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espanolEl objetivo de este trabajo fue estudiar el efecto del nivel de alimentacion (proximo a necesidades de man-tenimiento) en funcion del tipo de pienso (con distintos niveles de grasa: 7 % vs.4 %) y del tiempo, en elperfil graso subcutaneo de cerdos ibericos. La capa externa presento mayor proporcion de C18:0 y C20:0,y la capa interna mas C16:0 y C22:5n-3 con la dieta basada en carbohidratos. En cambio, con el suminis-tro del pienso alto en grasa se obtuvieron mayores proporciones de C18:2n-6 y C20:3n-9 en ambas capas.Respecto al efecto del tiempo en los cerdos que estuvieron proximos al mantenimiento, se produjo unadisminucion de C16:1n-7, C18:1n-7, total de n-7 y C18:4n-3 y un aumento en C18:0 en la capa externa. Enla capa interna, se produjo la disminucion de la concentracion del C18:1n-7, C18:3n-3, C20:5n-3 y C22:5n-3,sin cambios en los sumatorios de los principales grupos de acidos grasos. En conclusion, un tiempo de es-pera en mantenimiento de tres semanas supone una reduccion de las proporciones de acidos grasos mo-noinsaturados n-7 a nivel de la capa externa de grasa subcutanea, con cambios individuales en poliinsa-turados n-3 en ambas capas a causa de su utilizacion metabolica que no se manifiestan en el total de acidosgrasos n-3. No se observaron cambios en ambas capas con ambos factores (tipo de pienso y tiempo a ni-vel proximo a mantenimiento) lo que supone un avance para el manejo por el ganadero en el sector EnglishThe objective of this research was to study the effect of the feeding level (close to maintenance needs)depending on the type of feed (with different fat levels: 7 % vs. 4 %) and the time, on the subcutane-ous fat profile of Iberian pigs. The outer layer presented greater proportions of C18:0 and C20:0, andthe inner greater C16:0 and C22:5n-3 with the carbohydrate-based diet. On the other hand, with thesupply of high fat feed, greater proportions of C18:2n-6 and C20:3n-9 were obtained in both layers. Regarding the effect of time there was a decrease in C16:1n-7, C18:1n-7 and C18:4n-3 and an increase inC18:0 in the external layer in pigs close to maintenance level. In the inner layer, the proportion of C18:1n-7, C18:3n-3, C20:5n-3 and C22:5n-3 decreased but there were not changes in the sum of the main fattyacid groups. In conclusion, a maintenance waiting time of three weeks implies a reduction in the pro-portions of n-7 monounsaturated in subcutaneous fat of external layer and individual changes in n-3polyunsaturated fatty acids in both layers due to its metabolic utilization; however these changes werenot observed in the total of n-3 fatty acids. No changes were observed in both layer due to the inter-action of both factors (type of diet and time of feeding close to maintenance) which represents an ad-vance in for the management by the rancher in the sector

En un primer experimento se utilizaron tres grupos de cerdos Ibéricos, machos castrados, de la línea Retinto del Andévalo que entraron en montanera con pesos diferentes: 88,12 (peso bajo) 119,64 (peso intermedio) y 146,43 kg (peso alto) de peso medio respectivamente. Los cerdos de peso bajo e intermedio lograron un crecimiento diario significativamente superior que el de peso alto. De otra parte, en un segundo experimento, se recabaron los pesos al sacrificio de 100 cerdos de la línea genética precitada que fueron acabados en montanera en seis años consecutivos. Las canales se clasificaron según el peso al sacrificio (peso alto > 185 kg, intermedio 165-185 kg y bajo < 165 kg). El año tuvo influencia estadísticamente significativa sobre las características de la canal. El rendimiento canal fue significativamente más bajo en el grupo de cerdos sacrificado con peso bajo. El peso de los jamones, paletas y lomos aumentaron significativamente con el peso al sacrificio, pero el peso de los solomillos y la relación ponderal paletas/jamones no estuvieron afectados por el peso al sacrificio. El porcentaje en peso de los jamones, paletas, lomos y solomillos respecto al peso canal se redujo conforme aumentaba el peso canal. Los coeficientes alométricos de jamones paletas, lomos y solomillos respecto al peso canal fueron 0,563, 0,479, 0,422 y 0,353 respectivamente. La relación ponderal paletas/jamones aumentaba hasta un peso de la canal de 134 kg y disminuía después con el aumento del peso canal. Se concluye que sería interesante sacrificar los cerdos en torno a 160 kg de peso vivo para aumentar la proporción de partes nobles en la canal y no penalizar la relación ponderal paletas/jamones.

