Dark , Firm And Dry Research Articles

Rheological characteristics of fresh and frozen PSE, normal and DFD chicken breast meat

1. Textural and rheological differences among broiler breast meat ranging from pale, soft and exudative (PSE) to dark, firm and dry (DFD) in their fresh and frozen (and thawed) forms were investigated. 2. The PSE meat showed significantly higher lightness values and lower pH and water holding capacity values than normal and DFD meats; DFD meat was also significantly different from normal meat. 3. During cooking, PSE meat lost significantly more liquid and produced a softer gel than normal or DFD meats; texture profile analysis parameters were lower for the PSE meat. 4. The storage modulus values (G′, rigidity of elastic response of the gelling material) showed that DFD meat produced a more rigid gel during cooking (especially above 54°C) and later during cooling (back to 30°C) compared with the PSE meat. 5. Freezing resulted in a trend of lower G′ values before, during and after cooking. The results indicated that meat proteins were damaged during freezing and PSE meat was more severely affected, or that more protein denaturation occurred in the PSE meat.

Role of β-Adrenoceptor Signaling and AMP-Activated Protein Kinase in Glycolysis of Postmortem Skeletal Muscle

Postmortem glycolysis is directly linked to the incidences of PSE (pale, soft, and exudative) and DFD (dark, firm, and dry) meats, which cause significant economic loss to the meat industry. However, mechanisms controlling postmortem glycolysis are unclear. The objective of this study was to determine the role of beta-adrenoceptor signaling and AMP-activated protein kinase (AMPK) in postmortem glycolysis. Eighteen 2 month old C57BL/6J female mice were randomly separated into three groups. Group I received an intraperitoneal injection of saline solution only and served as the control; group II received a saline injection and then were forced to swim for 1 min; and group III received an injection of propranolol (1 mg/kg) in saline. In addition, six C57BL/6J female AMPK knockout mice were assigned to group IV, which received a saline injection and were forced to swim for 1 min. The longissimus dorsi muscle was sampled at 0, 1, and 24 h postmortem for pH and enzyme activity measurements. The objective is to elucidate the roles of beta-adrenoceptor signaling and AMPK in the glycolysis of postmortem muscle. Results showed that AMPK activity had a major role in determining the ultimate muscle pH, with an ultimate pH for control mice of 6.16 and AMPK knockout mice of 6.48. The beta-adrenoceptor signaling is essential for initial rapid glycolysis. Blocking beta-adrenoceptor signaling prevented the initial pH decline induced by stress. Activation of beta-adrenoceptor signaling due to preslaughter stress activates glycogen phosphorylase, resulting in a rapid glycolysis shortly after slaughter. On the other hand, the activation of AMPK is important for maintaining the activity of glycogen phosphorylase and pyruvate kinase, leading to a sustained glycolysis and a low ultimate pH.

Meat production using four terminal pig lines

AbstractThe influence of terminal sire (Duroc (D1 and D2), Large White/Pietrain (LW/P) and Large White (LW)) on several meat production and meat quality traits was investigated in 452 male and female offspring of Landrace/Large White dams. Age at slaughter, carcass length, carcass weight and dressing yield were similar for all lines, as was the production of shoulders, chops, and ribs with bacon. D2‐sired pigs produced more noble pieces as a percentage of their carcass weight than the other three lines. LW/P‐ and LW‐sired pigs were generally leaner than Duroc‐sired pigs. LW/P and LW pigs had the highest percentage of cuts (longissimus dorsi and semimembranosus muscle) classified as pale, soft and exudative (PSE) meat. There were no large differences between the lines in the occurrence of dark, firm and dry (DFD) cuts. Copyright © 2003 Society of Chemical Industry

Influence of the time of year on the incidence of PSE and DFD in Irish pigmeat

The conditions of PSE (pale, soft, exudative) and DFD (dark, firm, and dry) are significant causes for downgrading of pigmeat resulting in financial loss to the slaughter plant. The objective of this study was to document the variation in quality of pigmeat from one slaughter plant over a 15-month period, based on colour, appearance and pH. During 4 days of most weeks, 30 pigs were randomly selected from the slaughter line, resulting in a total number of 4560 pigs. Muscle pH between the third and fourth rib was measured 45 min, 90 min and 24 h after slaughter. Using a Minolta colorimeter (Hunter L, a, b scale), colour of the longissimus dorsi muscle was measured 24 h after slaughter. Muscle colour was also visually scored on a scale of 1–6. Carcass pH at 24 h post-mortem varied significantly with month of slaughter ( P<0.04) as did colour (Hunter L, P<0.001; Hunter a, P<0.001; Hunter b, P<0.001). It was concluded that meat quality as measured by 24 h pH and colour was poorest during the months of November and December. While this may be at least partly related to weather, it is probable that the increased slaughtering rates at this time and variable resting period before slaughter had the biggest impact.

