The effects of resting sheep after a long journey on concentrations of plasma constituents, post-mortem changes in muscles, and meat properties

1977 ◽  
Vol 28 (3) ◽  
pp. 509 ◽  
Author(s):  
WR Shorthose

After a 1110 km road journey, rams were rested either 18 hr with water available or 120 hr with feed and water before slaughter. Not all animals rested for 120 hr ate the feed offered. Animals rested for only 18 hr had less glycogen in the M. longissimus dorsi (LD) and liver at slaughter than those rested for 120 hr. The ultimate pH values of the LD (5.94) and M. semitendinosus (6.31) of rams rested for 18 hr were greater than those of the same muscles from animals that ate during their 120 hr rest period. Meat colour was darker in chops from animals rested for 18 hr than in those from animals rested 120 hr, although peak shear force values for this muscle did not differ between the two treatments.

1978 ◽  
Vol 26 (2) ◽  
pp. 229-232 ◽  
Author(s):  
W. C. Smith ◽  
A. Wilson

ABSTRACTMeasurements of longissimus dorsi pH at 45 min post mortem (pH1) were taken in 27 727 pig carcasses at four bacon factories. The overall least squares mean pH1 was 6·26 and 15·5% of carcasses had pHi values of 5·9 or less. Sex and commercial grade of carcass had little influence on muscle pHi or the incidence of values below pH 6·0. Factory differences were recorded in the distribution of muscle and within each there were marked producer effects in mean and the incidence of values below pH 6·0. Carcasses of Large Whites had fewer muscle pH1 values below 6·0 (12·4%) than those of British Landrace (18·7%), this being mainly due to a large breed effect at one factory. Although breed and testing background of sires of the carcasses examined and the first order interactions with factory had significant effects on muscle pHi and the incidence of values below pH 6·0, they were of little practical significance.


1975 ◽  
Vol 55 (4) ◽  
pp. 519-525 ◽  
Author(s):  
P. J. L’HIRONDELLE ◽  
A. H. MARTIN

Methods of estimating tenderness of beef muscle were evaluated on 282 steer and heifer carcasses. pH values (1 h and 2 h post-mortem) did not relate to shear values or panel tenderness scores on the cooked longissimus dorsi, evaluated after 6 days’ aging. Values obtained with the Armour tenderometer on the raw rib-eye were not useful predictors of tenderness of the cooked muscle (r2 < 6%). The Ottawa Texture Measuring System extrusion cell did not relate texture properties of the raw muscle to tenderness of the cooked meat. Marbling score explained 14% of the variance in panel tenderness scores. No satisfactory classification of carcasses into tenderness desirability groups was achieved with any of the methods examined.


2012 ◽  
Vol 55 (4) ◽  
pp. 385-390 ◽  
Author(s):  
D. Maj ◽  
J. Bieniek ◽  
I. Sternstein ◽  
A. Węglarz ◽  
P. Zapletal

Abstract. A study based on 150 carcasses of rabbit crosses of three breeds: Flemish Giant (FG), New Zealand White (NZW) and Californian (CAL) was conducted to determine the changes that occur within the first 24 h post mortem in the meat color parameters, i.e. lightness (L*), redness (a*), yellowness (b*), chroma (C*) and hue (H*), in the rabbits of different genetic groups and sexes. Four groups were formed: FN (FG bucks×NZW does); FC (FG bucks×CAL does); FN×C (FN bucks×CAL does); FN×FN (FN bucks×FN does). Meat colour was measured on the surface of Longissimus dorsi (LD) and biceps femoris (BF), 45 min and 24 h post mortem. The genetic groups differed significantly in the meat colour parameters of the LD and BF muscles at both times after slaughter. After 24 h, a* and b* values of the LD muscle were highest in FC group (18.05 and 6.65, respectively) and the lowest in FN×FN group (16.46 and 4.75, respectively). The greatest color difference (ΔE) of the LD muscle was in FN×FN rabbits (9.85) and the smallest in FC group (5.07). The differences between genetic group in color parameters of the BF muscle were smaller but significant, which indicates that crossbreeding may be used in practice to change meat color. Sex did not influence significantly the color parameters of the muscles at either time, although the a* and C* values of the BF muscle were higher in males than females.


