Carcass and meat quality traits of the Chato Murciano pig slaughtered at different weights

In order to evaluate the effect of slaughter weight and rearing system on the Chato Murciano pig carcass and meat quality traits, a total of 71 castrated male pigs were used. Forty-one pigs were reared in an outdoor system, divided in one heavy group (CHOHW) with an average live weight of 132.05 kg, and a second group with lower weights (CHOLW, 115.7 kg average). Simultaneously, 30 pigs were reared indoors and divided into one heavy group (CHIHW) with an average live weight of 144.3 kg, and a second group with lower weights (CHILW, 117.6 kg average).Heavier pigs showed higher values for several carcass parameters (hot carcass weight, carcass length, maximum perimeter of the ham, hand length, leg length, ham length, wrist perimeter) and meat cuts, higher Dorsal Fat Thickness (DFT) and Intramuscular Fat (IMF) levels, but no difference was found in the hot carcass yields (HCY). Differences in the colour parameters and several minerals (Ca, Mg, K and Na) were also due to the different slaughter weights. The rearing system had an influence on the HCY (it is higher in the outdoor system), on many carcass parameters, on meat the ultimate pH (it is higher for animals reared indoors) and on colour (this is variable). It also affected the levels of many minerals with the levels of Mg, P and K being higher for animals reared outdoors, whereas the Fe, Cu and Zn content were higher in the animals reared indoors. DFT and IMF levels were not influenced by the rearing system.     

Performance,carcass and technological meat quality of pigs in indoor and outdoor production systems

Abstract

This study aimed to compare different production systems, i.e., the combined effect of outdoor and indoor rearing of pigs and organic diets fed ad libitum or restrictively. Furthermore, the suitability of two breed crosses for outdoor rearing was studied. The effects on performance, carcass and technological quality traits were investigated. During two years, 240 pigs of Duroc x Large White (D*LW) and Swedish Landrace x Large White (L*LW) were allocated to three production systems: 1) Pigs kept outdoors, fed an organic diluted diet (20% alfalfa roughage) ad libitum; 2) Pigs kept outdoors, strategically fed a diluted organic diet up to a live weight of approximately 80 kg and thereafter an undiluted organic diet ad libitum; 3) Pigs kept indoors, fed an undiluted organic diet restrictively. For outdoor pigs, strategic feeding increased daily weight gain and backfat thickness, compared with feeding a diluted diet throughout (p≤0.01). L*LW pigs in both outdoor systems grew slower than in the indoor system (p≤0.001), whereas for D*LW pigs only outdoor pigs fed the diluted diet had a slower growth rate. Outdoor pigs had lower dressing percentage than indoor pigs. Glycogen content and L* values in M. longissimus dorsi were higher, whereas b* values were lower in meat from pigs in the indoor system. D*LW pigs had higher water-holding capacity (lower drip, thawing and cooking losses), lower shear force and higher intramuscular fat content compared with L*LW pigs.     

Carcass quality and technological and sensory meat quality of once-bred gilts in a seasonal outdoor rearing system

Seasonal application of once-bred gilts for piglet and meat production outdoors could be a worthwhile alternative rearing form to normal commercial production. Compared with growing/finishing pigs, payment for sow carcasses is considerably reduced because of an assumed decrease in meat quality and processing properties. The purpose of this study was to compare maiden and once-bred gilts for carcass quality, and technological and sensory meat quality. The control group of 14 gilts (LW*L and LW*D) was reared indoors and slaughtered unmated at an average live weight of 145 kg. In contrast, 38 once-bred gilts of the same breeds were initially reared like the maiden control, inseminated and then housed outdoors from one month before farrowing until slaughter. Carcass traits, technological meat quality (pH, internal and surface reflectance, water holding capacity, commercial processing yield (total yield) and laboratory processing yield (Napole yield), WB shear force and chemical composition of M. longissimus dorsi were measured. Sensory meat quality (taste panel) of oven-baked M. longissimus dorsi and cured and smoked M. semimembranosus et adductor was investigated. Carcass quality traits such as higher lean meat content and lower backfat thickness were preferable with the once-bred gilts. For technological meat quality characteristics, once-bred gilts had lower thawing loss, Napole yield, dry matter and higher total work of WB shear force and intramuscular fat, compared to maiden gilts. In general, sensory meat quality was comparable between the two groups. In processed meat only, once-bred gilts had higher juiciness and salinity and unfavourable increased stringiness, compared to maiden gilts. Thus, once-bred gilts produce valuable carcasses and are suitable for an outdoor seasonal rearing system.     