Consumer acceptability of dark, firm and dry (DFD) and normal pH beef steaks

The sensory attributes of dark, firm and dry (DFD) and normal pH beef, both raw and fried, were evaluated and compared by a consumer panel ( n=64). Consumer sensory evaluations indicated that the general appearance ( P<0.05), colour ( P<0.001) and acceptability ( P<0.01) of raw normal pH steaks were preferred to those of raw DFD steaks. Twice as many panellists preferred the raw normal pH than raw DFD steaks because of the more attractive red colour, compared to the almost black colour of raw DFD steaks. No significant differences were found between the hedonic ratings of the sensory attributes of fried normal pH and fried DFD steaks. It was expected but not confirmed that consumers would find the tenderness of the DFD steaks more acceptable compared to the normal pH steaks. However, when forced to choose, female consumers significantly preferred fried normal pH steaks to fried DFD steaks, presumably because of a better flavour and more acceptable colour.

Pork meat quality affects peptide and amino acid profiles during the ageing process

Twenty pork carcasses were classified in different pork meat qualities: red, firm and non-exudative (RFN), pale, soft and exudative (PSE), red, soft and exudative (RSE) and dark, firm and dry (DFD) meat. The content of peptides and free amino acids during the ageing process was analysed and compared within quality classes. Four peptide fractions were isolated through cation-exchange and reverse-phase chromatography. The main significant differences among qualities were obtained for peptide fractions 3 and 4. Peptide fraction 3 at 4 days and peptide fraction 4 at 2 h postmortem were higher in the ideal pork quality (RFN) than in the other quality classes. The ageing of pork meats produced a general increase in all free amino acid concentrations for the studied quality classes except for Gln, β-Ala, Taurine and Orn and the dipeptides carnosine and anserine. The DFD class showed higher increases in Lys, Ala and Met probably due to the activation of neutral aminopeptidases.

Objectively Predicting Ultimate Quality of Post-Rigor Pork Musculature:II. Practical Classification Method on the Cutting-Line

To investigate the practical assessing method of pork quality, 302 carcasses were selected randomly to represent commercial conditions and were probed at 24 hr postmortem (PM) by Danish Meat Quality Marbling (MQM), Hennessy Grading Probe (HGP), Sensoptic Resistance Probe (SRP) and NWK pH-K21 meter (NpH). Also, filter paper wetness (FPW), lightness (L*), ultimate pH (pHu), subjective color (SC), firmness/wetness (SF) and marbling scores (SM) were recorded. Each carcass was categorized as either PSE (pale, soft and exudative), RSE (Reddish-pink, soft and exudative), RFN (reddish-pink, firm and non-exudative) or DFD (dark, firm and dry). When discriminant analysis was used to sort carcasses into four quality groups the highest proportion of correct classes was 65% by HOP 60% by MQM 52% by NpH and 32% by SRP. When independent variables were combined to sort carcasses into groups the success was only 67%. When RSE and RFN groups were merged so that there were only three groups (PSE, RSE+RFN, DFD) differentiating by color MQM was able to sort the same set of data into the new set of three groups with 80% accuracy. The proportions of correct classifications for HGP, NpH and SRP were 75%, 61% and 35% respectively. There was a decline in predication accuracy when only two groups, exudative (PSE and RES) and non exudative (RFN and DFD) were sorted. However when two groups designated PSE and non-PSE (RSE, RFN, and DFD) were sorted then the proportion of correct classification by MQM, HGP, SRP and NpH were 87%, 81%, 71% and 66% respectively. Combinations of variables only increased the prediction accuracy by 1 or 2% over prediction by MQM alone. When the data was sorted into three marbling groups based on SM this was not well predicted by any of the probe measurements. The best prediction accuracy was 72% by a combination of MQM and NpH.