A total of 48 Duroc×(Landrace×Large White) pigs, 24 males and 24 females, with 85±3 d of age were used to study the effect of sex and immunocastration on growth performances and carcass and pork quality. There were 4 experimental treatments; surgical castrated males (SCM), immunocastrated males (ICM), entire females (EF) and immunocastrated females (ICF). The surgical castration had been carried out in 12 males when were 5±3 d of age. The immunocastration consisted in two vaccinations with Improvac®, in 12 boars and in 12 gilts, at the beginning of the trial and 28 d later (45.4 and 70.6 kg body weight as average, respectively). Pigs were intended for dry-cured ham elaboration; therefore, heavy body weight (126 kg and 167 d of age as average) and a minimum of carcass fat depth (20 mm) were required. During the overall period (from days 0–82), SCM were less efficient converting feed into gain than the rest of the treatments ( P =0.049). At slaughter, ICM were heavier than SCM and ICF with EF being intermediate ( P =0.05) and ICF were fatter, as much at 10th rib ( P =0.05) as at level of Gluteus medius muscle ( P =0.043), than EF with males (SCM and ICM) in an intermediate position. As a consequence, EF had the leanest carcasses ( P =0.048) and 25% of them were rejected for lack of fatness vs 0% in the other treatments ( P =0.02). Pork from ICF was redder (higher a*) than that from ICM ( P P =0.03) and tended to have lower level of oxymyoglobin ( P =0.061) and metmyoglobin ( P =0.082) than that from EF. The intramuscular fat content was not affected. The inmunocastration of males or females had limited influence on major fatty acids of subcutaneous or intramuscular fat. It can be concluded that immunocastration could be interesting in pigs intended for dry-cured ham elaboration because in males improved the feed conversion ratio with no penalization of carcass or meat quality, in comparison to surgical castration, and in gilts increased backfat thickness of carcass reducing to 0% the rejections at slaughterhouse for lack of fatness.

A total of 619 calvings and 547 intervals between calvings (IBC) from 97 cows, 15 Retinta cows and 82 crossbreed (Charolais x Retinta) cows, reared under continuous calving during eight consecutive years were controlled in the Dehesa ecosystem. The 39.25% of the calvings occured from December to February and only the 14.38% from August to October. The heifers and cows of seventh, eighth, tenth and eleventh and following calving showed an IBC higher than the cows of third, fourth, fitth and sixth calving. The variable “cow” had significant effect on the IBC, but the factors “gender of suckled calf”, “year”, “bull”, “calving month”, “fence” and, “body condition score at calving” had not significant influence on IBC. The age at first calving had not significant effect on IBC of heifer and average IBC of cows. Age at weaning of born calves from November to March was significantly lower than those born calves from May to July. The calf’s mortality seems affected by the genetic type of calf and the birth time. The use of Charolais bulls leads to a calves mortality at birth higher regarding Limousine bulls.

In the present work a simulation analysis for the calves fattening (males anf females) was achieved. In the simulation model were introduced as independent variables the purchase price of kilogram of weaned calf, sale price of carcass kilo of fattened calf, feed price and the conversion rate of feed, whereas the profit, gros margin and disposable income were considered as dependent variables. Females obtained higher profits, gross margins and disposable income than the males. The independent variables that had the highest contribution to the variance of dependent variables were the purchase and sale price of half, whereas the variable that had the lowest contribution to the variance was the conversion rate of feed.

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.

