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Vitamin A is a key regulator of gene expression, influencing adipogenesis and lipid metabolism in animal tissues. This experiment was conducted to assess the effect of dietary vitamin A level and administration time on productive traits, intramuscular fat (IMF) content in ham muscles, tissue fatty acid composition, and expression of a panel of adipogenic and lipogenic candidate genes in Iberian pigs. Sixty piglets of 16.3 kg (SD = 2.5 kg) live weight (LW) were either fed a vitamin A-enriched diet (10,000 IU vitamin A/kg; CONTROL, n = 20) or a diet without supplemented vitamin A, applied from 16.3 kg (SD = 2.5 kg; early restriction group, ER, n = 20) or from an average weight of 35.8 kg (SD = 3.1 kg; late restriction group, LR, n = 20). Two slaughters were performed when pigs reached the averaged weights of 101.4 (SD = 4.1 kg) and 157.9 kg LW (SD = 7 kg) and samples from liver, heart, and backfat were obtained in both sacrifice times. In addition, ham subcutaneous fat and Semimembranosus (SM) and Biceps Femoris (BF) muscles were sampled at the last sacrifice. Dietary vitamin A level produced no effect on carcass traits in any of the harvests, while a small effect was observed on fatty acid composition in backfat at 101.4 kg LW. However, at 157.9 kg LW, the ER and LR groups showed higher MUFA content and lower SFA content in backfat, ham fat, and IMF (P < 0.01). In IMF, a decrease in n-6/n-3 PUFA ratio was observed in the restricted groups (P < 0.005). Intramuscular fat content in SM muscle was greater (P < 0.05) in the ER group than in the CONTROL and LR groups, while no difference was detected in BF muscle. Little effect of dietary vitamin A was observed in liver. Regarding changes in gene expression, ACSL4, CEBPB, and IGF1 genes were upregulated (P < 0.0001, P < 0.0001, and P < 0.05, respectively) in the ER group in hepatic tissue, whereas CRABPII and SCD genes were upregulated (P < 0.05) in the same group in adipose tissue. On the other hand, was downregulated ( < 0.05) in the ER group in adipose tissue. Results found in this experiment show that long-term restriction of dietary vitamin A has a positive effect on nutritional and sensorial parameters of ham meat. Moreover, gene expression results were consistent with the vitamin A transcriptional regulation of adipogenesis and lipogenesis and with the changes observed in meat and fat composition.

This study aimed to determine the effects of piglet birthweight (BIW) and sex, and within-litter BIW variation, on postnatal growth traits and meat quality in fatty breeds of pig. In total, 406 crossbred piglets (half male, half female) born to Iberian sows were studied during their postnatal development until slaughter. After birth, piglets were classified into four BIW categories: very low, low, medium and high. There was a negative effect of low BIW on growth patterns and fatty acid (FA) composition, but effects of litter size and within-litter BIW variation were not found. The very low BIW piglets underwent a period of significant catch-up growth (P < 0.005) relative to high BIW piglets during the early postnatal phase, but also showed a higher feed conversion rate and lower average daily weight gain (P < 0.05 for both measures) throughout the study period. BIW affected development during the entire productive life, and the sex effect increased with age. As a result, the period to reach market weight was longer in very low BIW piglets, by 43 days for females and 15 days for males, compared with their high BIW counterparts. BIW and sex also influenced amount of intramuscular fat, n-3 FA content and monounsaturated FA composition. The study indicates that BIW, modulated by sex, is a critical point for productive traits in fatty pigs. These results provide a basis for future strategies to enhance productive efficiency and meat quality of traditional swine breeds.

The effect of feeding system (calves reared under free-range conditions supplemented with concentrate vs. calves fed on concentrate and cereal straw in confinement) during finishing period on growth performance, carcass traits and meat and fat quality was investigated. Fourteen entire males of Avileña-Negra Ibérica breed were used. The feeding system had no effect on growth performance, carcass characteristics, muscle colour, drip losses and intramuscular fat (IMF) percentage in Longissimus thoracis. Free-range calves had more content of vitamin E in omental fat and tended (p

A trial was performed to compare the effects of different dietary sources of MUFA on the fat- ty acid (FA) composition, lipid metabolism, and gene transcription in different tissues of Iberian pigs. Twenty- seven Iberian male pigs of 28 kg live weight (LW) were divided in 2 groups and fed with 1 of 2 isocaloric diets: a standard diet with carbohydrates as energy source (CH) and a diet enriched with high-oleic sunflower oil (HO). Ham adipose tissue was sampled by biopsy at 44 and 70 kg LW. At 110 kg LW pigs were slaughtered and backfat, loin, and liver tissues were sampled. Ani- mals of the HO group showed higher MUFA content and lower SFA in all the analyzed tissues (P < 0.001). These main effects were established early during the treatment and increased only slightly along time. Small diet effects were also detected on PUFA, which showed differences according to sampling time, tissue, and lipid fraction. Effects of diet on gene expression were explored with a combined approach analyzing adipose tissue transcriptome and quantifying the expression of a panel of key genes implicated in lipogenesis and lip- id metabolism processes in backfat, muscle, and liver. Backfat transcriptome showed small effects of diet on gene expression, in number and magnitude. According to the posterior probabilities (PP) of the probe-specific expression differences between dietary groups (PP < 0.01), 37 genes were considered differentially expressed (DE). Gene ontology allowed relating them with sev- eral biological functions including lipid metabolic pro- cesses. Quantitative PCR confirmed several DE genes in adipose tissue (RXRG, LEP, and ME1; P < 0.0001, P < 0.05, and P < 0.0001, respectively), but no DE gene was found in loin or liver tissues. Joint results agree with a metabolic adjustment of adipose tissue FA levels by the subtle effect of the diet on the regulation of several lipid metabolism pathways, mainly FA oxidation and pros- tanoid synthesis, with LEP, RXRG, and PTGS2 genes playing mayor roles.

