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In recent decades, agricultural intensification has led to a strong decline in biodiversity. Field margins act as shelters and dispersal corridors for biodiversity in highly disturbed landscapes, and are critical to the maintenance of ecosystem services. However, they are also impacted by agricultural practices in neighboring fields. Agricultural impacts are often studied at field to landscape scales, and rarely across biogeographic regions. One of the challenges in large-scale studies is the lack of standardized monitoring schemes including both biodiversity and accurate estimation of agricultural practices. Here, we take advantage of a national monitoring scheme in 462 sites in France, to assess the effects of agricultural practices on field margin flora at different extents and resolutions. We used spatial simultaneous autoregressive and generalized dissimilarity models to assess the response of plant richness and composition to climatic, soil and landscape conditions, and to agricultural (fertilization, herbicides) and margin management drivers. Analyses were repeated at the site-level, 40 and 75 km resolutions, and at regional and national extents. We found that the impact of agricultural practices on species richness was most important at the site-level, whereas climate and crop diversity became more important at the 75 km resolution. Compositional variations responded differently, with climate being more important at the site-level, and fertilization and crop diversity at the coarsest resolution. There was a strong variation in the variance explained by models among regions, but climate effects were weaker within biogeographic units compared to the national level, and different agricultural practices stood out as influential in different regions, suggesting that the regional context is fundamental in determining plant community structure. To efficiently conserve biodiversity, we therefore recommend the implementation of agricultural measures adapted to each region.

Biodiversity is a key component of agricultural ecosystems and belongs to one of the exceeded planetary boundaries. In the quest for innovation to mitigate impact, it is essential to have tools to assess the anthropogenic impact on biodiversity. In this study, we developed a new indicator, I-BIO that aimed to predict the impacts of management practices and the influence of the landscape on overall biodiversity at species group level. I-BIO encompassed four groups: microorganisms, vegetation, invertebrates and vertebrates. This predictive indicator was built using DEXi software that facilitates the design of hierarchical decision trees, based on input variables in the form of qualitative classes, aggregated using utility functions. I-BIO was constructed using data from a long-term platform in Scotland and then applied to two data sets in France and one in Scotland. The results showed that the lowest class is predominant for all branches especially for invertebrates and soil invertebrates. Monte Carlo sampling was used to test for sensitivity. Then, a validation step was carried out to compare I-BIO outputs with real data using data on the four groups from Scottish and French datasets. I-BIO predictions of weed and soil invertebrate abundance conformed to field data. Due to low numbers of samples, validation of microorganisms, flying invertebrates and vertebrates predictions require more data. Future developments of I-BIO will focus on predictions specifically to assess the impact of management on species richness. Avenues for improvement include a better integration of landscape features and the history of agricultural practices as they both have a great influence on biodiversity.

Skatole, androstenone and other compounds such as indole cause boar taint in entire male pork. However, female pigs also produce skatole and indole. The purpose of this experiment was to minimise boar taint and increase overall impression of sensory quality by feeding entire male and female pigs with fibre-rich feedstuffs. The pigs have been fed three organic diets for either 1 or 2 weeks prior to slaughter of which two diets contained different fermentable fibre-rich feedstuffs - 10-13.3% dried chicory roots or 25% blue lupines. These two treatments were compared with pigs fed with an organic control diet for either 1 or 2 weeks prior to slaughter. Lupines significantly reduced skatole in blood and backfat for both genders after 1 week. Moreover, lupines showed negative impact on growth rate and feed conversion whilst chicory showed no significant differences in this respect. However, the indole concentration was significantly lower in chicory than lupine fed pigs. From a sensory perspective, chicory and lupine feeding reduced boar taint since odour and flavour of manure related to skatole and urine associated to androstenone were minimised. The level of boar taint in the entire male pigs was most effectively reduced after 14 days by both fibre-rich feeds while lupine had the largest influence on "boar" taint reduction in female pigs.