A total of 48 Duroc × (Large White × Landrace) gilts of 46.8 kg BW (86 ± 3 days of age) were used to investigate the effect of diet during the growing and finishing periods on growth performance and carcass, meat and fat quality. The control diet consisted of a commercial feedstuff and the granulated barley diet had that cereal as the single major ingredient. There were three treatments: (i) control diet provided from 45.6 to 127.8 kg BW (C group), (ii) control diet from 47.0 to 91.8 kg BW and granulated barley from 91.8 to 129.7 kg BW (C + GB group) and (iii) granulated barley from 47.9 to 93.1 kg BW and control diet from 93.1 to 135.1 kg BW (GB + C group). Each treatment was replicated eight times, with two pigs per replicate. The C group grew faster (P < 0.001) and had a better feed conversion ratio (P < 0.001) than the GB + C group, with C + GB being intermediate. Carcasses from C + GB gilts had higher backfat depth than those from C gilts, with GB + C being intermediate (P < 0.05). Also, the main joints (ham + shoulder + loin) had a higher (P < 0.01) yield in carcass in the GB + C group than in the C group, with C + GB being intermediate. The intramuscular fat (IMF) content was higher (P < 0.001) in loin from C + GB and GB + C gilts than in C gilts. The IMF of loin from C + GB gilts had higher (P < 0.05) C18:1n-9 and total monounsaturated fatty acid (FA) proportions than that from C gilts, whereas the C18:2n-6 and total polyunsaturated FA percentages were lower (P < 0.05) in C + GB gilts than in the remaining gilts. The total saturated FA percentage was lower (P < 0.05) in loin from GB + C than in that from C gilts. Hams from C + GB and GB + C gilts had higher (P < 0.05) C18:1n-9 and total monounsaturated FA proportions and lower C18:2n-6 and total polyunsaturated FA contents than those from C gilts. We can conclude that granulated barley provided during the growing or the finishing period improved some carcass and meat characteristics of heavy gilts desirable for dry-cured ham production.

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 effect of the dietary vitamin A level and administration time on intramuscular fat (IMF) percentage and fatty acid composition of the subcutaneous outer layer, intramuscular and hepatic fat from lean pigs was investigated. One group received 13,000 IU of vitamin A/kg diet for 11 weeks (H); other group received 1300 IU during the same period (L) and a third group received a vitamin A-enriched diet (13,000 IU) for six weeks followed by a diet with 0 IU of vitamin A for the last five weeks previous to slaughter (H-0). The dietary vitamin A level had no effect on growth performance and carcass traits. Pigs fed L showed higher IMF in Longissimus dorsi muscle when compared with group H. The L group also showed a higher saturated fatty acid (SFA) proportion and decreased MUFA/SFA ratio in the subcutaneous backfat outer layer. The dietary vitamin A level had no effect on the fatty acid composition of muscle. The suppression of vitamin A five weeks prior to slaughter did not affect IMF and fatty acid composition of the subcutaneous backfat outer layer, while in liver decreased SFA and increased PUFA.

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.

This study aimed to assess the interaction between different dietary vitamin A (dVitA) levels and the same concentration of vitamin E (100 IU all-rac-α-tocopheryl acetate/kg feed) in growing-finishing pigs. In the first experiment, two fat sources × two dVitA levels (0 v. 100 000 IU) were used. The supplementation of 100 000 IU dVitA induced a range of 5.13 to 30.03 μg retinol/g liver, 62.78 to 426.88 μg retinol palmitate/g liver, and 0.60 to 1.96 μg retinol/g fat. Dietary fat did not affect retinol or retinyl palmitate deposition in pigs. The high concentration of dVitA produced lower fat and liver α-tocopherol concentrations, and increased susceptibility of muscle tissue to oxidation. A second experiment was carried out to study the retinol and α-tocopherol retention at different withdrawal times prior to slaughter (two dVitA levels; 0 v. 100 000 IU). A high dose of 100 000 IU vitamin A during a short 2-week period was enough to induce α-tocopherol depletion in liver and fat to a similar extent as when 100 000 IU were administered during the whole fattening. Muscle, fat and liver α-tocopherol concentrations were not affected by dVitA in the 1300–13 000 IU/kg range, but liver α-tocopherol concentration was higher when vitamin A was removed from the vitamin mix 5 weeks prior to slaughter (experiment 3).