A total of 48 Duroc × (Landrace × Large White) gilts of 33.2 kg BW were used to investigate the influence of immunocastration and diet on growth performance and carcass, meat and fat quality. Four treatments were arranged factorially (2 × 2) with two sexes (immunocastrated gilts: IG v. entire gilts: EG) and two dietary treatments (a commercial feedstuff as control v. granulated barley as a single major ingredient) provided during the finishing period (from 103 to 126 kg BW). There were four replicates of three pigs per treatment. At the end of the trial, the IGs grew faster (P

1. This work aims to quantify changes in fatty acid profile, melting point, abdominal fat accumulation and TBARS production depending on dietary fat source and age at slaughter, and to estimate the optimal date for the change from an unsaturated fat to a saturated fat diet, or vice versa.2. Treatments established were: 1) Birds fed 8% tallow from 21 to 49 d; 2) Birds fed 8%-tallow from 21-37 d and 8%-sunflower oil from d 38-49; 3) Birds fed 8%-sunflower oil from 21-37 d and 8%-tallow from d 38-49; 4) Birds fed 8%-sunflower oil from 21-41 d and 8%-tallow from d 42-49; 5) Birds fed 8%-sunflower oil from 21-49 d. Birds from each group were slaughtered on d 21, 29, 38, 40, 42, 44, 46 and 49.3. The PUFA proportion in the SSS group reached maximum values at d 40 and fitted a quadratic response. This group also showed a decrease in SAT and MUFA of lower intensity than the PUFA increase. The highest synthesis of SAT+MUFA was found in the SSS and TSS groups, whereas these had the lowest body-to-dietary PUF...

A total of 48 Duroc×(Landrace×Large White) gilts of 40.5±0.69 kg of initial body weight (BW) were used. During the growing period (40–100 kg BW), all pigs ate a conventional feed and during the finishing period (100–130 kg BW) animals received the experimental dietary treatments; a conventional feed based on barley, wheat and vegetable meals (control diet; 9.06 MJ of net energy/kg and 10.78% of crude protein) or a feed with 98.5% of granulated barley (barley diet; 9.63 MJ of net energy/kg and 8.96% of crude protein). There were twelve replicates of two pigs per treatment. Pigs were slaughtered at 130±1.66 kg BW because they were intended for dry-cured ham production. For the overall period, no differences were observed for average daily gain and feed conversion ratio, although the average daily feed intake was lower ( P P P longissimus thoracis muscle ( P >0.05). It is concluded that the replacement of a conventional feed by a diet based on barley from 100 and 130 kg BW had scarce effect on carcass and meat traits, without any penalisation of productive performance and with reduced feeding costs. Therefore, the use of granulated barley provided during finishing period might be interesting for heavy pigs.

The objectives of this experiment were to study the effect of dietary supplement of a commercial source of CLA, supplied either in the gestation/lactation period or during the post-weaning period, on sow and piglet performance and on the transfer of CLA into colostrum and milk. The experiment was designed to assess both the effect of dietary CLA supplementation to the sow in lactation and on the piglets in the nursery. There were four treatments for nursery piglets arranged factorially, two dietary treatments for origin sows (0 g/kg vs 10 g/kg CLA) and two treatments for weaned piglets (0 g/kg vs 10 g/kg CLA). Immediately after parturition, 10 mL of colostrum was collected from the functional glands of each sow. On day 23 after farrowing, milk samples were also collected. Lower backfat thickness was observed after 28 days of lactation in all groups, and the loss was higher for the control than CLA group (P c 9, t 11 and t 10, c 12 proportions (P n -7 (P n -7/C16:0 and C18:1 n -9/C18:0 (P c 9, t 11, t 10, c 12, C20:0, C20:1, C20:5 n -3 and SFA proportions (P n -9, C16:1 n -7, C17:1, C18:1 n -9, C20:4 n -6, MUFA, MUFA/SFA, C16:1 n -7/C16:0 and C18:1 n -9/C18:0 (P

The objective of this trial was to study the impact of slaughter weight (SW) class: heavy (≥120 kg) or light (

