Pork belly quality variation and its association with fatness level.

Belly is a very popular pork cut composed of different layers of fat and muscle tissue. This work aims to investigate the effect of belly fatness on the morphological, mechanical (firmness) and compositional characteristics of fresh pork bellies and the distribution of the fat within the belly slice. A total of 182 bellies, selected to ensure variability of fatness, sexes and genotypes, were scanned by computed tomography (CT) to determine the fat content which, together with the genotype, led to the formation of 5 classes: F1 class below 26%, F2 class from 26% to 33.9%, and F3 class above 33.9% of fat content from common commercial crossbred pigs; F4 class with an average fatness of 47.3% from pure Duroc pigs; and last, F5 class with 62.6% average fat content from Iberian×Duroc pigs. The distribution of the fat in the central belly slice obtained by CT revealed important differences by region although the fat content was proportional to the overall fatness of the belly. Both belly weight and belly firmness increased with higher fatness. In bellies from common commercial pigs, an increase of SFA and MUFA and a decrease of PUFA as fatness increased was observed. This study highlights variations in belly characteristics among different fat classes, indicating considerable differences in the quality of bellies currently available in the market. This may influence producers and consumers acceptability such that fat content could be considered as a quality criterion to pre-classify bellies and better match the raw product with its final destination.

Non-destructive evaluation of carcass and ham traits and meat quality assessment applied to early and late immunocastrated Iberian pigs.

Castration is a common practice in Iberian pigs due to their advanced age and high weight at slaughter. Immunocastration (IC) is an alternative to surgical castration that influences carcass and cut fatness. These traits need to be evaluated in vivo and postmortem. The aims of the present work were (a) to determine the relationship between ham composition measured with computed tomography (CT) and in vivo ultrasound (US) and carcass fat thickness measurements, (b) to apply these technologies to early (EIP) and late (LIP) immunocastrated Iberian pigs in order to evaluate carcass fatness and ham tissue composition and (c) to assess meat quality on these animals and to find the relationships between meat quality traits (namely, intramuscular fat (IMF)) and fat depot thicknesses. For this purpose, 20 purebred Iberian pigs were immunocastrated with three doses of Improvac ®, at either 4.5, 5.5 and 9 or 11, 12 and 14 months of age (EIP or LIP; respectively; n = 10 each) and slaughtered at 17 months of age. Fat depots were evaluated in vivo by US, in carcass with a ruler and in hams by CT. Carcass and cut yields, loin meat quality and loin acceptability by consumers were determined. Also, IMF was determined in the loin and three muscles of the ham. Carcass weight was 14.9 kg heavier in EIP vs LIP, and loin backfat thickness (US- and ruler-measured) was also greater in EIP. Similarly, CT-evaluated ham bone and fat contents were greater and smaller for EIP vs LIP, respectively. Loin and ham IMF were also greater in EIP, but the other meat quality parameters were similar. The acceptability of meat by consumers was high and it did not differ between IC protocols. Correlations between several fat depots measured with the different technologies were high. In conclusion, all these technologies allowed fat depot measurements, which were highly correlated despite being obtained at different anatomical locations.

Intramuscular fat content in different muscles, locations, weights and genotype-sexes and its prediction in live pigs with computed tomography.

