Effect of a high linoleic acid diet on lipogenic enzyme activities and on the composition of the lipid fraction of fat and lean tissues in the pig

The aim of this study was to examine the influence of a high linoleic acid diet on lipogenic enzyme activities in pig tissues and on the dietetic quality of these tissues (subcutaneous adipose tissue, Semimembranosus and Diaphragma muscles). Pigs were fed diet M containing 4% of maize oil or diet T containing 4% of tallow from 40 to 100 kg live weight. We did not observe any differences in growth or slaughter performances that could be attributed to diet. Lipogenic enzyme activities were higher in the adipose tissue of pigs fed diet M. However, diet had no effect on lipogenesis in the muscles. The lipid, linoleic acid, and cholesterol contents were higher in the adipose tissue of pigs fed diet M whereas the oleic acid concentration of the adipose tissue was lower. No significant increase in the lipid content of either muscle was however observed in pigs fed diet M. The linoleic acid and cholesterol contents were higher in both muscles of pigs fed diet M than in muscles of pigs fed diet T.     

Influence of dietary conjugated linoleic acid (CLA) and age at slaughtering on performance, slaughter- and meat quality, lipoproteins, and tissue deposition of CLA in barrows

To assess the effects of dietary conjugated linoleic acid (CLA) on performance, slaughter and meat quality, 100 Danish barrows were fed diets containing 0.5% sunflower oil (control) and 0.5% CLA from 40 kg live weight until slaughter at either 100 or 130 kg live weight. Plasma total cholesterol (P=0.006) and HDL-cholesterol (P=0.021) was reduced, and plasma FFA-concentration increased (P=0.06) in pigs fed CLA. CLA supplementation improved (P=0.01) the feed utilisation by 4.7% and 4.3% for pigs slaughtered at 100 and 130 kg, respectively. Daily gain tended (P=0.06) to increase with the CLA-treatment (1.236 versus 1.194 kg for CLA- and control, respectively). Dietary treatments had no effects on slaughter- (meat percentage and backfat thickness) and meat quality responses (pH, temperature and water holding capacity). CLA tended (P=0.09) to reduce the intramuscular cholesterol, but had no influence on the total content of intramuscular fat.     

Comparison of characteristic components from chickens of different genotype kept in intensive and extensive farming systems

Male and female Broiler chickens and male of Transylvanian naked-neck chickens kept in extensive and intensive farming systems were investigated. The leg and chest muscle of these chickens were used for the analysis. Muscle weight and muscle to bone ratio were significantly higher but protein content had a lower tendence in the muscle of Broiler chickens kept intensively as compared to the extensive way. There was no difference in the level of cholesterol between the animals from the two farming systems although the fat contents were much higher in the chickens kept intensively. The level of conjugated dienes and thiobarbituric acid reactive substances (TBARS) were found significantly less in the muscles of Broiler chickens kept extensively than those raised intensively which may be related to the lower fat content. Extensive farming system proved to be superior for Broiler (mainly in legs) and Transylvanian naked-neck chickens in the aspect of lowered lipid peroxidation and significant higher iron, zinc and thiamin levels. The higher protein and zinc levels showed a relationship with the better water binding capacity (WBC) in the legs of Broiler chickens kept extensively. Myristic and palmitic acid concentration in the fatty acid composition were higher in intensive Broilers as compared to the chickens kept extensively.     

Quality, palatability and weight loss of pork as affected by electrical stimulation

