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1.
Variations in chicken breast meat quality: implications of struggle and muscle glycogen content at death 总被引：1，自引：1，他引：0
Berri C Debut M Santé-Lhoutellier V Arnould C Boutten B Sellier N Baéza E Jehl N Jégo Y Duclos MJ Le Bihan-Duval E 《British poultry science》2005,46(5):572-579
1. Pectoralis major (P. major) muscle pH and meat quality traits were studied in relation to bird response to ante-mortem stress in three chicken lines: a fast-growing standard line (FGL), a slow-growing French 'Label Rouge' line (SGL) and a heavy line (HL). Ninety-nine birds of the three genetic types were slaughtered at their usual marketing age (6, 12 and 6 weeks for FGL, SGL and HL birds, respectively) on the same day. The birds of each line were divided into three different ante-mortem treatment groups: minimum stress (shackling for 10 s) (C), shackling for 2 min (SH) and acute heat plus shackling stress (exposure to 35 degrees C for 3.5 h and shackling for 2 min before stunning) (H + SH). 2. Regardless of chicken line, wing flapping duration (WFD) between hanging and stunning was strongly negatively related to P. major muscle pH at 15 min post-mortem. It was also moderately negatively related to P. major muscle glycolytic potential (GP), which represents glycogen level at death. Increasing WFD induced an increased ultimate pH (pHu) only in HL. The consequences of increased WFD for breast meat traits were dependent on the chicken line: it induced lower L* and b* and higher a* and drip loss in SGL while it only increased breast a* in HL birds. By contrast, WFD variations did not alter breast meat quality traits of FGL birds. Regardless of the chicken line, increased GP was associated with lower pHu and higher L* and drip loss. In SGL, it also increased b* and decreased curing-cooking yield of breast meat. 3. Struggling activity on the shackle line and muscle glycogen content at death could partly explain line and pre-slaughter variations in breast meat pH and quality traits. The water holding capacity of the raw and cooked meat was impaired by long shackling in the case of SGL birds while it was barely affected by ante-mortem conditions in the two standard lines. In conditions which minimised bird struggling (C), SGL and FGL birds had meat with a better water holding ability than that of broilers from the heavy line. However, when broilers were subjected to SH or H + SH conditions, the breast meat water holding capacity of SGL birds was lowered to the same level as that of the heavy line birds. 相似文献
2.
A breast support conveyor has the potential to improve bird welfare by avoiding the need to invert and suspend broilers by their legs as they move from the point of shackling to entry into the electric waterbath. To evaluate its effect on welfare under commercial conditions, a breast support conveyor was installed under the conventional shackle line of a small poultry processing plant. A structured assessment of the behaviour of the birds indicated a significant decrease in struggling and wing flapping at the point of shackling, on the straight conveyor and at entry into the waterbath. This resulted in a lower prevalence of red wing tips and bruising in the first wing joint. The shackle line and conveyor in this installation, however, passed around a 90° corner, which appeared to cause more disturbance to the birds on the conveyor than to comparable birds suspended from shackles in the traditional manner. The results indicate that a breast support conveyor has the potential to improve bird welfare on straight shackle lines and that, because struggling activity and duration following shackling are reduced, the time between shackling and stunning could also be reduced using this method, further improving bird welfare. Breast support conveyors should not be used when the shackle lines have sharp bends. 相似文献
3.
Shackling can induce wing flapping in chickens. In this survey of 30 chicken processing plants the proportion of birds flapping their wings had usually subsided to less than 0.5 per cent after the birds had been conveyed 2 m away from the shackling area. Thereafter, there were many causes of wing flapping, of which the following were thought to be important; tight fitting shackles on the birds' shanks, electric shocks at the water bath stunner before stunning, sudden bright sunlight, bends in the line, temporary loss of visual contact between neighbouring birds, and unevenness in the line which jolted the birds. If it is decided that legislation is required to prescribe a minimum 'hang-on' period before stunning it is suggested that birds should not be put through the stunner less than 12 seconds after shackling because after this time 99.7 per cent of the birds had stopped flapping. 相似文献
4.