Dietary integration with oregano (Origanum vulgare L.) essential oil improves growth rate and oxidative status in outdoor‐reared,but not indoor‐reared,pigs

The effects of a diet supplemented with oregano essential oil on performance, oxidative status, pork quality traits and sensorial properties were evaluated. In two studies, 72 pigs in indoor or outdoor conditions were assigned to either a control diet or an identical diet supplemented with 0.2% oregano essential oil. Pigs reared outdoor showed lower live weight, average daily gain and average gain:feed ratio compared to indoor pigs. The oregano supplementation improved the growth performance of the outdoor‐ but not the indoor‐reared animals. The serum oxidative status was influenced by the diet. A higher oxidative stability was observed in the oregano‐supplemented groups. As for the rearing conditions, the data suggest that after an initial adapting period, the free‐range farming systems could be better tolerated by pigs. Meat derived from pigs reared outdoor showed higher pH and a* values. Lightness was influenced by both the diet and the rearing conditions. The control group reared indoor showed shear force values higher than both supplemented groups, while no differences were detected with the control group reared outdoor. In the consumer test performed under blind conditions, the oregano groups achieved higher consistency scores compared with the control. Under informed conditions, the meat derived from the oregano‐supplemented pigs reared outdoor received the highest scores for consistency and overall liking regardless of the rearing system. The same result for the overall liking score was obtained in the expectation test. The data obtained showed that dietary oregano essential oil can be effective in reducing performance losses due to the outdoor‐rearing system, increasing the oxidative status of the animal and oxidative stability of the meat, without modifying the meat quality traits and improving consumer perceptions of the meat quality.     

Meat quality of fully or partly outdoor reared pigs in organic production

Abstract

Outdoor production on pasture is considered an option in organic pig production. The aim of the present trial was to study the influence of feeding strategies combining outdoor and indoor rearing on pig meat quality. The experiment was carried out with 245 pigs in 5 replicates, and commenced following weaning at day 52. Five treatments were compared: 1) pigs fed ad libitum and reared indoors with access to an outdoor concrete area (In-A); 2) pigs fed restrictively on pasture until 40 kg body weight and then kept indoors with access to an outdoor concrete area and fed ad libitum until slaughter (In-40A); 3) pigs fed restrictively on pasture until 80 kg body weight and then kept indoors with access to an outdoor concrete area and fed ad libitum until slaughter (In-80A); 4) pigs reared on pasture and fed restrictively during the whole period of growth (Out-R); and 5) pigs reared on pasture and fed ad libitum during the whole period of growth (Out-A). All pigs had free access to roughage (clover-grass silage/fresh clover grass). Restrictive feeding in the weight range from weaning to 40 kg body weight (In-40A) resulted in a reduced daily gain; however, following transfer to indoor facilities and ad libitum feeding these pigs compensated in growth and the overall daily gain did not differ from the In-A control pigs. Pigs fed restrictively from weaning to 80 kg body weight were unable to compensate completely following transfer to indoor facilities. Out-R pigs had the lowest overall daily gain, while In-A pigs and Out-A pigs had similar daily gain. Meat quality assessments were performed on longissimus dorsi (LD) samples from a subsample of 100 pigs (2 castrates and 2 female pigs from each treatment in each replicate). Compared to meat from either ad libitum treatments (In-A and Out-A), meat from Out-R and In-80A pigs was less red due to a lower pigmentation, and had a higher ratio of polyunsaturated:saturated fatty acids. In addition, Out-R female pigs had numerically (6–10 Newton) higher shear force than In-A and Out-A. Treatments did not affect the concentration of α-tocopherol of meat. Introducing a finishing period with free access to concentrates following 40 kg body weight until slaughter prevented the deterioration in meat quality. However, a finishing period following 80 kg body weight was not sufficient. In conclusion, ad libitum feeding in the organic production system gave superior meat quality compared to a restrictive feeding strategy. However, including a finishing period indoors with ad libitum feeding of concentrates may prevent the detrimental effect of restrictive feeding on meat quality.     