The influence of feeding and rearing systems on the accumulation and evolution of α- and γ-tocopherols in relation to storage time in dry-cured ham slices and pieces was investigated. The accumulation of γ-tocopherol in Musculus Biceps femoris or fat of cured hams was lower in groups fed acorns indoors than in those fed outdoors. However, these differences were not detected in M. Semimembranosus. Hams from pigs fed acorns had higher proportion of RRR-α-tocopherol stereoisomer and could also be used to discriminate the feeding background of the animals but not the rearing system. Loss in α- and γ-tocopherols of ham slices with storage was not affected by the rearing system but by the feeding. The discrimination between groups is better during the first 7 days of analysis. Loss in redness and yellowness was lower in ham slices from outdoor group which would indicate that exercise or other compounds provided by grass are also of interest in these quality parameters

Twenty castrated male Iberian pigs were divided into two groups of 10 pigs each according to the experimental diet received daily during the fattening period in confinement (acorn fed ad libitum or 4 kg of a formulated diet rich in C18:1 n—9). Dietary effects on performance, carcass characteristics and backfat, intramuscular, and liver fatty acid composition were assessed. Pigs fed only with acorns ate less, leading to a lower growth performance and carcass quality than pigs fed the formulated diet. Pigs fed acorns had lower C16:0 proportions in outer, inner, and subinner subcutaneous backfat layers. The C18:1 n—9 proportions in the inner and subinner subcutaneous backfat layers were higher in pigs fed acorns than in those fed the formulated diet. Pigs fed acorns had higher C18:2 n—6 proportion than those fed the formulated diet in outer subcutaneous backfat layer. The diet did not affect outer, inner, and subinner subcutaneous backfat melting points. Except a higher C18:0 in intramuscular fat polar lipids and higher C16:1 n—9 in the liver polar lipid fraction in pigs fed acorns, the diet had no significant effect on intramuscular and liver fatty acid composition.

The effect of dietary fat saturation (dFat) and dietary vitamin A (dVitA) level (0 IU vs. 100,000 IU) on performance, carcass characteristics and fatty acid composition in the offspring of two terminal sires: Duroc (DU) and Landrace×Large White (LD×LW) was studied. In the inner backfat layer, the DU-sired pigs had higher C16:0 proportion (P

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 (100,000 IU/kg) ( n = 16) and control diet with a basal level (7500 IU/kg) ( n = 16). The pigs were slaughtered at an average weight of 125.9 kg. 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.

BACKGROUND: Restricted feeding before fattening is a common procedure in the production of Iberian pigs, but little scientific information about its consequences on productive traits and characteristics of fat is available. This work studied the effect of a severe feeding restriction previous to the free-range fattening on carcass and fat quality traits in Iberian pigs, considering two different feeding levels (high restriction: HR; versus maintenance level: M) before free-range fattening. RESULTS: Animals from the M group showed longer and higher-perimeter hams and tended (P < 0.10) to show higher slaughter and carcass weights, carcass inner length and loin and sirloin weights than HR ones. Animals from the HR group showed lower proportions of total saturated fatty acids (SFA) and higher total monounsaturated fatty acids in the backfat inner layer than those from the M group. Total polyunsaturated fatty acids in intramuscular neutral lipids were higher in HR pigs than in M ones, while stearic acid (C18:0) was lower. The average daily gain, fatty acid profile of the outer backfat layer and that of the hepatic polar and neutral lipids and the rheological features of backfat inner layer remained unaffected. CONCLUSION: A severe reduction of the feeding level previous to free-range fattening does not produce compensatory growth, tends to diminish carcass quality and to slightly increase IMF content and improves the fatty acid profile of the inner backfat layer. Copyright © 2007 Society of Chemical Industry

Department of Animal Producion, Veterinary Faculty of Complutense University 28040 Madrid, Spain(Received 22 November 2006; revised version 6 June 2007; accepted 6 September 2007)ABSTRACTThe present study aims to determine the effect of feeding system for Iberian pigs during the fattening period on tissue fatty-acid composition and rheological properties. Twenty-four Iberian barrows of the same age with an average initial liveweight of 100.2 kg were randomly distributed into three groups of eight pigs each. One group was fed under free-range conditions for 117 d. The other two groups were fed in confinementeitherwithacornsfromQuercus rotundifolia or a concentrate diet. Differences on subcutaneous backfat fatty-acid composition were found among feeding systems with the outer layer of backfat in concentrate-fed pigs containing more SFA and total n-6 and less MUFA, directly reflectingdietaryfatty-acidcomposition.Thelongissimus dorsi intramuscular neutral lipids (NL) of free-range pigs contained higher C18:1 n-9, MUFA and lower SFA proportions than those fed with acorns or the concentrate diet. The liver NL in pigs fed acorns in confinementcontainedhigherC18:1n-9,MUFAandlowerSFAproportionsthanthosefedaconcentrate diet or in free-range. Subcutaneous fat from pigs fed the concentrate diet was higher in hardness than those fed acorns in confinementorinfree-range,whileadhesivenesswashigherinpigs fed acorns in confinementthanintheremaininggroupsofpigs.KEY WORDS: fat, free-range, confinement feeding, fatty acid profile, rheological properties,Iberian pig