Intramuscular fat (IMF) content depends on sex, genotype and diet and varies with pig growth. The aim of the present work was to determine the evolution of IMF by genotype-sex, muscle and muscle location, to determine relationships between IMF content of different muscles and to predict IMF in live pigs with computed tomography (CT). For this purpose, 155 pigs of seven combinations of genotype-sex were CT scanned and slaughtered at 70, 100 and 120 kg. From the carcasses, fat thickness was measured at several locations along the midline. Loin samples from three anatomical positions (between the eighth and ninth last ribs, between the third and fourth last ribs and between the third and fourth lumbar vertebrae) and three ham muscles (biceps femoris, semimembranosus and gluteus medius) were extracted, weighed and IMF was determined with near-IR equipment. From CT images, the distribution of volume by Hounsfield value (unit related with the density) was obtained for each muscle and anatomical location. Marbling was evaluated in the three loin locations. The effects of genotype-sex and live weight and their interaction were included in the statistical model. For prediction of IMF with CT images, partial least square regression was used. The results show differences in IMF content by genotype-sex and muscle. In general, the most cranial part of the loin presented higher IMF content, as well as the biceps femoris muscle of the ham. Depending on the genotype-sex, IMF content increased during all growth or increased until 100 kg and then became constant. Correlation coefficients between IMF content by muscle/location were between 0.74 and 0.83 within loin locations and between 0.53 and 0.70 for ham muscles. Correlation coefficients between marbling and IMF content evaluated at the same location varied between 0.51 and 0.66. Prediction of IMF content from CT images is not accurate enough (residual predictive deviation statistical values lower than 1.3). Muscle weight increase with animal growth and allometric coefficients varied between 0.89 and 0.97 for the muscles evaluated. The conclusions of the present work are that IMF content differs between and within muscle, during growth and by genotype-sex and that prediction of IMF in CT images of live pigs is not accurate.

Presence, mobility and bioavailability of toxic metal(oids) in soil, vegetation and water around a Pb-Sb recycling factory (Barcelona, Spain).

The work was conducted to establish contamination from improper disposal of hazardous wastes containing lead (Pb) and antimony (Sb) into nearby soils. Besides other elements in the affected area, the biological role of Sb, its behaviour in the pedosphere and uptake by plants and the food chain was considered. Wastes contained 139532 ±â€¯9601 mg kg-1 (≈14%) Pb and 3645 ±â€¯194 mg kg-1 (≈0.4%) Sb respectively and variability was extremely high at a decimetre scale. Dramatically high concentrations were also found for As, Cd, Cu, Mn, Ni, Sn and Zn. In adjacent natural soils metal(oid)s amounts decreased considerably (Pb 5034 ±â€¯678 mg kg-1, Sb 112 mg kg-1) though largely exceeded the directives for a given soil use. Metal(oid)s potential mobility was assessed by using H2O→KNO3→EDTA sequential extractions, and EDTA extracts showed the highest concentration suggesting stable humus-metal complexes formation. Nevertheless, selected plants showed high absorption potential of the investigated elements. Pb and Sb values for Dittrichia viscosa grown in wastes was 899 ±â€¯627 mg kg-1 and 37 ±â€¯33 mg kg-1 respectively. The same plant showed 154 ±â€¯99 mg kg-1 Pb and 8 ±â€¯4 mg kg-1 Sb in natural soils. Helichrysum stoechas had 323 ±â€¯305 mg kg-1 Pb, and 8 ±â€¯3 mg kg-1 Sb. Vitis vinifera from alongside vineyards contained 129 ±â€¯88 mg kg-1 Pb and 18 ±â€¯9 mg kg-1 Sb, indicating ability for metal uptake and warning on metal diffusion through the food chain. The biological absorption coefficient (BAC) and the translocation factor (TF) assigned phytoextraction potential to Dittrichia viscosa and Foeniculum vulgare and phytostabilization potential to Helichrysum stoechas. Dissolved metal (oid)s in the analysed water strongly exceeded the current directive being a direct threat for livings. Data warned against the high contamination of the affected area in all its compartments. Even though native plants growing in metal-contaminated sites may have phytoremediation potential, high risk of metal diffusion may threat the whole ecosystem.

Growth of total fat and lean and of primal cuts is affected by the sex type.