This study aims to explore the potential of evoked non-invasive surface electromyography (SEMG) analysis, in predicting meat quality traits in livestock. Evoked SEMG is a system that records, transdermally, electrical signals generated in muscle fibres upon external stimulation. These signals are reported as compound muscle action potentials (CMAP). CMAP parameters of LD correlated negatively and significantly to ultimate pH (pH 24h) at day 61, but not at day 153 after birth, and a similar albeit positive correlation was observed for muscle glycogen content. Muscle glycogen content and pH 24h correlated negatively in LD and BF. Negative significant correlations between CMAP parameters and shear force were found in LD at day 153 after birth, which might, in the range of the recording electrodes, reflect the combined effect of large cross-sectional area fibres and reduced perimysium content per unit volume of muscle. The fact that correlations between CMAP characteristics and quality traits of both metabolic and non metabolic origin could be established, warrants a fuller investigation of this method in terms of its potential as a predictive tool for meat quality traits in live animals.

The significance of early postmortem (pm) temperature and pH decline and the level of the muscle metabolites creatine phosphate (CP) and adenosine triphosphate (ATP) on the colour of porcine M. longissimus dorsi was studied in a factorially designed experiment. Two stress levels peri mortem (minimal stress vs treadmill exercise and electrical stunning of the pigs) and four genotypes (Duroc boars crossed with Landrace-Yorkshire sows vs. Hampshire-Duroc boars crossed with Landrace-Yorkshire sows, including carriers and non-carriers of the halothane and RN(-) genes, respectively) were included. Early pm muscle temperature and the accompanying pH decline had a significant influence on the pork colour independent of genotype. The combination of high temperature and low pH early pm increased lightness and yellowness, which is ascribed to inactivation of oxygen-consuming enzymes and protein denaturation. The effect of early pm temperature and pH on pork redness was more complex. It appears to be closely related to the extent of heat generation, CP and ATP levels and pH immediately pm in the muscle, which influence the activity of oxygen-consuming enzymes.

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

Colour stability and development of lipid oxidation were followed during chill storage for 6 days of chops from M. Longissimus dorsi produced from pigs with high (6.3) and low (5.5) ultimate pH (pH(u)). The chops from the same individual pigs were either chill stored at 2 days post-mortem or after frozen storage for 30 months (pre-frozen). Initial redness, measured as tristimulus parameter a(*), was lower for pre-frozen chops than for fresh chops. Chops with the high pH(u) had a stable a(*)-value during chill storage, while chops with the low pH(u) showed a rapidly decreasing a(*)-value both for fresh and pre-frozen chops. In contrast, initial lipid oxidation, measured as TBARS, was similar for pre-frozen and fresh chops prior to chill storage for both the high and the low pH(u) meat but developed most significantly in pre-frozen, low pH(u) meat. Individual differences in colour stability and development of lipid oxidation between pigs were notable for pre-frozen low pH(u) meat and need to be considered in quality control since meat from single pigs otherwise might give problems.

Post-mortem proteolysis was examined in muscle homogenates from porcine m. longissimus dorsi (LD), m. semitendinosus (ST), m. semimembranosus (SM), m. vastus intermedius (VI), and m. soleus (S). During post-mortem storage, desmin and troponin-T degraded faster in LD and SM than in ST, VI and S. ST exhibited the same rate of degradation as VI and S. These differences could not be explained solely by differences in fibre type distribution, indicating that other muscle-specific traits independent of fibre type determine myofibrillar degradation post-mortem. Thus, the rate of post-mortem proteolysis seems to depend more on muscle-to-muscle variations than on fibre type composition.

In commercial production, chickens are subjected to feed withdrawal prior to slaughter and exposed to stress during transport and handling of the animals at the slaughterhouse; this causes plasma glucose and glycogen stores in liver and muscle to decrease, which has a negative impact on meat quality. The aim of the present study was to investigate how supplementation of the energy complements creatine and pyruvate during the fasting period would affect postmortem pH decrease, water-holding capacity, and color of the meat. Female Ross 208 broilers were supplemented with glucose combined with either pyruvate or creatine via the drinking water for 18 or 42 h prior to slaughter, i.e., before and throughout the fasting period. Chickens were slaughtered at 42 or 43 d of age. Temperature and pH were measured at 1, 10, 30, and 45 min and 1, 2, 4, 8, and 12 h postmortem. The results showed that the pyruvate and glucose supplementation increased the pH at 45 min postmortem by 0.25 units and decreased drip loss of musculus pectoralis major (PM) by 50 to 65% in chickens supplemented for 42 h. The creatine and glucose supplementation reduced pH at 3 and 4 h postmortem by 0.32 to 0.42 units, increased the lightness (L*) by 2.3 to 5.6 units, and increased drip loss by 51 to 137% in the PM of chickens supplemented for 18 and 42 h. Pyruvate and glucose supplementation thus appear beneficial but whether this is concomitant with an overall improvement in meat quality remains to be determined.

