Residual Blood Content Research Articles

Bleeding Efficiency and Meat Oxidative Stability and Microbiological Quality of New Zealand White Rabbits Subjected to Halal Slaughter without Stunning and Gas Stun-killing.

A study was conducted to compare the effect of halal slaughter without stunning and gas stun killing followed by bleeding on residual blood content and storage stability of rabbit meat. Eighty male New Zealand white rabbits were divided into two groups of 40 animals each and subjected to either halal slaughter without stunning (HS) or gas stun-kill (GK). The volume of blood lost during exsanguination was measured. Residual blood was further quantified by determination of haemoglobin content in Longissimus lumborum (LL) muscle. Storage stability of the meat was evaluated by microbiological analysis and measuring lipid oxidation in terms of thiobarbituric acid reactive substances (TBARS). HS resulted in significantly higher blood loss than GK. HS had significantly lower residual haemoglobin in LL muscle compared to GK. Slaughter method had no effect on rabbit meat lipid oxidation at 0, 1, and 3 d postmortem. However, at 5 and 8 days of storage at 4°C, significant differences (p<0.05) were found, with meat from the GK group exhibiting significantly higher levels of MDA than that from HS. At day 3, greater growth of Pseudomonas aeroginosa and E. coli were observed in the GK group (p<0.05) with B. thermosphacta and total aerobic counts remained unaffected by slaughter method. At days 5 and 7 postmortem, bacterial counts for all tested microbes were affected by slaughter method, with GK exhibiting significantly higher growth than HS. It can be concluded that slaughter method can affect keeping quality of rabbit meat, and HS may be a favourable option compared to GK due to high bleed out.

Investigation of the Role of FcγR and FcRn in mAb Distribution to the Brain

To evaluate the role of Fc receptors (FcR) on IgG distribution to the brain, the disposition of 8C2, a murine monoclonal IgG1 antibody, was investigated after intravenous administration in FcRn α-chain knockout mice, FcγRIIb knockout mice, FcγRI/RIII knockout mice, and C57BL/6 control mice. (125)I-8C2 was co-administered with (51)Cr-labeled red blood cells to allow accurate assessment of residual blood content in brain samples. Blood and brain tissues were harvested from subgroups of three mice at several time-points up to 10 days, and radioactivity was counted. The blood and brain areas under 8C2 concentration vs time curves (AUCs) were calculated using the linear trapezoidal rule, and the associated standard deviations (SD) were assessed using a modified Bailer method. Concentration data were also analyzed with a semiphysiological population pharmacokinetic model. The brain/blood AUC ratios were comparable across all strains of mice (ratios ± SD): 0.00774 ± 0.000452, 0.00841 ± 0.000535, 0.00636 ± 0.000548, and 0.00917 ± 0.000478 for C57BL/6 control mice, FcγRI/RIII knockouts, FcγRIIb knockouts, and FcRn α-chain knockout mice (p > 0.05). Statistically significant improvement in model fitting of the data was shown with incorporation of a strain-specific parameter for antibody clearance for FcRn knockout mice; however, no significant improvements in model fitting were found for strain effects on any other parameter, including the brain uptake clearance or efflux clearances for 8C2. The predicted 8C2 brain efflux clearance was found to be ∼135-fold faster than the brain uptake clearance, consistent with the observed low ratio of brain-blood exposure. The experimental results and modeling results indicate that, in mice, FcRn and FcγR do not contribute to the "blood-brain barrier" that limits mAb uptake into the brain.