Objectively Predicting Ultimate Quality of Post-Rigor Pork Musculature: I. Initial Comparison of Techniques

A total of 290 pork loins were selected to include a wide variation of quality to investigate the quality categories into which most pork falls, selection criteria for these categories and methods to objectively assess ultimate pork quality. They were probed at 24 h postmortem (PM) for the following: A) light reflectance by Danish Meat Quality Marbling (MOM), Hennessy Grading Probe (HGP) and Sensoptic Invasive Probe (SIP); B) electrical properties by NWK LT-K21 conductivity (NLT) and Sensoptic Resistance Probe (SRP): and C) pH by NWK pH-K21 (NpH). Also, measurements of % drip loss (PDL) and filter paper wetness (FPW), color brightness (L*), ultimate pH (pHu), lipid content, subjective color (SC), firmness/wetness (SF) and marbling scores (SM) were assessed. Each loin was categorized as either pale, soft and exudative (PSE), reddish-pink, soft and exudative (RSE), reddish-pink, firm and non-exudative (RFN) or dark, firm and dry (DFD). Statistically comparing coefficients of determination (CD), the results indicated that overall, the HGP predicted quality groups slightly better than MQM (CD=71 and 62% respectively), NpH and SRP were less effective (CD= 56 and 44% respectively), and SIP and NLT had the lowest values (CD=36 and 5% respectively). Combining various independent variable did not greatly improve the variation accounted for. When the data was sorted into marbling groups based on lipid content, this was not accurately predicted by any of the probe measurements. The MQM probe remained the best predictor for marbling class and accounted for about 25% of the lipid content variation. This was slightly improved to 33% when pHu was combined with MQM.

EFFECTS OF INJECTION OF A DILUTE PHOSPHATE‐SALT SOLUTION ON PORK CHARACTERISTICS FROM PSE, NORMAL AND DFD CARCASSES

ABSTRACTPhosphate‐salt pump effects were evaluated on sensory characteristics of pale, soft, exudative (PSE) pork, normal and dark, firm and dry (DFD) pork. Water‐holding capacity, instrumental color (L*, a*, b*), pH, and muscle color scores were determined at 24 h postmortem on pork loin pairs (n=21 pairs). Based on color score, paired loins were assigned to PSE, normal or dark, firm, dry groups. PSE muscles were lighter, redder and more yellow than normal or DFD muscles; hue angle indicated that DFD muscles were actually closer to the true red axis of the CIE Lab Color Space. Drip and purge losses were higher (p&lt;0.05) in PSE muscles. Paired loins were pumped with water (controls) or 0.3% tripolyphosphate solution (0.25% salt) to 110% of original weight, vacuum packaged, frozen, cut into chops, and cooked to 70 or 80C. Phosphate‐salt pumped loins were juicier and more tender (p&lt;0.05) than water‐pumped loins regardless of muscle condition. Loins cooked to 70C were juicier, were more tender (sensory) but required more force to shear than those cooked to 80C.

The influence of meat pH on mechanical and sensory textural properties of dry-cured ham

The texture of dry-cured ham is one of the most important factors in consumer quality perception of the product. In this study the texture and mechanical properties of normal and Dark, Firm and Dry (DFD) dry-cured hams were studied as well as the relationship between them. DFD hams were softer, pastier, more crumbly and more adhesive than normal ones despite having lower non-protein nitrogen ( p<0.05). One of the reasons for the texture characteristics of DFD hams could be the higher level of moisture observed in the Biceps femoris muscle and the high pH value. The mechanical parameters studied also showed clear differences between the two groups of hams, specially in the inner part which was less affected by the drying process. In general the correlation coefficients between sensorial and mechanical parameters were not very high (0.23–0.62). The use of a non-destructive mechanical test, compressing the ham with a spherical probe, makes it possible for DFD hams to be detected in the earlier stages of the manufacturing process and means that technological changes can be made in order to reduce the problematic texture obtained from this kind of meat.

Using pork to teach students quality variations and how they are measured. 1998 UW-AS-305 Class.