In order to ameliorate a negative effect of stress on meat quality characteristics, chickens were fed a diet supplemented with a combination of ascorbic acid (1,000 ppm) and alpha-tocopherol (200 ppm) or oregano (3%), which has a high content of antioxidants. Chickens were slaughtered by cervical dislocation in the stable (no stress) or after transport and electrical stunning at the slaughter plant (stress). Activities of antioxidative enzymes (catalase, superoxide dismutase, and glutathion peroxidase) in pectoralis major (PM), iliotibialis (IL), and liver were unaffected by supplementation. However, erythrocyte stability, which is a more complex model system for determining oxidative status, increased with ascorbic acid-alpha-tocopherol supplementation and tended to increase after oregano supplementation. In nonstressed birds, this improved antioxidative status was reflected in decreased TBA-reactive substances (TBARS) in PM and liver of ascorbic acid-alpha-tocopherol-supplemented chickens and likewise in liver from oregano-supplemented chickens compared to that of nonstressed control birds. However, postmortem temperature, pH, and water-holding capacity were not affected by supplementation. Drip loss from oregano-supplemented chickens showed increased protein oxidation in specific bands, but this did not relate to water-holding capacity or antioxidative status. When exposed to stress, the concentration of TBARS in the control animals increased in PM and IL. Ascorbic acid-alpha-tocopherol supplementation protected IL, and oregano supplementation protected PM from stress-induced increases in TBARS. This differential effect between muscles may indicate differences in protection mechanisms. In conclusion, ascorbic acid-alpha-tocopherol and oregano supplements to chickens protect against stress-induced increase in TBARS, in different muscles.

Pre-slaughter physiological conditions (A serving as control, B subjected to treadmill exercise immediately prior to stunning, C epinephrine injection 15 h prior to slaughter, and D epinephrine injection 15 h prior to slaughter and subjected to treadmill exercise immediately before stunning) were found to significantly affect colour and lipid oxidation of sliced, retail packed roast ham, produced from nitrite-cured (78 ppm nitrite) M. Longissimus dorsi. The pre-slaughter treatment resulted in variations in the level of glycogen, lactate, ATP and IMP and pH development as monitored in Longissimus dorsi muscles, with the lowest ultimate pH (pH(u)) in muscles from non-epinephrine treated pigs (treatments A and B). The initial tristimulus L(∗)-value and the L(∗)-value during chill storage of sliced roast ham packed in laminates with low or with very low oxygen transmission rate (OTR=40 and <0.5 cm(3)/m(2)/atm/24 h, respectively) were significantly affected by treatment, although the effect of the treatments was different during storage for 28 days (interaction between treatment and storage time). Roast ham from treatments A and B generally had a paler appearance (higher L(∗)-values) than from treatments C and D. No differences in the initial tristimulus a(∗)-values (redness) were found. During chill storage, a pronounced colour fading (decrease in a(∗)-values) was seen for laminate with low OTR, with a tendency of better colour stability for treatment C than A, but with no differences for the other treatments. For laminates with very low OTR, the cured meat pigment was stable with no decreases in a(∗)-values during storage. Lipid oxidation (thiobarbituric acid reactive substances, TBARS) in products in laminates with low OTR increased during storage and was significantly higher for roast ham from non-epinephrine treated pigs (A and B) than for ham from epinephrine-treated pigs (C and D). Statistical analysis relating pH and the level of glycogen, lactate, creatine phosphate, ATP and IMP in the individual pigs to the product quality parameters revealed that the ultimate level of lactate was the most important single parameter affecting product quality. After 28 days of chill storage, roast ham from pigs subjected to treatments C and D were more likely to support bacterial growth than from treatments A and B. In conclusion, the results show that pre-slaughter physiological conditions are of importance for chemical as well as for microbiological changes in retail stored roast ham.