1. Experiments were conducted to study the welfare and meat quality effects of shackling. In experiment 1, broilers with or without leg problems were shackled (S) for 4 min on a moving line and blood sampled; or handled (H), returned to the crate and sampled after 4 min; or sampled immediately after removal from the crate (control, C).
2. Plasma corticosterone (CORT) concentrations, as measured by radioimmunoassay, were highest in S and lowest in C, while the H group was intermediate. Leg problems had no effect on CORT.
3. In experiment 2, tonic immobility (TI) was induced in broilers after 2 min inverted handling to determine fear responses. One week later, the birds were fasted, transported and then shackled on a moving shackle line for 0, 1, 3 or 4 min, then unshackled and blood sampled. Wing flapping during shackling was also quantified.
4. Shackling time did not influence CORT concentrations. There was a negative correlation (r= ? 0.714) between CORT and wing flapping duration in the 1 min shackling treatment. There was no relationship between TI and wing flapping or CORT.
5. In experiment 3, broilers were exposed to two food withdrawal (FW) times (food withdrawn overnight or during crating only) and held for 4 h prior to processing, shackled (0, 2 or 4 min shackling time, ST), and then killed by exsanguination. Blood samples were collected during the neck‐cut. Pectoralis superficialis and Supracoracoideus samples were either collected after 15 min and individually quick frozen (IQF) in liquid nitrogen or collected at 4 h post mortem from carcases chilled on slush ice (COI).
6. CORT increased significantly with increased ST. There was a FW × ST interaction effect on the initial pH of fillets. ST influenced the b*, chroma and Hue values of the COI fillets. FW influenced the L* and Hue values of both IQF and COI fillets as well as the a* value of the COI fillets.
7. In summary, CORT increased with shackling time when birds were held after transport. FW and ST also influenced the colour of fillets, although it is not clear whether these changes are perceptible to the consumer. The duration of wing flapping during shackling did not appear to be related to fearfulness, although it was influenced by properties of the shackle line. We suggest that there be a maximum time lapse between shackling and stunning or killing of 2 min to minimise stress and meat quality changes. 相似文献
5.
The aim of this study was to identify the most relevant welfare indicators for unloading, lairage, stunning, killing and post-mortem inspection in a poultry slaughter plant. Different indicators were unloading duration, lairage time, environmental variables in the lairage facilities, shackling time and electrical variables used in the water bath.
Lairage time did not correlate strongly with dead on arrival. Heat stress was limited by means of ventilation systems, correct cage placement and appropriate stocking density per crate. The acceptable shackling period was about 30 s.
The presence of a corneal reflex showed that an animal was alive, while spontaneous wing flapping, spontaneous eye blinking and response to a painful stimulus were regarded as indicators of stunning efficiency.
It was concluded that the presence of recent traumatic injuries during the post-mortem inspection could be a valid means to establish whether corrective measures concerning the handling, transport and loading procedures should be taken.
6.
1. The welfare and carcase quality implications of stunning/killing 7-week-old Japanese quail with either an electric current, 90% argon in air or a mixture of 30% carbon dioxide and 60% argon in air were investigated in 3 separate experiments. 2. The results showed that exposure of quail to either argon or the carbon dioxide-argon mixture resulted in loss of posture on average at 9 and 8 s respectively. In both gas mixtures, convulsions started 6 s after the loss of posture and the duration of clonic phase (wing flapping) did not differ significantly between the 2 gas mixtures. However, the duration of the tonic phase was found to be slightly longer with the carbon dioxide argon mixture than with argon alone (P<0.05). 3. The absence of a positive response to toe pinching performed soon after the loss of posture indicated that the birds became unconscious and insensible to pain before the onset of convulsions. 4. Carcase dissection showed that, in comparison with the electrical stunning, gas stunning/killing of quail in transport containers eliminated the problem of broken bones and significantly reduced haemorrhaging in breast and leg muscles. 相似文献
7.
1. Histochemical (fibre type distribution and areas) and biochemical (myosin isoforms) characteristics of three muscles, M. anterior latissimus dorsi, M. pectoralis major and M. sartorius, were compared among male chickens of two lines at 11 and 55 weeks of age.