Forty-five swine (n = 15, stress-susceptible pigs, fasted for 18 h; n = 15, normal pigs, fasted for 48, 60 or 72h; n = 15, normal pigs, fasted for 18 h) were slaughtered. One side of each pig was electrically stimulated (ES)-550 V, 2-6 A, seventeen impulses, 1·8 s on and 1·8 s off per impulse-and the opposite side was not stimulated (NS). Ham and loin temperatures were monitored at 12 and 24 hours post mortem. Carcass quality-marbling, loin eye colour, loin eye firmness, subcutaneous fat firmness and belly firmness-was evaluated at 24 hours post mortem. Sides were fabricated into four lean cuts at 48 hours; cuts were placed on open metal racks in a 2°C cooler and weight loss was measured after 24, 48 and 72 hours storage. At 120 hours post mortem, loin chops were cut, frozen (-24°C for 45 days) and subsequently used to determine thaw loss, cooking loss, Warner-Bratzler shear (WBS) force and palatability. Ham temperatures (12 h) were significantly (P < 0·05) lower for the ES sides from the stress-susceptible, short-fast (SSF) group but not for normal, long-fast (NLF) or normal, short-fast (NSF) groups. ES produced lighter coloured, softer loin eyes in the SSF group but darker coloured, firmer loin eyes and firmer subcutaneous fat in the NLF group. No significant differences (P > 0·05) were detected for thaw loss, cooking loss, palatability ratings or WBS values between ES and NS in the SSF group but chops from ES sides of NLF animals had significantly (P < 0·05) higher ratings for muscle fibre tenderness, overall tenderness and overall palatability. Weight losses of the lean cuts from the ES sides were higher (P < 0·05) than those from NS sides in only three of sixty comparisons of cuts from the three groups of swine. These data suggest that ES had very minimal effects on quality, palatability or weight loss of pork.     

Effect of increasing amounts of a linoleic-rich dietary fat on the fat composition of four pig breeds. Part II: Fatty acid composition in muscle and fat tissues

This paper studies the change of fatty acid profile in four different tissues of the pig (backfat, abdominal fat, and the muscles trapezius and longissimus thoracis et lumborum) in response to four diets containing increasing amounts (0%, 2%, 4% and 8%) of a high linoleic acid fat blend, in a sample of 48 pigs of four different breeds (Landrace, Large White, Duroc and a crossbreed Landrace × Duroc). The effects of dietary fat and breed on this profile have been separately tested for each tissue. The diet effect (increasing % of linoleic acid intake) was positive on linoleic acid deposit in all tissues, meanwhile it was negative on palmitic and stearic levels, as well as for the oleic acid. However, this effect was clear in the four tissues for the linoleic acid, while the differences did not follow the same pattern for the saturated fatty acids in trapezius muscle and abdominal fat. Although the levels of arachidonic acid in muscle tissues were higher than those found in adipose tissues, the increasing effect of the diet was stronger, in relative terms, in adipose tissues. The breed effect was, in general, lower than the diet effect. Landrace showed the higher ability to increase linoleic acid levels, particularly in the loin (longissimus thoracis et lumborum), whereas Duroc pigs seemed to be the most resistant to change of fatty acid composition according to the diet.     

Dietary β‐cyclodextrin reduces the cholesterol levels in meats and backfat of finishing pigs

BACKGROUND: A hypocholesterolemic effect of β‐cyclodextrin (βCD) has been recently reported in various animals. This study was performed to determine the effect of dietary βCD on hypocholesterolemic effect, and its relationship to bile acid changes of 120 finishing pigs fed a commercial diet containing 0%, 5%, 7%, or 10% βCD for 30 days before slaughter. RESULTS: Plasma total lipids, triacylglyceride, and total cholesterol of βCD supplemented pigs were lower (P < 0.05) than the control pigs. When 5%, 7%, or 10% βCD was supplemented to pigs, cholesterol levels of the plasma were reduced by 26.0%, 28.2%, and 31.3%, respectively. Excretion of total sterol increased (P < 0.05) with increasing βCD supplementation and the composition of excreted bile acid was significantly altered in pigs fed βCD. The cholesterol levels of pig backfat, belly, loin, and ham were reduced as βCD supplementation increased (P < 0.05) in the diet. CONCLUSION: These results suggest that supplementing the finishing diet of swine with βCD resulted in reducing not only circulating lipids and cholesterol but also cholesterol level of pork lean meat and fat, and may provide the method of low‐cholesterol pork production to the swine industry. Copyright © 2008 Society of Chemical Industry     