To clarify the physiological prerequisites for the course of energy metabolism post mortem, 80 pigs consisting of four females from each of 20 litters of crossbreeds (Duroc as sireline and Danish Landrace×Danish Large White as dam line) were within litter allocated to four different treatments (A, B, C and D) to provide a large variation in the concentration of the key metabolites glycogen, ATP and creatine phosphate at the time of stunning. (A) no stress before stunning, (B) physical stress consisting of treadmill running (3.8 km/h for 10 min) immediately before stunning, (C) intermediate reduction of glycogen at stunning achieved by application of adrenaline (0.2 mg/kg live weight 15-18 h before stunning), and (D) maximal reduction of glycogen achieved by application of adrenaline (0.3 mg/kg live weight 15-18 h before stunning) and treadmill running (3.8 km/h for 5 min). Compared with resting values (measured in samples taken in the pen the day before slaughter by needle biopsy), longissimus muscle glycogen (16, 13, 57 and 66% for A, B, C and D, respectively), creatine phosphate (17, 22, 12 and 9% for A, B, C and D, respectively) and ATP levels (10, 15, 38 and 31% for A, B, C and D, respectively) measured immediately before stunning were all reduced by the treatments. Stunning caused a rather uniform reduction in creatine phosphate level in all the models. Glycogen concentrations were also further reduced in treatments A, C and D, but not in B, and although ATP levels increased in all the models during stunning, this was only significant for the B model. Consequently, the effect of CO(2) stunning on glycogen and ATP levels depends on pre-slaughter handling. It was also shown that an inverse relationship between ultimate pH and glycogen concentration at the time of stunning existed only when glycogen levels at stunning were below 53 mmol/kg (r=0.88, P<0.001). The validity of this threshold value is discussed. Furthermore, the possibility to standardise the physiological prerequisites of the post mortem pH decreases represents a potent tool to investigate metabolic causes of variations in meat quality characteristics.

Early post mortem metabolism and structural changes from 3 to 24 h, together with pH, temperature and impedance Py development were investigated in 37 Duroc×Landrace×Large White (DLY) pigs covering a range of drip loss from 2.2 to 12.6%. Multivariate statistical analysis was used to assess the impacts of different metabolites, pH and temperature, impedance, cytoskeletal protein degradation and extracellular cross-sectional area on drip loss. Taken as single factors, the concentration of lactate could explain 80% of the variation in drip, inosine monophosphate (IMP) and adenosine triphosphate (ATP) concentration explained 71 and 68%, respectively, whereas inosin and glycogen levels explained only 59 and 60%. The extracellular area was found to explain 39% of the variation in drip. The area between fibres provided more significant information than did the area between fibre bundles. The degradation of the cytoskeletal proteins was not related to drip loss. Impedance Py development over 24 h could explain 66% of the variation in drip, whereas pH and temperature explained 85 and 87%, respectively. A model including all measured variables could explain 83% of the variation in drip. However, only pH, temperature, impedance, [ATP](1 h) and [lactate](1 h and 2 h) were significant in relation to drip. By reducing the variables in the multivariate analysis, 89% of the variation in drip could be explained by a model containing only pH(2 h) and temperature(1 min). To explain variation in drip loss, pH and temperature measurements at significant time points were sufficient. Variation in post-mortem metabolites did, however, explain why variation in pH and temperature occurred. Development of drip channels was ruled by pH and temperature while impedance development was highly correlated to pH. This multi-faceted study shows those parameters, which can best be used to indicate or predict WHC, as well as those indicating the basic mechanism underlying variations in drip.

