Prevalence and risk factors for bruises in Chilean bovine carcasses

Records of cattle slaughtered at two Chilean slaughterhouses (SLH1 and SLH2) were used to determine prevalence and risk factors for carcasses with bruises. Bruise prevalence amounted to 12.3% but differed between slaughterhouses (20.8% for SLH1 and 8.6% for SLH2 respectively). Bruise severity grade 1 (mild) was most frequently recorded. The type of the animal, source of animal, the level of fat cover and lairage time were associated with the presence of bruises. Older categories of animals and animals that pass through a market before being moved to the slaughterhouse are more prone to show bruises. The results also indicate that under the reported Chilean circumstances animals that have longer lairage times (over 12 h) have a significantly reduced risk for bruises, except for oxen. Presence of bruises is also significantly associated with increased carcass pH values.     

Effect of pre-slaughter management regarding transportation and time in lairage on certain stress parameters, carcass and meat quality characteristics in Kivircik lambs

Thirty Kivircik lambs were used to investigate effect of pre-slaughter treatment on certain haematological and biochemical parameters, carcass and meat quality characteristics. Lambs were divided into three treatments: 75 min transport and lairage for 18 h (TS-L18 h); 75 min transport and lairage for 30 min (TS-L30 min) and no pre-slaughter transport and lairage for 30 min (NTS). Treatment, as a main effect, did not influence haematological and biochemical parameters, but sampling time significantly affected these parameters, except total protein. Plasma cortisol concentration at exsanguination in TS-18 h, TS-30 min and NTS treatments were 117.34, 119.23 and 72.51 ng/ml, respectively. pH of longissimus dorsi muscle was higher in TS-L30 min than other treatments. TS-L30 min lambs had the highest shear force value, the lowest WHC and cooking loss. TS-L30 min treatment yielded the darkest meat immediately after cutting and 1 h later. Meat redness, yellowness and chroma values were similar in treatments.     

Effects of different lairage times after long distance transportation on carcass and meat quality characteristics of Hungarian Simmental bulls

The objective of this study was to determine the effects of three lairage times (24 h, 48 h and 72 h) on the meat quality of tame trained to lead Hungarian Simmental bulls subjected to long commercial transportation of approximately 1800 km. A total of 30 bulls, with an average age of 24 months, were used. During the lairage, bulls received 0.5 kg concentrate feed per animal per day and ad libitum access to the hay and water. As the lairage duration increased, the pH_ult decreased (P < 0.05). Bulls lairaged for 24 h had lower L*, b* and H* values than those lairaged for 48 h and 72 h (P < 0.05). The effect of lairage time on WHC, cooking loss and Warner–Bratzler shear force values was not significant. The b* value was considered the best predictor of muscle pH_ult. In conclusion, 72 h quiet lairage time is recommended after transportation in order to prevent the adverse effects of transportation on meat quality.     

Effect of lairage duration on rabbit welfare and meat quality

This study determined whether short (2 h) or long (8 h) lairage at an abattoir had an effect on plasma stress indicators (haematocrit, glucose, lactate, creatine phosphokinase and corticosterone), instrumental meat quality (pH24, water holding capacity, colour, raw and cooked texture) and sensory meat quality (using a trained sensory panel) in rabbits. The effect of the position of the animals on a multifloor rolling cage stand during lairage was also assessed. Lairage time had a significant effect on blood stress indicators, but only a slight effect on meat quality traits. A lairage duration of 6–8 h is recommended.     

Effects of lairage time on welfare indicators,energy metabolism and meat quality of pigs in Beijing

A total of forty Duroc–Landrace–Large White female pigs (90 ± 5 kg) were used to study the effects of different lairage times (0 h, 3 h, 8 h, 24 h) on welfare, energy metabolism and meat quality. The results showed that lairage time of 3 h led to a lower blood cortisol, a decreased drip loss and a delayed degradation of glycogen in muscles compared with pigs without rest, while lairage times of 8 h and 24 h resulted in a significant increase in pork toughness. It was concluded that three hours of lairage was appropriate to reduce pre-slaughter stress and obtain better meat quality for pigs transported for 4 h in winter, under the most frequent commercial conditions in Beijing, China. No lairage, or excessively long lairage time, might compromise animal welfare and meat quality.     