The aim of this study was to investigate the fatty acid composition of the outer, inner and subinner subcutaneous backfat layers from Iberian pigs raised under free-range conditions. The pigs were fattened on acorns and grass under free-range conditions from 101 to 155 kg of live weight. Proportions of C16:0, C18:0 and C20:0 were lower in the outer than in the inner layer, while the C12:0, C16:0 and C18:0 contents were higher in the subinner layer than in the inner layer. The outer layer had higher C15:1, C16:1 n-7, C17:1, C18:1 n-7 and similar C16:1 n-9, C18:1 n-9 and C20:1 n-9 proportions than the inner layer, while the subinner layer had lower C17:1, C18:1 n-9, C20:1, similar C15:1, C16:1 n-7, C18:1 n-7 and higher C16:1 n-9 proportions than the inner layer. Only the concentrations of C18:3 n-3, C18:4 n-3 and C20:3 n-3 were lower in subinner than in inner layer. The content of all polyunsaturated fatty acids (PUFA) was higher in the outer than in the inner layer except for the C20:4 n-6 fatty acid. A tendency (P < 0.1) to a higher Σ n-6/Σ n-3 fatty acids ratio was found for the inner and subinner layers than for the outer layer. Significant correlation coefficients were observed between the proportions of C14:0, C16:0, C18:1 n-9, C18:2 n-6, C18:3 n-3 and C20:3 n-9 of the inner layer and subinner layer. The outer layer melting point (MP) was lower than those of the inner and subinner layers, although no difference for MP between inner and subinner layers was observed.

The experiment was conducted to assess the influence of a moderate feed restriction during the growth period on overall performance, corporal traits and fatty acid composition in pig backfat in pigs raised under high environmetal temperatures. A hundred Large White x (Large White x Landrace) barrows with an average initial weight of 34.5 kg were randomly distributed, in pens (10 pigs per pen). Fifty pigs were fed ad libitum for 36 days (AL pigs) and another fifty were restricted by 25% of their ad libitum consumption during the same period (R pigs). During the subsequent re-feeding period (64 days) all pigs were fed ad libitum. The only diet used contained 13.4 MJ ME kg -1 , 17% crude protein and 1.3% lysine. The minimum, maximum and mean average temperatures recorded during the feed restriction and post-restriction periods were, oC: 21.5 ± 1.2, 28.6 ± 1.3 and 25.0 ± 1.1, and 22.6 ± 0.9, 31.2 ± 1.0 and 26.9 ± 0.9, respectively. Considering the whole study period, the average daily gain and average daily feed intake were higher (P 0.05) (2.95 vs 2.95 kg . kg -1 ). At the end of experiment, no differences for dorsal fat thickness and area and for longissimus dorsi muscle depth, width and area, measured at site of the last rib by means of a real-time ultrasound device, were found between experimental groups. The linolenic acid proportions of the subcutaneous fat outer and inner layer were higher in AL than in R pigs (P

The experiment was undertaken to provide information on the influence of grass intake in a high fat diet based on acorns, in either free-range or confinement, on the carcass yield and characteristics, and on the accumulation of fatty acids and tocopherols. Groups raised free-range or with acorns and grass in confinement had the highest total backfat. Grass addition to the feed did not significantly modify the carcass weight and cut yield. However, outdoor raising produced lower carcass weights and yield, Longissimus dorsi muscle and ham weights than those fed the formulated diet or acorns and grass in confinement. Neither grass intake nor outdoor rearing did modify significantly the proportion of saturated fatty acids of the backfat. However, a lower proportion of saturated fatty acids was found in the intramuscular neutral lipids from pigs fed outdoors. Pigs reared free-range had significantly (P = 0.0001) higher proportions of C18:1n − 9 in the inner layer and in the intramuscular neutral lipids than the other groups. The grass intake significantly (P = 0.0001) increased the proportion of C18:3n − 3 in the inner and outer fat layers and intramuscular neutral lipids, while the outdoor rearing system not only affected on the proportion of linolenic acid but also C22:5 and C22:6 of the inner backfat layer and intramuscular polar lipids. These results suggest that the outdoor rearing allows a higher accumulation of n − 3 fatty acids maybe due to an increased activity of the desaturase and elongase enzymes. On the other hand, the accumulation of tocopherols was not significantly modified neither by the grass intake nor the outdoor rearing, while differences were detected by the type of feeding (diet vs. acorns/acorns and grass). It is concluded, that the outdoor rearing system affects the nutritional value of meat, mainly by improving the fatty acid composition.

Twelve barrow Iberian pigs with an average weight at slaughter of 109.2kg were used to evaluate bioelectrical impedance procedures to predict the body composition of live pigs. Twelve hours before slaughter pigs were weighed, and a four-terminal body composition analyser (Model BIA-101, RJL Systems, Detroit, MI) was utilized to determine resistance (R(s) in Ω) and reactance (X(c) in Ω). The length values (L in cm) were measured between detector electrodes with a flexible steel tape. Twenty four hours after slaughter the left side of each carcass was separated using a scalpel into fat, lean, bone and skin. Multiple regression equations for estimating lean, fat, bone and skin amounts and lean, fat, bone and skin proportions with respect to slaughter weight were calculated. The live weight (LW) and L independent variables predicted 85.3% and 64.3% of the variability of the lean amount and lean proportion, respectively. The LW, X(c) and L variables accounted for 96% and 91.6% of the variation in fat quantity and fat proportion, respectively. The LW and R(s) accounted for 58.9% of the variation in bone amount, and the same variables predict 79.1% of the variability of bone percentage. The R(s) and L variables explained 68% of the variability of skin quantity and LW, R(s) and X(c) predicted 83.1% of the variation of skin proportion. Results from this experiment indicate that bioelectrical impedance may be of interest for body composition prediction of live Iberian pigs.

