Carcass and meat quality of finishing Friesian steers fed the β-adrenergic agonist L-644,969

The effect of the β-adrenergic agonist L-644,969 on selected parameters of carcass and meat quality was examined in Friesian steers. Four groups of 18 steers were individually offered ad libitum a pelleted diet that contained 0, 0·25, 1·0, or 4·0 ppm L-644,969 for 12 weeks prior to slaughter. L-644,969 quadratically increased carcass weight (3·7, 9·3, and 8·5%, P < 0·001) and altered the distribution of lean meat such that a greater (0·3–5%; P < 0·01) proportion was in the more valuable cuts. There were no effects of L-644,969 on carcass-chill loss and on the water-holding capacity of the longissimus thoracis et lumborum (LTL) muscle. The intramuscular-fat concentration of the LTL was decreased (27–50%; P < 0·01) and the effects on muscle ultimate pH were small and commercially unimportant. Fibre-optic-probe measurements of the LTL indicated darker (P < 0·01) meat due to β-agonist treatment. L-644,969 increased the shear force required to cut through cooked muscle from the LTL (159%, 209%, and 217%, P < 0·001). It is concluded that L-644,969 treatment improved the quantity and distribution of lean in the carcass but impaired meat quality, primarily through a reduction in tenderness.     

The effect of chilling, electrical stimulation and conditioning on pork eating quality

The effect of three different post-slaughter treatments and subsequent conditioning times on the eating quality of pork was studied, using a total of 72 pigs (80–90 kg live wt). The treatments were: (A) holding in air at > 10°C for 3 h, followed by chilling in air at 1°C; (B) chilling in air at 1°C; (C) high voltage electrical stimulation (ES) at 20 min post-slaughter, followed by Treatment B. The quality attributes were measured in M. longissimus thoracis et lumborum (LTL) and in M. semimembranosus (Sm).

There was little difference in cooling rate between the three treatments; the major effect on quality came from the use of ES in Treatment C. ES reduced pH at 45 min by approximately 0·3 units, and achieved pH values at 3 h post-slaughter of 5·64 (LTL) and 5·87 (Sm) but did not produce PSE meat. Drip losses were generally low, but were slightly higher with Treatment C. By all three instrumental texture parameters, LTL from Treatment C was significantly more tender than from A and B at 4, 7 and 12 days post-slaughter, suggesting that either some cold toughening with A and B was overcome by ES in treatment C or that ES had some other beneficial action. Conditioning at 1°C improved the tenderness of LTL from 4 to 7 days and further to 12 days. Taste panelling of loin chops and Sm roasts confirmed that Treatment C gave significantly more tender meat than A and B, and that ageing from 4 to 7 days and further to 12 days significantly improved tenderness. High voltage electrical stimulation at 20 min post-slaughter followed by cooling in air at 1°C (Treatment C) produced loin muscle which was more tender at 4 days than at 12 days with the other treatments.     

The relationship of muscle fibre size to tenderness of beef

Steaks were removed from loins of beef carcasses at 1, 3, 6 or 14 days post mortem for fragmentation index (MFI), Warner-Bratzler Shear Force (SF) and sensory panel tenderness evaluation. Also, after 1 day of storage, samples were removed for histological observations. Greatest improvement in tenderness, SF and MFI occurred within the first 6 days of storage. Sensory panel tenderness was correlated (P < 0·01) with SF and MFI. Average muscle fibre size was correlated (P < 0·01) with tenderness and SF at days 1 and 3, but not at days 6 and 14. Evidently, muscle fibre size is important to tenderness prior to post-mortem storage of meat and proteolysis, but becomes less of a factor in tenderness after 6 days of storage.     

Identification of halothane genotypes by calcium accumulation and their meat quality using live pigs

The three halothane genotypes (NN, Nn, and nm) were identified by measuring the capacity for Ca²⁺ accumulation by sarcoplasmic reticulum in whole muscle homogenate preparations of M. longissimus dorsi with a Ca²⁺ specific electrode at 35°C. Significant differences (P < 0·001) in deterioration (%) of Ca²⁺ accumulation, 12% for NN, 35% for Nn, and 81% for nn pigs, were observed after ageing the whole muscle homogenate preparations for 24 h in ice.