Effects of fasting prior to slaughter on technological and sensory properties of the loin muscle (M. longissimus dorsi) of pigs

The aim of this study was to investigate the effect of pre-slaughter fasting time, sex and feeding regime on water-holding capacity (WHC), colour and sensory properties and their relationship with pH in M. longissimusdorsi (LD) in pigs. 270 pigs of the commercial Norwegian crossbreed Noroc (Norwegian Landrace × Yorkshire sow and Norwegian Landrace × Duroc boar) were used involving two sexes (gilts and castrates), two feeding regimes (restricted and ad libitum) and four fasting treatments: (F4) 4 h fasting (control), (F175) 17.5 h fasting on the farm, (FO175) 17.5 h fasting overnight at the abattoir, and (FO265) 26.5 h fasting overnight at the abattoir. Additionally, the pigs experienced two abattoir lairage times as fasting treatments F4 and F175 had a lairage time of 1.5 h, while fasting treatments FO175 and FO265 had a lairage time of 23.0 h. A short fasting time of 4 h led to a delayed decline in pH post-mortem and a lower ultimate pH (pHu) in the LD compared with a fasting time of 26.5 h which resulted in a rapid pH decline early post-mortem and a high pHu. Prolonged fasting reduced drip loss, resulted in a darker colour and tended to improve tenderness of the LD. Castrates showed lower drip loss, higher lightness and improved tenderness and juiciness compared with gilts, while ad libitum feeding improved tenderness compared to restricted feeding. There are obvious negative relationships between pHu and drip loss, lightness and tenderness of LD.     

Finishing diet,temperament and lairage time effects on carcass and meat quality traits in steers

Sixty Hereford (H) and Braford (B: 3/8 Zebu and 5/8 H) steers were finished on: D1) rangeland plus corn grain (1% of live weight) (H n = 15, B n = 15); and D2) high quality pasture (H n = 15, B n = 15) to study the effect of diet, temperament and lairage time on carcass and meat quality. Steers were slaughtered the same day in two groups, spending 15 and 3 h in pens, respectively (50% from D1, 50% from D2 in each group). Animals from D1 had better carcass performance without effect of the diet on meat quality. Regardless of breed, calmer steers showed higher average daily gain and lower shear force values. Carcasses from animals in the long lairage group had a better rate of pH decline and more tender meat, suggesting that more than 3 h preslaughter time should be necessary to rest and recover, mainly depending on lairage conditions.     

Bayesian meta-analysis of the effect of fasting, transport and lairage times on four attributes of pork meat quality

Technological meat quality is a significant economic factor in pork production, and numerous publications have shown that it is strongly influenced both by genetic status and by rearing and slaughter conditions. The quality of meat is often described by meat pH at different times postmortem, as well as by color and drip loss. A meta-analysis based on a database built from 27 studies corresponding to a total of 6526 animals classified was carried out. The purpose of this meta-analysis was to study the effect of fasting, lairage and transport durations on four main attributes of the technological pork meat quality. A Bayesian hierarchical meta-regression approach was adopted.The results of our meta-analysis showed that fasting time had a significant effect on pH measured 24 h post-mortem (pHu) and drip loss (DL) measured in longissimus muscle. While, lairage affected only the pHu in semimembranosus muscle. Interestingly, we found that DL was the lone attribute that was affected by transport time and its interaction with fasting time.     

The prevalence of PSE characteristics in pork and cooked ham — Effects of season and lairage time

A total of 180 pigs was slaughtered in the same slaughterhouse, but divided in six different trials distributed over Winter (December–March) and Summer (April–September). Meat quality measurements (pH, electrical conductivity, color and/or water-holding capacity) were carried out 30 min, 24 and/or 35 h after slaughter in three different muscles: M. gracilis, M. semimembranosus and M. longissimus dorsi. A tendency towards a higher proportion of PSE meat during Summer was found in the examined muscles. Moreover a higher protein, higher dry matter content, a lower water/protein ratio and a lower slicing yield were found for the cooked hams suggesting a higher PSE prevalence in the Summer. A lairage time between 2 and 4 h during Summer and less than 2 h during Winter was related to a lower proportion of PSE meat. The correlation coefficients between the individual meat quality variables were moderate, but showed the predictive power of the pH measured 24 h post-mortem in the M. gracilis for meat quality.     