Knowledge of tissue and cuts growth depending on the sex could be used to improve performance and efficiency. Computed tomography (CT) is a non-invasive technology that enables the study of the body composition of live animals during growth. The aims of the present study were (1) to evaluate variation in the body composition of four sex types (SEX) of pigs (castrated males (CM), immunocastrated males (IM), entire males (EM) and females (FE)) at the live weight of 30, 70, 100 and 120 kg, assessed using CT; (2) to model the growth of the main tissues and cuts; and (3) to predict the mature BW (MBW) of the four SEX and establish the relationships between the growth models and the MBW. There were significant phenotypic differences in the allometric growth of fat and lean among SEX. For the lean tissue, FE and EM showed higher values of the b coefficient than CM and IM (1.07 and 1.07 v. 1.00 and 1.02, respectively) all of them close to unity, indicating a proportional growth rate similar to live weight and that this tissue developed faster in FE and EM than in CM and IM. However, these differences were not related to differences in estimated MBW. There were significant differences in estimated MBW among SEX, being higher in IM and EM than in CM and FE (303 and 247 v. 219 and 216 kg), however, the MBW may have been overestimated, especially for the IM. The poorer accuracy of the MBW estimate for the IM could be due to a maximum live weight of 120 kg in the experiment, or to the fact that this particular SEX presented two clear behaviours, being more similar to EM from birth to the second injection of the vaccine (130 days) and comparable with CM from that point to the final BW.

Comparison of meat quality parameters in surgical castrated versus vaccinated against gonadotrophin-releasing factor male and female Iberian pigs reared in free-ranging conditions.

This study compared carcass and meat quality traits between 16 vaccinated (VF), 19 castrated (CF) and 8 entire (EF) female Iberian pigs, and between 21 vaccinated (VM) and 19 castrated (CM) male Iberian pigs reared in free ranging conditions. Vaccination consisted in the application of Improvac® at the age of 11, 12 and 14 months in VF and VM. Pigs were slaughtered at 16 months. In females, carcass and meat quality were found to be very similar regardless of the treatment. In males, VM had a leaner carcass, lower (P < 0.05) percentage of intramuscular fat, higher shear force and more rancidity than CM(P < 0.05 in all cases). It could be concluded that vaccination or suitable for free-range conditions in terms of product qualities. Vaccination in females did not alter carcass and meat quality, and specific interests should consider reproductive behavior in free-range conditions.

Predicting the carcass chemical composition and describing its growth in live pigs of different sexes using computed tomographys.

The aims of this study were (1) to evaluate the ability of computed tomography (CT) to predict the chemical composition of live pigs and carcasses, (2) to compare the chemical composition of four different sex types at a commercial slaughter weight and (3) to model and evaluate the chemical component growth of these sex types. A total of 92 pigs (24 entire males (EM), 24 surgically castrated males (CM), 20 immunocastrated males (IM) and 24 females (FE)) was used. A total of 48 pigs (12 per sex type) were scanned repeatedly in vivo using CT at 30, 70, 100 and 120 kg and slaughtered at the end of the experiment. The remaining 44 were CT scanned in vivo and slaughtered immediately: 12 pigs (4 EM, 4 CM and 4 FE) at 30 kg and 16 pigs each at 70 kg and 100 kg (4 per sex type). The left carcasses were CT scanned, and the right carcasses were minced and analysed for protein, fat, moisture, ash, Ca and P content. Prediction equations for the chemical composition were developed using Partial Least Square regression. Allometric growth equations for the chemical components were modelled. By using live animal and carcass CT images, accurate prediction equations were obtained for the fat (with a root mean square error of prediction (RMSEPCV) of 1.31 and 1.34, respectively, and R 2=0.91 for both cases) and moisture relative content (g/100 g) (RMSEPCV=1.19 and 1.38 and R 2=0.94 and 0.93, respectively) and were less accurate for the protein (RMSEPCV=0.65 and 0.67 and R 2=0.54 and 0.63, respectively) and mineral content (RMSEPCV from 0.28 to 1.83 and R 2 from 0.09 to 0.62). Better equations were developed for the absolute amounts of protein, fat, moisture and ash (kg) (RMSEPCV from 0.26 to 1.14 and R 2 from 0.91 to 0.99) as well as Ca and P (g) (RMSEPCV=144 and 71, and R 2=0.76 to 0.66, respectively). At 120 kg, CM had a higher fat and lower moisture content than EM. For protein, CM and IM had lower values than FE and EM. The ash content was higher in EM and IM than in FE and CM, while IM had a higher Ca and P content than the others. The castrated animals showed a higher allometric coefficient for fat and a lower one for moisture, with IM having intermediate values. However, for the Ca and P models, IM presented higher coefficients than EM and FE, and CM were intermediate.