2. The lines were derived from a divergent selection based on growth rate. Cockerels from the Fast Growing Line (FGL) were 2‐3 times heavier than those from the Slow Growing line (SGL) when 11 weeks old and 1–7 times at 55 weeks of age. The latter age was chosen as representative of the adult stage and the 11‐week age because, at this time, FGL cocks weighed as much as SGL cockerels at 55 weeks.
3. At both ages, the two lines showed similar fibre type distributions, but the total number in the ALD muscle, and the size (cross‐sectional areas) of fibres in each muscle were higher in the FGL compared with the SGL (14–6% and 33% more at 11 and 55 weeks of age respectively in favour of the FGL birds).
4. The two lines displayed similar myosin isoform patterns when adult muscles were compared (55 weeks). They differed slightly at 11 weeks of age, muscle differentiation being completed only in the FGL.
5 Comparisons of the two lines at the same live weight (i.e. FGL cockerels at 11 weeks of age and SGL cockerels at 55 weeks) showed larger muscle fibres in the SGL and no difference in the isomyosin patterns. 相似文献
8.
H. REMIGNON A.D. MILLS D. GUEMENE V. DESROSIERS M. GARREAU-MILLS M. MARCHE 《British poultry science》1998,39(3):372-378
1. The influence of acute stress before slaughter on muscle and meat quality was studied in adult male quail from lines divergently selected for long (LTI) or short (STI) duration of tonic immobility (TI) and from the unselected (C) control line. 2. When subjected to acute stress, birds from the long TI line responded differently to those of the control or the low fear lines. LTI birds exhibited: a higher plasma creatine kinase and a smaller increase in plasma corticosterone levels, a higher pHu and drip loss values for breast meat associated with no differences in L*a*b* colour values; a higher percentage of fast glycolytic myofibres (IIb) and correspondingly (correlate) higher glycolytic (activity) in the pectoralis major (PM) muscle, and consequently lower oxidative enzyme activity in the PM muscle. 3. It is concluded that acute stress affected muscle metabolism differently in the STI, C and LTI lines. Hence, selection for TI, which is correlated with underlying fearfulness, can indirectly lead to differences in meat quality. 相似文献
9.
Wenzlawowicz MV Holleben KV Bostelmann N 《DTW. Deutsche tier?rztliche Wochenschrift》2000,107(3):116-122
Stunning of poultry is still not solved satisfactorily. This concerns the requirements of animal welfare, meat quality and working conditions in the lairage, stunning and debleeding area. In an investigation of combined CO2-/O2-stunning in a new gas stunning system stress reactions of the animals during the induction phase and stunning effectivity were recorded in 7,000 chicken and 3.825 turkeys. During the induction phase (here: chicken 41 sek./turkeys 25-65 sec.) the animals first staid calm and then showed beak-opening as a consequence of the breathing stimulating effect of CO2. As a further sign of the aversiveness against CO2 the animals showed head shaking and wing flapping. The used settings of gas concentrations and stunning time in the system investigated lead to a very deep stunning resp. Killing of the animals. Therefore the debleeding cut could be performed late (chicken 44-55 sec., turkeys 54-90 sec.) after leaving the system without animals regaining consciousness. The stunning of turkeys with a mixture of CO2 and oxygen is an improvement according to animal welfare requirements because unnecessary pain and suffering, happening very often with electrical stunning, can be avoided. As far as animal welfare in chicken stunning is concerned it must be evaluated if gas stunning means an improvement because stress during the till now relatively long induction phase must be put into relation with comparably lower stress caused by hanging upside down and a fast and safe working electrical stunning unit. 相似文献
10.
Broken bones in domestic fowl: handling and processing damage in end-of-lay battery hens 总被引：3，自引：0，他引：3
1. 3115 end-of-lay battery hens and carcases were sampled at set points in the sequence of events that occurred between depopulation of the battery cages at the layer farms and the end of the evisceration line in two processing plants. Live birds were killed in a convulsion-free manner and carcases were dissected to determine the incidence of broken bones. 2. Of the live battery birds 29% had broken bones by the time they reached the waterbath stunner, with on average 0.5 broken bones per bird. Removing birds from the battery cages and hanging them on the slaughter line were identified as causes of broken bones. 3. By the time birds left the end of the eviscerating line, 98% of carcases had broken bones, with on average 6 broken bones each. The stunning, plucking and eviscerating processes caused most of this damage. In particular, stunning broke the furculum, coracoid and scapula, plucking broke the ischium, pubis and ribs, and evisceration damaged the ischium and pubis. 相似文献
11.