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

Diet influences animal body and tissue composition due to direct deposition and to the nutrients effects on metabolism. The influence of specific nutrients on the molecular regulation of lipogenesis is not well characterized and is known to be influenced by many factors including timing and physiological status. A trial was performed to study the effects of different dietary energy sources on lipogenic genes transcription in ham adipose tissue of Iberian pigs, at different growth periods and on feeding/fasting situations. A total of 27 Iberian male pigs of 28 kg BW were allocated to two separate groups and fed with different isocaloric feeding regimens Standard diet with carbohydrates as energy source (CH) or diet enriched with high oleic sunflower oil (HO). Ham subcutaneous adipose tissue was sampled by biopsy at growing (44 kg mean BW) and finishing (100 kg mean BW) periods. The first sampling was performed on fasted animals, while the last sampling was performed twice, with animals fasted overnight and 3 h after refeeding. Effects of diet, growth period and feeding/fasting status on gene expression were explored quantifying the expression of a panel of key genes implicated in lipogenesis and lipid metabolism processes. Quantitative PCR revealed several differentially expressed genes according to diet, with similar results at both timings RXRG, LEP and FABP5 genes were upregulated in HO group while ME1, FASN, ACACA and ELOVL6 were upregulated in CH. The diet effect on ME1 gene expression was conditional on feeding/fasting status, with the higher ME1 gene expression in CH than HO groups, observed only in fasting samples. Results are compatible with a higher de novo endogenous synthesis of fatty acids (FA) in the carbohydrate-supplemented group and a higher FA transport in the oleic acid-supplemented group. Growth period significantly affected the expression of most of the studied genes, with all but PPARG showing higher expression in finishing pigs according to a pattern dissimilar from the usual in cosmopolitan pig breeds. Feeding/fasting status only influenced PPARG gene transcription. The lack of effects of feeding/fasting status on lipogenic gene expression and the higher ME1 response to diet in fasting samples than in postprandial sampling, suggest the persistence of de novo lipogenesis during fasting. Overall results improve the understanding of the influence of different factors on lipid metabolism regulation in Iberian pigs. © The Animal Consortium 2016.

This work studies the effect of starting age of the fattening period on productive traits and fatty acid (FA) composition of backfat (BF) of Iberian pigs. Three groups of eight Iberian barrows (body weight 101.25 ± 2.8 kg) started the fattening period at 14 (P14), 12 (P12) and 8 (P8) months of age. During the pre-fattening period pigs received 1.3, 1.5 and 2.5 kg/day of a commercial feed (for P14, P12 and P8, respectively). The P8 pigs showed lower slaughter weight, average daily gain (ADG), carcass weight, carcass outer length, backfat thickness and ham length than P14 and P12 pigs. In the subcutaneous outer backfat layer P14 pigs had significantly higher proportion of oleic acid (C18:1 n-9) (P

The influence of feeding system on growth performance, carcass characteristics, and fatty acids profile of subcutaneous backfat and lipogenic enzymes activity was studied. The following feeding systems were applied: HH: group of 12 pigs fed with a high feeding level during growth and fattening periods; HL: group of 12 pigs fed with a high feeding level during growth period and a low feeding level during fattening period; LH: group of 12 pigs fed with a low feeding level during growth period and a high feeding level during fattening period; LL: group of 12 pigs fed with a low feeding system during growth and fattening periods. The high and low feeding levels applied during growth and fattening periods were 70 and 35 g feed/kg live weight 0.75 (LW 0.75 ) day and 121 and 87 g feed/kg LW 0.75 day, respectively. The duration of the growth period was 163 days in all groups. The ages at slaughter of HH, HL, LH and LL pigs were approximately 383, 406, 439 and 503 days, respectively. The HH and LL pigs had the higher and lower average daily gain respectively, while the LH pigs presented the best feed conversion ratio during fattening period. At slaughter, the LL pigs had the higher value of loin width and the lower values of backfat thicknesses and Longissimus dorsi muscle intramuscular fat percentage (P n -9 and ΣMUFA (monounsaturated) acids than those from HH and HL pigs. The subcutaneous backfat inner layer from LL pigs had a lower C16:0 and ΣSFA (saturated) acids proportions than those from remaining groups of pigs. The activity of the fatty acid synthase (FAS) and glucose-6-phosphate dehydrogenase (G6PD) enzymes, measured in subcutaneous backfat, at the end of growing period was significantly (P