The effect on meat quality of a low stress handling system (LSS) compared with a traditional handling system (TS) was investigated in Duroc×(Landrace×Yorkshire; n=117) and (Hampshire×Duroc)×(Landrace×Yorkshire) pigs (n=110) under commercial conditions. In the low-stress handling system the pigs were kept in groups of 15 during lairage and movement up to the stunner. Before the stunner the groups were divided into three groups of five pigs for the CO(2)-stunning in a specially designed set-up. The pH and temperature were determined in m. longissimus dorsi (LD) and m. biceps femoris (BF) at various times post mortem. Immediately after exsanguination a biopsy was taken from the LD and analysed for the concentration of glycogen, lactate and creatine phosphate. The day after slaughter the pH was determined in the LD, BF, m. semimembranosus (SM) and m. semispinalis capitis (SC). The temperature was determined in the LD and BF, the internal reflectance was determined in the LD, SM and BF, the colour was determined in LD, the drip loss was determined in LD and BF, and the amount of blood splashing/bruising was evaluated in LD. There was a tendency for a higher concentration of creatine phosphate in the LSS-group (P=0.06). The pH in both the LD and BF on the day of slaughter decreased more slowly from 5 min post mortem to 40 min post mortem in the LSS-group than in the TS-group (P<0.001). From 40 min to 6 h post mortem the rate of the pH decline was similar in the two groups producing the lowest pH-level in the TS group. The day after slaughter the pH was similar in the two groups in the LD and SC, whereas in the BF and SM it was lower in the LSS-group than in the TS-group. The drip loss was lower in the LSS-group in both LD (P<0.01) and BF (P<0.05) whereas the internal reflectance was only different in LD with the lowest value in the LSS-group (P<0.001). The lightness (L*) was higher in the LSS-group (P<0.05). There was no effect of stunning system on the amount of blood splashing/bruishing in the LD. The study showed that by using a low stress stunning system it is possible to decrease drip loss, possibly by increasing the concentration of creatine phosphate and thereby delaying the acceleration of pH fall in muscles after death.

The physiological condition of the live animal was found to significantly affect colour, lipid oxidation and water holding capacity of chill stored pork chops (M. Longissimus dorsi) in a study, where various pre-slaughter conditions were achieved by the following four treatments: (A) control; (B) subjected to treadmill exercise immediately prior to stunning; (C) given epinephrine injection 15 h prior to slaughter; and (D) given epinephrine injection 15 h before slaughter and further subjected to treadmill exercise immediately before stunning. The treatments resulted in variations in energy metabolites (glycogen, lactate, creatine phosphate, ATP) and ultimate pH (pH(u)), with the lowest pH(u) in chops from treatments A and B, and in significantly different tristimulus colour L(∗)-, a(∗)- and b(∗)-parameters, although the effect of treatment on colour was not consistent during the chill storage period of 6 days. Overall, chops from treatments A and B had significantly higher L(∗)- and b(∗)-values (were paler and less blue) than chops from C and D during storage under conditions typical for retail trade. The initial a(∗)-values were higher (redder) in chops from treatments A and B, but the colour, as judged by the a(∗)-values, was less stable in meat from these treatments compared with treatments C and D. Lipid oxidation, evaluated by thiobarbituric acid reactive substances (TBARS) in the fresh meat, and drip loss, measured after 6 days of storage, were both significantly higher in chops from treatments A and B compared to chops obtained from treatments C and D. Statistical analysis relating the pH and the level of various energy metabolites post-mortem in the individual animals to the measured quality parameters, revealed that pH(u) was the most important factor affecting product quality. In conclusion, over all product quality depends on obtaining a pH(u) in the narrow range where both meat quality parameters such as colour, lipid oxidation and drip loss as well as microbiological aspects have to be considered.

Four spectroscopic instruments, a fibre optical probe (FOP), a visual (VIS) and near infrared (NIR) reflectance spectrophotometer, a reflectance spectrofluorometer and a low-field (1)H nuclear magnetic resonance (LF-NMR) instrument were used to perform measurements on two muscles (longissimus dorsi and semitendinosous) from 39 pigs, 18 of which were carriers of the Halothane gene. Water-holding capacity (drip loss and filter paper wetness) and chemical composition (intramuscular fat and water) of the muscle samples were determined for spectroscopic calibration. Prediction models were established by partial least squares regression to evaluate the potential of using the spectroscopic techniques in an on-line slaughterhouse system. VIS data gave good prediction models, indicating that current industrial colour systems can be advanced into more specific meat evaluation systems by including the entire visible spectral range. The FOP and fluorescence measurements were less successful, and suffered from sampling problems since they measure only a small area. The best regression models were obtained from LF-NMR data for all reference quality measures and yielded a correlation coefficient of 0.75 with drip loss. LF-NMR proved able to distinguish between the two muscles and the results for their longitudinal relaxation times, T(21), were proportional to their average myofibrillar cross-sectional areas reported in the literature.