The objective of this study was to identify bilateral differences in pork carcass quality as influenced by single leg shackling and suspension of electrically stunned pigs. Fifty-six Genepacker x EB market barrows (118 kg) were rendered unconscious and insensible to pain via electrical stimulation. Pigs were then shackled and suspended by the right hind leg before exsanguination and remained suspended until scalding. Initial (45-min) pH values of the LM at the 10th to 11th rib interface were different (P = 0.016); shackled side loins possessed a greater i.m. pH than those loins associated with the free side of the carcass (6.26 vs. 6.10). At 24 h postmortem, loins from the shackled side had lower (P < 0.001) L* values than loins from the free side in both the sirloin (53.08 vs. 57.61) and blade (54.61 vs. 57.09) regions. Additionally, b* values were greater (P < 0.001) for loins from the shackled side than loins from the free side in the center (13.81 vs. 13.01) and blade (14.72 vs. 13.68) regions, and in the blade region, a* values were greater (P < 0.001) in the LM from the shackled side than loins from the free side (7.37 vs. 6.26). Moreover, LM chops of loins from the shackled side that were aged 21 d were rated less (P < 0.05) tough (2.74 vs. 3.95) and more (P < 0.05) juicy (4.24 vs. 3.19) than chops from the free-hanging side. However, these differences were not evident after 41 d aging. From the results of this study, it can be concluded that bilateral differences exist within the LM of a pork carcass and that these differences are likely associated with the single-leg shackling and suspension of electrically stunned pigs. 相似文献
12.
This study examined the effects of inducing a cardiac arrest at electrical stunning, in combination with impaired bleeding and severe plucking, on the incidence of haemorrhages and broken bones in chicken carcases. It was concluded that with the possible exception of breast muscle haemorrhages none of the downgrading conditions were attributable solely to electrical stunning. Poor neck cutting, too severe plucking and flapping of the wings before death also played a part. 相似文献
13.
Abeyesinghe SM McKeegan DE McLeman MA Lowe JC Demmers TG White RP Kranen RW van Bemmel H Lankhaar JA Wathes CM 《British poultry science》2007,48(4):406-423
1. The effects of controlled atmosphere stunning on the behaviour, physiology and carcase and meat quality of broiler chickens were studied experimentally in a pilot scale plant. 2. Gas mixtures tested were: single phase anoxic mixture (90% Ar in air, <2% O(2)); single phase hypercapnic anoxic mixture (60% Ar, 30% CO(2) in air, <2% O(2)); and biphasic hypercapnic hyperoxygenation mixture (anaesthetic phase, 40% CO(2), 30% O(2), 30% N(2); euthanasia phase, 80% CO(2), 5% O(2), 15% N(2)). 3. Anoxic stunning resulted in the least respiratory disruption, mandibulation and motionlessness, but most head shaking, leg paddling and twitching. Loss of posture occurred soonest with hypercapnic anoxia with the earliest and most twitching and wing flapping in individuals and earliest leg paddling. Biphasic birds were most alert, exhibited most respiratory disruption and mandibulation, and had the latest loss of posture and fewest, but longest bouts of wing flapping and least leg paddling and twitching. 4. Significant and sudden bradycardia and arrhythmia were evident with all gas mixtures and were not related solely to anoxia or hypercapnia. Birds stunned by Ar anoxia showed a slightly more gradual decline from baseline rates, compared with hypercapnic mixtures. 5. Few differences were found between gas mixes in terms of carcase and meat quality. Initial bleeding rate was slowest in biphasic-stunned birds, but total blood loss was not affected. Acceleration of post-mortem metabolism in anoxic-stunned birds was not sufficient to allow de-boning within 5 h without the risk of tough meat. 6. On welfare grounds and taking into account other laboratory and field studies, a biphasic method (using consecutive phases of anaesthesia and euthanasia) of controlled atmosphere stunning of broilers is potentially more humane than anoxic or hypercapnic anoxic methods using argon or nitrogen. 相似文献
14.