Production Results and Technological Meat Quality for Pigs in Indoor and Outdoor Rearing Systems

The objective of the study was to compare production results and technological meat quality for pigs born outdoors and reared indoors or outdoors during the summer period. A total of 279 pigs was reared in a large pen on deep litter, or outdoors. Daily weight gain and lean meat percentage were higher for pigs outdoors than indoors during year one (864 vs. 841g; 56.9 vs. 55.9%), but were similar for year two (859 vs. 844g; 55.9 vs. 55.6%). Outdoor pigs grew faster when fed ad libitum, but slower during the second phase when restricted, with inferior feed conversion. Most technological meat quality traits (surface and internal reflectance, marbling, pH_BF, filter paper wetness, cooking loss and maximal Warner-Bratzler shear force) were similar between rearing systems, whereas pH_LD was higher indoors. Total work of Warner-Bratzler shear force was lower in outdoor reared pigs. Maternal sire breed (Duroc or Landrace) and sex (castrate or gilt) did not notably affect meat quality traits. RN genotype had a stronger impact on meat quality than rearing system. It can be concluded from the similarities in production results and meat quality in both systems, that both indoor and outdoor rearing are good alternatives for summer rearing of pigs.     

Effect of single-sex or mixed rearing and live weight on performance,technological meat quality and sexual maturity in entire male and female pigs fed raw potato starch

Abstract

The aim of our study was to investigate the effect of rearing system (mixed or single-sex) on performance and carcass quality of entire male and female pigs slaughtered at around 90 or 115 kg live weight. We also studied the combined effect of live weight and dietary supplement of raw potato starch (RPS) on technological meat quality for both sexes, and boar taint compounds in entire male pigs. Furthermore, we investigated pre-slaughter routines (pen-wise or mixing with unfamiliar pigs) and sexual maturity. A total of 408 growing/finishing pigs were included in this two-year study. Performance did not differ significantly between entire male and female pigs irrespective of rearing system, except for daily weight gain in the interval from 90 kg to slaughter. Mixed pigs had significantly higher daily weight gain in this interval than single-sex pigs. Entire male pigs had higher carcass lean meat content than female pigs (1.6 percentage units). Technological meat quality differed only slightly between the sexes. Females reared in mixed pens were sexually more mature than female pigs reared in single-sex pens, and mature females had higher growth rate but lower meat content in carcasses than immature females. In contrast, female contact did not influence sexual maturity of entire male pigs. Mixing entire male pigs with unfamiliar pigs at the abattoir resulted in more damaged skin compared with pen-wise keeping whereas female pigs had almost no visible skin damage. We therefore recommend that entire male pigs are not mixed with unfamiliar pigs during transport and at the abattoir, because of fighting and subsequent skin damage. The levels of skatole in fat were significantly lower in high-weight entire male pigs fed RPS compared to high-weight pigs without RPS. Androstenone levels in fat were high in all groups.     

Influence of rearing conditions on performance, behavioral, and physiological responses of pigs to preslaughter handling, carcass traits, and meat quality

A total of 120 crossbred [synthetic line x (Large White x Landrace)] pigs (castrated males and females) were used to evaluate the influence of rearing conditions for growing-finishing pigs on growth performance, carcass, stress reactions at slaughter, and meat eating quality. At approximately 35 kg of live weight (LW), littermates were allocated to either a conventional (fully slatted floor, 0.65 m2/pig, considered as control, CON) or an alternative (sawdust bedding with free access to an outdoor area, 2.4 m2/pig, OUT) system, until slaughter at approximately 110 kg of LW. Pigs had free access to standard growing and finishing diets. The trials were conducted in spring, summer, and winter, with each season involving 2 pens of 10 pigs in each system. Compared with the CON, the OUT pigs exhibited a greater growth rate (+10%, P < 0.001) due to their greater feed intake (+0.23 kg/d, P < 0.01), resulting in a greater body weight at slaughter (+7 kg, P < 0.001). The OUT pigs had thicker backfat (+2.4 mm, P < 0.01) and lower lean meat content (- 2.0% points, P < 0.001) than the CON pigs. The OUT system did not (P > 0.10) influence the behavioral activities of pigs during lairage at the slaughterhouse, or the urinary levels of catecholamines and cortisol, and plasma levels of ACTH, cortisol, lactate, creatine kinase, and FFA immediately after slaughter. The OUT pigs had similar (P > 0.10) pH values 30 min postmortem (pH1) in the LM, biceps femoris (BF), and semimembranosus (SM) muscles, similar ultimate pH (pHu) in LM, but lower pHu in SM (- 0.07 unit, P < 0.001) and in BF (- 0.03 unit, P = 0.029). Despite nonsignificant effects of production system on stress reactions at slaughter, assessed by urine and plasma indicators and muscle metabolism at 30 min postmortem, meat from OUT pigs had more LM drip loss after 2 (+1.0%, P = 0.003) and 4 (+1.1%, P = 0.010) d than did meat from the CON pigs. The OUT system slightly increased meat yellowness (b* value) in the LM (+0.7 unit, P = 0.001), BF (+0.5 unit, P = 0.014), and SM (+0.5, unit P = 0.041), whereas redness (a*) and lightness (L*) of the 3 muscles were unaffected (P > 0.07). Intramuscular fat content was greater in the LM (+17%, P = 0.001), BF (+14%, P = 0.004), and SM (+17%, P = 0.003) of the OUT pigs. Outdoor rearing during summer and winter improved meat juiciness, whereas odor, flavor, and tenderness were unaffected (P > 0.10). Influence of rearing conditions on all the other traits studied did not depend on the season.     