Nutrient profiles in retail cuts of bison meat

The objectives were to determine the nutrient composition and variation in eight cuts of bison meat in bulls and heifers and identify nutrient relationships in the clod and sirloin by principal component analysis. The nutrients analyzed were: energy, protein, total fat, saturated fat, monounsaturated fat, polyunsaturated fat, transfat, cholesterol, vitamin A, Ca, Fe, Na and moisture. Differences were observed in fat components between cuts and bulls had higher (P < 0.05) amounts of total, saturated, monounsaturated and polyunsaturated fat in the blade compared to the other cuts. The sirloins had less (P < 0.05) cholesterol than all the other cuts in bulls and the clod in heifers. Fat varied more than protein and moisture in all cuts. Four principal components (PC) accounted for 63.9% of the total variation of the nutrient composition. Total, monounsaturated and saturated fats were in PC1 and cholesterol in PC2 showing that cholesterol is independent of other fats. If dietary alterations elicit changes in bison meat fatty acid profiles, it may be possible to reduce cholesterol independent of total, monounsaturated or saturated fat.     

Effect of feeding partially hydrogenated lard on trans-fatty acid content of muscle and backfat of heavy pigs

The incorporation of fat in diets for heavy pigs may be necessary in order to increase their energy intake in the finishing period. Lard may be a good lipid source but it contains 10–13% of linoleic acid, which makes the subcutaneous fat less suitable for long term curing of raw ham. Partial hydrogenation of lard decreases linoleic acid content, but increases trans-fatty acid content.

This trial involved two groups of pigs of 114 kg live weight, fed for the last two months before slaughter with diets containing 3% lard (L) or 3% partially hydrogenated lard (PHL). The PHL contained about 10% trans-fatty acids and 2.5% linoleic acid.

Rearing performance and carcass characteristics were unaffected by treatment. The group fed PHL showed a lower percentage of linoleic acid in the backfat (PHL 12.28% vs. L 13.04%) and a higher percentage of C18:1 trans-fatty acids both in backfat (0.5% vs. 0.06%) and in intramuscular fat (0.2% vs. 0.04%).     

Effect of organic pig production systems on performance and meat quality

The present study was carried out to establish knowledge of consequence for setting up guidelines of importance for production of competitive organic pork of high quality. Performance and meat quality characteristics were compared between three organic pig production systems based on indoor housing with access to an outdoor area and a Danish conventional indoor system including 100% concentrate during the finishing feeding stage.

The three organic systems used the following three feeding regimes: 100% organic concentrate according to Danish recommendations, 70% organic concentrate (restricted) plus ad libitum organic barley/pea silage and 70% organic concentrate (restricted) plus ad libitum organic clover grass silage, respectively.

With exception of a slightly lower daily gain in organic pigs fed 100% concentrate, no significant difference was found in performance and meat quality characteristics compared with results obtained in the conventional system. In contrast and independent of roughage used, organic pigs raised on 70% concentrate had a significant reduction in daily gain (P < 0.001) compared with pigs raised on 100% concentrate, despite the fact that no difference in feed conversion rate was seen between the tested production systems. However, the percentage of leanness increased significantly in meat from organic pigs raised on 70% concentrate plus roughage compared with meat from pigs given 100% concentrate. This was reflected in higher yield (weight) of lean cuts and lower yield of cuts with high fat content from pigs fed 70% concentrate plus roughage. In general, organic feeding resulted in a significantly higher content of polyunsaturated fatty acids in the back fat (1.8%), which increased further when restricted feeding plus roughage (4%) was used. Restricted concentrate feeding gave rise to a decrease in tenderness compared with pork from pigs fed 100% concentrate.     

Genetic parameters for meat and fat quality and carcass composition traits in Iberian pigs

Carcass composition and quality traits were measured in heavy Iberian pigs after extensive handling. The weights of trimmed hams, forelegs and loins were recorded on 2170–2553 pigs, intramuscular fat content in M. longissimus (IMF) on 1489 and percentages of palmitic, stearic, oleic and linoleic acids in the subcutaneous fat on 1495 pigs, slaughtered at about 160 kg live weight. For carcass traits the heritability estimates ranged from 0.28 to 0.41. Heritability estimate for IMF was 0.25 and estimates of heritability for the measured fatty acids ranged from 0.29 to 0.41. The estimated genetic correlations (rg) suggest antagonism between IMF and weights of hams (rg=−0.30) and loins (rg=−0.33) and an unfavourable positive association of premium cuts with linoleic acid content (rg: 0.31–0.57). The incorporation of meat and fat quality traits to the selection aims of the breeding scheme for Iberian pigs seems advisable.     