Effect of heat stress on oxidative stress, lipid peroxidation and some stress parameters in broilers 总被引：6，自引：0，他引：6
1. This study was conducted to determine the effects of heat stress on fearfulness, leucocyte components, oxidative stress and lipid peroxidation in two commercial broiler strains, Cobb (C) and Ross (R). 2. At 36 and 37 d of age birds were exposed to 38 +/- 1 degree C for 3 h. Rectal temperatures, duration of tonic immobility (TI), haematocrit values, proportions of leucocyte components (heterophil, lymphocyte, basophil, eosinophil, monocyte), malondialdehyde (MDA) concentrations and antioxidant enzyme activities (CAT, SOD, GPx) of all the birds were determined, before and after heat treatment. 3. Rectal temperatures increased and haematocrit values decreased in birds exposed to heat stress. Heat stress caused a significant increase in heterophil/lymphocyte and in basophil ratios. 4. Exposing birds to heat stress increased duration of TI, suggesting heat-stressed birds tended to be more fearful. 5. Heat stress resulted in a significant Genotype x Treatment interaction for MDA concentration. CAT, SOD and GPx activities; MDA concentrations in heat-stressed R strain birds were greater than in heat-stressed C strain birds. 相似文献
15.
As chickens may rapidly regain consciousness after gas stunning, the effects of a two minute exposure to a carbon dioxide-argon mixture on survival rate were investigated. Broilers were stunned in batches of 10 per transport crate with a mixture of 10, 20 or 30 per cent carbon dioxide in argon with 5 per cent residual oxygen. The birds were exposed to the gaseous atmosphere for two minutes. A control group of birds was electrically stunned (120 mA for four seconds; 50Hz sinusoidal waveform). In addition, the incidence of carcase downgrading conditions after stunning with 20 per cent or 30 per cent carbon dioxide in argon with 5 per cent residual oxygen was compared with the incidence after electrical stunning. The results showed that stunning with 10 and 20 per cent carbon dioxide in argon with 5 per cent residual oxygen resulted in survival rates of 24 and 1 per cent, respectively. Stunning with 30 per cent carbon dioxide in argon with 5 per cent residual oxygen resulted in the death of all the broilers. Electrical stunning resulted in a significantly (P less than 0.001) larger number of broilers with breast muscle haemorrhaging and broken furculum and coracoid bones, whereas stunning with gas mixtures resulted in a significantly (P less than 0.001) higher incidence of broilers with damaged wing bones. Electrical stunning of broilers resulted in a significantly higher pH in the breast muscles 20 minutes post mortem than stunning with carbon dioxide-argon mixtures.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
16.
Berri C Le Bihan-Duval E Debut M Santé-Lhoutellier V Baéza E Gigaud V Jégo Y Duclos MJ 《Journal of animal science》2007,85(8):2005-2011
The structural and metabolic characteristics of the pectoralis major (P. major) muscle (i.e., breast muscle) and the quality of the resulting meat were studied in relation to breast muscle fiber development in broiler chickens. Six hundred birds originating from a commercial, grand parental, male heavy line (Hubbard-Europe, Chateaubourg, France) were kept under conventional breeding methods until their usual marketing age of 6 wk. For all birds, the plasma creatine kinase activity and the P. major muscle fiber cross-sectional area (CSA), glycolytic potential, lactate content, pH at 15 min postmortem, as well as the ultimate pH, CIELAB color parameters [lightness (L*), redness (a*), and yellowness (b*)], and drip loss of breast meat, were measured. Increased breast weight and yield were associated with increased fiber CSA, reduced muscle glycolytic potential, and reduced lactate content at 15 min postmortem. Therefore, P. major muscle exhibiting larger fiber CSA exhibited greater pH at 15 min postmortem and ultimate pH, produced breast meat with lower L* and reduced drip loss, and was potentially better adapted to further processing than muscle exhibiting small fiber CSA. 相似文献
17.