Author(s):  
Ivo Ingr ◽  
Radomír Božek ◽  
Miroslav Jůzl

High-powered means of slaughter chickens production cause on certain individuals abnormal biochemical development of postmortal changes in their muscles. It consequently lead to interferences of sensory quality of the chicken meat. So called myopathies of the chicken breast meat occur in the low extent. It is typical variation in dark colouring of breast muscle. Veterinary supervision confiscates chickens embodying myopathy by reason of sensorical unacceptable dark muscle colour. Deepness of colour is evaluated by adspection of veterinary supervisors. It is tendency leading to find out objective parameters for evaluating this sensual chicken meat colour variation. Incidence of the chickens with myopathy has been evaluating for 3 years in big poultry slaughter, therewithal high-quality chickens and chickens with perspicuous myopathy have been taking out of slaughter-line. Electric conductivity values and pH values were measuring during 60 till 330 minutes post mortem in breast muscles. Aproximately 9 millions chicken was annually slaughtered and 13 thousands of them was confiscated out of the slaughter line by reason of myopathy. It amounts to 0.14 per cent of annually count of processed chickens. Myopatical chickens had significantly higher muscle pH values as compared with healthy ones. Healthy chicken muscles decreased on ultimative pH values aproximately past 3 hours post mortem. It means pH 6.03, and after 300 minutes decreased to pH 5.82. However, myopatical chickens values varied from pH 6.46 to pH 6.30. Concurrently measured values of electric conductivity significantly corellated with pH values. Whereto, it's predication of similarity chicken myopathies and dark, firm, dry (DFD) pork or turkey meat. Beyond unacceptable dark meat colour have disadvantage in poor post mortem acidifying of the meat and in consequence of microbial proteolyse. Significantly correlation between pH and electric conductivity values foreshadows on identification of myopatical chicken meat by means of conductivity measuring.


2009 ◽  
Vol 2009 ◽  
pp. 115-115
Author(s):  
B W Moss ◽  
A Gordon

Prediction of eating quality of beef at an early stage post mortem would enable selection of carcases for specific markets. Shackelford (2004) reported the design of near infra red (NIR) equipment suitable for measurement of larger areas of the muscle and also the prediction of 14 day slice shear force values from NIR measurements made at 2 days post slaughter (Shackelford 2005). The aim of the present study was to evaluate the use of equipment of a similar design and manufacture to that used by Shackelford et al (2005), to evaluate repeatability and time of measurement of NIR spectra on the prediction of Warner-Bratzler Shear force values.


1970 ◽  
Vol 45 (3) ◽  
pp. 255-262
Author(s):  
KY Modika ◽  
L Frylinck ◽  
KW Moloto ◽  
PE Strydom ◽  
PH Heinze ◽  
...  

The study describes the relationship between visual and instrumental measurements for colour and tenderness between five South African beef breeds: Bos indicus (Brahman), Sanga type (Nguni), British Bos taurus (Angus), European Bos taurus (Charolais) and the composite (Bonsmara). Ten animals per genotype were used (total = 50). The carcasses were split and the right sides were electrically stimulated, while the left sides were not stimulated. Steaks were aged until three days post mortem on polystyrene plates and until 9, 14 and 20 days post mortem in vacuum bags. The steaks were evaluated by visual analysis for colour, marbling, fibre separation, surface texture and structure integrity by a 10-member trained panel. Colour was also measured by the CIE L*, a*, b* system using a Minolta meter, and tenderness was measured by means of Warner-Bratzler shear force. High negative correlations were observed between the visual colour and L* (r = −0.809), b* (r = −0.698) and high positive correlations were observed between the visual colour and hue (r = 0.797). There were also negative correlations between shear force and structure integrity (r = −0.410) and fibre separation (r = −0.401). Very low negative correlations were observed between colour and shear force (r = −0.242). Therefore, although it may be possible to judge meat colour by visual analysis, it does not appear possible to predict tenderness by colour judgment. There is potential for an experienced eye to predict tenderness by observing visual structural properties such as fibre separation and structural integrity.Keywords: Meat colour and tenderness, tenderness prediction, trained visual panel, visual analysis


1988 ◽  
Vol 39 (1) ◽  
pp. 97 ◽  
Author(s):  
JR Wythes ◽  
RJ Arthur ◽  
RM Dodt ◽  
WR Shorthose