Assessing and influencing the fractional contribution of erythrocyte-bound 59Fe to individual 59Fe tissue content in murine 59Fe distribution studies

Background Murine proteins of iron homoeostasis are frequently manipulated to investigate the mechanisms of iron-distribution and their toxicological consequences. Beyond subtracting erythrocyte-bound 59Fe of the residual blood content determined for each tissue (subtraction method), procedures are needed to determine 59Fe distribution in murine models of, e.g. inflammation or diabetes that cause local hyperaemia and changes in microcirculation. Aim Two new methods were developed to correct total 59Fe tissue content individually for erythrocyte-bound 59Fe-labelled haem iron. Methods Iron-deficiency and iron-overload was induced in male C57BL6 mice by feeding of respective diets. Distribution of 59Fe between different tissues was determined 24 h, 14, and 28 days after intravenous injection of 59Fe trace amounts. Haem-bound 59Fe was separated from non-haem 59Fe in homogenates from all tissues by dispersion in a mix of lipophilic cyclohexanone and hydrophilic H 3PO 4 (separation method). Moreover, the reduction of 59Fe-labelled tissue blood content was determined in all organs after in vivo saline perfusion via the left ventricle (perfusion method). Results and discussion 59Fe-labelled non-haem iron determined by the separation method was not significantly different from values determined by the subtraction method, except for the iron-deficient spleen 14 and 28 days after 59Fe injection when the separation method yielded ∼20% higher values. Approximately 20% of 59Fe-labelled haem iron spilled over into the hydrophilic phase. The impact of this error decreases in parallel to 59Fe radioactivity in the residual tissue blood content: thus, it is higher in iron-deficient mice which accumulate more 59Fe in their erythrocytes than iron-adequate and iron-rich mice. For the same reason this type of error is more marked after long distribution periods and in organs with high residual blood content. Saline perfusion via the left ventricle reduced total blood content in mice to less than 10%. Liver (95%) and duodenum (94%) showed the highest removal of blood while it is lowest in spleen (66%) and lungs (69%). Conclusions The separation and the perfusion method can be used to correct the impact of erythrocyte-bound haem iron individually. A margin of error below 10% was determined for all organs except for spleen, lungs, and fat. Both methods can be applied sequentially to obtain satisfactory results in spleen, lungs, and fat.

A method to assess 59Fe in residual tissue blood content in mice and its use to correct 59Fe-distribution kinetics accordingly

Background Dysregulation of body iron-distribution may induce oxidative damage. To investigate the molecular mechanisms of iron homeostasis, corresponding essential genes are manipulated by many working groups. This asks for a simple method to pursue the resulting impact on body iron-distribution in mice. Aim To develop a method for the assessment of 59Fe in residual tissue blood content and to correct this influence in 59Fe body distribution studies. Methods Iron status in male adult C57BL6 mice was adjusted by feeding diets with different iron content. Fractional contribution of organs to total body weight was determined after dissection. 59Fe-labelled blood was injected in recipient mice to estimate total blood volume and residual blood content in all organs and tissues. The main experiment used these data to correct total 59Fe tissue content at six intervals after 59Fe injection (12 h–28 days). Results and discussion The sum of 59Fe in all organs was the same as determined in each mouse before dissection. 59Fe in whole blood remained constant from the 4th day after injection on, and was highest in iron-deficiency. As in other species, residual blood content was highest in spleen and lungs. Nevertheless, 59Fe in the iron-deficient spleen decreased to zero and intestinal 59Fe-content also decreased significantly over time after correction for 59Fe in residual blood. These findings suggest correct assessment of compartment sizes and 59Fe in residual blood in each organ. Conclusions Differences in 59Fe-distribution between iron status reflected changes in the expression of proteins of iron-transport and its regulation correctly. Thus, the method seems suitable to analyse body iron-distribution in consequence to genetic manipulations of murine iron homeostasis which is a prerequisite to assess possible toxicological consequences of iron supplementation.

