potential to improve pork quality.

The impact of dietary fat withdrawal on carcass iodine value, belly characteristics, and changes in body fat over time

The inclusion of unsaturated fats in pig diets has raised issues related to pork carcass fat quality. The objective of this experiment was to understand how withdrawal from the diet of unsaturated dietary fat before slaughter impacts the composition of jowl fat during the growth cycle and at market. Fifty individually housed pigs (PIC 337 × C22/29; initial BW = 59.3 ± 0.55 kg) were allotted based on sex and initial BW to 10 treatments for an 82-d experiment as follows: 3 dietary fat withdrawal times before slaughter (21, 42, or 63 d) by 3 dietary fat unsaturation loads (DFUL), which includea high intake of unsaturated fatty acids supplied through an inclusion of 5% corn oil (HIGH), a high intake of a mixture of saturated and unsaturated fatty acids supplied through an inclusion of 5% animal-vegetable blend (MED), and a moderate intake of unsaturated fatty acids supplied through an inclusion of 2.5% corn oil (LOW). Pigs were weighed and jowl adipose samples were collected on d 0, 21, 42, and 63 and at harvest on d 82. Data were analyzed using PROC MIXED with treatment and sex as fixed effects. At market (d 82), increasing the withdrawal of dietary fat further away from market increased 18:1 (P = 0.045) and tended to increase 14:0 concentrations (P = 0.054). It also significantly decreased 18:2 (P < 0.001) and tended to decrease 18:3 concentrations (P = 0.081). A HIGH DFUL resulted in the greatest 18:2 concentrations in jowl fat followed by LOW; MED resulted in the lowest 18:2 levels (P < 0.001). Dietary fat withdrawal before market significantly reduced carcass iodine value (IV) measured at d 82 (P = 0.006). In conclusion, elevated 18:2 intake makes lowering carcass IV in the depot fat very difficult and may take as long as 61 d. The withdrawal of unsaturated dietary fat apparently altered the fat depot to be more reflective of fat synthesized de novo, resulting in a more saturated depot fat. Importantly, this alteration of deposited fat composition did not translate into improved belly firmness, depth, weight, or fat color.

Impact of dietary protein level and source of polyunsaturated fatty acids on lipid metabolism-related protein expression and fatty acid concentrations in porcine tissues

The study assessed the effects of reduced protein (RPD) vs high protein diet (HPD) in combination with n-3/n-6 PUFA-containing plant oils [linseed oil (LO)/sunflower seed oil (SO)] supplementation on lipid metabolism-related protein expression and fatty acid concentrations in porcine tissues. Forty male Landrace pigs (castrates) were allocated into four groups fed diets different in dietary protein and PUFA level and one control group. SCD-1 protein expression in pig muscle, back fat, and liver was not affected by diet. The protein expression of precursor (pSREBP-1c) and active nuclear form of SREBP-1c (mSREBP-1c) in muscle and back fat was affected by diet, however not in liver of pigs. In contrast, the expression of ACC and FAS expression was significantly affected by diet only in the liver. The fatty acid concentrations in muscle, liver, and back fat resulted in higher n-3 PUFA concentrations of LO groups compared to the SO groups.

Impact of dietary fat source and concentration and daily fatty acid intake on the composition of carcass fat and iodine value sampled in three regions of the pork carcass

The increased inclusion of unsaturated fats in pig diets has raised issues related to pork carcass fat quality. The objective of this experiment was to more precisely measure how differing levels of daily fatty acid intake alters the fatty acid composition in 3 different fat depots. A total of 42 gilts and 21 barrows (PIC 337×C22/29) with an average initial weight of 77.80±0.38 kg were allotted randomly based on sex and BW to 7 treatments: 3 and 6% of each of tallow (TAL; iodine value [IV]=41.9), choice white grease (CWG; IV=66.5), or corn oil (CO; IV=123.1) and a control (CNTR) corn-soybean meal-based diet with no added fat. Pigs were individually housed to allow accurate measurement of individual feed intake, in particular, daily dietary fatty acid and energy intake. Fat samples were collected from the jowl, belly, and loin at slaughter. Diet and carcass fat samples were analyzed for IV. Belly weights were recorded at slaughter along with a subjective belly firmness score (1=firmest to 3=least firm). Carcass lipid IV was increased (P<0.001) by increasing the degree of unsaturation of the dietary fat source (66.8, 70.3, and 76.3 for TAL, CWG, and CO, respectively). Carcass lipid IV for TAL and CWG was not affected (P>0.05) by inclusion levels; however, carcass lipid IV was greater (P<0.001) in pigs fed 6 than 3% CO (80.0 vs. 72.6), and carcasses of gilts had greater IV (P<0.001) than carcasses of barrows (71.5 vs. 69.1). Increasing the level of TAL and CO but not CWG from 3 to 6% decreased the apparent total tract digestibility of GE, resulting in a source×level interaction (P<0.05). Dietary fat source had no effect (P≥0.66) on apparent total tract digestibility of either DM or GE, but feeding 6% dietary fat increased G:F (P=0.006) over pigs fed 3% fat (0.358 vs. 0.337). Of all the fatty acids measured, only linoleic acid intake presented a reasonable coefficient of determination (R2=0.61). Overall, IV product (IVP) was approximately equal to linoleic acid intake as a predictor of carcass IV (R2=0.93 vs. R2=0.94). When inclusion of dietary fat and PUFA intake increased, IVP placed more emphasis on the dietary fat inclusion level rather than the dietary fat composition. Linoleic acid intake corrected the overemphasis placed on dietary fat inclusion by IVP. To conclude, linoleic acid intake showed a strong relationship with carcass IV and can be used as a predictor.

Different dietary protein and PUFA interventions alter the fatty acid concentrations, but not the meat quality, of porcine muscle

The present study investigated the effect of a reduced protein diet in combination with different vegetable oils (sunflower seed oil or linseed oil) on carcass traits, meat quality and fatty acid profile in porcine muscle. Forty male Landrace pigs were allocated into four experimental groups (each n = 8) and one control group (n = 8) at a live weight of approximately 60 kg. The pigs were fed ad libitum from 60 kg to 100 kg live weight and restricted to 2.8 kg/day until they reached 120 kg. In contrast to other studies, the intramuscular fat content (IMF) did not increase in animals of groups fed a reduced protein diet and vegetable oils. The IMF ranged between 1.2% and 1.4%. The growth performance and meat quality of the longissimus muscle was not affected by the diet, but the average daily gain (ADG) and drip loss were affected. The muscle fatty acid concentrations were significantly affected by the diet, resulting in higher n-3 FA concentrations up to 113 mg/100 g muscle and lower n-6/n-3 PUFA ratio for pigs fed linseed oil-containing high- and reduced protein diets, compared to sunflower seed oil-containing diets.