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 undertaken to quantify the α and γ-tocopherols accumulation in muscle and backfat from Iberian pigs given food free-range as affected by the time of free-range feeding or the weight gained during the fattening in free-range. Pigs were given their food in a free-range production system with pasture and acorns (Quercus rotundifolia) for different periods of time: 46 days (free-range 3), 83 days (free-range 2) and 111 days (free-range 1). A control was given food free-range for 0 days. In addition another experiment was developed to determinate the effect of the the weight gained on the tocopherols accumulation at a similar period of time (111 days) given food free-range: one group gained 68·7 kg of weight (free-range A) and the other 43·6 kg (free-range B). The concentration of γ-tocopherol significantly (PP< 0·0001) higher concentration of α and γ-tocopherols in the inner and outer backfat layers, and α-tocopherol in the BF muscle than those given food free-range B. However, no differences were detected in the proportion of α-tocopherol in the LD and γ-tocopherol in the LD and BF. The γ-tocopherol content of LD and BF muscles depending on the days of feeding were adjusted to linear and quadratic regressions (R2=0·8705 and 0·8697, respectively), while the outer and inner backfat layers were linear equations (R2=0·8480 and 0·8119, respectively). However, the γ-tocopherol concentration as affected by the weight gained in free-range showed in all tissues a linear and a quadratic trend that were adjusted to exponential responses. The α-tocopherol content was affected by the γ-tocopherol concentration in muscle and outer backfat layer. The tocopherol concentration (α and γ-tocopherols) in the backfat layers may discriminate better between the pigs of high quality that were given food free-range for a long period of time and those that stayed an intermediate period. However, to discriminate between the pigs on formulated food and those given food free-range, the quantification of the γ-tocopherol concentration in muscle could be a better indicator.

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.

A group of 11 pigs was fed with 70 g feed per kg of metabolic weight (H pigs) and another group of 11 pigs was fed with 50g feed per kg of metabolic weight (L pigs). In both experimental groups (H and L pigs), it was observed that the higher initial proportion of C16:0, C18:0 and C18:2 (n-6) in backfat at the beginning of the free-range feeding period, the greater decrease rate of these fatty acid proportions regarding weight gain during the free-range fattening period took place. On the other hand, the greater initial proportion of C18:1 (n-9), the smaller increase rate in the concentration of this fatty acid was observed. The intramuscular neutral lipids from L pigs had higher C18:3 (n-3) and lower proportions of monounsaturated fatty acids (MUFA) than those from H pigs, while intramuscular polar lipids from L pigs had significantly higher proportions of C18:0, PUFA, C18:3 (n-3) and (n-3) and significantly lower MUFA and C18:1 (n-9) proportions than those from H pigs. The alpha-tocopherol concentration found in Longissimus dorsi from L pigs was significantly higher (p0.012) than those from H pigs.

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.

Vitamin supplementation is a widely extended practice in swine nutrition. Certain vitamins such as vitamins A and E are related to meat quality and have been reported as antagonists. Thus, their tissue levels are of interest for swine producers and consumers. This experiment was undertaken to study the effect of dietary vitamin A supplementation or withdrawal duration and timing on the evolution of vitamin A deposition in tissues, α-tocopherol accumulation and gene expression in heavy pigs. Eighty weaned Iberian piglets (16.3 ± 2.5. kg) were either fed a vitamin A-enriched diet (10,000. IU vitamin A/kg) (CONTROL) or given a diet without added vitamin A applied from the beginning of the trial at 16.3. kg (early restriction group, ER) or from an average weight of 35.8. kg (late restriction group, LR). Pigs fed ER and LR had lower ADG and worse feed efficiency than those from the CONTROL group at 101.4. kg (P=0.001 and P=0.034, respectively). However, final weight, average daily gain, average daily intake and feed conversion efficiency were not statistically affected by dietary treatment during the starter (

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.