Predictions of meat quality in live pigs (n = 34) based on the values for water-holding capacity, assessed as fluid (g/0·5 g wet wt LD), and pH (fluid) by using small biopsy LD samples (Cheah et al. 1993) were performed on all the halothane genotypes. The halothane genotype NN (n = 11) showed a fluid value of 0·37 ± 0·01 and a pH (fluid) value of 6·62 ± 0·03 as compared with 0·61 ± 0·02 and 5·84 ± 0·04, respectively, for the halothane genotype nn (n = 13). The Nn pigs (n = 10) showed fluid (0·49 ± 0·03) and pH (fluid) (6·19 ± 0·11) values between those values observed for the two homozygotes (NN and nn). Predictions of meat quality in live pigs from biopsy LD muscles were confirmed from assessments on post-mortem LD muscles based on pH₁ and fibre optic probe (FOP) measurements.

The extent of deterioration (%) in Ca²⁺ accumulation showed high correlations with fluid (r = −0·861) and pH (fluid) (r = −0·831) in the biopsy LD samples, and with pH₁ (r = 0·663), FOP (r = −0·812), and drip (%) loss (r = −0·777) in the post-mortem LD samples.     

The effect of post-exsanguination infusion on the composition, exudation, color and post-mortem metabolic changes in lamb

Twenty-four lamb carcasses were assigned to three treatment groups: (1) control (Ctr), (2) infused with 10% (vol/wt) of a tenderizing blend (NCa), and (3) NCa plus 0·015 CaCl₂ (WCa). Results indicated that the infused carcass solution was retained in the following order: shoulder > lion > leg. Infusion had no effect (P > 0·05) on drip and cooking losses in refrigerated samples. Samples frozen and then thawed from infused carcasses had greater thaw drip (P < 0·05) and cooking losses (P < 0·01) than control samples. The amounts of drip and cooking losses were in the order: WCa > NCa > Ctr. Frozen storage preserved the red color but lowered the lightness and yellowness of ovine muscles; the opposite effect was observed following refrigerated storage. Infused samples were lighter and yellower than control in both fresh and frozen samples (P < 0·01). WCa had less red color (P < 0·01) than NCa and Ctr at all times and storage conditions. Infusion lowered (P < 0·05) the temperature of carcasses over the first 3 h postmortem (pm) compared with Ctr. The rate of glycolysis was higher in infraspinatus (IS) than in longissimus thoracis et lumborum muscle (LTL or longissimus). In both IS and LTL, glycolysis was completed within the first 6 h postmortem in NCa, whereas in Ctr and WCa, it took 12–24 h for glycolysis to be completed. The rate of glycolysis was in the order: NCa > WCa > Ctr.     

Performance and carcass characteristics of bulls as influenced by exogenous hormones

One-hundred and forty-four weanling bulls of Angus (A, n = 48), Simmental x Hereford (SH, n = 8) and Simmental (S, n = 48) breeding were either castrated, left intact, left intact and implanted with Ralgro or left intact and implanted with Synovex S. Cattle were slaughtered after 190, 246 or 315 days of high-energy feeding. The right side of each carcass was electrically stimulated. Steers were inferior to intact treatments for most performance and carcass cutability traits, but steers were superior in marbling and lean quality (P < 0·05). There were no differences (P>0·05) in dressing percentage or ribeye area per 100 kg of carcass weight among treatments. Relative to intact bulls, Ralgro and Synovex S increased carcass masculinity. Implanted intact treatments did not differ from nonimplanted intacts for feed conversion, average daily gain, yield grade characteristics, percent longissimus dorsi chemical fat and 9–10dash11th rib composition (P >0·05).     

A modified hot processing strategy for beef: functionality of electrically-stimulated and hot-boned meat preblended with different NaCl concentrations

Chucks from 20 electrically-stimulated hot-boned (HB) and cold-boned (CB) beef carcasses were preblended with different concentrations of NaCl (0, 0·5, 1·0, 1·5 and 2·0% w/w). Preblends were analysed for pH, 2-thiobarbituric acid (TBA) values, protein extraction and emulsifying capacities. Bologna (with and without added sodium tripolyphosphate) and ground meat patties prepared from these preblends were also evaluated for cooking yield, color and texture parameters. Ultimate pH values of HB preblends increased with increasing NaCl concentration. At 1% NaCl, HB had higher ultimate pH than CB preblends (P ≤ 0·05) but preblending HB meat with 2% NaCl reduced TBA values (P ≤ 0·05) because the pH was maintained above 6·0. Higher amounts of protein were extracted from HB than from CB preblends (P ≤ 0·01), but boning and salting treatments did not affect their emulsifying capacities (P > 0·05). Two percent NaCl was required to fully achieve the prerigor salting effect. At this concentration, cooking yields of bologna prepared from HB preblends and phosphate containing bologna prepared from CB preblends were not different (P > 0·05) and were higher than those of bologna without added phosphate made from CB preblends (P ≤ 0·05). No meaningful effects were observed on color and texture parameters. Cooking losses were lower in patties made from HB than CB preblends (P ≤ 0·05) independent of NaCl concentration, but boning and salting treatments had no further effects on color or textural parameters (P > 0·05). Therefore, the superior functional properties of electrically stimulated prerigor meat can be maintained by the addition of 2% NaCl up to 2 h post-mortem.     