Uptake and metabolism of plasma-derived erucic acid by rat brain

We examined the ability of erucic acid (22:1n-9) to cross the blood-brain barrier (BBB) by infusing [14-14C]22:1n-9 (170 microCi/kg, iv and icv) into awake, male rats. [1-14C]arachidonic acid (20:4n-6) [intravenous (i.v.)] was the positive control. After i.v. infusion, 0.011% of the plasma [14-14C]22:1n-9 was extracted by the brain, compared with 0.055% of the plasma [1-14C]20:4n-6. The [14-14C]22:1n-9 was extensively beta-oxidized (60%), compared with 30% for [1-14C]20:4n-6. Although 20:4n-6 was targeted primarily to phospholipid pools, 22:1n-9 was targeted to cholesteryl esters, triglycerides, and phospholipids. When [14-14C]22:1n-9 was infused directly into the fourth ventricle of the brain [intracerebroventricular (i.c.v.)] for 7 days, 60% of the tracer entered the phospholipid pools, similar to the distribution observed for [1-14C]20:4n-6. This demonstrates plasticity in the ability of the brain to esterify 22:1n-9 in an exposure-dependent manner. In i.v. and i.c.v. infused rats, a significant amount of tracer found in the phospholipid pools underwent sequential rounds of chain shortening and was found as [12-14C]20:1n-9 and [10-14C]oleic acid. These results demonstrate for the first time that intact 22:1n-9 crosses the BBB, is incorporated into specific lipid pools, and is chain-shortened.

Zur Beurteilung der Fleischqualität bei Schalenwild

The carcasses of 140 roe deer, 129 wild boars, 81 red deer and 55 fallow deer were examined to determine meat quality with respect to the influence of typical hunting situations. After hunting, many carcasses had not been cooled, which significantly influenced meat-quality parameters. The pH-value, detected electrochemically, gave the most reliable results out of all the meat-quality parameters investigated. Determination of the pH-value with regard to the pH indexes ascertained for different points of measurement and types of game is helpful in properly judging the substantial quality of venison. Determination of electrical conductivity and water-holding capacity (Q) can be helpful in judging meat quality. The value of residual-blood content in judging substantial venison quality is, however, doubtful. The measurement of rapid glycolysis and the evaluation of rigor mortis are not appropriate for determining the substantial quality of venison.

Regional lung hematocrit variation and assessment of acute lung injury

Estimating blood content in the lung remains a key step in calculating lung water volume and microvascular permeability. We studied the effect of regional lung hematocrit (Hct) variation on assessment of acute lung injury. Escherichia coli endotoxin was administered in guinea pigs intravenously. Lung injury was evaluated by measuring the wet-to-dry weight ratio (W/D) and transvascular 125I-labeled albumin leakage for 3 h [tissue-to-plasma 125I-albumin ratio (T/P)] in five tissue samples from each animal. Residual blood content was corrected using either 51Cr-red blood cells as a blood cell marker, 99mTc-albumin as a plasma marker, or both, injected 10 min before the guinea pigs were killed. Lung Hct, estimated from the marker counts of lung and peripheral blood samples, was lower than peripheral blood Hct; intraindividual variation, represented by the standard deviation in each subject, was 0.024 +/- 0.015 for the control group (coefficient of variation 8.0 +/- 5.1%) and 0.026 +/- 0.013 for the endotoxin group (coefficient of variation 8.5 +/- 4.1%). Uncorrected W/D for residual blood content was greater than the corrected W/D. 99mTc-albumin correction gave values closer to the W/D corrected by both markers. T/P corrected by 99mTc-albumin showed smaller data variations than the values obtained with 51Cr-red blood cell correction, which was affected by variations in lung Hct. We recommend using a plasma marker to correct for blood content in assessing acute lung injury by W/D and T/P.

Studies on blood engorgement in beef carcasses

AbstractThis study examined whether delayed bleeding at slaughter affected the overall appearance and residual blood content of beef. Three muscles were analysed for residual blood content, and when delayed bleeding was performed only the forequarter muscle showed high blood levels indicating that engorgement occurred where blood had gravitated within the carcass. Electrical stimulation of the carcass immediately before delayed bleeding did not expel any of the retained blood. In terms of the overall appearance of the carcass, the worst sites for blood engorgement were the thymus, lungs and subcutaneous fat at the brisket and neck. A trial was also conducted which showed that inducing a cardiac arrest helped to reduce the expression of bruises inflicted at stunning or slaughter.