Predicting fat, lean and the weights of primal cuts for growing pigs of different genotypes and sexes using computed tomography.

The aim of the present study was to find single equations to predict the amounts of fat, lean, and the weights of the primal cuts (ham, loin, belly, and shoulder) as well as ham composition of pigs from 30 to 120 kg BW of different genotypes (GEN; Exp. 1) and sexual conditions (SEX; Exp. 2). Two types of regression equations, taking into account different work situations, were developed: 1) research applications, using computed tomography (CT) parameters, and 2) potential on-farm applications, which could be obtained using easily accessible equipment. Two data sets were used: Exp. 1 included 90 gilts from 3 different GEN: 30 Duroc × (Landrace × Large White), 30 Pietrain × (Landrace × Large White), and 30 Landrace × Large White, and Exp. 2 included 92 Pietrain × (Landrace × Duroc) pigs of different SEX: 24 each of females, entire males, castrated males, and 20 immunocastrated males. Pigs were fully CT scanned in vivo at 30, 70, 100, and 120 kg BW. A subsample of pigs of each GEN ( = 5) or SEX ( = 4) were slaughtered at 30, 70, and 100 kg BW, and all remaining pigs were slaughtered after weighing and scanning at 120 kg BW. For all the slaughtered pigs, the 4 main cuts were fully (GEN) or partially dissected (SEX). CT images were analyzed and used to predict the lean and fat contents as well as the weights of the primal cuts and the composition of the ham. Total amounts of fat and lean for both populations were predicted with high levels of accuracy ( = 0.994 and 0.993, respectively) and proportions of random error for GEN and SEX effects (0.998 and 0.946 for the fat and 0.997 and 0.836 for the lean predictions, respectively). Moreover, the composition of ham (fat, lean, and bone) was very well predicted with high proportions (> 80%) of random error for GEN and SEX effect using CT and potential on-farm predictors.

Use of an anti-GnRF vaccine to suppress estrus in crossbred Iberian female pigs.

Antibodies against GnRF elicited by vaccination with Improvac are expected to have the same effects on the gonads of female pigs as those observed in males and thus suppress estrus. The objective of this study was to evaluate whether a 3- or a 4-dose regimen of Improvac was effective in inducing and maintaining suppression of estrus in intact Iberian female pigs through 14 months of age. Sixty 18-week-old gilts were randomly assigned to one of the following three treatment groups: control (PBS injected), V3 (3-dose Improvac regimen), and V4 (4-dose Improvac regimen). Animals were tested for the presence of standing estrus in the presence of a boar three times per week until study completion at 60 weeks of age. Blood samples were regularly collected to determine the serum levels of anti-GnRF antibodies and progesterone. The weight and size of the uterus and the weight and activity of the ovaries were assessed at the time of euthanasia. For both treatment groups V3 and V4, a large reduction in the incidence of standing estrus was observed when compared to the control group (P < 0.0001). No significant differences between the V3 and V4 groups were observed. Both V3 and V4 groups had higher serum anti-GnRF antibody levels than the control group from 28 days after the first vaccination until the end of the study. In addition, both V3 and V4 groups had lower levels of progesterone than the control group from Day 112 until the end of the study (P < 0.0001 in all cases). Mean ovary weights at study end in treatment groups V3 and V4 were significantly lower (P < 0.0001) than those for the control group and not significantly different between the V3 and V4 groups. An onset of immunity of 2 weeks after the second vaccination and a long-lasting immunity of at least 20 weeks after the third vaccination were observed. In summary, both the 3-and 4-dose Improvac regimens were efficacious in reducing the incidence of standing estrus, serum progesterone levels, and the development of the uterus and ovaries.