Effect of low voltage electrical stimulation of pig carcasses and ageing on sensory attributes of fresh pork

The effect of electrically stimulating pig carcasses and ageing on sensory attributes of pork was evaluated in this study. A total of 48 female pigs [Duroc×Large White/Landrace (A; n=24) and Large White/Landrace (B; n=24)] were randomly allocated immediately prior to slaughter to one of two low voltage stimulation treatments; no stimulation or 150 mA applied for 30 s at 2 min post-exsanguination. Each side of the carcass was then randomly allocated to an ageing treatment of either 2 or 7 days post-slaughter. Muscle pH of the M. longissimus lumborum was lower (P<0.001) in electrically stimulated carcasses when measured from 40 min to 8 h post-slaughter compared with non-stimulated carcasses. Percentage drip loss, muscle lightness and PSE incidence were not influenced (P>0.05) by electrical stimulation. Electrical stimulation of pig carcasses and ageing pork for 7 days post-slaughter both improved (P<0.001) consumer scores for tenderness, juiciness, overall liking and quality category, however the interaction term of electrical stimulation and ageing was not significant for any of the sensory attributes. Pork from non-stimulated carcasses that was aged for 2 day post-slaughter was less tender (P<0.01) compared with pork in all other treatments. These results indicate that electrical stimulation (150 mA applied for 30 sec at 2 min post-exsanguination) was effective in improving eating quality attributes of pork, particularly when pork was aged for only 2 days post-slaughter, without detrimentally affecting colour or drip loss.     

Variation in haem pigment concentration and colour in meat from British pigs

Variation in chemically determined total haem pigment concentration and instrumentally determined colour was examined in 223 samples of M. longissimus dorsi (LD) representative of the majority of slaughter pigs currently produced in the UK. Whether pigs were sired by White (Large White or Landrace) or Meat-line boars did not affect any measured characteristic but source breeding company influenced total haem pigment concentration (P < 0·01). Haem pigment concentration was higher in muscles from gilts, compared with castrates, boars being intermediate. Gilts also had darker muscles, based on EEL Reflectance values (P < 0·05), and lower hue values (P < 0·05). When compared with animals fed ad-libitum, restricted-fed pigs had higher concentrations of muscle haem pigment (P < 0·001) and this resulted in meat that was slightly darker (P < 0·05), despite having lower ultimate pH (pHu) (P < 0·05), and had a lower hue value (P < 0·001). Measurements of reflectance, total soluble protein and pHu indicated that differences in the incidence of potentially pale, soft, exudative or dark, firm, dry muscle were unlikely to be important contributors to variation in the colour of the meat in this study.     

Feeder cattle frame size, muscle thickness and subsequent beef carcass characteristics

Sixty feeder steers were assigned scores for frame size (small, medium or large) and muscle thickness (No. 1, No. 2 or No. 3), fed for 112 days and slaughtered. Grade data were collected for all 60 carcasses; 12 sides (four from each muscle thickness group) were fabricated into boneless, closely trimmed retail cuts and the 12 rounds from each of these sides were also physically separated into muscle, fat and bone. Marbling score and USDA quality grade varied inversely (P < 0·05) with frame size. Carcass quality grades were: 33·3% Choice; 67·7% Good and 0·0% Standard for small-framed cattle; 30·3% Choice, 42·4% Good and 27·3% Standard for medium-framed cattle and 5·5% Choice, 66·7% Good and 27·8% Standard for large-framed cattle. Analysis of variance showed significant (P < 0·05) differences among all muscle thickness groups in the longissimus muscle area and carcass weight but no difference in yield grade between the No. 1 and No. 3 muscle thickness groups; the larger mean longissimus muscle area of carcasses from steers in the No. 1 muscle thickness group was offset by their heavier carcass weight and their greater thickness of fat over the longissimus muscle. However, when analysis of covariance was used to hold fatness or fatness and frame size constant, the difference in yield grade between muscle thickness groups No. 1 and No. 3 was significant (P < 0·05). Also, carcasses from cattle assigned muscle thickness scores of No. 1, as feeders, had the highest (P < 0·05) muscle to bone ratio of the round (4·1 to 1) while carcasses from cattle assigned thickness scores of No. 3, as feeders, had the lowest (P < 0·05) muscle to bone ratio of the round (3·4 to 1).     