The variation in pig muscle glycolytic potential during lairage-an in-vivo study

The variations in glycolytic potential (GP, very close to glycogen content) were studied during lairage in pig m. longissimus dorsi using biopsy sampling. Pigs were sampled on arrival at the abattoor and after treatment. Post-mortem measurements including pH(1), pH(u) and FOP(u) were performed on both longissimus dorsi (LD) and biceps femoris (BF) muscles. The animals underwent one of the following treatments: 2 h lairage mixed or unmixed; 24 h lairage mixed or unmixed with access to water only; 24 h lairage mixed or unmixed with access to a sugar solution. A significant depletion in GP occurred during lairage except when pigs were fed liquid sugar. The extent of this depletion was irrespective of lairage duration or mixing. Pigs lairaged 24 h with access to water only exhibited a significantly lower pH(1) in m. BF suggesting a higher propensity to develop PSE meat. Values of pH(u) were low (pH < 5·5), and did not vary significantly between the treatments since muscle GP remained high, despite the depletion induced by lairage. This was attributed to the high level of muscle glycogen characterizing the Hampshire crossbred pigs used in this experiment. These results suggest that interaction between breed and handling procedure may be important regarding meat pH(u).     

Postmortem changes in cazon fish muscle stored on ice

The biochemical, chemical and physical postmortem changes and their relation to the cazon muscle eating quality were studied during an 18 day storage period at 0 °C (ice). Content of ATP and breakdown products, K value, pH, trimethylamine (TMA-N), total volatile bases (TVB-N), water-holding capacity (WHC), colour and texture changes were examined. At the beginning of the study, the cazon muscle showed a low concentration of ATP and a high value of IMP. Regarding to the signs of freshness and deterioration, K value presented a linear increase (r² = 0.97) with an initial value of 1.05% and a final value of 58.9%. The TBV-N and TMA-N significantly increased (P < 0.05). As for the physical analysis whereas the pH and the WHC changed (P < 0.05); texture was not affected (P < 0.05). The overall results of this study indicated that the edible quality of cazon fish muscle was maintained during at least 18 days of ice storage.     

Freshness assessment of ray fish stored in ice by biochemical,chemical and physical methods

Ray fish were caught, filleted, and stored in ice. Fillets were analysed for 18 days to determine the chemical, biochemical and physical changes and their relation to the muscle eating quality. Trimethylamine (TMA-N), total volatile bases (TVB-N), ATP content and breakdown products, K value, pH, texture, water-holding capacity (WHC) and colour changes were monitored. At the beginning of the study, the ray fish muscle showed a low concentration of ATP and a high value of inosine 5′-monophosphate (IMP). Regarding to the signs of freshness and deterioration, K value presented an exponential increase (r2 = 0.95) with an initial value of 4.7% and a final value of 47.5%. Furthermore, the TBV-N and TMA-N significantly increased (P < 0.05) during the storage in ice. As for the physical analysis whereas the texture changed (P < 0.05); pH and the WHC were not affected (P < 0.05). The overall results of this study indicated that the edible quality of ray fish muscle was maintained during at least 15 days of ice storage.     

Examination of the effect of ageing and temperature at rigor on colour stability of lamb meat

A study of factors (ageing period, rigor temperature and vitamin E level) impacting on the colour stability of lamb m. longissimus thoracis et lumborum (LL) during 3 days of simulated retail display was undertaken. The LL were taken from 84 lambs from 3 slaughters. Slices of LL were measured fresh (24 h post-mortem) or after ageing for 5 days in vacuum packaging. The oxy/met ratio (630/580 nm), declined with display time, and increased with increasing temperature at pH 6.0. Redness (a*) values also declined with display time and a reduction in redness values was observed as LL pH at 24 h post-mortem and/or pH at 18 °C increased. There was no effect of ageing period or vitamin E level on the oxy/met ratio or a* values when the vitamin E level averaged 3.76 mg/kg LL. These results suggest that maximising vitamin E levels in lambs and achieving a moderate rate of pH decline will optimise colour stability irrespective of ageing period.     