From a series of experiments aimed at manipulating and relating the resting levels of glycogen and creatine phosphate (CP) in the live muscle four models were selected to induce different rates and extents of pH decrease post mortem in pig muscle. Model A served as the control, animals being slaughtered under minimal stress, in model B animals were subjected to 10 min treadmill exercise at 3.8 km/h immediately prior to stunning, in model C, animals were given 0.2 mg adrenaline/kg live weight 16 h prior to slaughter, and in model D they were given 0.3 mg adrenaline/kg live weight 16 h before slaughter and subjected to 5 min of treadmill exercise immediately before stunning. After slaughter, the decline in pH and temperature post mortem was recorded in M. longissimus dorsi (LD), M. biceps femoris (BF), M. semimembranosus (SM) and M. psoas major (PM) from 1 min to 24 h after bleeding. Significant differences in ultimate pH and the time course of pH decrease were observed, both as an effect of model as well as type of muscle. No differences in ultimate pH between model A and model B were observed in any of the muscles. Ultimate pH in the C and the D models were significantly higher than in A and B. In the B model lower pH values were observed from 1 min to 6 h post bleeding compared to the other three models. No differences in rate of pH decrease were observed between the A and the B models in any of the muscles. Within the A model no differences in ultimate pH between muscles were seen, indicating that the frequently observed differences in ultimate pH are caused by environmental factors rather than by differences in physiological and morphological characteristics. The exercise bouts caused elevated temperatures during the first hour after bleeding (model B and D). The BF muscle in all the models displayed the fastest rate of pH decrease and SM the slowest; a slower rate of temperature decline occurred in the BF than in the SM.

Forty-one autumn-born Friesian bull calves were allocated to two production systems (Extensive='E' and Intensive='I'). In the E-system, animals were loose-housed and fed a roughage-based diet from October to May, followed by a grazing period from May to October. Ten animals were slaughtered directly from pasture (360 kg BW) and 11 after a 10-week finishing feeding in tie-stalls (460 kg). E-bulls were compared with intensively fed tie-stall housed young bulls (I) slaughtered at comparable weights (360 kg, n=11 and 460 kg, n=9). Semitendinosus (ST), longissimus dorsi (LD), and supraspinatus (SU) muscles were analysed histochemically, and the meat analysed for colour and pigmentation. In LD and SU, Type I % was higher in E- compared with I-bulls (P<0.05-0.006). In ST and LD, Type IIA % was higher in E- compared with I-bulls (P<0.01-0.009). As a result, Type IIB % was lower in all three muscles in E- compared with I-bulls (P<0.05-0.001). In E- compared with I-bulls, Type IIA and IIB fibre areas were larger in ST (P<0.05-0.03) and capillarization was higher in both ST and LD (P<0.001). In all three muscles, the activity of citrate synthase was higher (P<0.07-0.001) and that of lactate dehydrogenase lower (P<0.003-0.001) in E- compared with I-bulls. E-bulls had lower glycogen content than I-bulls in ST and LD at 360 kg, but higher at 460 kg following finishing feeding (P<0.008-0.001). Meat colour (lightness) was darker (P<0.001) and pigmentation was higher (P<0.001) in ST and LD of E- compared with I-bulls, with no effects in SU. In conclusion, histochemically different muscles respond differently to changes in the production system, and differences between the extensive and the intensive production system were narrowed after the finishing feeding.