Forty three-castrated male Iberian pigs of the Torbiscal line with an average initial weight of 102.27kg were used. A group of 22 pigs was fed according to the traditional way in free-range conditions with acorn and grass from November to January. Another group of 21 animals was fed 3.72kg/day of a conventional feed that contained 12.53MJME/kg, 16.21% crude protein, 4.94% fat and 6.64% of crude fiber, during the same period. Measurements of backfat thickness and Longissimus dorsi muscle area at the last rib were taken by means of a real-time ultrasound device (Kretz Technick Inc., 600 V-V2.32, Sonovet, Austria) in all pigs before slaughter. After slaughter, carcass, ham and foreleg weights and backfat and muscle area measurement from the last rib chop were recorded. The average daily gain, carcass yield, fat thickness, loin area, ham weight and proportion of hams were significantly higher (P0.05) in the pigs fed in confinement than in those fed extensively (653.36g, 77.97%, 56.46mm, 3031mm(2), 22.26kg and 14.32% vs 501.48g, 76.94%, 51.74mm, 2673mm(2), 21.52kg and 13.79%, respectively). This paper shows the prediction equations for hams, forelegs and total hams and forelegs weights and proportions with respect to slaughter weight and live ultrasound measurements in pigs fed either extensively or in confinement. The ultrasound measurements better predicted the carcass cuts absolute amounts (R(2)=0.591-0.875) than the carcass cuts proportions (R(2)=0.23-0.40). The use of real-time ultrasound should be used with caution to predict the absolute quantities of hams and forelegs from Iberian pigs since the ultrasound measurements are only moderately accurate.

The effects of dietary fat composition and vitamin E supplementation on the quality characteristics of dry-cured Iberian hams ripened for two years were studied. Thirty Iberian Duroc pigs were fed diets containing three levels of poly and monounsaturated fatty acids. Within each dietary fat treatment, one group was fed a basal level of vitamin E (20mg α-tocopheryl acetate/kg diet) and the other group received a supplemented level (200mg α-tocopheryl acetate/kg diet). Dietary fat composition significantly affected total saturated fatty acids content of neutral and polar lipids from dry-cured Iberian ham ( p 0.012 and p 0.003, respectively). However, diet fatty acids composition did not influence either total monounsaturated or total polyunsaturated fatty acids of neutral and polar lipids. Vitamin E supplementation significantly enhanced dry-cured Iberian ham α-tocopherol content ( p 0.001). This, in turn, led to significantly lower levels of TBARS on days 6 and 9 of storage in slices from dry-cured Iberian hams made of vitamin E supplemented pigs and also lower oxidation levels in an induced lipid oxidation test in samples from those pigs. Dietary fatty acid composition did not significantly affect either TBARS during slices storage or malonaldehyde content in the induced oxidation test. No effect of vitamin E supplementation was observed in ham volatile aldehyde profile, but dietary fat significantly affected hexanal ( p 0.02), heptanal ( p 0.05) and total aldehyde content ( p 0.02), with those pigs fed a diet rich in PUFA showing higher values. Using diets supplemented in α-tocopherol and rich in monounsaturated fatty acids seemed adequate dietary strategies for feeding Iberian hams reared indoors.

The effects of partial replacement of dietary polyunsaturated fatty acid (PUFA) with monounsaturated fatty acid (MUFA) on fatty acid profiles of subcutaneous and intramuscular fat and rheological properties of fat were studied in heavy pigs. No effect of dietary fat was observed on total saturated fatty acids proportion in outer and inner backfat layers or intramuscular neutral and polar lipids. The partial substitution of dietary PUFA by MUFA produced a rise in MUFA of intramuscular polar lipids (p < 0.01) but neutral lipids were not affected. Moreover, it also decreased (p < 0.01) the n-6 proportion of outer and inner backfat layers and intramuscular polar lipids, but no effect was observed for the n-6 in the intramuscular neutral lipids. No significant effect of dietary fat treatment was observed on n-3 fatty acids in outer and inner backfat layers, but the partial substitution of PUFA by MUFA increased (p < 0.01) the n-3 proportion of intramuscular lipid fractions and the consequent decreased in the n-6/n-3 ratio in all lipid location. Significant effects of dietary vitamin E were observed on springiness, cohesiveness and adhesiveness of backfat inner layer. However, consistency was not affected by dietary fat. Further research is needed to establish the effects of different ranges of dietary oil combination in the feeding of heavy pigs.

The aim of this study was to investigate whether dietary vitamin A level is associated with differences in adipocyte differentiation or lipid accumulation in Iberian pigs at early growing (35.8. kg live weight) and at finishing (158. kg live weight). Iberian pigs of 16.3. kg live weight were allocated to two feeding groups, one group received 10,000. IU of vitamin A/kg diet (control); the other group received a diet with 0. IU of vitamin A (var) for the whole experimental period. The dietary vitamin A level had no effect on growth performance and carcass traits. The early suppression of vitamin A increased the preadipocyte number in Longissimus thoracis (LT) muscle in the early growth period (P.

