Lairage Time Research Articles

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.

Risk assessment of skin damage due to pre-slaughter conditions and RYR1 gene in pigs

A polychotomous logistic regression was used to assess the risk factors for skin damage prior to slaughter. A total of 116 deliveries (15,695 pigs) from commercial farms to five Spanish pig abattoirs were surveyed. The skin damage condition was described as an ordinal response (1: no damage; 2: very slight damage; and 3: slight or more damage). The abattoir by the season ( p < 0.01), the floor surface of the lorry ( p = 0.02), and the mixing of unfamiliar pigs at loading ( p = 0.01) influenced the occurrence of skin blemishes. Skin damage increased with on-farm fasting time ( p < 0.01), loading time ( p < 0.01), lairage time ( p < 0.01), as well as with carcass weight ( p < 0.01). In winter transports the risk of skin damage decreased ( p < 0.01) at higher space allowance in the lorry. The risk of developing PSE and DFD pork increased with the skin damage score ( p < 0.01). The nn genotype for the RYR1 gene was less prone to skin damage but at the same time it is more sensitive to skin damage in relation to PSE risk. It is concluded that the skin damage score can be used as a rapid indicator of animal welfare and pork quality.

Physical conditions in a cattle vehicle during spring and autumn conditions in Japan, and reactions of steers to long distance transport

ABSTRACTThe objective of this study was to investigate transportation conditions and behavioral and physiological responses of beef steers to long distance commercial transport in Japan. In spring (May) and autumn (September), eight (16 in total) Japanese Black × Holstein steers (7.8 ± 0.6 month of age; 310.3 ± 13.9 kg) were transported by truck. The transport distance was 1013.1 km (25 h including lairage periods) comprising 627.6 km (6.4 h) on expressways, 143.5 km (3.5 h) on arterial roads and 242.0 km (10.5 h) by ferry. The loading space of the truck gave a space allowance of about 1.62 m2/head. Internal temperature (±SD) and humidity (±SD) of the truck were 14.7 ± 4.7°C and 72.7 ± 22.4% in spring, 24.4 ± 2.8°C and 70.8 ± 14.4% in autumn. Vibration acceleration (±SD) of the truck in the longitudinal direction was greater in spring (−0.19 ± 0.43 m/s2) than in autumn (−0.15 ± 0.20 m/s2) (P &lt; 0.05). There were no effects of season and driving conditions on the internal noise. Internal airflow velocity (±SD) of the truck was greater in spring (0.75 ± 0.70 m/s) than in autumn (0.45 ± 0.40 m/s) (P &lt; 0.05), and it was greater while moving on expressways (0.77 ± 0.40 m/s) and arterial roads (0.63 ± 0.61 m/s) than when parked (0.16 ± 0.26 m/s) (both P &lt; 0.05). Steers lay down more frequently while moving on expressways than the expected frequency (χ2 = 121.9, P &lt; 0.01). Steers were oriented parallel to the direction of travel (to the front cabin: 27.9%; to the tailgate: 23.4%) more frequently than the expected probability (12.5%). Blood glucose concentration, serum ALT activity and plasma cortisol concentration were greater in spring than in autumn (all P &lt; 0.05). Serum pH was higher in autumn than in spring (P &lt; 0.01). Blood glucose concentration was significantly higher at the market before transport, and serum total protein, triiodothyronine and total cholesterol concentrations were also significantly higher at the market and just after transport than 1 week after transport (all P &lt; 0.05). However, the other physiological measurements such as plasma cortisol and blood lactate concentrations, serum pH and heart rate did not change after transport. The results indicate that in Japanese spring and autumn conditions, long distance transport with appropriate conditions including low stocking density and enough lairage time with provision of food and water might not cause severe stress for steers.

Effects of Slaughter Date, On-Farm Handling, Transport Stocking Density, and Time in Lairage on Digestive Tract Temperature, Serum Cortisol Concentrations, and Pork Lean Quality of Market Hogs

The objective of this study was to evaluate the effect of on-farm handling intensity (conventional vs. passive), transport stocking density: (high vs. low), and preslaughter lairage time (45min vs. 3h) on digestive tract temperature, serum cortisol concentrations, and pork quality of market pigs slaughtered in November (NOV; n = 111), February (FEB; n = 113), and August (AUG; n = 112). Pigs slaughtered in FEB had greater (P ≤ 0.027) digestive tract temperatures before loadout than pigs slaughtered in NOV or AUG. The digestive tract temperature of pigs slaughtered in AUG was greater (P ≤ 0.027) during than before loadout. Pigs afforded 3h of lairage tended to have greater (P = 0.068) digestive tract temperatures than pigs given 45min of lairage. When pigs were slaughtered in AUG and NOV, those afforded 3h of lairage had greater (P = 0.042) cortisol concentrations than pigs given only 45min of lairage. Carcasses of pigs slaughtered in AUG had a paler (P ≤ 0.032) LM than carcasses of pigs slaughtered in NOV and FEB, and greater (P ≤ 0.032) LM purge losses than pigs slaughtered in FEB. Pigs given a 45min lairage had greater (P = 0.036) 30-h LM pH values, darker LM (P = 0.008), greater (P = 0.012) subjective color scores, and tended (P = 0.069) to have lower purge loss percentages than pigs given a 3-h lairage. Results indicated that pigs should have less than 3h of lairage when the day\\s low ambient temperature is ≤ 22°C to decrease antemortem stress and improve lean quality.