Time lag between pulmonary congestion and pulmonary edema in dogs.

The time course of pulmonary congestion and pulmonary edema was examined using a gravimetric method in 19 open-chest anesthetized dogs. Balloon catheters in the left atrium (LA) were inflated to elevate LA pressure more than 25 mmHg. The dogs were divided into 4 groups (G) according to the duration of the elevated LA pressure: G.1 (n = 6) as control; G.2 (n = 4) for 15 minutes; G.3 (n = 4) for 30 minutes; and G.4 (n = 5) for 60 minutes. Although no significant increase of extravascular lung water content (an indicator of pulmonary edema) was observed in G.2 (4.97 +/- 0.85 g/kg) and G.3 (4.46 +/- 0.96) compared with G.1 (4.02 +/- 0.88), a significant increase was observed in G.4 (6.81 +/- 1.21, p less than 0.05). Residual pulmonary blood content (an indicator of pulmonary congestion) was significantly increased in G.2, 3 and 4 compared with G.1. By light and electron microscopes, pulmonary congestion was revealed in G.2, whereas interstitial pulmonary edema was demonstrated only in G.4. Thus, it was concluded that pulmonary congestion occurred within 15 minutes, but pulmonary edema occurred 30 to 60 minutes after left atrial pressure was elevated more than 25 mmHg. This time lag may be an important factor in explaining the discrepancy between the elevated left atrial pressure and the clinical manifestation of pulmonary edema.

Effect of cardiac arrest at slaughter on residual blood content of hide

AbstractInducing a cardiac arrest between stunning and sticking in cattle had no effect on the residual blood content of the hide. Skin from animals which had been dead for about 15 min, but not bled, contained twice as much blood as skin from animals slaughtered in a normal manner. It is concluded, therefore, that the fellmongering problems which are associated with excessive amounts of blood in the hide should not be a problem when stunning methods which simultaneously induce a cardiac arrest are used. This should hold true provided the animal is stuck promptly after it has undergone heart failure.

Blood content of broiler chicken carcases prepared by different slaughter methods.

Two trials using broiler chickens were undertaken to determine if variations in commercial slaughter techniques affected either the appearance or the residual blood content of the carcases produced. In the first trial groups of broilers were either stunned (55, 80 or 105 volts), electrocuted (240 volts) or anaesthetised and the subsequent bleed-out volumes after one, two, three and four minutes exsanguination were measured. The method of slaughter made no difference to the amount of blood lost after venesection. Haemoglobin content of the pectoral muscle was used to measure residual blood and was uniformly low in all groups (0.7 to 0.16 mg haemoglobin/g of muscle). In the second trial groups of chickens were either stunned and bled out, electrocuted, electrocuted and bled out, decapitated or halal killed before processing. The edible portions of the carcases were minced and the average haemoglobin content for each group was 0.19, 0.36, 0.22, 0.17 and 0.17 mg/g of soft tissue. The appearance of chickens that were stunned and bled out was the same as that of chickens that were electrocuted and bled out. The authors conclude that killing chickens by electrocution before exsanguination does not adversely affect the carcase appearance. Furthermore, electrocution ensures that broiler chickens are humanely slaughtered.

Exsanguination of animals at slaughter and the residual blood content of meat

About 40 to 60 per cent of the total blood volume is lost at exsanguination. The loss can be influenced slightly by differences in traditional slaughter techniques and is considerably reduced after cardiac arrest in sheep and cattle. Blood not lost at sticking is probably largely retained in the viscera rather than the carcase. The residual blood content of lean meat is 2 to 9 ml/kg muscle. There is no evidence that this amount is affected by different slaughter methods or that large amounts of residual blood influence the microbiology of meat.

Identification of transferrin as the principal plutonium-binding protein in the blood serum and liver cytosol of rats: immunological and chromatographic studies.