Using a total of eight pork loins representing DFD (dark, firm, and dry) and PSE (pale, soft, and exudative) conditions, 35 students conducted a series of objective and subjective measurements to demonstrate extremes in meat quality in a single 2-h laboratory. Students learned to objectively assess appearance, water-holding and water-binding capacity, ultimate pH (pHu), and shear force (cooked samples) by operating seven commonly known laboratory instruments. They also learned how to prepare and present samples for organoleptic analysis using hedonic and triangle tests. Finally, the students learned the factors related to meat quality and how extremely they can vary. Within one laboratory, they observed that DFD, when compared with PSE, averaged 1.5 units higher in pHu, 4.7% (absolute) less drip loss, bound 136% (absolute) more water, was darker in color (26 units lower L* value), was firmer with a more attractive structure requiring 1 kg/cm less force to shear, and was superior in organoleptic properties (overall 21% more desirable). Having 35 replicates to use for the data set, the results illustrated statistically significant variations in meat-quality traits and how they could be objectively measured. Nine months later, 12 of the students were surveyed. It was their perception that the laboratory was not any more effective than other laboratories in the same class, but they were able to remember 85% of the methods used to measure quality; about twice that of other methods taught in other laboratory sessions.

Consumer‐rated Quality Characteristics as Related to Purchase Intent of Fresh Pork

ABSTRACTConsumers (n=556) rated pink color, wet/dry appearance, overall acceptability and purchase intent of normal, pale, soft and exudative (PSE), and dark, firm and dry (DFD) pork loin slices in PVC packages in five retail supermarkets. DFD samples appeared driest and PSE samples appeared wettest. Samples in the higher ranked two purchase intent categories appeared more wet than those in the lower three categories. The pinker PSE samples and all DFD samples were in the higher ranked purchase intent categories. Purchase intent generally paralleled overall acceptability; however, prediction equations indicated that wet/dry appearance, color and overall acceptability all contributed to purchase intent decision depending on muscle condition.

A repeat national survey of muscle pH values in commercial pig carcasses

Measurements of pH values at 45 min post-slaughter (pH 1) in m. longissimus were taken in a total of 5598 commercial bacon weight carcasses. pH values at 24 h post-slaughter (pH 2) were taken on a further 5598 carcasses. The overall mean pH 1 was 6.39 with 15.1% of values less than 6.0. The overall mean pH 2 was 5.64, none of the values recorded were greater than 6.5. This survey shows a small increase over the 1983 study in the incidence of potentially Pale Soft and Exudative (PSE) carcasses. It found no evidence of a Dark, Firm and Dry (DFD) problem related to high ultimate pH.

Biophysical aspects of meat tenderness

Biophysical aspects of meat tenderness is reviewed, where the meat structural origin of variation in meat tenderness is tried to be elucidated. Processes, such as rigor development and ageing, known to influence the properties of the structural components, is covered, and variables that influence those processes, such as chilling, electrical stimulation and stress ante-mortem, are discussed. Meat tenderness can be evaluated both by sensory and instrumental methods. The relationships between mechanical and sensory assessments tend to be non-linear, which can be due to non-linearity in the sensory evaluation and that muscle fibre orientation is easier to control in instrumental than in sensory evaluation. Structural changes of the meat occuring during rigor development are both longitudinal and lateral contraction of the myofibrillar mass. Other structural events, based on the proteolytic action, are the loosing up of the myofibrils held together laterally, weakening of the myofibrillar length and myofibril fragmentation. Using instrumental recordings of meat toughness (Warner-Bratzler (W-B) peak force), it decreases significantly with degree of contraction, when raw, but the reverse is found, when meat is cooked above 60 °C. A structural explanation to this behaviour is suggested to be the following. When meat is raw the lateral contraction of the meat fiber increases with shorter sarcomeres, giving rise to a larger viscous component and hence a lower W-B peak force. On heating, however, with a larger extracellular space, when shortened, there is more room for the connective tissue to contract without being restricted by the myofibrillar mass. This in turn gives a higher number of fibers per unit cross-sectional area, hence a larger elastic modulus and a higher W-B peak force, when cooked. When chilling of muscle during rigor both warm- and cold-shortening occur. Minimal shortening region is for beef M. longissimus dorsi (LD) 10–15 °C and for M. semimembranosus (SM) 7–13 °C. For the SM muscle there is a high correlation between percentage shortening and ultimate tenderness both in the warm- and cold-shortening region. But for the LD muscle this is only the case in the cold-shortening region. This observation suggests that the LD muscle is a more enzymatically active muscle than SM. The influence of low-voltage electrical stimulation (ES) was followed in the cold-shortening region for muscles LD and SM. A significant effect on tenderness 15 days post-mortem was only observed for LD at 1 °C and 4 °C, but not for SM. It was suggested that enhanced proteolysis could be the reason for the improved tenderness on ES of LD, as colds-hortening was not prevented by ES. Long-term and short-term stress ante-mortem can give rise to DFD (dark, firm and dry)-and PSE (pale, soft and exudative)-meat, respectively. DFD-meat (pH u > 6.0 in LD) has relatively short sarcomere lengths, but still it is swollen laterally and has consequently a small extracellular space. Therefore DFD-meat usually is tender. PSE-meat has a large variation in sarcomere length. The long sarcomeres of PSE-meat is suggested to be caused by reduced shortening, due to the denaturation of the sarcoplasmic proteins during rigor. The short sarcomeres can be caused by a higher percentage of rigor development in the warm-shortening region and that the denaturation of the myosin heads cause both longitudinal and lateral contraction of the myofibrillar mass. There is also a large variation in tenderness of PSE-meat, but it has been found that this variation is positively correlated to the sarcomere length (r = 0.52**), as has been shown for the other variables that governs the rigor process.