Low birth weight is associated with enlarged muscle fiber area and impaired meat tenderness of the longissimus muscle in pigs

The objective of this study was to determine the relationships between birth-weight-associated modifications in histological or chemical muscle characteristics and meat quality traits in pigs. At 68 d of age, Pietrain x (Large White x Landrace) female littermates were allocated into 2 groups on the basis of low birth weight (LW = 1.05 +/- 0.04 kg; n = 15) or high birth weight (HW = 1.89 +/- 0.02 kg; n = 15). Pigs were reared in individual pens with free access to a standard diet up to slaughter at approximately 112 kg of BW. During the growing-finishing period, LW and HW pigs had a similar daily feed consumption, whereas G:F was lower (P = 0.009) for LW pigs than for HW littermates. At final BW, LW pigs were 12 d older (P < 0.001) than HW littermates. Estimated lean meat content, relative proportions of loin and ham in the carcass, and weights of LM and semitendinosus muscle (SM) were decreased (P < 0.05) in LW pigs compared with HW pigs. Conversely, the LW pigs exhibited a fatter carcass, greater activity levels of fatty acid synthase and malic enzyme in backfat (n = 15 per group), and enlarged subcutaneous adipocytes (n = 8 per group) compared with the HW pigs. Similarly, lipid content was increased by 25% (P = 0.009), and mean adipocyte diameter was 12% greater (P = 0.008) in the SM from LW pigs compared with that from HW pigs, whereas lipid content did not vary in the LM of either group. Mean myofiber cross-sectional areas were 14% greater in the LM (P = 0.045) and the SM (P = 0.062) of LW pigs than of HW pigs. Conversely, the total number of myofibers was less (P = 0.003) in the SM of LW vs. HW pigs. There were no differences between groups for glycolytic potential at slaughter and rate and extent of postmortem pH decline in both muscles, as well as for LM drip losses. A trained sensory test panel judged the roast loin meat to be less tender (P = 0.002) in LW pigs relative to HW pigs. Scores for juiciness, flavor, flouriness, and fibrousness of meat did not differ between groups. Overall, negative but somewhat low correlation coefficients were found between LM tenderness score and ultimate pH (r = -0.36; P = 0.06) and between LM tenderness and mean cross-sectional area of myofibers (r = -0.34; P = 0.07). This study demonstrates a lower tenderness of meat from pigs that had a LW, partly as a result of their enlarged myofibers at market weight.     

Effect of rearing environment and age on gut development of piglets at weaning

Outdoor reared pigs are reported to be larger at weaning than indoor reared pigs and respond better to the weaning process. This may be due to enhanced gut development associated with increased size. Eighty sows were allocated to either indoor or outdoor farrowing on the basis of size, parity and past performance. Resulting litters were weaned at either 4 or 6 weeks of age. On days 26 and 40 of age, 40 (10/treatment) and 20 piglets (10/treatment still unweaned) were killed to measure intestinal morphology. Data were analysed as a 2 × 2 factorial using the GLM procedures of Minitab 12.2. Pigs reared outdoors were larger than those reared indoors at both weaning ages, pigs weaned at 6 weeks were heavier than those weaned at 4 weeks, 8.4 versus 7.4 kg at 4 weeks and 12.9 versus 10.5 kg at 6 weeks respectively (± 0.25, P ≤ 0.001). There were no differences in small intestine size relative to body weight due to rearing environment and no differences in gut morphology. When corrected for body weight, 6 week pigs had heavier small intestines than 4 week pigs, 0.39 (± 0.010) versus 0.34 (± 0.007) g/cm length, respectively (P ≤ 0.001). Six week unweaned pigs had similar villus heights to 4 week unweaned pigs but wider villi (P < 0.05) and deeper crypts, for example, at the 25% site crypt depths were 236 and 193 μm (± 7.7/5.5) respectively (P < 0.001). Hence increased piglet size due to outdoor rearing did not advance gut maturation whereas increased piglet size due to age did influence maturation of gut structure.     