Muscle composition of steers treated with the β-agonist, cimaterol

The effect of the β-adrenergic agonist, cimaterol, on the nature and amount of collagen in three individual muscles (Longissimus dorsi, Vastus lateralis and Semitendinosus) from young steers was investigated.

β-Agonist-treated animals showed similar rates of liveweight gain to those of control animals but the weight and protein content of the Longissimus dorsi and Vastus lateralis muscles were significantly increased (muscle weights 1216 versus 1494 g, P < 0·05; 514 versus 642 g, P < 0·01, respectively, for control and cimaterol animals). The Semitendinosus muscle, however, showed no significant increase in weight or protein content (P > 0·05).

The total collagen content and the proportion of heat-soluble collagen varied considerably between muscles, but no significant muscle × treatment interactions were detected (P > 0·05). Cimaterol treatment reduced total muscle collagen content (controls 15·2, cimaterol 12·5mg/g fresh tissue, P < 0·05) and also reduced the percentage of heat-soluble collagen (controls 18·9%, cimaterol 13·0%, P < 0·05).     

Improving pork quality by electricalstimulation or pelvic suspension ofcarcasses

This investigation compared the separate and combined effects on meat quality of electrical stimulation (ES) and pelvic suspension of pig carcasses chilled rapidly or conventionally. Sides from 80 pigs, 80–90 kg live weight, were allocated to one of four treatments followed by either conventional chilling (1°C for 24 h) or rapid chilling (-20°C for 2–3 h, before 1°C until 24 h post-slaughter). The four treatments were: Achilles suspended, with and without high voltage ES, and pelvic suspended, with and without ES.

The quality attributes: pH, colour and opacity, drip loss, instrumental and sensory texture were measured in M. longissimus thoracis et lumborum, at 10 days post-slaughter. Rapid chilling reduced the evaporative weight loss by 0·5% There were no significant effects of treatment on colour or opacity, although ES samples were slightly paler. Drip loss was also slightly greater with ES, particularly when combined with pelvic suspension, but in no case was the meat classified as PSE. Instrumental measurements of 'texture showed improved tenderness from both ES and pelvic suspension, even after 10 days ageing. The improvement was less pronounced when ES and pelvic suspension were combined Taste panelling confirmed that samples treated by ES or pelvic suspension, separately or combined, were significantly more tender than samples from non-ES, Achilles hung sides. ES and pelvic suspension were equally effective in improving the tenderness of pork loin. Pelvic suspension did not suffer the disadvantage of increased drip loss that occurred with ES in this study.     

Tenderness of pork muscles as influenced by chilling rate and altered carcass suspension

Tenderness improvements in porcine muscles (M. longissimus dorsi, LD; M. semimembranosus, SM; M. biceps femoris, BF) were evaluated in a total of 72 carcasses by using combinations of three different chilling rates (fast, delayed fast, slow) and two different suspension methods (Achilles tendon, pelvic bone).

Tenderness was improved by fast chilling in LD, SM and BF by the pelvic suspension as compared to conventional suspension in the Achilles tendon (P < 0·05). The lengthening of the sarcomeres in SM and BF as produced by pelvic suspension exceeded those found in LD, without having proportional additional effect on the tenderness. While the pelvic-induced tenderization did not change significantly by delayed fast chilling, additional tenderization in BF and SM was obtained by combining pelvic suspension with slow chilling. In conventionally suspended sides, tenderness was unaffected by delayed fast chilling—with slow chilling, however, improvements were observed in LD and SM to a similar extent as obtained by the pelvic suspension. In the LD muscle, the tenderizing effect produced by treatments was largest in muscles having pH values 45 min post stunning above 6·1 (P < 0·05).     

Effect of different electrical stimulation and chilling treatments on pork quality

The effect of different chilling and electrical stimulation (ES) treatments on the carcass and eating quality of pork has been examined. Preliminary trials (Study I), with a variety of ES treatments, indicated that, on the basis of pH fall, drip loss and tenderness, the most effective was that using 700 V peak at 12·5 Hz for 90 s applied at 20 min post-slaughter. These ES parameters were used throughout the main study (II) using 80 pigs, one side of which was stimulated and the other not, before being chilled rapidly (10°C in deep loin within 2–3 h of slaughter) or conventionally (10°C in deep loin within 5 h of slaughter).