Evaluation of the sustainability of contrasted pig farming systems: development of a market conformity tool for pork products based on technological quality traits.

A market conformity tool, based on technological meat quality parameters, was developed within the Q-PorkChains project, to be included in a global sustainability evaluation of pig farming systems. The specific objective of the market conformity tool was to define a scoring system based on the suitability of meat to elaborate the main pork products, according to their market shares based on industry requirements, in different pig farming systems. The tool was based on carcass and meat quality parameters that are commonly used for the assessment of technological quality, which provide representative and repeatable data and are easily measurable. They were the following: cold carcass weight; lean meat percentage; minimum subcutaneous back fat depth at m. gluteus medius level, 45 postmortem and ultimate pH (measured at 24-h postmortem) in m. longissimus lumborum and semimembranosus; meat colour; drip losses and intramuscular fat content in a m. longissimus sample. Five categories of pork products produced at large scale in Europe were considered in the study: fresh meat, cooked products, dry products, specialties and other meat products. For each of the studied farming systems, the technological meat quality requirements, as well as the market shares for each product category within farming system, were obtained from the literature and personal communications from experts. The tool resulted in an overall conformity score that enabled to discriminate among systems according to the degree of matching of the achieved carcass and meat quality with the requirements of the targeted market. In order to improve feasibility, the tool was simplified by selecting ultimate pH at m. longissimus or semimembranosus, minimum fat thickness measured at the left half carcass over m. gluteus medius and intramuscular fat content in a m. longissimus sample as iceberg indicators. The overall suitability scores calculated by using both the complete and the reduced tools presented good correlation and the results obtained were similar. The tool could be considered as robust enough to discriminate among different systems, since it was tested in a wide range of them. It also can be used to detect improvement opportunities to enhance sustainability of pig farming systems. The final objective of the study was achieved, since the market suitability tool could be used in an integrated sustainability analysis of pig farming systems.

Effect of reducing dietary protein and lysine on growth performance, carcass characteristics, intramuscular fat, and fatty acid profile of finishing barrows.

Intramuscular fat is an important quality trait in pork. Lysine and protein have been reported to influence this trait, but most studies have modified both factors simultaneously. In this study, the effects of dietary Lys and protein were investigated in finishing pigs to determine if either of the 2 factors alone or in combination influence the deposition of intramuscular fat. One hundred and four barrows (Landrace × Duroc) were fed 1 of 4 experimental diets, including control protein-control Lys (CPCL), control protein-low Lys (CPLL), low protein-control Lys (LPCL), and low protein-low Lys diets (LPLL) with 10 pens per treatment and 2 or 3 pigs per pen. Pigs fed CPLL showed a trend to decrease feed efficiency (P < 0.10) compared with those fed CPCL, but pigs fed LPLL performed similarly to the CPCL pigs, indicating that CP levels can be reduced to 12% for pigs between 62 and 97 kg and to 9.8% afterward without negative effects on performance. In the longissimus thoracis, intramuscular fat increased in pigs fed LPCL or CPLL (P < 0.05) compared with CPCL. In the semimembranosus muscle, intramuscular fat was reduced in pigs fed LPLL compared with those fed CPLL (P < 0.05), and the same trend was observed in the longissimus thoracis (P < 0.10). Dietary protein reduction tended to increase back fat thickness (P < 0.10) and reduced SFA and MUFA (P < 0.05) and PUFA, particularly in subcutaneous fat (P < 0.05), whereas the effect on MUFA in the longissimus thoracis was less pronounced. A reduction of n-3 FA (P < 0.05) and PUFA (P < 0.01) in the semimembranosus muscle and in the liver, respectively, was observed when the level of dietary protein was reduced. These results indicate that the effect of a reduction of dietary protein and Lys on growth and intramuscular fat is not independent, and reduction of protein, while maintaining Lys, may improve meat quality without impairing performance.

Majorcan Black Pig as a traditional pork production system: improvements in slaughterhouse procedures and elaboration of pork carpaccio as an alternative product.