Effect of rearing and slaughter conditions on behaviour, physiology and meat quality of Large White and Duroc-sired pigs

The present study investigated the effect of outdoor rearing and genetic background on behaviour and meat quality traits in heavyweight pigs. Large White and Duroc-sired pigs were reared in groups of 3 castrated males and 3 females, conventionally or in fields, from April to October, in a study with two replicates. Compared to indoor pigs, outdoor pigs were more active and showed a larger range of behaviour suggesting improved welfare from a behavioural point of view. During 5 h of isolation, outdoor pigs were less active and had lower heart rates, and in another test, they reacted less to a non-familiar object (traffic cone). Pigs were slaughtered at 150 kg live weight, half of each treatment group after mixing, short transport, and overnight lairage and half immediately following short transport. Outdoor pigs were less aggressive during pre-slaughter mixing. Ante- and post-mortem glycogen content of the Longissimus lumborum (LL), Semimembranonus (SM) and Semispinalis capitis (SC) muscles depended on slaughter conditions, sire breed, rearing conditions, gender and year of experimentation, sometimes influencing ultimate pH. Effects of rearing on muscle glycogen content and post-mortem pH were stronger during the second year of rearing. Effect of slaughter conditions on glycogen content and ultimate pH depended on fighting levels during pre-slaughter mixing. Outdoor rearing increased muscle redness. Drip and cooking loss were higher in Large White than Duroc-sired pigs. Drip and cooking loss were correlated with early post-mortem and ultimate pH. Thawing loss was correlated with early post-mortem temperature and ultimate pH. Finally, reactivity to isolation had a predictive value as pigs more active during isolation had less skin damage due to fighting during pre-slaughter mixing. In conclusion, despite large effects of year of experimentation, outdoor rearing, sire breed, and slaughter conditions influenced behaviour and muscle characteristics.     

Live weights at slaughter significantly affect the meat quality and flavor components of pork meat

One‐hundred‐twenty crossbred pigs finished at 175–185 days of age were used to investigate the effects of live weights at slaughter on the meat quality, volatile flavor compounds, and sensory attributes of pork meat. Based on the live weights at slaughter, three weight groups (n = 36 per group) were classified as follows: light weight (LW: 100 kg), medium weight (MW: 110 kg), and heavy weight (HW: 120 kg). After slaughter, longissimus dorsi muscle samples were taken and used for the analyses of aforementioned parameters. The HW group had higher fat content and water holding capacity compared to the LW or MW group (p < 0.05). The HW group also showed higher levels for majority of unsaturated fatty acids and total polyunsaturated fatty acids than the LW group (p < 0.05). The slaughter weight significantly affected the amounts of 11 among the 47 flavor compounds identified. Significantly higher amounts of fatty acids oxidation‐derived flavor compounds (aldehydes) were found in the HW group than in the other groups. Noticeably, increasing slaughter weight was associated with higher sensorial scores for flavor, juiciness, and acceptance scores (p < 0.05). Based on the obtained results, 120 kg body weight is recommended as the market weight for this commercial breed without compromising the meat quality.     

Performance and body composition of fatteningpigs of two strains during protein deficiency and subsequent realimentation