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.

The present study was conducted to determinate the responsiveness of different levels of dietary conjugated linoleic acid (CLA) on intramuscular fat (IMF) and fatty acid composition of skeletal muscle and fat in pigs fed from 59.5 to 133.5kg. Forty female Large Whitex(Large WhitexLandrace) pigs were used. Four levels (0%, 0.5%, 1% and 2%) of a commercial enriched CLA oil supplementation (60% of CLA isomers, 30% cis-9, trans-11 and 30% trans-10, cis-12) were fed to pigs. Carcass, ham, foreleg and loin weights were recorded. Dietary CLA enrichment increased the loin weight (P

The effects of rearing (outdoor vs indoor) and feeding systems (acorn and grass vs mixed diets) on ham quality from Duroc x Iberian pigs were studied. Seven groups of 5 females each were used. One group was reared under freerange conditions and fed with acorns and grass (outdoor pigs). Six group were fed mixed diets in confinement (indoor pigs) under a factorial design 3 x 2 with three types of dietary fat: monounsaturated, polyunsaturated and medium (monounsaturated and polyunsaturated) and two levels of α-tocopheryl-acetate. The α-and γ-tocopherol contents were higher (P < 0.05) in hams from outdoor pigs than in hams from indoor pigs. The hams from indoor pigs were lighter than hams from outdoor pigs and redness values were larger in hams from outdoor pigs than in hams from indoor pigs. At 4 days of storage ham samples from outdoor pigs showed a tendency (P < 0.10) to lower weight loss than those from pigs fed a basal level of vitamin E. These results indicate that rearing outdoor and feeding Iberian pigs by acorn and grass increase the α-and γ-tocopherols and improve color and weight losses in dry-cured hams.Se ha estudiado el efecto del régimen de producción (en libertad vs estabulados) y el sistema de alimentación (bellota y pasto vs piensos formulados) en la calidad del jamón de cerdos Ibéricos cruzados con Duroc. Siete grupos de 5 hembras cada uno fueron usadas. Un grupo fue criado en condiciones de libertad y alimentado con bellotas y pasto (Cerdos en libertad). Seis grupos fueron alimentados con dietas formuladas en confinamiento (Cerdos estabulados) usando un diseño factorial de 3 x 2 con tres tipos de grasa en la dieta: monoinsaturada, poliinsaturada y media (monoinsaturada y polinsaturada) y dos niveles de acetato de α-tocoferol. Los contenidos de α- y γ-tocoferol fueron más altos (p < 0.05) en jamones de cerdos criados en libertad que en jamones de cerdos estabulados. Los jamones de cerdos estabulados pesaron menos que los jamones de cerdos en libertad y los valores de color rojo fueron mayores en jamones de cerdos en libertad que en cerdos estabulados. Después de 4 días de almacenamiento, la muestra de jamón de cerdos en libertad mostraron una menor tendencia (p < 0.10) a perder peso que aquellos de cerdos alimentados con un nivel basal de vitamina E. Estos resultados indican que cerdos Ibérico criados en libertad y alimentados con bellota y pasto incrementan su contenido en tocoferoles y mejoran el color y las pérdidas de peso de los jamones curados.

In a first experiment one group of pigs was maintained in free-range conditions according to the traditional way in a Mediterranean forest (exercised-1) and another group was housed individually and received acorns (sedentary-1). In a second experiment two groups of pigs were fed a mixed diet for the whole experimental period. One of these groups was housed individually in 8 m 2 pens (sedentary-2). The other group was housed in a corridor and forced to walk daily (exercised-2). The subcutaneous fat and neutral lipids of muscle from the exercised pigs fed acorns had higher C18:1 n -9, MUFA, C18:1/C18:0, MUFA/SAT and lower C16:0 and SAT when compared with the fat from the pigs fed acorns in confinement. Those exercised animals fed the mixed diet had also lower C16:0 and SAT in subcutaneous fat and lower SAT and higher C18:2, C18:3, PUFA and MUFA/SAT in neutral lipids when compared with the sedentary pigs, which may indicate that delta-9-desaturase activity was higher in exercised than in sedentary pigs. Exercised pigs had higher acid and neutral esterases and lower neutral lipase activity than sedentary pigs. No differences in the α-tocopherol concentration and TBARS values of meat samples among the pigs that received a mixed diet either exercised or sedentary were observed. The moderate exercise reduced the postprandrial concentrations of triglycerides in plasma, but did not reduce other plasma levels.

The effects of physical activity on performance, carcass traits, Psoas major lysosomal and exoprotease acitivies and meat quality were studied in 24 castrated male Iberian pigs during the last fattening period (from 111.1 ± SD 5.2 kg). Pigs were randomly distributed in three groups. Two groups receiving the same diet were reared in confinement, one housed in individual pens of 8 m2 (sedentary group) and the other was housed outdoor with daily (up to 2 km) forced walking (exercise group).;one group was reared under the traditional production system walking daily several km and fed mostly with acorn from Quercus ilex and Quercus rotundifolia and grass (free-range group). No differences were found in performance and carcass traits. In exercised pigs a lower activity of cathepsin B + L and total cathepsins (P < 0.05) was observed. Exercise induced the inhibition of dipeptidyl peptidases II and III and arginyl aminopeptidase and the activation of dipeptidyl peptidases IV and leucyl aminopeptidase (P < 0.05). Although no effects on total free amino acids in Psoas major muscle were observed the concentration of branched chain amino acids decreased in the free-range pig group probably related to an increase in physical activity. Exercise had no effects in Psoas major postmortem tenderness and water holding capacity. © 2007.