Changes in pH and temperature during chilling were observed and, after chilling, quality assessments on LD and Sm muscles included drip loss, muscle opacity and instrumental toughness at 3 days post-slaughter.

Electrical stimulation, 20 min post-slaughter, improved tenderness of the LD and, to a lesser extent, the Sm of rapidly chilled pig sides. This advantage was gained without producing PSE pork. In fact, drip loss from the LD was consistently less from the sides which had been stimulated.     

Effect of dietary ractopamine on tenderness and postmortem protein degradation of pork muscle

Twenty-four finishing pigs with a mean starting weight of 82 kg were assigned to two dietary regimens: (1) a corn–soybean meal basal diet (control; n = 12), and (2) the basal diet supplemented with 20 ppm ractopamine HCl (RAC; n = 12). After 28–30 days on the feeding trial, pigs were slaughtered, and the growth and carcass characteristics were measured. Furthermore, the 3rd–13th rib section of longissimus muscle was excised at 48 h postmortem, sliced into 19-mm thick chops, vacuum packaged, stored at 2 °C, and subjected to Warner–Bratzler shear force (WBSF) and electrophoretic tests after 2, 4, 7, 10, 14, and 21 days (postmortem). RAC feeding increased (P < 0.01) pig carcass weight and percent lean, but it also increased the day-2 muscle WBSF by 20% (P < 0.01). The shear force difference between control and RAC pig muscles gradually decreased and vanished by day 10 (P > 0.05) when both muscle groups became more tender. The muscle from RAC-fed pigs exhibited a slower protein degradation rate than muscle from the control animals, notably for proteins in the 15–45 kDa range. The results suggested that the tenderness difference between ractopamine-treated and control pig muscles was related to the proteolysis rate, and could be diminished with adequate postmortem ageing.     

Effect of genetic origin, diet and weaning weight on carcass composition, muscle physicochemical and histochemical traits in the rabbit

Fifty rabbits originating from the crossing of one dam strain with three sire strains, Hy+, INRA 9077 and INRA 3889, were studied. The adult body weights of the sire strains were 5·1, 4·1 and 3·1 kg, respectively. After weaning, the Hy+ and the INRA 9077 rabbits were fed either an H (11·99 MJ DE kg DM⁻¹) or L diet (9·67 MJ DE kg DM⁻¹). The INRA 3889 rabbits were fed only the H diet. In each of these five blocks, two weaning weights were studied and the rabbits were slaughtered when the average body weight of each block reached 2·5 kg. Slaughter yield, carcass fatness and hindleg meat to bone ratio were determined. Muscular tissue was described using (1) physicochemical criteria (ultimate pH, L^*a^*b^* colour) of the biceps femoris (BFE), tensor fasciae latae (TFL) and semimembranosus accessorius (SMA) muscles and (2) histochemical characteristics of the longissimus lumborum muscle (LL) through computerised image analysis (fibre type composition, cross-sectional area). At slaughter, the rabbits of INRA 3889 sire origin, which had the highest degree of maturity (72%), gave the best slaughter yield (p<0·01), the heaviest reference carcass weight (p<0·01), and highest LL proportion (p<0·01), hindleg meat to bone ratio (p<0·05) and fatness (p<0·01); their LL muscle showed the lowest percentage of βR fibres, while the cross-sectional area of their muscular fibres was the highest (p<0·05). When all sire × diet combinations were put together, the heavier the weaning weight, the lower the daily gain (p<0·01) and the lightness (L*) of thigh muscles (p<0·05). The lower the DE content of the diet, the lower the growth rate, the slaughter yield, the reference carcass weight (p<0·01) and the cross-sectional area of all types of muscle fibres of the rabbits of both Hy+ and INRA 9077 sire origin.     

Beef tenderness and sarcomere length

A wide range of muscle glycolytic rates was produced in 60 beef carcasses by applying different forms and periods of electrical stimulation immediately after decapitation; a further seven carcasses were not stimulated. The sides were subjected to normal chilling, and at 48 h one short loin per carcass was taken for tenderness evaluation and determination of sarcomere length (SL).