Forty-one autumn-born Friesian bull calves were allocated to two production systems (Extensive='E'and Intensive='I'). In the E-system, animals were loose-housed and fed a roughage-based diet from October to May, followed by a grazing period from May to October. Ten animals were slaughtered directly from pasture in October [360 kg body weight (BW)] and 11 after a 10-week finishing period in tie-stalls (460 kg). The E-bulls were compared with intensively-fed tie-stall-housed young bulls (I) slaughtered at comparable weights (360 kg, n=11 and 460 kg, n=9). The myofibril fragmentation index (MFI) was measured 24 h post mortem in semitendinosus (ST), longissimus dorsi (LD), and supraspinatus (SU) muscles, and meat quality characteristics and sensory evaluation of LD were performed on aged meat. Intramuscular fat content was lower (P<0.001) in all three muscles of E- compared with I-bulls. MFI of ST and LD was lower in E-bulls compared with I-bulls, but only at 360 kg. In contrast, MFI of SU was higher in E- compared with I-bulls at 360 kg. In E- compared with I-bulls, shear force value of ST was higher (P<0.003) at 360 kg, but not at 460 kg. Panel scores for tenderness, taste and juiciness were all lower (P<0.006 to 0.001) and remarks for off-flavour higher in E- compared with I-bulls, the effects being most pronounced at 360 kg. A 10-week finishing period improved all meat and eating quality characteristics of E-bulls. In LD, the correlation between MFI and tenderness was 0.79 (P<0.001), which indicates a potential of MFI as an early predictor of tenderness.

Histo- and biochemical characteristics of the longissimus dorsi muscle at 65-70 kg body weight and their relationships to performance and meat quality at 100 kg were examined in Danish Landrace and Danish Large White female and castrated male pigs. Breed differences were observed for feed conversion rate, and a number of histochemical and biochemical traits. The organoleptic traits, flavour (13%), tenderness (15%) and overall acceptability (13%) were rated higher in Large White pigs. Significant correlations between histological and biochemical traits of the live muscle on the one side and performance, meat quality and organoleptic traits on the other side, could be demonstrated. However, these correlations were generally low (r < 0.35), and can thus only explain a small part of the variation in the measured quality traits. Consequently live muscle traits measured at 65-70 kg are poor predictors of meat quality characteristics after slaughter at 100 kg.

Ninety-six female and male pigs were assigned to one of three treatments, 'confined' (C),'trained'(T) or 'free' (F) allowing for different levels of physical activity during the growth interval from 30 to 100kg. Treatment C consisted of individual housing in pens of 2.5 m(2); treatment T of individual housing and regular treadmill training and treatment F of housing in pens of 36 m(2) (40 pigs/pen). In m. biceps femoris (BF), the activity of lactate dehydrogenase (LDH) was decreased between 9 and 12% by training (treatment T vs C). Likewise, in BF from female pigs, training increased the activity of citrate synthase (CS) and of 3-OH-acyl-CoA-dehydrogenase (HAD) by 18 and 21%, respectively. Spontaneous activity (treatment F) reduced the activity of LDH for five muscles between 10 and 16% when compared with treatment C. Around the time of slaughter, glycogenolysis of BF was less for treatment F (6-17%) than for C and T (33-38%). Moreover, in BF from female pigs in treatment F, the initial but not the ultimate pH was increased when compared with treatment C. In comparison to C and T, treatment F improved juiciness in BF from male pigs and increased the amount of salt soluble protein in m. longissimus dorsi.

A total of 300 female broiler chickens were reared from day-old to 10 d of age on the same starter diet. Then they were divided into five groups, receiving a control diet (Group 1) relatively rich in fat (14.3%) and unsaturated fatty acids (87.6%) and standardized with respect to vitamins and minerals, supplemented with 100 mg (Group 2) and 500 mg (Group 4) of RRR-alpha-,gamma-,delta-tocopheryl acetate/kg feed (40.6% alpha-, 41.1% gamma-, 18.3% delta-) or 100 mg (Group 3) and 500 mg (Group 5) all-rac-alpha-tocopheryl acetate/kg feed until slaughter at 6 wk of age. No differences between the supplemented groups were observed with respect to weight gain, feed consumption, packed cell volume (PCV), plasma enzyme activities of creatine kinase (CK) and glutathione peroxidase (GSH-Px), fatty acid composition, and enzyme activities of citrate synthase (CS), and total lactate dehydrogenase (LDH), and 3-OH-acyl-coenzyme A-dehydrogenase (HAD) of breast (Pectoralis major) and thigh (Gastrocnemius interna) muscle. Increasing levels of alpha-, gamma-, and delta-tocopherol were found in blood plasma with increasing dietary levels of these tocopherols. Only alpha-tocopherol was detectable in skeletal muscle and in higher concentrations in thigh than in breast muscle. Hemolysis in vitro and plasma activity of aspartate aminotransferase (ASAT) were lower (P < .01) in Groups 2 and 4 than in Groups 3 and 5. Interactions were observed between dietary type and concentration of tocopherols for plasma CK, GSH-Px, Na+, and K+. No measurable excretion of ethane and pentane was observed in any of the groups. The findings indicate that the oxidative stress in the live animals was minimal. The mixture of natural source RRR-alpha-,gamma-,delta-tocopherols was as efficient in protecting the live chickens as the all-rac-alpha-tocopheryl acetate, when provided on a weight basis as judged from the chosen in vivo parameters of vitamin E status.