The effect of partial replacement of poly- (PUFA) with monounsaturated (MUFA) fatty acids in pig diets on fatty acid composition of subcutaneous and intramuscular fat and on fat and lean firmness was studied. No effect of dietary fat was observed on total saturated fatty acid concentration in any of the backfat layers or intramuscular lipid fractions. No significant effect of dietary fat was observed for the MUFA concentration in the outer layer, but a marked effect was evident for the inner layer (P < 0·001). A linear effect of dietary MUFA was observed for MUFA (P < 0·001) and PUFA (P < 0·001) in polar lipids. No significant effect of dietary treatment was observed on total concentration of n-3 fatty acids in any lipid location but a marked effect was observed for total n-6 fatty acid concentration. The response of pig fatty acid n-6 concentration was different depending on the lipid location. The neutral lipid fraction showed significantly lower n-6/n-3 fatty acid ratio than the subcutaneous fat. Intramuscular polar lipids showed no significant response of n-6/n-3 ratio. A linear effect of dietary MUFA concentration was observed on the melting point on the inner backfat layer (MP = 34·4 (s.e. 2·51) + 0·15 (s.e. 0·07) ✕ dietary MUFA (g/kg dry matter) (R2 = 0·24, P < 0·05)), indicating that the partial substitution of dietary PUFA by MUFA produced a fat of higher consistency. No response of the melting point of the outer layer to dietary treatment was observed. A marked effect of dietary fat was shown for backfat hardness (P < 0·001), gumminess (P < 0·001) and chewiness (P < 0·001). No effect of dietary fat was observed on the rheological properties of longissimus lumborum muscle.

Cinquante-six lactations : 23 de truies primipares et 33 de 11 truies multipares Large White × Landrace ont ete controlees. La production de lait a ete estimee par le procede direct de double pesee de la portee avant et apres tetee grâce a 12 controles realises chaque heure entre 9 h et 20 h aux jours 7, 14, 21, 28, 35 et 42 de lactation. La production totale de lait, et la production par porcelet sevre durant les 6 semaines de lactation ont ete de 170 ± 48,8 kg et 29,5 ± 7,3 kg respectivement pour les primipares et de 210,9 ± 33,6 kg et 26,9 ± 5,1 kg respectivement pour les multipares. Dans les deux groupes de truies, la production maximale de lait a ete obtenue pendant la troisieme semaine de lactation et la production minimale dans la sixieme: 33,5 ± 14,3 kg et 23,3 ± 9,9 kg pour les truies primipares et 43,3 ± 11,1 et 28,0 ± 9,8 pour les truies multipares. La courbe de lactation a ete ajustee a une fonction « gamma » (R 2 = 0,86 pour primipares et R 2 = 0,91 pour multipares). Pour les truies primipares la date de mise bas n'a pas eu d'effet significatif (P < 0,05) sur la production totale de lait ni sur celle exprimee par porcelet sevre. Toutefois par porcelet sevre supplementaire la production totale de lait a augmente (P < 0,001) de 25 kg tandis que la production de lait par porcelet sevre a diminue de 1,01 kg, diminution non significative (P < 0,02). Pour les truies multipares la production totale de lait et par porcelet sevre est affectee significativement (P < 0,05) par la truie et le numero de mise bas. Les productions obtenues durant la quatrieme lactation ont ete superieures a celles obtenues durant la troisieme et deuxieme lactations. Le nombre de porcelets sevres a affecte la production de lait par porcelet sevre (P

L'etude a porte sur 1 051 porcelets, provenant de 95 portees de 39 truies Large White × Landrace accouplees avec des mâles Pietrain × Duroc. Le taux de mortalite a la naissance et durant la periode de lactation a ete respectivement de 3,2 et de 28,32 %. Le nombre de porcelets mort-nes par portee a augmente (p 1 250 g, compris entre 1 000 et 1 249 g et < 1 000 g, des taux de mortalite de 20, 39 et 61 % ont ete respectivement observes apres mise bas. Les porcelets morts durant la periode de lactation etaient ceux qui avaient perdu du poids ou avaient eu de faibles gains de poids journaliers.