Influence of betaine and conjugated linoleic acid on development of carcass cuts of Iberian pigs growing from 20 to 50 kg body weight

Twenty Iberian gilts (20 kg body weight, BW) were fed diets containing no betaine or conjugated linoleic acid (CLA) (Control), 0.5% betaine, 1% CLA, or 0.5% betaine+1% CLA. Additionally, 5 pigs were killed at 20 kg BW for the initial points of the allometric equations. At 50 kg BW, left semicarcasses were cut into primal cuts, hams and shoulders trimmed and dissected. CLA alone did not affect any analyzed parameter. Betaine increased (23 and 21%, respectively) the yield of shoulder butt and spine and decreased allometric growth coefficient of belly and backfat, compared to Control diet. Tenderloins and trimmed hams of pigs fed CLA+betaine diet developed later and were heavier (22 and 5%, respectively) than Control pigs. Also, leaf fat developed earlier and had lighter weight (32%). Furthermore, pigs fed CLA+betaine diet had heavier lean (5%) and fat free lean (6%) of shoulders compared to Control pigs.     

Effect of organic pig production systems on performance and meat quality

The present study was carried out to establish knowledge of consequence for setting up guidelines of importance for production of competitive organic pork of high quality. Performance and meat quality characteristics were compared between three organic pig production systems based on indoor housing with access to an outdoor area and a Danish conventional indoor system including 100% concentrate during the finishing feeding stage.The three organic systems used the following three feeding regimes: 100% organic concentrate according to Danish recommendations, 70% organic concentrate (restricted) plus ad libitum organic barley/pea silage and 70% organic concentrate (restricted) plus ad libitum organic clover grass silage, respectively.With exception of a slightly lower daily gain in organic pigs fed 100% concentrate, no significant difference was found in performance and meat quality characteristics compared with results obtained in the conventional system. In contrast and independent of roughage used, organic pigs raised on 70% concentrate had a significant reduction in daily gain (P < 0.001) compared with pigs raised on 100% concentrate, despite the fact that no difference in feed conversion rate was seen between the tested production systems. However, the percentage of leanness increased significantly in meat from organic pigs raised on 70% concentrate plus roughage compared with meat from pigs given 100% concentrate. This was reflected in higher yield (weight) of lean cuts and lower yield of cuts with high fat content from pigs fed 70% concentrate plus roughage. In general, organic feeding resulted in a significantly higher content of polyunsaturated fatty acids in the back fat (1.8%), which increased further when restricted feeding plus roughage (4%) was used. Restricted concentrate feeding gave rise to a decrease in tenderness compared with pork from pigs fed 100% concentrate.     

Cholesterol and fat contents of Spanish commercial pork cuts

A study was carried out to determine the fat and cholesterol contents of several commercial pork cuts as function of sex. Fat and cholesterol content ranged from 2.7% and 57 mg/100 g in loin to 30.3% and 116 mg/100 g in dewlap. The higher the fat content the higher was the cholesterol content. Sex did not influence fat content and the fat/cholesterol ratio, but cholesterol content was higher in females than in males.     

Halothane genotype and pork quality. 1. Carcass and meat quality characteristics of three halothane genotypes