The Majorcan Black Pig (MBP) was used as a model of differentiated traditional system within the Q-PorkChains project. The MBP farms were taken as an example of traditional system using a local breed which claims for high meat quality products. Welfare Quality® protocol was applied at the slaughterhouse and improvement strategies related to ante-mortem conditions and technological meat quality were defined. Pork carpaccio from MBP was elaborated to evaluate its sensory properties as an alternative to the existing MBP products. MBP tenderloins were better suited than those from pigs from a commercial breed to elaborate this product.

Surface-enhanced laser desorption/ionisation time-of-flight mass spectrometry: a tool to predict pork quality.

Expression of water soluble proteins of fresh pork Longissimus thoracis from 4 pure breed pigs (Duroc, Large White, Landrace, and Piétrain) was studied to identify candidate protein markers for meat quality. Surface-enhanced laser desorption/ionisation time-of-flight mass spectrometry (SELDI-TOF-MS) was used to obtain the soluble protein profiles of Longissimus thoracis muscles. The pure breeds showed differences among the studied meat quality traits (pHu, drip loss, androstenone, marbling, intramuscular fat, texture, and moisture), but no significant differences were detected in sensory analysis. Associations between protein peaks obtained with SELDI-TOF-MS and meat quality traits, mainly water holding capacity, texture and skatole were observed. Of these peaks, a total of 10 peaks from CM10 array and 6 peaks from Q10 array were candidate soluble protein markers for pork loin quality. The developed models explained a limited proportion of the variability, however they point out interesting relationships between protein expression and meat quality.

Stunning pigs with nitrogen and carbon dioxide mixtures: effects on animal welfare and meat quality.

The aim of this study was to assess the effect of exposure to the gas mixtures of 70% nitrogen (N2) and 30% carbon dioxide (CO2; 70N30C), 80% N2 and 20% CO2 (80N20C) and 85% N2 and 15% CO2 (85N15C) on aversion, stunning effectiveness and carcass, as well as meat quality in pigs, and to compare them with the commercial stunning of 90% CO2 (90C). A total of 68 female pigs were divided into four groups and stunned with one of the gas mixtures. During the exposure to the gas, behavioural variables (retreat attempts, escape attempts, gasping, loss of balance, muscular excitation and vocalizations) were recorded, and at the end of the stunning, corneal reflex and rhythmic breathing were assessed. After slaughter, meat quality parameters such as pH at 45 min post mortem (pH45) and at 24 h post mortem (pHu), electrical conductivity, drip loss and colour, in the Longissimus thoracis (LT) and Semimembranosus (SM) muscles were measured, and the presence of ecchymosis on the hams was noted. The PROC MIXED and the PROC GENMOD of SAS® were used to analyse the parametric and binomial variables, respectively. The 'gas mixture' was always considered a fixed effect and the 'live weight' as a covariate. To assess the correlation between meat quality and behaviour measures, PROC CORR was used. Pigs exposed to 90C showed a higher percentage of escape attempts and gasping, a lower percentage of vocalization and shorter muscular excitation phase than pigs exposed to the other N2 and CO2 mixtures (P < 0.05). After stunning, no pig exposed to 90C showed corneal reflex or rhythmic breathing, whereas 85% and 92% of the animals exposed to N2 and CO2 mixtures showed corneal reflex and rhythmic breathing, respectively. Animals stunned with 80N20C and 85N15C had a lower pH45 (P < 0.01) than animals exposed to 90C. Electrical conductivity in the SM muscle was lower (P < 0.001) in 90C and 70N30C pigs than in 80N20C and 85N15C pigs, whereas in LT, it was lower (P < 0.05) in 90C pigs than in 85N15C. As the CO2 concentration of the gas mixture was decreased, the prevalence of exudative pork increased. Twenty-five percent of animals exposed to N2 and CO2 mixtures (n = 68) had ecchymosis in their carcasses, whereas no animal stunned with 90C had ecchymosis. In conclusion, although N2 and CO2 stunning exhibit fewer signs of aversion than 90C, their induction time to unconsciousness is longer, and this may negatively affect meat and carcass quality.