INITIAL POSTMORTEM PORCINE MUSCLE PH EFFECT ON HEAT‐INDUCED GELATION PROPERTIES

ABSTRACTHeat‐induced gelation properties of the semimembranous muscle from induced DFD (dark, firm and dry) and normal pigs were characterized to evaluate the effect of muscle pH on strength and cooking loss of gels induced by a heating at 0.7C/min. The pH of muscle slurries (10% protein with 2% Nacl) were adjusted to 5.5, 6.0, 6.5, or 7.0 with 1 M 2‐[N‐Morpholino] ethanesulfonic acid buffer. Muscle with a high initial pH (DFD) had lower cooking losses at all adjusted pHs. Force required to penetrate the gel (Pf), force required to move plunger through the gel (Fp), and viscosity index of the gel were consistently higher for DFD muscle at each adjusted pH except pH 5.5. These results indicate that ultimate pH influences the thermal gelation properties of a meat product if the pH is ≥ 6.0. DFD muscle had desirable protein functionality and cooking yield.

The effects of selection for lean growth and the halothane allele on carcass and meat quality of pigs transported long and short distances to slaughter

Carcass and lean quality traits were studied in two genetic lines of pigs in which the halothane allele n was segregating with the normal allele N. One line had been selected for high growth rate and low backfat depth and the other line maintained as an unselected control. Pigs of the three segregants NN, Nn and nn from both lines were grown at two locations, one near the abattoir (1 h by road) and the other far (10 h) from the same abattoir. Pigs from both locations were fasted for 20 h before slaughter. Relative to control line pigs, those from the selected line had lower backfat depths, greater ham weights, eye muscle areas and carcass lengths but lower dressing percentages. The n allele had little effect on carcass traits but for lean quality traits, the n allele acted additively to increase acidity, paleness, water lost through drip, centrifugation and cooking and to reduce cured yield. Independently of the n allele, selection for lean growth increased the incidence of dark, firm and dry (DFD) pork. This was highest in carcasses of NN pigs from the selected line grown far from the abattoir. nn pigs from the control line grown near the abattoir produced the most pale, soft, exudative (PSE) pork.

The influence of inherent muscle quality upon the storage life of chilled pork stored in CO 2 at −1.5 °C

A total of 120 pork loin sections (1 kg) representative of five inherent muscle quality groups [24 each; extremely PSE (pale, soft and exudative), PSE, normal, DFD (dark, firm and dry), and extremely DFD]were used to evaluate the effects of inherent muscle quality on the keeping quality of chilled pork stored for up to 15 weeks in CO 2 at −1.5 °C. B. thermosphacta, pseudomonads, and enterics did not grow on any muscle quality group during storage in 2.5 1 of carbon dioxide per kg of product. Lactic acid bacteria became the dominant flora on all muscle quality groups during storage and reached maximum numbers during the first six weeks of storage. Purge losses increased during the first three weeks of storage from all muscle quality groups but were generally the highest from pork with normal muscle quality throughout storage. The pH of pork with PSE characteristics tended to normalize with extended storage, and the color of pork with extremely aberrant quality appeared to normalize by approximately one level of muscle quality after 15 weeks of storage. Pork with DFD characteristics required the longest duration of storage to display surface discoloration. The retail appearance of pork from all muscle quality groups was well within the acceptable range after 15 weeks of storage, but the retail appearance of pork with normal and DFD characteristics deteriorated progressively during storage. Off-odors became detectable in all muscle quality groups after 12 weeks of storage but were more pronounced from pork with DFD characteristics. However, the intensity of these off-odors did not become more than slight even in DFD samples. Although the odor acceptability began to decline after 12 weeks of storage, all samples remained quite acceptable in odor after 15 weeks of storage. Muscle quality exerted little influence on cooking times and losses throughout storage. Pork with normal quality characteristics was generally less tender prior to storage. Although muscle quality exerted little influence on other palatability attributes, both flavor desirability and overall palatability deteriorated during storage in all samples and reached the point of unacceptability after six weeks of storage, when lactic acid bacteria attained maximum numbers.