Porcine M. longissimus dorsi from 12 carcasses were used to study the effect of ante mortem exercise treatment, time of boning and different ageing periods on tenderness and tenderisation in pork. The pigs were randomly allocated into three groups, of which the pigs (in two of them) were exposed to work on a treadmill: (1) 30 min rest after work, then slaughtered; (2) slaughtered without rest after work; and (3) controls, which were not exposed to work before slaughter. At 1 and 6 h post-stunning, samples from right side of each carcass were excised and immediately chilled in icewater until 24 h post-stunning. The left side loins were used as controls and were chilled on the carcasses at 12-14°C for 90 min and then at 2°C before boning at 24 h post-stunning. The effect of ageing, 0 or 7 days at 2°C, was studied. No parameter in this study was significantly affected by ante mortem treatment. WB shear force decreased significantly with increasing boning time and was correlated to the degree of muscle shortening in unaged excised samples. Muscle shortening for the 1 h excised cuts showed an average value of 27·4%, while an average value of only 6·1% was obtained for 6 h excised cuts. Ageing for 7 days resulted in only minor (7·3%) tenderness improvement for the 1 h excised cuts as compared to the 24·5% decrease in WB shear force obtained from the 6 h excised, less cold-shortened cuts. These differences in ageing rate, however, did not result in detectable changes in the degradation profile of myofibrillar proteins as analysed by SDS-PAGE.

Treatment of lean female pigs with porcine growth hormone (placebo or 80 μg pGH per kg body weight per day) for 6 weeks from 50 kg to 86 kg body weight did not change the frequency and the percentage area of muscle fibre types (ST, FTa and FTb fibres) and muscle capillarity of M. longissimus dorsi, M. gluteus medius and M. psoas major. The mean fibre cross-sectional area increased 5·3%, albeit nonsignificantly, corresponding to a 6·6% increase in carcass meat. The muscles contained slightly less dry matter and protein, and the lipid content of M. longissimus dorsi decreased 19% after pGH treatment. In the backfat the fatty acid composition changed towards a higher ratio of polyunsaturated to saturated fatty acids. The pH(u) of M. longissimus dorsi was unaltered, while the pH(45) was reduced by pGH. The muscle glycogen level and the activity of lactate dehydrogenase (LDH), citrate synthetase (CS), and 3-OH-acyl-CoA-dehydrogenase (HAD) of M. longissimus dorsi were unchanged by pGH. The haem pigment, shear force, sarcomere length and eating quality of loin chops, were unaffected by pGH treatment. The results show that pGH treatment did not change the muscle characteristics in a way that affects the meat quality of M. longissimus dorsi in lean female pigs.

The development of PSE (pale, soft and exudative) meat is characterized by a rapid decrease in pH post-mortem and/or a low ultimate pH. We investigated some physiological properties of the live muscle (the glycogen content, the non-bicarbonate buffering capacity and 'resting pH'), which could influence both the decrease in pH and the ultimate pH. Measurements were performed on three halothane genotypes, hal(N)hal(N), hal(N)hal(n) and hal(n)hal(n), with their known predispositions for PSE meat. It was demonstrated that the glycogen content in both the groups of double recessive and heterozygous individuals was higher than the levels in the group of homozygous dominant pigs. No difference was found in non-bicarbonate buffering capacity between the groups. The groups with the highest glycogen levels also had the lowest 'resting pH' values. The results indicate that measurement of glycogen content in vivo may be superior to the halothane test in detecting PSE-prone individuals. The lower pH values of carriers of the hal(n) gene further indicate that the characteristic rapid decrease after slaughter may not be as fast as generally accepted, as even very low pH values can be observed in the muscles of live pigs., (Copyright © 1992. Published by Elsevier Ltd.)