Altering physically effective fiber intake through forage proportion and particle length: chewing and ruminal pH

Alfalfa silages varying in theoretical chop length and diets high and low in forage proportion were used to evaluate whether increasing the physically effective (pe) neutral detergent fiber (NDF) content of dairy cow diets reduces the risk of acidosis. The experiment was designed as a replicated 4 × 4 Latin square using 8 ruminally cannulated lactating dairy cows. Treatments were arranged in a 2 × 2 factorial design; 2 forage particle lengths (FPL) of alfalfa silage (short and long) were combined with low (35:65) and high (60:40) forage:concentrate (F:C) ratios [dry matter (DM) basis]. Dietary peNDF content (DM basis) was determined from the sum of the proportion of dietary DM retained on either the 2 sieves (8 and 19 mm) or the 3 sieves (1.18, 8, and 19 mm) of the Penn State Particle Separator multiplied by the NDF content of the diet. The dietary peNDF contents ranged from 9.6 to 19.8% using 2 sieves, or from 28.6 to 34.0% using 3 sieves. Intake of peNDF was increased by increasing both the F:C ratio and the FPL of the diets. However, F:C ratio and FPL affected chewing activity differently; increasing F:C ratio increased chewing time but increasing FPL only increased chewing when a high-forage diet was fed. Mean ruminal pH was increased by 0.5 and 0.2 units with increasing F:C ratio and FPL, respectively. Cows fed the low F:C diet had > 10 or 7 h daily in which ruminal pH was below 5.8 or 5.5, respectively, compared with 1.2 and 0.1 h for cows fed the high F:C ratio diet. Increased F:C ratio reduced ruminal VFA concentration from 135 to 121 mM but increased the acetate:propionate ratio from 1.82 to 3.13. Dietary peNDF content when measured using 2 sieves was positively correlated to chewing time (r = 0.61) and mean ruminal pH (r = 0.73), and negatively correlated to the time that pH was below 5.8 or 5.5 (r = −0.46). This study shows that the risk of ruminal acidosis is high for cows fed a low F:C diet, particularly when finely chopped silage is used. Intake of dietary peNDF is a good indicator of ruminal pH status of dairy cows. Increasing the proportion of forage in the diet helps prevent ruminal acidosis through increased chewing time, a change in meal patterns, and decreased ruminal acid production. Increasing FPL elevates ruminal pH, but in low-forage diets increased FPL does not completely alleviate subacute acidosis because the fermentability of the diet is high and changes in chewing activity are marginal.     

Effects of long distance transportation and CO2 stunning on critical blood values in pigs

The aim of the study was to evaluate the effect of two stressful stimuli, long transportation and 80% CO₂ stunning on metabolic-physiological variables, hemodynamic and gas exchange in slaughter pigs imported from the U.S. to Mexico City with a journey time of 27 h, with 8 h of lairage at the abattoir. A total of 589 pigs from three genders were monitored. Overall results show that both stimuli caused metabolic and physiological disturbance. Gilts were more efficient in controlling glycemia after a long transport journey (24 h), than castrated males (P < 0.05), whose glucose was increased above the 30 mg/dL basal level. Females on arrival had 23 mg/dL more lactate compared to basal levels (P < 0.05). Stunning caused more physiological effects compared to transportation. Regarding the gender factor, females and entire males were more susceptible to transport stress and stunning compared to the castrated pigs, and entire males showed more complications restoring the gas exchange compared to females and barrows.     

Colour,lipid and protein stability of Rhea americana meat during air- and vacuum-packaged storage: Influence of muscle on oxidative processes