Effect of vaccination against gonadotrophin-releasing factor on growth performance, carcass, meat and fat quality of male Duroc pigs for dry-cured ham production.

The aim of this study was to compare production, carcass and meat quality parameters, boar taint compounds and fat composition of green and dry-cured hams, between immunocastrated (IM), surgically castrated (CM) and female (FE) Duroc purebred pigs (n=75, 138.7±8.27kg). Liveweight and fat and muscle thicknesses were measured and average daily gain was calculated during growth. Carcass, meat and fat quality parameters were measured. Immunocastrated grew faster than CM or FE after the second dose of vaccine. IM had the lowest dressing percentage but similar % of ham and carcass lean to FE and CM. The effect of the immunocastration on carcass fatness depended on the location, did not affect fat and meat quality and reduced skatole and androstenone levels. Both in green and dry-cured ham, immunocastration slightly altered FA composition. Thus, Duroc pigs vaccinated with Improvac are suitable for the production of high quality dry-cured ham.

Effect of an elevated monounsaturated fat diet on pork carcass and meat quality traits and tissue fatty acid composition from York-crossed barrows and gilts.

Fifty-seven York-crossed barrows and gilts were fed either a grain and soy diet (CONTROL with 28% C18:1) or a similar diet enriched with oleic acid (HO with 43% C18:1, Greedy-Grass OLIVA®). There were no interactions between dietary treatment and gender and there were no differences in intramuscular and subcutaneous fatty acid composition between sexes (P>0.05). Similar primal cut yields, composition of major primal cuts, and carcass and meat quality characteristics were found for HO and CONTROL fed pigs. Apart from a few significant but small differences for some fatty acids, intramuscular fatty acid composition was similar for both dietary treatments. Subcutaneous fat from HO fed pigs had a 6.9% increase in total monounsaturated fatty acids and a 9.3% reduction in total polyunsaturated fatty acids (P<0.05) compared with CONTROL fed animals, without adversely affecting carcass quality and producing suitable hams for processing by the meat industry.

Effect of housing system, slaughter weight and slaughter strategy on carcass and meat quality, sex organ development and androstenone and skatole levels in Duroc finished entire male pigs.

This study aimed at evaluating the effect of housing system (HS), slaughter weight (SW) and strategy (SS) on carcass a nd meat quality, sexual organ development and boar taint in entire males. Twelve pens of 10 pigs were used (two trials). Half of male pens were allowed visual contact with females (MF) and half with males (MM). Half MM or MF were slaughtered at 105 or 130 kg in trial 1, or penwise or by split marketing in trial 2 at 120 kg. Housing system showed no significant effect on carcass or meat quality. MF presented significantly longer testicles and heavier bulbourethral glands compared to MM. The distribution of androstenone and skatole levels was affected by SW but not by HS or SS, samples with androstenone >1 µg/g of the different groups falling within the range of 16 to 22%. All correlations between androstenone and sex organs were significant. Housing system and slaughter strategy did not reduce the risk of boar tainted carcasses.

Carcass and meat quality characteristics and fatty acid composition of tissues from Pietrain-crossed barrows and gilts fed an elevated monounsaturated fat diet.