The carcass and meat quality characteristics of three halothane genotypes in pigs were evaluated. Sixty crossbred Landrace×Large White pigs (NN=25, Nn=19, nn=16) of ±86 kg live weight were slaughtered, the carcasses chilled for 24 h at 2°C, certain carcass and meat quality traits determined and the shoulder and leg cuts deboned and cut into primal cuts. Dressing percentage of the Nn pigs was higher (P<0.05) than that of the NN and nn pigs. Carcass length was the longest (P<0.05) for the nn pigs. Midline fat measurements as well as measurements at the 2nd-3rd last rib (45 mm from the midline) indicated that the nn pigs had less fat (P<0.05) and a larger eye muscle width (P<0.05), depth (P<0.001) and area (P<0.001) than the NN or Nn pigs. This resulted in the nn pigs having the highest (P<0.05) percentage predicted carcass lean content. Fat, bone and lean yield of the shoulder identified the nn pigs with the least bone (P<0.05) and fat (P<0.001) and the highest lean yield (P<0.05), expressed as a percentage of total shoulder weight. Yield from the legs identified the nn pigs as having the lowest fat (P<0.001) and highest lean (P<0.05), expressed as a percentage of total leg weight. The primal lean cuts (topside, silverside, thickflank and rump) from the legs showed that the nn pigs had the highest values (P<0.05) for lean as a fraction of cold carcass weight. This resulted from the higher weight of these cuts (P<0.05) in the nn pigs. Calculation of bone yield in the legs showed that the femur weights were highest (P<0.05) for the Nn pigs, also when expressed as percentage of leg weight (P<0.05) and as a fraction of cold carcass weight (P<0.05). Comparison of meat quality traits show that the nn pigs had poor quality with regard to pH(45) (P<0.001), pH(24) (P<0.05), drip loss (P<0.001) and reflectance values (P<0.05).     

Effect of Conjugated Linoleic Acids in Pig Nutrition on Quality of Meat

Relationships among conjugated linoleic acid (CLA) in pig nutrition and carcass quality parameters (hot carcass weight, carcass yield and meatiness) and meat quality parameters (initial and pH value after 24, 48 and 72 h, temperature, drip loss, sensory color and marbling) were determined in pigs (crossbreeds Yorkshire x Landrace). Commercial CLA preparation containing 60% CLA isomers was included in the diet. No significant differences in performance parameters were found between pigs fed with CLA and control group during 60 days period. CLA supplementation in feed significantly increased SFA and decreased MUFA and PUFA fraction in pig muscles.     

A feasibility study on the use of near-infrared spectroscopy for prediction of the fatty acid profile in live Iberian pigs and carcasses

This work reports on the development and optimisation of NIRS technology for fat characterization both in live pigs and in carcasses in the slaughterhouse; use of this technology would enable implementation of a real-time traceability and control system based on non-destructive sensors. A total of 52 Iberian pig fat samples were analysed using a LabSpec^®Pro A108310 spectrophotometer (Analytical Spectral Device Inc.), with a high-intensity fiber-optic contact probe. Spectra were collected in five analysis modes: from the live animal, from the carcass in the slaughterhouse, from a subcutaneous fat sample with skin, from a skin-free subcutaneous fat sample and from a transverse section. Calibrations were developed for the prediction of the four main fatty acids in Iberian pig fat, obtaining for palmitic acid SECV values of 1.24% for in vivo analysis and 0.82% for carcass analysis, for stearic acid 0.67% and 0.94%, for oleic acid 1.42% and 1.48% and for linoleic 0.36% and 0.55%, respectively. The calibrations accounted for between 60% and 74% of the variation recorded in live animals, and between 31% and 87% of variation in carcasses. These results confirm the feasibility of NIRS technology for the on-site inspection and control of Iberian pig, both in the field and in the slaughterhouse.     

Bioaccumulation of dioxin-like substances and selected brominated flame retardant congeners in the fat and livers of black pigs farmed within the Nebrodi Regional Park of Sicily