The influence of protein restriction and subsequent realimentation on protein and lipid depositionas studied. Between 28 kg and 65 kg live weight (LW ), entire male pigs of two strains (a commercial and a sire strain) were given diets either deficient or adequate in protein content. From 65 to 105 kg LW all pigs were fed a protein-adequate ration. Animals were slaughtered and dissected at start, 65 and 105 kg LW. Body composition and deposition rates of protein, lipid, lean and fatty tissue for both the restriction period (28–65 kg LW) and the realimentation period (65–105 kg LW) were calculated. Protein restriction reduced feed intake (28%), live weight gain (60%), and rate of protein (75%) and lipid deposition (15%) between 28 and 65 kg live weight. A165 kg, restricted animals had twice as much lipid and were 60 days older than controls. During realimentation, previously restricted pigs (compared to controls) had slightly (7%) reduced feed intake and 15% increased weight gain and efficiency. Protein deposition rate beyond 65 kg LW was increased by 13% and ratio of lipid to protein deposition was decreased from 1.69 to 1.23. At 105 kg, the previously restricted pigs still were older and fatter than controls, so compensation was not complete. Strains of pigs responded similarly to both restriction and realimentation. Dissection at 105 kg LW was not sensitive enough to show the effects revealed by chemical analysis. The experiment revealed that nutritional history may influence the relation between lipid deposition rate and protein deposition rate.     

长白山野猪与杜洛克猪杂交1代猪肌内脂肪代谢酶HSL和MDH活性的发育性变化规律及其对肌内脂肪沉积影响的研究

为了研究长白山野猪与杜洛克猪杂交1代猪肌内脂肪代谢酶激素敏感脂酶（hormone-sensitive lipase,HSL）和苹果酸脱氢酶（malate dehydrogenase,MDH）活性的发育性变化规律及其对肌内脂肪沉积的影响,试验以5个体重组（20、35、50、70和90 kg）的长白山野猪与杜洛克猪的杂交1代猪（简称野杜F1代猪,各40头,公、母各半）为研究对象,研究了肌肉组织中脂肪代谢酶活性的发育性变化规律与肌内脂肪含量和肌肉嫩度的关系。结果表明,在生长期随着体重的增加,肌肉组织中HSL和MDH的活性差异显著（P<0.05）,野杜F1代猪HSL活性均高于莱芜黑猪的活性（90 kg除外）,且在35 kg时,野杜F1代猪和莱芜黑猪差异极显著（P<0.01）;肌肉组织中的MDH活性变化,野杜F1代猪呈先升后降的趋势,活性最高点在70 kg;在90 kg时野杜F1代猪中MDH活性极显著低于莱芜黑猪（P<0.01）。不同体重阶段,肌肉嫩度差异显著（P<0.05）,且随着体重的增加而呈不断升高的趋势。相关分析结果表明,野杜F1代猪90 kg时肌肉组织中MDH活性与肌内脂肪含量呈极显著正相关（r=0.97,P<0.01）,HSL和MDH的活性与肌肉嫩度呈显著正相关（P<0.05）。研究结果提示,肌肉组织中的HSL和MDH对肌内脂肪的沉积量有一定的影响,可以通过控制其活性调节肌内脂肪的含量,且肌内脂肪的沉积量与肌肉嫩度有一定的联系。     

Environmental effects on pig performance, meat quality, and muscle characteristics

The objective of this experiment was to determine the effect of diverse production systems on pig performance, muscle characteristics, and their relation to pork quality measures. Birth and rearing conditions were evaluated using 48 barrows during the fall/winter months. Pigs were farrowed in either indoor crates or outdoor huts. At weaning, indoor- and outdoor-born pigs were allotted randomly to treatments arranged in a 2 x 2 factorial design with two birth (indoor vs. outdoor) and rearing (indoor vs. outdoor) environments. Pigs housed indoors were on concrete-slatted flooring (1.2 m2/pig), and pigs housed outdoors were on an alfalfa pasture (212 m2/pig). Body weight data were collected. Muscle samples were removed within 1 h postmortem from the longissimus (LM) and semimembranosus (SM) muscles. Muscle samples were stained histochemically to identify type I, IIA, and IIB/X muscle fibers. Boneless loins were collected from the left side of each carcass and aged for 14 d. Objective and subjective color measurements were taken on the longissimus muscle at the 10th rib on d 14 postmortem. Loin chops were evaluated for sensory attributes, shear force, and retail display features. Pigs born outdoors were heavier and had a greater ADG at most growth intervals postweaning (d 28, 56, and 112; P < 0.05) than pigs born indoors. Pigs reared outdoors were heavier (P = 0.02) at d 140 (120.1 vs. 112.9 +/- 4.9 kg), and had higher (P = 0.01) ADG (2.2 vs. 1.9 kg/d) and gain:feed ratios (0.41 vs. 0.37) than did pigs reared indoors. Birth x rearing environment interactions were not significant (P > 0.10) for most measures. Carcass and meat quality measures did not differ (P > 0.05) among treatment groups, but loin chops from outdoor born or reared pigs had higher (P < 0.05) a* values than chops from pigs born or reared indoors. The LM muscle of pigs born outdoors had a higher (P < 0.01) percentage of type I, and a lower (P < 0.05) percentage of type IIA fibers than did pigs born indoors. Pigs reared outdoors had a higher (P < 0.01) percentage of IIA fibers and a lower (P < 0.05) percentage of IIB/X fibers than did pigs reared indoors for the LM and SM muscles. Outdoor production systems may influence growth, pork color, and muscle fiber types.     