Physicochemical characteristics and oxidative stability during storage were determined in Gastrocnemius pars interna (GN) and Iliofiburalis (IF) muscles of Rhea americana. Glycolytic potential (GP) and pH decline of muscles were measured within the first 24 h post mortem. Colour, lipid and protein stability were determined during storage of meat, i.e. 5 days under air-packaging at 4 °C, or 28 days under vacuum-packaging at 4 °C. In parallel, anti-oxidant status of muscles was estimated by measuring α-tocopherol content and anti-oxidant enzyme activities (superoxide dismutase and catalase), while pro-oxidant status was evaluated by determining haeminic iron and long chain fatty acids (especially polyunsaturated fatty acids). The ultimate pH was similar in both muscles, but the GP value was significantly higher in IF than in GN muscle. Haeminic iron and alpha-tocopherol content differed between muscles, with 30% more haeminic iron (p < 0.05) and 134% more alpha-tocopherol (p < 0.001) in IF than GN muscle. The IF muscle presented higher lipid content and lower PUFA/SFA ratio (polyunsaturated fatty acids/saturated fatty acids) than GN muscle. With storage under air-packaging, lipid and protein oxidation of rhea muscles increased up to 275% and 30%, respectively. This increase was more rapidly and marked in IF muscle. The IF also showed high level of metmyoglobin accumulation after 3 days of storage (47%) and was rejected by 1 consumer out of 2 in sensorial analysis. Under vacuum-packaging, both muscles showed a high stability of colour and no oxidation of lipids and proteins.     

Increasing physically effective fiber content of dairy cow diets through forage proportion versus forage chop length: Chewing and ruminal pH

A study was conducted to evaluate whether the risk of acidosis in dairy cows can be lowered by increasing the physically effective fiber (peNDF) concentration of the diet, either through increased theoretical chop length of alfalfa silage or higher proportion of forage in the diet. The experiment was designed as a replicated 4 × 4 Latin square using 8 ruminally cannulated lactating dairy cows. Treatments were arranged in a 2 × 2 factorial design; 2 forage particle lengths (FPL) of alfalfa silage (short and long) were combined with low (35:65) and high (60:40) forage:concentrate (F:C) ratios [dry matter (DM) basis]. Dietary peNDF concentration (DM basis) was determined from the sum of the proportion of dietary DM retained either on the 2 sieves (8 and 19 mm) or on the 3 sieves (1.18, 8, and 19 mm) of the Penn State Particle Separator multiplied by the neutral detergent fiber concentration of the diet. The dietary peNDF concentrations were altered by changing the F:C or the FPL, and ranged from 10.7 to 17.5% using 2 sieves, or from 23.1 to 28.2% using 3 sieves. Intake of peNDF was increased by increasing FPL but not by increasing F:C ratio because of the reduction of DM intake at the higher F:C ratio. Chewing activity, including number of chews and chewing time, increased with increasing F:C ratio or FPL. Mean ruminal pH was elevated by 0.4 and 0.2 units with increasing F:C ratio and FPL, respectively. Lowering the F:C ratio decreased the duration that ruminal pH was below 5.8 (1.2 vs. 8 h/d). Increased F:C ratio or FPL reduced ruminal volatile fatty acids concentration from 137 to 122 or from 133 to 126 mM, respectively, whereas acetate:propionate ratio was increased from 2.55 to 3.46 with increasing F:C ratio. Dietary peNDF concentration measured using 2 sieves was correlated to chewing time (r = 0.57) and mean ruminal pH (r = 0.75), whereas dietary peNDF concentration measured using 3 sieves was correlated to mean ruminal pH (r = 0.83) and negatively correlated to the time that pH was below 5.8 (r = −0.78). This study shows that the risk of ruminal acidosis is high for cows fed a low F:C diet. Increasing the proportion of forage in the diet helps prevent ruminal acidosis through increased chewing time, a change in meal patterns, and decreased ruminal acid production. Increasing FPL elevates ruminal pH, but in low forage diets, increased FPL does not alleviate subacute acidosis because the fermentability of the diet is high and changes in chewing activity are marginal.     

Risk assessment of DFD meat due to pre-slaughter conditions in pigs

A polychotomous logistic regression model was used to identify and assess the risk factors for pork becoming dark, firm and dry meat (DFD). A total of 116 deliveries, comprising 3075 commercial pigs delivered from different farms to five commercial Spanish pig abattoirs were surveyed. The DFD condition was described as an ordinal response variable (normal, moderate and serious) based on measurements of pH₂₄ in the Semimembranosus muscle. The abattoir, the floor of the lorry, the season, the gender, and the stocking density during transportation influenced the risk of DFD, as well as on-farm fasting time, lairage time and estimated carcass lean content. No effect of the RYR1 gene in the risk of DFD was found. Abattoirs should be especially careful with females slaughtered in winter, where the risk of serious DFD is 4.6% higher than with males slaughtered in summer. The risk of DFD increased with high stocking density and lairage time, and with on-farm fasting times longer than 22 h. Our results revealed that lowering the stocking density from 0.37 to 0.50 m² per 100 kg pig during transport would increase the risk of DFD pork by 11%.     