In the 19 relatively slow-glycolysing loins—those of 3-h pH (pH₃) above 6·3—tenderness extended over almost five panel units on a 1–8 scale, and included both the tenderest two and the toughest 10 muscles of the entire study. In the 48 loins of pH₃ below 6·3, on the other hand, tenderness ranged over only 2·5 units, and on average was a full panel unit higher than that of the high-pH₃ muscles. The most striking difference between the two groups, however, was in the relationship between toughness and shortening; the correlation of panel tenderness on SL was remarkably high in the slow glycolysers (r = 0·84), but negligible in those of faster pH decline (r = 0·16). Thus although shortening occurred to about the same extent and over the same range in both groups, it influenced tenderness and tenderness variability only when glycolysis was quite slow. A loin pH₃ of below 6·3, however, is unusual in non-stimulated carcasses, so slow glycolysis and the very wide tenderness diversity accompanying it must be expected in commercial operations that do not use electrical stimulation.     

Should electrical stimulation be applied when cold shortening is not a risk?

This experiment was designed to show whether delayed high voltage stimulation (ES) is more beneficial than no stimulation (NS) to secure tenderness under circumstances where rigor conditions are difficult to control due to variations in carcass size, fatness and/or chilling capacity. Ten Charolais carcasses were split during slaughter, the left sides were stimulated at 45 min post-mortem for 45 s, and the right sides were left unstimulated. The carcass sides were then chilled at a medium chilling rate. Sarcomere length measurements confirm that there was neither cold nor heat shortening in the M. longissimus (LD). LD from ES sides aged for 2 days was more tender than non-stimulated LD (NES), although prolonged ageing eroded the advantage of ES to a non-significant advantage after 14 days. Initial tenderness differences coincided with lower 24 h calpain activity, suggesting an early onset of proteolysis and ageing (tenderisation). In contrast to conventional early ES, delayed ES, appears to be beneficial for the early development of tenderness without too much interference with enzyme. Myofibril fragment length (MFL) was a good indicator of the development of tenderness during prolonged ageing but not for the early post-mortem variation in tenderness. No colour (L*, a*, b*) differences, occurred due to stimulation treatment, while drip loss was slightly higher at 24 h post-mortem for ES meat.     

Indigenous legume fermentation: Effect on some antinutrients and in-vitro digestibility of starch and protein

Indigenous fermentation of coarsely ground dehulled black-gram dhal slurry at 25, 30, and 35°C for 12 and 18 h reduced the levels of phytic acid and polyphenols significantly (P < 0·05). The unfermented legume batter had high amounts of phytic acid (1000 mg/100 g) and polyphenols (998 mg/100 g), and these were reduced to almost half in the product fermented at 35°C for 18 h. In-vitro digestibility of starch and protein improved significantly (P < 0·05) with increase in the temperature and period of fermentation. A significant (P < 0·01) and negative correlation found between the in-vitro digestibility and the anti-nutrient further strengthens these findings.     

Effects of rigor temperature and electrical stimulation on venison quality

The effects of rigor temperature and electrical stimulation on venison quality were assessed using venison longissimus dorsi muscle. In the first trial, effect of rigor temperature (0, 15, 25, 30, 35 and 42 °C) and time post-mortem (at rigor, 3, 7 and 14 days) on drip and cooking losses, % expressible water (water holding capacity, WHC), sarcomere length, protein solubility, meat tenderness and colour were investigated. In the second trial, the effects of rigor temperature (15 and 35 °C), electric stimulation (stimulated or not stimulated) and time (at rigor, 3 and 6 weeks post-mortem) on tenderness and colour were further investigated. Results of the first trial showed no clearly established trends of the effect of rigor temperature and time on the cooking and drip losses and protein solubility except venison muscles that went into rigor at 42 °C tended to have higher drip loss and lower protein solubilities compared to muscles that went into rigor at the other temperatures. Venison water holding capacity (WHC) decreased with the increase in rigor temperature (P < 0.001) and venison became more tender with time post-mortem. Venison colour improved with increasing rigor temperature. During display, samples that went into rigor at 15, 25 and 35 °C had the lowest and those at 0 and 42 °C had the highest rate of change of redness (a^*) value with time. In the second trial, tenderness was improved by stimulation (P = 0.01). Redness (a^*) values were affected by rigor temperature (P < 0.01) and post-mortem time (P < 0.001) but not by electrical stimulation. It is concluded that venison tenderness can be improved via the manipulation of rigor temperature to obtain acceptable level of tenderness early post-mortem with less damaging effect on colour stability.