Fifty-one (Landrace *Large White) *Pietrain barrows and gilts were used to compare the effect of a diet rich in oleic acid (HO) by feeding a by-product of the olive industry (Greedy-Grass OLIVA(R): 1.4% growing, 3.8% finishing) or a grain and soy diet (CONTROL) on carcass characteristics, meat quality and fatty acid profile of intramuscular and subcutaneous fat. Gilts had leaner (P<0.05) carcasses with lower fat percentage in major primal cuts, and less (P<0.05) saturated fat compared with barrows with no interaction (P>0.05) between dietary treatment and gender. Source of dietary fat had no effect (P>0.05) on primal cut yields, composition of major primal cuts, or carcass and meat quality characteristics. Intramuscular fat from HO fed pigs had higher (P<0.05) percentage of saturated (SFA) and monounsaturated (MUFA) fatty acids, and lower (P<0.05) polyunsaturated fatty acids (PUFA) and n-6:n-3 ratio compared with CONTROL animals (37.4% vs. 36.8%, 44.7% vs. 40.1%, 17.9% vs. 23.2%, and 18.9 vs. 21.8 ratio, respectively). Subcutaneous fat from pigs fed HO had greater (P<0.05) MUFA percentage, lower (P<0.05) SFA and PUFA percentage, and lower (P<0.05) n-6:n-3 ratio than pigs fed CONTROL diet (51.4% vs. 48.0%, 30.5% vs. 32.9%, 18.1% vs. 20.1%, and 9.83 vs. 11.3 ratio, respectively). Intramuscular fat had higher proportion of SFA and lower of MUFA showing a higher degree of tissue saturation compared with subcutaneous fat. Feeding Greedy-Grass increased MUFA and decreased PUFA proportions in fat depots reducing the risk of production of carcasses that are soft and oily which result in lower technological and processing quality.

Effect of source of dietary fat on pig performance, carcass characteristics and carcass fat content, distribution and fatty acid composition.

Seventy gilts were used to compare the effect of including 10% tallow (T), high-oleic sunflower oil (HOSF), sunflower oil (SFO), linseed oil (LO), a fat blend (FB), or an oil blend (OB) in finishing diets vs. feeding a semi-synthetic diet with no added fat (NF) on pig performance, carcass traits and carcass fatty acid (FA) composition. Carcasses from SFO-fed gilts had greater fat and lower lean compositions than carcasses from T-fed gilts. Gilts fed NF had greater loin fat than FB-fed gilts, and greater flare fat, loin intermuscular fat and fat:lean than T-fed gilts. Bellies from NF-fed gilts had lower lean and higher intermuscular fat and fat:lean than other diets except HOSF. Fat source had minor effects on animal performance, carcass characteristics and carcass fat content and distribution, whereas feeding NF resulted in carcasses and major cuts with higher fat content. Diets rich in polyunsaturated FA (PUFA) did not reduce fat deposition in separable fat depots with respect to monounsaturated FA (MUFA) and saturated FA (SFA). Carcasses from gilts fed NF had a high degree of saturation (40.6% SFA) followed by carcasses of T- and FB-fed gilts. Feeding HOSF, SFO and LO enriched diets elevated the percentages of MUFA (56.7%), n-6 (30.0%) and n-3 (16.6%) PUFA, respectively, whereas carcasses from gilts fed OB had greater percentages of n-3 FA (14.8% n-3, 0.9% EPA, 1.0% DPA, 3.1% DHA) than gilts fed FB (6.72% n-3, 0.1% EPA, 0.4% DPA, 0.1% DHA).

Risk assessment of DFD meat due to pre-slaughter conditions in pigs.

A polychotomous logistic regression model was used to identify and assess the risk factors for pork becoming dark, firm and dry meat (DFD). A total of 116 deliveries, comprising 3075 commercial pigs delivered from different farms to five commercial Spanish pig abattoirs were surveyed. The DFD condition was described as an ordinal response variable (normal, moderate and serious) based on measurements of pH(24) in the Semimembranosus muscle. The abattoir, the floor of the lorry, the season, the gender, and the stocking density during transportation influenced the risk of DFD, as well as on-farm fasting time, lairage time and estimated carcass lean content. No effect of the RYR1 gene in the risk of DFD was found. Abattoirs should be especially careful with females slaughtered in winter, where the risk of serious DFD is 4.6% higher than with males slaughtered in summer. The risk of DFD increased with high stocking density and lairage time, and with on-farm fasting times longer than 22h. Our results revealed that lowering the stocking density from 0.37 to 0.50m(2) per 100kg pig during transport would increase the risk of DFD pork by 11%.