The relationship within and between production performance and meat quality characteristics in pigs from three different genetic lines

Ninety-six pigs from Large White (LW), Synthetic Genex 3000 (SG) and Meishan-derived dam line (M) genetic lines, each with a mean live body weight (BW) of 20.7 ± 4.2 kg, were used to investigate the relationship that exist between production performance and meat quality parameters for these three genotypes. The animals were assigned to pens in groups of eight and slaughtered at 109.6 ± 3.78 kg BW. At the end of the trial, the LW pigs had the highest (P < 0.001) average daily feed intake and average daily gain and protein deposition rates, the M pigs showed (P < 0.001) the worst feed conversion, the highest daily backfat gain and the lowest residual energy intake, and the SG pigs had the lowest (P < 0.001) daily fat deposition rate. The longissimus muscle of the M pigs had higher a (P < 0.01) and b (P < 0.05) values than the LW pigs, with the SG pigs in between. The M loins also had the highest (P < 0.01) shear force value, which may be explained by the lower (P < 0.01) soluble collagen content. In spite of their lowest fat deposition rate, the highest (P < 0.001) intramuscular fat content was measured in the SG loins, and the highest (P < 0.01) protein content was found in the M loins. Eight canonical correlations were obtained between performance and meat quality data, with the first three correlation coefficients of 0.87, 0.66 and 0.64 being significant. Performance and meat quality data were related to a certain extent. Pigs with a higher average daily feed intake also had a higher average daily gain, an average protein deposition rate, residual energy intake and gain-to-feed ratio, and lower meat dry matter, intramuscular fat, a values and pigment content. Body water content seems to be higher in fast-growing pigs. Furthermore, fast-growing pigs also have lower intramuscular fat, a values and pigment content. However, there is some indication that the magnitude of these correlations can be breed-dependent. The differences among the studied genotypes are much higher in terms of growth performance than in terms of meat quality traits.     

Effect of dietary Rhodobacter capsulatus on cholesterol, triglycerides concentration, and meat quality of finishing pigs

The study was designed to investigate the effect of Rhodobacter capsulatus on serum and meat cholesterol, fatty acid composition in meat, as well as meat quality of finishing pigs. A total of 16 120-day-old Landrace female pigs of about 60 kg initial body weight were randomly assigned into two groups. The pigs were fed a supplemented diet with 0.04% dietary R. capsulatus or a control diet for 60 days. Total cholesterol and low density lipoprotein-cholesterol concentration in serum was significantly lowered ( P  < 0.05) in the pigs fed the R. capsulatus supplemented diet compared to the control diet. Carcass weight, carcass length, shoulder fat, back fat and loin fat thickness, longissimus muscle (LM) area, and color score did not differ significantly between the pigs fed the R. capsulatus supplemented diet and control diet. Among the nutrient composition of LM meat, neutral fat and triglyceride concentration were significantly ( P  < 0.05) reduced in the finishing pigs by dietary supplementation of R. capsulatus . The proportions of n-6 PUFA were higher ( P  < 0.05) in the pigs fed the R. capsulatus supplemented diet than in the pigs fed the control diet. The supplementation of dietary R. capsulatus to finishing pig diet played important roles in reducing serum cholesterol and meat triglycerides, as well as in increasing polyunsaturated fatty acid content in LM meat.     

Chato Murciano pig and its crosses with Iberian and Large White pigs, reared outdoors. Comparative study of the carcass and meat characteristics

The Chato Murciano pig is an autochthonous breed genetically adapted to the south-east of Spain local conditions and extensive production system. In this work we aimed to compare the quality of the carcass and meat of this local breed and its crosses in outdoor rearing conditions. Samples were taken from the longissimus lumbar muscle of 38 pigs, belonging to three different groups, Chato Murciano (CH), Chato Murciano crossed with Iberian (CH × IB) and Chato Murciano crossed with Large White (CH × LW). The pH values measured at 24 h postmortem were within the normal range. The levels of intramuscular fat were 10.47% for CH, 8.97% for CH × IB, and 11.17% for CH × LW. The CH × LW group showed the highest weights for the most valuable meat cuts. The meat of the Chato Murciano pig and its crosses revealed high levels of iron, copper and phosphorus, and low levels of calcium and sodium.     