Influence of lairage environmental conditions and resting time on meat quality in pigs

This study investigated the influence of lairage environmental conditions and resting time on pig carcasses and meat quality. The experimental material consisted of 1001 cross Pietrain-Duroc-Hampshire × Belgium-LR-LW pigs, held in lairage for either ≈30 min (direct slaughter) or between 2-3 h under 12 °C/90% relative humidity (RH), 20 °C/80% or 90% RH and 35 °C/50% or 85% RH. Prior to arrival at the lairage plant they were transported for about 45-60 min and subjected to a fasting period of 36 h before loading. Unloading operation and the driving of pigs to the point of stunning were carried out according to the practices used in the plant (sticks and electrical goads were used). Batches of 20-30 mixed pigs were used in each trial, held at a stocking density of approximately 0.55 m(2)/pig (≈100 Kg live weight). Lairage environmental conditions (LC), significantly affected almost all measurements, but not pH(1), in Semi-membranosus (SM) and Longissimus dorsi (LD) muscles and the carcass damage score. The influence of resting time (RT) was basically exerted on pH(u), deep ham temperature and in pH(1), of SM, the internal muscle reflectance being mostly unaffected. There were also significant batch (B) effects in a large range of parameters. Factors greatly interacted their influence on carcass and meat quality, denoting LC × B, LC × RT × B and LC × RT the most significant effects. RT × B only showed two low significant interactions for rigor value and pH(1), in SM, suggesting that, conversely to the lairage environmental conditions the influence of resting time is practically unaffected by the day of slaughter. The increase of lairage temperature decreased the frequency of normal carcasses, followed by an expressive higher incidence of PSE status. The influence of lairage relative humidity on the PSE/DFD muscle incidence depended on the associated temperature, but the most important detrimental effects were noticed in experiments carried out at 35 °C. In respect to lairage resting time, the influence on meat quality is strictly related to environmental conditions, mainly the temperature. Nevertheless, and excepting the assays at 35 °C/85% RH, direct slaughter of pigs (= 30 min in pens) generally produced less carcasses of normal quality than resting periods up to 2-3 h.     

Muscle structure responses and lysosomal cathepsins B and L in farmed Atlantic salmon (Salmo salar L.) pre- and post-rigor fillets exposed to short and long-term crowding stress

Atlantic salmon (average body weight 2.9 ± 0.1 kg) were subjected to either minimal pre-slaughter crowding stress (NS group), 20 min (short-term stress, SS group) or about 24 h pre-slaughter crowding stress (long-term stress, LS group). Significant negative effects were mostly seen due to long-term stress (LS) at early stages post-mortem, but also short-term stress (SS) had significant negative impacts on muscle quality of pre- and post-rigor fillets. Pre-slaughter long-term stress (LS) significantly lowered muscle pH, softened the fillets and increased muscle cathepsin L gene expression, immediately post-mortem. A tendency of increased cathepsin B gene expression and cathepsin B total activity was also seen. Stress further accelerated the incidence of myofibre–myofibre detachments, increased the percentage of myofibre–myocommata detachments over the storage period and increased the percentage of myofibre breakages and contracted myofibres 96 h post-mortem. Significant correlations were observed between muscle pH and cathepsin B + L activity, muscle texture and muscle degradation parameters. Cathepsin B activity was correlated to muscle degradation and cathepsin L gene expression to muscle degradation and texture. Pre-slaughter stress, especially long-term stress (LS), thus seems to accelerate cathepsin activity, resulting in faster muscle degradation, directly or indirectly connected to the low initial muscle pH. No significant variation was observed between pre-rigor and post-rigor filleting, except that pre-rigor filleting significantly increased the percentage of myofibre breakages.