In two experiments, we examined the effects on carcass weight, bruising and muscle properties of resting cattle during a long rail journey and for various periods at an abattoir before slaughter. In experiment 1, 170 Shorthorn bullocks (mean liveweight 556 kg) were transported 90 km by road and 650 km by rail, with three groups (34 per group) going directly to an abattoir and two groups resting once for one day midway during the rail journey. The resting periods at this abattoir were 2, 3, 4,2 and 3 days, respectively. In experiment 2, 240 cows (mean liveweight 424 kg) were transported 190 km by road and 965 km by rail, with three groups (40 per group) going directly to another abattoir, two groups resting once for one day and one group twice for one day during the rail journey. The resting periods at this second abattoir were 1.5, 2.5, 3.5, 1, 2 and 1 day(s), respectively. All cattle had access to feed and water during resting periods and to water until slaughter. As the total resting period after the start of the rail journey and before slaughter increased, the percentage of carcasses with high pH values for M. longissimus dorsi decreased (P < 0.05); correlations for pH 24 h post mortem and ultimate pH were -0.97 and -0.71, respectively. The correlation between total resting period and shear values (initial yield and peak force) were c. -0.5. A resting period during the rail journey was as effective as that time spent resting at the abattoir. Cattle transported directly by rail to the abattoir had a greater bruise score than those rested en route, although cows rested twice were as bruised as those going direct. Treatment had no significant effect on carcass weight or systematic effect on cooking loss. Very high incidences of high ultimate pH values in one group of bullocks (29.4%) and another of cows (20.5%) occurred following periods of stress when slaughtering was interrupted by unavoidable stoppages.


1980 ◽  
Vol 31 (4) ◽  
pp. 849 ◽  
Author(s):  
JR Wythes ◽  
WR Shorthose ◽  
PJ Schmidt ◽  
CB Davis

After a long journey of 1420 km, bullocks were watered without feed for 0, 3.5, 7, 28 or 32 h or watered with feed for 32 h prior to a 16 h preslaughter fast (no water and feed). The 108 bullocks in the first three treatments (36 per treatment) were slaughtered after resting for 1 day and the remaining 108 after resting for 2 days. Bullocks lost 10.4% of initial liveweight (656 kg) in transit. Mean liveweight of 588 kg on arrival increased when bullocks had access to water, so that after 3.5 h on water the net liveweight loss was reduced (P < 0.05) to 6.0 % of initial liveweight and after longer periods the loss varied from 6.8 to 7.3%. The net loss of the group also offered lucerne hay was 6.7%. More importantly, re-hydration increased (P < 0.01) gross hot carcass weight from 369 kg to 383 kg when bullocks were watered for 3.5 and 7 h, 381 kg after 28 h on water alone and 379 kg after 32 h on water and feed. However, this increment was not maintained, since the carcasses of bullocks on water alone for 32 h averaged 376 kg and were lighter (P < 0.05) than those of other bullocks on water. The water content of fat-free muscle reflected the same pattern as carcass weight (P < 0.01), although muscle water content peaked at 78.16% when bullocks were watered for 28 h compared with 76.01 % for those bullocks not offered water. Resting bullocks for 2 days rather than 1 day reduced (P < 0.01) the pH values of the M. longissimus dorsi 24 h post mortem from 5.64 to 5.57.


2018 ◽  
Vol 87 (2) ◽  
pp. 173-180 ◽  
Author(s):  
Josef Kameník ◽  
Alena Saláková ◽  
Ladislav Kašpar

The muscles of the pork topside – musculus adductor (AD) and m. semimembranosus (SM), and of the silverside – m. biceps femoris (BF) and m. semitendinosus (ST) were analysed and their properties compared with the m. longissimus thoracis (LT) and m. supraspinatus (SS) muscles. Colour (CIE L*a*b*), D/L-lactic acid content, and pH values were measured 45 min and 24 h post mortem. The basic chemical composition of muscles was analysed 24 h after slaughtering. A significant correlation (r = -0.61, P < 0.001) was found between the pH values and the level of lactic acid 45 min post mortem, though not 24 h after slaughter (r = -0.25, P > 0.05). The results confirmed that a direct comparison cannot be made between the fall in pH values in meat and the increase in the level of lactic acid. The lightness L* 24 h post mortem was higher (P < 0.05) in AD, BF, ST and LT muscles than those in samples measured 45 min after slaughter. The toughest muscle was biceps femoris, with a mean value of shear force of 90.5 N. The differences in shear force between the individual analysed muscles were significant (P < 0.05). There were significant differences in the intramuscular fat content between the topside and silverside muscles (P < 0.05). The results of the present study are of value to meat producers who might intend to substitute these parts of the leg with one another during the production, particularly in the case of whole-muscle meat products.


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