Influence of a conjugated linoleic acid mixture on growth, organ weights, carcass traits and meat quality in growing pigs

Grain soybean meal diets, either with 2% of a conjugated linoleic acid (CLA) preparation or with 2% rapeseed oil (control), were tested in 2 × 40 pigs, Pietrain × (Landrace × Large White), each group with 20 female in the live weight range 23.5–117.0 kg and 20 male-castrated pigs in the live weight range 23.5–110.6 kg. The CLA-content of the preparation amounted to 54.0% cis / trans + trans / cis , 8.7% cis/cis and 32.7% trans / trans isomers. Daily weight gain, feed intake and feed : gain ratio were not influenced by the diets tested. The carcass lean increased significantly from 57.2% of the control group to 58.7% in the CLA group (p   < 0.05). The male-castrated showed a stronger CLA effect than the female pigs – not only was the carcass lean significantly increased by 2%, but backfat thickness was significantly decreased by 2.8 mm, i.e. minus 11% (as compared with barrows of the control). The meat of CLA-fed pigs had a higher conductivity. A CLA effect on further meat quality characteristics (pH 45 min post-mortem, impedance, colour criteria, intramuscular fat, drip loss, frying loss, shear force, sensory attributes) could not be detected. There were some significant correlations between the meat quality attributes.     

Free-range rearing of pigs during the winter: adaptations in muscle fiber characteristics and effects on adipose tissue composition and meat quality traits

This research aimed to determine whether outdoor free-range rearing during the winter (average ambient temperature of 5 degrees C) vs. indoor housing (22 degrees C) affects meat quality, muscle metabolic traits, and muscle fiber characteristics. Forty Large White gilts and barrows were blocked by weight within each gender (20 per gender) and allotted randomly into two groups of pigs, with one reared indoors (IN) in individual pens (2.6 m2) and the other reared outdoors (OUT) from December to March in a 0.92-ha pasture. Both groups had free access to the same grower-finisher diet from 23 to 105 kg. At slaughter, adipose (backfat [BF] and omental fat [OF]) and muscle tissues (longissimus muscle [LM], rectus femoris [RF], and semitendinosus [ST]) were obtained from the right side of each carcass. Muscle fibers were stained and classified on the basis of stain reaction as slow-oxidative (SO), fast oxidative-glycolytic (FOG), and fast glycolytic (FG); fiber area and distribution were determined. Also assessed were carcass characteristics, initial and ultimate pH, L*a*b* values, drip loss percent, glycolytic potential (GP), and intramuscular lipid content, as well as the fatty acid profile of each muscle and adipose tissue. The OUT pigs had lower (P < 0.05) ADG and leaner (P < 0.05) carcasses than IN pigs. Rearing environment did not (P > 0.63) affect the intramuscular lipid content of the ST, but intramuscular lipid content was lower (P < 0.01) in the LM and tended to be higher (P = 0.06) in the RF of OUT than in those of IN pigs. In the BF outer layer of the OUT pigs, the higher PUFA content was compensated by both a lower (P < 0.01) saturated and monounsaturated fatty acid (MUFA) content, whereas in the OF, LM, and dark portion of the ST, only the percentage of MUFA was decreased (P < 0.01). In all tissues of the OUT pigs, the linolenic acid content was higher (P < 0.01) and the n-6:n-3 ratio was lower (P < 0.01). The GP of all muscles was higher (P < 0.01), and the ultimate pH of the RF and ST was lower (P < 0.01), in OUT compared with IN pigs. Lightness (L*) values were lower (P < 0.01) in the LM. Percentages of drip loss were higher (P < 0.05) in the LM and light portion of the ST of OUT than in those of IN pigs. The LM and RF of OUT pigs had more (P < 0.01) FOG and fewer (P < 0.01) FG fibers than muscles of IN pigs. Results suggest that rearing pigs outdoors increases aerobic capacity of glycolytic muscles but has little concomitant influence on meat quality traits.