Somatosensory evoked responses (SEP) in a turkey's brain were determined after water-bath stunning with a 150-mA (constant current) delivered with 50, 300 or 600 Hz, or with 75 mA, delivered with 50-Hz alternating current (AC) in order to evaluate the effectiveness of stunning. Ninety-four BUT 9 turkey hens 12 weeks of age were surgically implanted with EEG recording and left wing nerve stimulating electrodes 4 hours before stunning. They were individually stunned by immersion of the head and upper part of the neck in a water bath for 4 s. Using a 150-mA current, all birds stunned at 50 Hz showed cardiac arrest and a flat EEG immediately after the stun with no SEP recovery. The incidence of cardiac arrest at stunning decreased with increasing current frequency but SEP were lost in all birds. In birds that survived the stun, the duration of SEP abolition was on average 69 and 34 seconds at 300 and 600 Hz, respectively. Stunning with a 75-mA AC, delivered with 50 Hz, induced cardiac arrest in 32 per cent of turkeys. SEP were abolished in only 71 per cent of the birds that survived the stun, with an average duration of SEP of 66 seconds. The results indicate that increasing the frequency of a 150-mA AC current leads to a decreased stunning efficiency. A current of 75 mA per bird is unacceptable since 29 per cent of the birds do not show SEP abolition. 相似文献
18.
ABSTRACT1. This trial investigated the effect of forced locomotor activity (training) on walking ability, leg posture, and growth performance, as well as carcass composition and meat quality in male fattening turkeys.2. A flock of 744 commercial turkeys was divided into three experimental groups, either without any training period (control), training from weeks 2 to 8 (short-term), or training from weeks 2 to 21 (long-term). All birds were slaughtered at an age of 21 weeks. To study the effect of short vs. long time lapse between shackling and stunning (suspension time), each training group was split into two halves that were hooked on the shackle for either 15 s or 3 min prior to stunning.3. Long-term physical training, compared to short-term or no training, resulted in better walking ability and in a lower percentage of leg malposition, as assessed at the end of fattening. No effect on final body weight was detected.4. In a subsample, the composition of 80 carcasses was determined by dissection. Long-term training favoured the percentage of the drumstick over that of the breast cut in comparison to the group without any training.5. Meat quality parameters were determined for breast muscle. The pH values 20 min post-mortem were reduced by long-term training, and the highest value was observed for a combination of no training with short suspension. After 24 h, pH values did not differ between experimental groups. The breast muscles were characterised as fast-glycolysing. Prolonged suspension time resulted in higher electrical conductivity after 24 h, and in higher a* values (redness).6. In conclusion, the study revealed that a long-term training period improved walking ability and leg posture of heavy male turkeys. Thus, training can contribute to the improvement of animal welfare in turkey husbandry. Meat quality variables of breast muscles were partially influenced by locomotor activity and suspension time. 相似文献
19.
1. An experiment was conducted to determine the effect of selection for high (H) or low (L) incidence of tibial dyschondroplasia for 7 generations on processing performance of broilers. 2. Birds were obtained from diallel matings of the H and L lines (HH, HL, LH, and LL) and a randombred control (CC) line. Birds were reared to 7 weeks of age under standard management conditions. All birds were processed at 7 weeks of age. Body weight at 7 weeks, carcase weight, and carcase part weights were recorded on each bird. 3. An interaction between sire line and dam line was caused by lighter body and carcase weight at 7 weeks of age in HH birds than from the birds of the other crosses. 4. Birds by L line dams had heavier drumstick weights. The influences of sire line and dam line on weight of total breast muscle were not significant. Thigh weights and Pectoralis minor weights were lighter in HH line birds than those other matings. 5. Heterosis for body weight and for weights of carcases, drumstick and thigh was negative. Total breast muscle weight and P. major weight did not show significant heterosis. 6. It was concluded that selecting against TD does not reduce processing yield of broilers. 相似文献
20.
Information was collected on the slaughter procedures used in 12 processing plants in Australia. The processing line speed varied from 25 to 125 birds/minute; the voltage in the electrified waterbath varied from 55 to 165 V; the duration of stunning was 2.0 to 7.5 seconds and the time allowed for exsanguination was 45 to 180 seconds. As a result of the variables, some birds were dead on leaving the stunner and prior to exsanguination, while it was probable that others were not dead before entering the scald tank. 相似文献