An observational study was designed to assess the bioaccumulation of polychlorodibenzodioxins (PCDD) and polychlorodibenzofurans (PCDF), dioxin-like polychlorobiphenyls (DL-PCB), and 13 selected polybromodiphenylethers (PBDE) in autochthonous pigs reared in the Nebrodi Park of Sicily (Italy). Perirenal fat and liver samples were drawn from animals representative of three different outdoor farming systems and from wild pigs and then analyzed for the chemicals mentioned previously. The highest concentrations of PCDD + PCDF and DL-PCB were detected in the fat (0.45 and 0.35 pg World Health Organization toxicity equivalents [WHO-TE] per g of fat base [FB], respectively) and livers (12.7 and 3.28 pg WHO-TE per g FB) of the wild group, whereas the free-ranging group showed the lowest levels (0.05 and 0.03 pg WHO-TE per g FB in fat and 0.78 and 0.27 pg WHO-TE per g FB in livers). The sum of PBDE congeners was highest in wild pigs (0.52 ng/g FB in fat and 5.64 ng/g FB in livers) and lowest in the farmed group (0.14 ng/g FB in fat and 0.28 ng/g FB in livers). The contamination levels in fat and livers of outdoor pigs had mean concentration values lower than those levels reported for intensively indoor-farmed animals. In wild pigs, bioaccumulation was associated with their free grazing in areas characterized by bush fires. The results of this study aid to emphasize the quality of the environment as a factor to guarantee food safety in typical processed pig meat products, specifically from outdoor and extensive Nebrodi farming systems.     

OXIDATIVE STABILITY OF PORK PEPPERONI DURING PROCESSING AND DIFFERENT PACKING AND STORAGE CONDITIONS AS INFLUENCED BY FAT SOURCE

Pepperoni made from pigs fed diets containing fishmeal and different fat sources was studied for changes in fatty acid composition, oxidation and sensory characteristics during ripening and different storage condition. Fatty acid composition did not change during processing and ripening. Oxidation was low for all groups after processing and ripening, and vacuum and MAP packing kept oxidation low at 6C. Pepperoni from pigs fed lamb tallow (LT) and hydrogenated fish oil (HFO) had, however, developed unacceptable flavor changes at 6C. Oxidation proceeded rapidly at 23C with the HFO group leading. Lower storage quality of the HFO group pepperoni could be from more polyunsaturated fatty acids. Inclusion of HFO and LT at 5% into pig feed was determined unacceptable but 9% high quality fishmeal without any added fat sources appears acceptable. Measured oxidation values (peroxide and p-anisidine values) may not be good indicators of flavor changes of pepperoni during storage.     

The effects of two alleles of IGF2 on fat content in pig carcasses and pork

The different fat infiltration capabilities of two alleles of IGF2 (G3072A) have been investigated in pigs of a Landrace-Large White × Duroc cross. Paternally inherited G allele carrier pigs show an increased content of adipose rich meat cuts such as the lard or the belly and 4 mm larger backfat thickness values. Paternally inherited A carrier pigs on the other hand contain larger muscle tissue rich cuts such as the loin, the ham and the tenderloin and have 0.19 units lower feed conversion index. No substantial differences have been found neither in intramuscular fat content in several muscles nor in meat quality in both pig groups. Hams of paternally inherited G carrier pigs are richer in both subcutaneous adipose tissue (23.1 vs 19.1 mm backfat thickness) and intermuscular fat content. The suitability and the economics of using any of the two of both genotypes for cured ham production are discussed.     

The effect of genotype, sex and management strategy on the eating quality of pork

Two hundred and sixteen (Large White×Landrace×Duroc) crossbred pigs were used to determine the influence of genotype, sex, and management strategies on pork quality. The experiment was a 2×3×3 factorial design with the main treatments being genotype (A?- 50% and B?- <25% Duroc bloodline), sex (females, surgical barrows and immunological barrows) and management strategy (control?- C, dietary conjugated linoleic acid supplementation?- CLA, and porcine somatotropin administration?- pST). Genotype A pigs had less backfat (P2 site), higher intramuscular fat percentage, higher muscle ultimate pH (pH(u)) and surface exudate, and the pork was tougher and less acceptable compared with Genotype B pigs. Female pigs had lower muscle pH(u), higher surface exudate and tougher pork compared with both surgical and immunological barrows. Pigs fed the control diet had lower muscle pH(u) and higher surface exudate compared with pigs fed the CLA supplemented diet or administered pST. Pigs fed the control diet had higher consumer likeness scores for flavour, tenderness, juiciness and overall acceptability compared with pigs fed the CLA supplemented diet or administered pST. The results from this experiment indicate that pork eating quality is reliant on a complex interaction between genotype and sex. The results also indicate that management strategies such as pST administration and CLA supplementation, while being effective in reducing backfat, have the potential to have a negative impact on pork quality.