5 pages, 5 tables., Sixteen Iberian barrows of the same age with an average initial live weight of 100.1 kg were randomly distributed in two groups of eight pigs each. One group was fed healthy acorns and the other group received acorns infested of Curculio sp. The subcutaneous backfat from pigs fed healthy acorns had higher C18:1n–9, MUFA and C20:5n–3 and lower C18:0 and SFA proportions than that from the pigs fed acorns infested with Curculio. The consumption of acorns infested with Curculio sp. led to a reduction of C18:1n–9, MUFA, C18:2n–6, C18:3n–3, C22:5n–3 and PUFA proportions in neutral lipids from Longissimus dorsi muscle with respect to consumption of healthy acorns, whereas in polar lipids it produced a reduction in C18:1n–9, MUFA and C18:4n–3 proportions and an increase in C18:2n–6, C20:4n–6, n–6 and C20:5n–3 proportions and of n–6/n–3 ratio with respect to the healthy acorns consumption. The pigs fed healthy acorns had higher intramuscular fat percentage in Longissimus dorsi than pigs fed with acorns infested with Curculio (9.95 vs 7.09% SEM = 0.60)., This research was supported by CICYT AGL 2004- 03989 (Ministerio de Educación y Ciencia).

This experiment was undertaken to provide information on the effect of feeding system applied during the finishing period (100-150kg) on the quality of Iberian pig meat. Four feeding systems were applied: pigs fed under free-range conditions with acorns and grass fully available during 111 days (FR(111)), pigs fed concentrate diet in confinement during 28 days and free-range with acorns and grass fully available during 83 days (CDC(28)+FR(83)), pigs fed concentrate diet in confinement during 65 days and free-range with acorns and grass fully available during 46 days (CDC(65)+FR(46)) and pigs fed concentrate diet in confinement with a feed average daily amount of 3.1kg during 111 days (CDC(111)). The CDC(111) pigs had more muscular carcasses characteristics than the remaining groups of pigs. However, the higher concentration of C18:1 n-9 in subcutaneous backfat was found in FR(111) pigs. In the neutral lipids from intramuscular fat of Longissimus dorsi only the C18:2 n-6 and C18:3 n-3 proportions were affected by feeding system, and the n-6/n-3 ratio observed was lower in FR(111) and CDC(28)+FR(83) pigs than in CDC(111) pigs. In the neutral lipids from hepatic fat the proportion of n-6 fatty acids was lower in FR(111) pigs than in CDC(65)+FR(46) and CDC(111) pigs.

The experiment was undertaken to provide information of the influence of feeding either free-range or in confinement with different dietary MUFA/PUFA ratios and α-tocopheryl acetate supplementation (40 vs. 200 mg/kg) on tocopherol content and susceptibility to lipid oxidation of muscle and microsomes in Iberian pigs. The grass provided to the pigs had a similar α-tocopherol concentration to that observed for diets supplemented with 200 mg/kg α-tocopheryl acetate, and acorns supplied fourfold higher content of γ-tocopherol than the experimental diets. The α- and γ-tocopherol contents of muscle reflected the tocopherol concentration of the diets. Mono and Medium diets produced a similar MUFA/PUFA ratio in neutral and polar lipids of pig muscle to those fed outdoors. The lowest TBARS numbers were found in muscle samples from pigs fed a MUFA-enriched diet in confinement. No significant influence of free-range feeding or dietary fat on drip loss was found. However, α-tocopheryl acetate supplementation reduced (P

The effect of gender (entire males vs females) on growth performance, carcass traits and meat and fat quality of Avileña-Negra Ibérica calves, fattened under free range conditions and supplemented with concentrate, were investigated. The average daily gain, leg width and thorax depth were higher in males than in females. Carcass conformation score, fore-quarter weight and percentage in carcass were higher in males than in females, whereas dressing percentege, loins and flank percentages in carcass and carcass fatness degree were higher in females than in males. Instrumental colour variables of muscle were not affected by gender at days 1, 3, 7 and 9 of refrigerated storage. In muscle, the L*, a*, b*, chroma, oxymyoglobine and oxymyoglobine/metmyoglobine ratio values observed 9 days after slaughter were lower than those at days 1 and 3 after slaughter. Intramuscular fat percentage of Longissimus thoracis muscle was higher in females than in males. Gender had no effect on α-tocopherol content in intramuscular fat (IMF) from Longissimus thoracis muscle. The omental and IMF of females had lower C18:2 n-6, Σ n-6 and Σ PUFA proportions than those from the males. In IMF C16:1, C18:1 n-9 and Σ MUFA proportions were greater in females than in males. The IMF percentage in Longissimus thoracis affected significantly to its fatty acid composition.