Segun un diseno experimental factorial que observo dos lineas paternales comerciales de la raza Duroc: M (magra) y G (grasa), y dos sexos (machos castrados vs hembras) se utilizaron 43 cerdos Duroc x (Landrace x Large White) destinados a la produccion de Jamon de Teruel. La fase de cebo transcurrio entre los 22,50 y 125,26 kg, y todos los animales consumieron el mismo pienso durante el periodo experimental. Los cerdos procedentes de la linea G consumieron mas pienso que los de la M y los machos castrados exhibieron mayor consumo y crecimiento que las hembras. Los cerdos derivados de la linea G tuvieron valores superiores del perimetro del jamon, espesor de grasa a nivel de la decima costilla y cobertura grasa a nivel del musculo Biceps femoris. El espesor de grasa a nivel de la decima costilla fue superior en los machos castrados que en las hembras. El porcentaje rechazado de canales de hembras en el matadero fue superior que el de machos castrados. La linea paterna no tuvo efecto sobre los porcentajes de humedad (H), proteina (P) y grasa intramuscular (GIM) del musculo Longissimus dorsi, pero el pH del lomo, tomado 45 minutos despues del sacrificio (pH45), fue superior en los cerdos procedentes de la linea M que en los de la G. Los machos castrados tuvieron mayor porcentaje de GIM que las hembras. Los cerdos procedentes de la linea G tuvieron mayores proporciones de C10:0, C15:1, C16:0 y total de acidos grasos saturados (�° SAT) y menores proporciones de C20:3 n-9 y C20:4 n-6 que los de la linea M. Los machos castrados tuvieron proporciones superiores de C14:0, C16:1, C18:1n-9 y total de acidos grasos monoinsaturados (�° MONO) e inferiores proporciones de C18:2 n-6, total de acidos grasos poliinsaturados (�° POLI) y n-6 (�° n-6) que las hembras. El porcentaje de GIM afecto a las proporciones: C14:0, C16:0, C17:0, C18:1n-9, C18:2 n-6, C20:1, C20:4 n-6, �° SAT, �° MONO, �° POLI, �° n-6 y a las relaciones �° n-6/�° n-3 y �° POLI/ �° SAT y detectadas en la GIM. Se concluye que la utilizacion de una linea paterna Duroc grasa no afecta negativamente a los resultados productivos, incrementa ligeramente el engrasamiento de la canal y satura la GIM. Los machos castrados presentan una canal mas adecuada que las hembras para la produccion del jamon de Teruel.