Plasma and muscle cortisol measurements as indicators of meat quality and stress in pigs

Post-slaughter blood samples and muscle samples were collected from pigs slaughtered at the completion of a live-animal performance trial. There were two lines of pigs in which the halothane allele (n) was segregating. The lines were a lean line selected for rapid lean growth and an unselected fat line. There were homozygous normal (NN), homozygous halothane positive (nn) and heterozygous (Nn) genotypes in both lnes. Cortisol was measured in the plasma of the blood samples and in muscle juice obtained by high-speed centrifugation. Meat quality was assessed using pH, colour, fibre-optic probe, drip loss and cure yield measurements. Plasma cortisol concentrations in the fat line were significantly ( P < 0·05) greater than thosein the lean line but concentrations did not differ significantly for the three halothane genotypes. Carcasses classified as dark, firm and dry (DFD) had significantly ( P < 0·05) greater muscle cortisol concentrations than those classified as normal. Plasma and muscle cortisol concentrations of carcases classified as pale, soft and exudative (PSE) did not differ significantly from those classified as normal. Correlations between muscle cortisol and meat quality attributes were generally highly significant ( r = 0·31 to r = 0·51, P < 0·001) There was a highly significant correlation ( r = 0·73, P < 0·0001) between plasma and muscle cortisol concentrations.

GLYCOLYTIC POTENTIAL IN PORCINE LONGISSIMUS MUSCLE BEFORE AND AFTER TRANSPORT: AN IN VIVO STUDY

The purpose of this research was to study the effect of transport on the glycolytic potential (GP, very close to glycogen content) measured in vivo of porcine Longissimus muscle. Four groups of 9 (Landrace × Yorkshire) × Hampshire crossbred pigs, corresponding to 4 rearing pens, were transported unmixed for 2 h. Biopsy samplings were performed immediately before and after transport on each pig. GP did not vary significantly when compared before and after transport (–2.2%). As shown by postmortem pH and internal light scattering measurements, no tendency toward the PSE (pale, soft and exudative) or DFD (dark, firm and dry) conditions was observed. It was concluded that a relatively short transport time (2 h) without mixing unfamiliar animals, did not induce high stress, as shown by the stability of muscle glycogen stored in vivo and the lack of deviation in meat quality traits postmortem.

Effects of feed withdrawal before delivery on pork quality and carcass yield

A total of 270 pigs from a Yorkshire/Duroc/Landrace 3-way cross, reared under an ad libitum feed regimen, were delivered for slaughter after fasting (with access to water) for 24 and 0 h (Exp. 1), 16 and 0 h (Exp. 2) and 24, 16 and 0 h (Exp. 3). The interval between delivery and slaughter was 4–5 h. Feeding until delivery resulted in a lower pH at 45 min post mortem in the longissimus muscle. Ultimate pH values of longissimus and semimembranosus muscles were higher after feed restriction for 24 h. However, the incidence of dark, firm and dry (DFD) (pH > 6·2) was also increased after fasting in Exp. 1. Assessment of meat quality in samples taken from the longissimus at 20 h post mortem showed that, in comparison with feeding until delivery. Hunter L ∗ (Lightness)-values and drip loss decreased and firmness improved by prolonged fasting (24 h). Fasting for 16 h did not reduce drip loss, but colour was improved (lower Hunter L ∗-values) in Exp. 3, although not in Exp. 2. Feeding until delivery resulted in better meat quality in Exp. 2 than in Exp. 1 and 3. A significant reduction in dressing percentage as a result of fasting was only found in Exp. 1. There appears no economic disadvantage in restricting feed for 16 h prior to delivery. Although the incidence of DFD may also increase, a fasting period of 16–24 h is recommended to reduce pale, soft and exudative (PSE) muscle, while losses in carcass yield are minimized. Other advantages of fasting are discussed.