An analysis of 239Pu-labelled protein complexes in serum and liver cytosol fractions prepared from rats injected intravenously with 239Pu-citrate indicated that among the possible metal-binding proteins, ferritin, transferrin and metallothionein, 239Pu was bound almost exclusively to transferrin. The method employed for the quantitative determination of 239Pu-transferrin was chromatography on immobilized rabbit anti-rat apo-transferrin. There was no evidence that transferrins from serum and liver cytosol are serologically different. The residual blood content of perfused and non-perfused liver was measured using 51Cr-labelled red blood cells and the amounts of blood-derived 239Pu and 239Pu-transferrin in the liver cytosol were calculated. The results are discussed with respect to the possible role of transferrin in the uptake of Pu into cells.

Residual blood in lamb muscles

The effect of slaughter method on the residual blood content of the M. longissimus dorsi, the microbiological status of the meat and its tenderness was examined with lambs. There were no differences in any of the characteristics examined between the various stunning procedures used, even though there were marked differences in the amount of blood collected after slaughter.

The influence of slaughter method on the residual blood content of meat

AbstractThe effect of slaughter method on the residual haemoglobin content of the M. longissimus dorsi and the amount of blood lost at exsanguination of sheep was investigated. The influence of stunning method (electrical, 90 V, or captive bolt pistol), pithing and bleeding‐out position were examined. Sheep bled lying lost more blood than those bled hanging and electrically‐stunned animals lost more blood than those stunned with a captive bolt pistol; pithing had no effect. The residual haemoglobin content of the muscle did not vary significantly between methods and there was no relationship between it and the amount of blood lost at slaughter.

Factors affecting the residual blood content of meat

From estimates of the residual blood content of muscles from rats killed while stressed or under barbiturate anaesthesia it appears that, at slaughter, the stress associated with stunning and exsanguination will normally produce peripheral vasoconstriction through the action of released catecholamines. This will result in minimal retention of blood in the skeletal muscles while factors which reduce vascular tone will lead to higher levels of residual blood in meat.

Haemoglobin concentrations in beef

AbstractHaemoglobin was used as an index of residual blood in beef muscles from various sources. Factors determining the amount of residual blood appear to operate in a similar way throughout the carcass musculature. Only one in 60 samples of M. longissimus thoracis et lumborum showed any evidence of poor bleeding and the increased blood content was very small. M. psoas major from cows and bulls contained significantly higher amounts of haemoglobin than those from steers, and in the case of cows this appeared to be due to their greater age, more blood being retained in the muscles of older animals. It is estimated that between 1.1 and 4.3% of the total blood volume of the live animal is retained in the musculature of a normal steer carcass and that the average residual blood content of normal butcher 's meat is about 0.3%.

The residual blood content of meat—A review

AbstractThere seems to be no unequivocal experimental evidence to support the widely held view that the efficiency of bleeding out of slaughter animals affects the eating or keeping qualities of meat. Neither are the effects of different slaughter procedures on bleeding efficiency clear, due partly to confusion over the relationship between the residual blood content of meat and the amount of blood lost at slaughter and partly to differences in the methodology used by various authors. As yet no really accurate and specific technique for determining whole blood in meat has been described.

A comparison of 125I and 51Cr for measurement of total blood volume and residual blood content of tissues in the rat; evidence for accumulation of 51Cr by tissues

The total blood volume of rats and the blood content of selected rat tissues have been measured by labelling plasma with 125I-labelled human serum albumin and 51CrCl 3. Unacceptably high values were obtained with 51Cr caused by accumulation of the isotope in the tissues. Spleen showed the greatest mean retention of 51Cr followed by kidney, heart, liver, brain and muscle in decreasing order, although there was considerable variation between animals. The results for total blood volumes obtained with 125I-labelled human serum albumin were within the normal range. Values for tissue blood content were in agreement with published data based on plasma markers.