The objective of this experiment was to study the effect of gender on growth performance and carcass and meat quality of calves of Avileña-Negra Ibérica breed. Sixteen calves, eight males and eight females, were used. The calves were fattened under intensive conditions, housed in confinement and fed with the same feed and cereal straw from 230.7 to 478.3 kg. The males grew more than the females (1.390 vs 0.932 kg day–1 respectively). Carcass weight, carcass length, leg length, leg perimeter, carcass and leg compactness, legs, fore-quarters and loins weights and forequarters percentage regarding carcass weight were higher (p < 0.05) in males than in females. The gender had not significant influence on CIE a*, b*, chroma and hue variables but CIE L* value was significantly (p < 0.05) lower in males than in females. The a* value decreased and b* and hue values increased with ageing time. The subcutaneous backfat from the females had significantly (p < 0.05) higher C14:0, C16:0, C16:1, C18:1 n-9, Σ MUFA and lower C10:0, C18:0, C18:2 n-6, C18:3 n-3, C20:0, C20:3 n-9, C20:4 n-6, C22:5 n-3, Σ n-6, Σ n-3 and Σ PUFA proportions than that from males. It is concluded that the gender has influence on growth performance, carcass traits and fatty acid composition of subcutaneous backfat; gender does not have effect on instrumental colour variables; and meat colour can reach acceptable values for consumers until four days after slaughter., El objetivo fue estudiar la influencia del sexo sobre los resultados productivos y calidad de la canal y de la carne de terneros de raza Avileña-Negra Ibérica. Dieciséis terneros, 8 machos y 8 hembras, fueron cebados en estabulación alimentados con el mismo pienso y paja de cereales suministrados desde los 230,7 hasta los 478,3 kg. Los machos crecieron más que las hembras (1,390 vs 0,932 kg día–1 respectivamente). El peso y longitud de la canal, la longitud y perímetro de la pierna, la compacidad de la canal y de la pierna y los pesos de la pierna, cuarto delantero y lomo y el porcentaje de cuarto delantero respecto al peso canal fueron más elevados en los machos. El sexo no tuvo influencia sobre las variables del color del músculo a*, b*, chroma y hue pero el valor de L* fue más bajo (p < 0,05) en los machos. El valor de a* decreció y los de b* y hue crecieron con el tiempo de maduración de la carne. La grasa dorsal subcutánea de las hembras tuvo proporciones más altas (p < 0.05) de C14:0, C16:0, C16:1, C18:1 n-9 y total de monoinsaturados y más bajas de C10:0, C18:0, C18:2 n-6, C18:3 n-3, C20:0, C20:3 n-9, C20:4 n-6, C22:5 n-3, total de n-6, n-3 y poliinsaturados que la de las hembras. Se concluye que el sexo tiene influencia sobre los resultados productivos, características de la canal y composición de ácidos grasos de la grasa dorsal subcutánea; el sexo no tiene efecto sobre las variables del color; y el color de la carne puede tener valores aceptables para los consumidores hasta cuatro días después del sacrificio.

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 objective of this experiment was to study the effect of housing system during the finishing period on growth performance and fat quality of Iberian pigs. Thirty barrows were used. During the finishing period, sixteen pigs were reared indoor and fourten pigs were reared outdoor in paddocks. The pigs housed in outdoor paddocks had higher (p = 0.0001) feed average daily intake than those housed reared indoor and tended (p = 0.087) to show a worse feed efficiency. The C12:0 and C20:0 proportions in subcutaneous backfat from the pigs housed in outdoor paddocks were lower than those from the pigs housed reared indoor, whereas C17:0, C17:1 and C20:1 proportions tended (p = 0.09) to be lower. However, C18:1 n-9 and C18:3 n-3 proportions and C18:1 n-9/C18:0 ratio tended (p = 0.10) to be higher in the outdoor pigs than in the indoor pigs. In intramuscular fat from Longissimus dorsi muscle the C18:3 n-3 proportion tended (p = 0.07) to be higher in outdoor pigs than in indoor pigs. It is concluded that the finishing period of Iberian pigs in outdoor paddocks has a negative effect on feed conversion ratio but may improve the fat quality. El objetivo de este experimento fue estudiar el efecto del tipo de alojamiento durante el periodo de acabado sobre los resultados productivos y calidad de la grasa de cerdos Ibéricos. Se utilizaron 30 machos castrados, 16 de los cuales permanecieron durante la fase de acabado en nave cerrada y 14 en parques al aire libre con refugios protectores. Los cerdos alojados en parque tuvieron un consumo medio diario de pienso (p = 0,0001) superior que los alojados en nave y tendieron (p = 0,087) a presentar un índice de transformación del pienso peor. En los cerdos que permanecieron durante la fase de acabado en parques, las proporciones de C12:0 y C20:0, observadas en la grasa dorsal subcutánea, fueron significativamente más bajas que en los cerdos acabados en nave cerrada y las proporciones de C17:0, C17:1 y C 20:1 tendieron (p = 0,09) a ser menores. Sin embargo, la proporción de C18:1 n-9 y la relación C18:1 n-9/C18:0 tendieron (p = 0,10) a ser mayores en los cerdos acabados en parques que los acabados en nave. En la grasa intramuscular del músculo Longissimus dorsi la proporción de C18:3 n-3 tendió (p = 0.07) a ser mayor en los cerdos acabados en parques que en los acabados en nave. Se concluye que el acabado de cerdos Ibéricos en parques al aire libre empeora el índice de transformación del pienso, pero puede mejorar la calidad de la grasa.