The objective of this preliminary experiment was to study whether bioelectrical impedance analysis (BIA) can accurately predict the components of fresh pig hams. The trimmed right hams from 20 Iberian barrows were used. Six measures of resistance and reactance were taken by a bioelectrical impedance analyser. Simple and multiple regression equations were calculated for estimating bone, lean, intermuscular fat (IF), subcutaneous fat (SF), total fat (TF) and skin weights and percentages with respect to ham weight (HW). The HW accounted for 22% (P < 0.05) and 35% (P < 0.01) in the variations in lean and skin percentages, respectively. The ham compactness index (HCI), calculated as HW (in g)/(ham length, in cm)2, accounted for 20% (P < 0.05) and 38% (P < 0.01) in the variations in SF and TF percentages, respectively. The HW and BIA variables accounted for 60% (P < 0.001) of the variation in skin percentage; the HCI and BIA measures accounted for 79% (P < 0.0001), 66% (P < 0.001) and 78% (P < 0.0001) of the variation in lean, IF and SF percentages; and BIA variables accounted for 72% (P < 0.0001) of the variation in bone percentage. To determine the accuracy of the calculated regression equations, five additional trimmed fresh hams from Iberian barrows were used. Actual and predicted values were compared. The HW accurately predicted lean weight and skin percentage in linear regression equations, and HCI adequately predicted SF and TF weights in simple linear regression equations, and also SF percentage in inverse function. The additional inclusion of HW, HCI or BIA variables in the regression models did not improve the accuracy of the equations. It is concluded that BIA might be applied to predict the components of fresh hams but more studies are needed to determine whether levels of accuracy and precision are sufficient for this method to be used in practice.

The experiment was organized in a 3 x 2 factorial arrangement with three dietary fat blends and a basal (20 mg kg(-1) diet) or supplemented (220 mg kg(-1)) level of alpha-tocopheryl acetate. Dietary vitamin E and monounsaturated to polyunsaturated fatty acid ratio (dietary MUFA/PUFA) affected muscle alpha-tocopherol concentration (alpha-tocopherol [log microg g(-1)] = 0.18 (+/- 0.105) + 0.0034 (+/- 0.0003) x dietary alpha-tocopherol [mg kg(-1) diet] (P0.0001) + 0.39 (+/- 0.122) x dietary MUFA/PUFA (P0.0036)). An interaction between dietary alpha-tocopherol and dietary MUFA/PUFA exists for microsome alpha-tocopherol concentration (alpha-tocopherol [log microg g(-1)] = 1.14 ( +/- 0.169) (P0.0001) + 0.0056 ( +/- 0.00099) x dietary alpha-tocopherol [mg kg(-1) diet] (P0.0001) + 0.54 (+/- 0.206) x dietary MUFA/PUFA (P0.0131) - 0.0033 (+/- 0.0011) x dietary alpha-tocopherol [mg kg(-1))] x dietary MUFA/PUFA (P0.0067)), and hexanal concentration in meat (hexanal [ng x g(-1)] = 14807.9 (+/- 1489.8)- 28.8 (+/- 10.6) dietary alpha-tocopherol [mg x kg(-1)] (P0.01) - 8436.6 (+/- 1701.6) x dietary MUFA/PUFA (P0.001) + 24.0 (+/- 11.22) x dietary alpha-tocopherol-dietary MUFA/ PUFA (P0.0416)). It is concluded that partial substitution of dietary PUFA with MUFA lead to an increase in the concentration of alpha-tocopherol in muscle and microsome extracts. An interaction between dietary alpha-tocopherol and fatty acids exists, in which at low level of dietary vitamin E inclusion, a low MUFA/ PUFA ratio leads to a reduction in the concentration of alpha-tocopherol in microsome extracts and a concentration of hexanal in meat above the expected values.

Thirty-two Duroc × (Large White × Landrace) barrows of 86.6 kg of body weight (BW) were used to investigate the effect of diet (control or granulated barley) provided during the finishing period on growth performance, meat quality and costs of production. The control diet consisted in a commercial feedstuff and the granulated barley diet consisted in the use of this cereal as only ingredient. The pigs were assigned to pens in groups of two (eight replicates per treatment) and were slaughtered at 130 kg BW. All the animals received the same feeding and management before the trial. No differences were observed for the growth performance and carcass traits between treatments. Pigs fed granulated barley had higher (P < 0.01) feed conversion ratio but lower production costs per kg of live (P < 0.001) and carcass (P < 0.01) weight than those on the control diet. The intramuscular fat (IMF) percentage in Longissimus dorsi muscle tended to be higher (P = 0.07) and had higher (P < 0.01) C18:1n-9 and total monounsaturated fatty acid (FA) percentages and lower (P < 0.05) C17:0, C17:1, C18:2n-6, C18:3n-3, C20:3n-9, Σn-6, Σn-3 and total polyunsaturated FA proportions in pigs fed granulated barley than in the control pigs. It is concluded that the use of barley as single ingredient in the diet provided during the finishing period of pigs may increase the IMF percentage, the C18:1n-9 proportion in IMF and some colour parameters of meat. Additional key words: dry-cured meat product, fattening pigs, loin characteristics, protein/lysine deficiency.