Increasing feed withdrawal and lairage times prior to slaughter decreases the gastrointestinal tract weight but favours the growth of cecal Enterobacteriaceae in pigs

The objective of this study was to evaluate the influence of different feed withdrawal and lairage times prior to slaughter on the gastrointestinal tract (GIT) weight and on the fermentation pattern and numbers of Enterobacteriaceae in the cecum of pigs. A total of 72 finishing pigs (6 pens, 12 animals each) were included in the study and were sent to the slaughterhouse on three consecutive days. On each day pigs from two pens were deprived of feed for either 2 or 12 h before leaving the farm. Pigs from each of the two pens were divided in sub-groups (4 pigs each) on the moment of loading onto the truck and followed the same distribution at the slaughterhouse. Once there, each sub-group corresponding to the same feed withdrawal time was held in different holding pens for 0, 5 or 10 h before slaughter. The weight of the gastro-intestinal tract (GIT) was determined and cecal content was collected to evaluate pH, short chain fatty acids (SCFA) and ammonia (NH 3) concentrations as well as lactobacilli and Enterobacteriaceae numbers. Total GIT weight decreased as feed withdrawal ( P < 0.0001) and lairage time ( P < 0.001) increased within a range between 6.69 and 4.59 kg. Cecal pH increased with feed withdrawal ( P < 0.0001) and lairage time ( P = 0.0001) (ranging from 5.79 to 6.79) in parallel to a decrease in the total SCFA concentration ( P < 0.005) (from 211 to 100 mM). The percentages of acetic and propionic acid were not modified by the experimental treatments but significant decreases were registered in the percentage of butyric acid with the increased times of both withdrawal ( P < 0.0001) and lairage ( P < 0.005). The percentage of valeric and branched SCFA and also NH 3 concentration showed an increase with withdrawal ( P < 0.005, P < 0.0001 and P < 0.005 respectively) and lairage ( P < 0.005, P < 0.0001 and P < 0.001 respectively). Lactobacilli numbers decreased as lairage time increased (from 9.97 to 8.63 log 16S rRNA gene copies/g FM; P < 0.05) and Enterobacteriaceae numbers increased with both, feed withdrawal ( P < 0.05) and lairage ( P < 0.05) (ranging from 8.53 to 9.95 log 16S rRNA gene copies/g FM). The previous to slaughter increase in feed withdrawal and lairage times decreased the GIT weight but involved changes in the gut microbial ecosystem caused through changes in the fermentation pattern that lead to the increase of Enterobacteriaceae numbers. This increase could represent a higher risk of carcass contamination by the enteropathogens of this group such as Salmonella. However this potential risk should be further investigated.

Effect of lairage duration on some blood constituents and beef quality in bulls after long journey

With the aim to contribute to the determination of an adequate resting time for cattle after long transportation, the effects of different lairage times on some haematic parameters and meat quality of bulls subjected to long commercial journeys were investigated. Thirty-nine Limousine bulls supplied by one farm located near to Saragoza (Spain) were examined after 5 consignments at the final destination, following a journey of 2,550 km to the “San Giorgio” abattoir (Palermo, Italy). Transport time was of 53.6±10.9h; lairage duration for bulls of the 1st, 3rd and 5th consignments was of 31h on average (“Short Lairage” group), whereas, for those of the 2nd and 4th consignments, was of 59 and 57h, respectively (“Long Lairage” group). As regards the blood cell counts, data showed a significant effect (P>0.001) of the lairage duration on leukocyte and platelet counts. No significant effect was observed for erythrocyte count, haemoglobin and hematocrit in relation to the lairage duration, although the repeated measure analysis of variance showed that, irrespective of lairage duration, the hematocrit increased significantly between unloading and slaughter. Haematological parameters showed a significant (P>0.05) effect of the lairage time only on CK and Cortisol. CK enzyme showed an increase in the “Short Lairage” group (33.2% vs. 14.3%) whereas, Cortisol showed a decrease in the “Long Lairage” group (36.3% vs. 3.8%). The different lairage duration did not significantly (P>0.05) affect the incidence of slight and severe carcass bruises. As regards meat quality, lairage duration significantly influenced the pHu which was higher (P>0.01) in the muscle of the “Long Lairage” group, the luminosity at 24h post mortem which was significantly higher (P<0.05) in animals of the “Short Lairage” group, and the red and yellow indices which were higher in the “Long Lairage” group. The “Short Lairage” group showed a lower (P>0.01) value of cooking loss and higher (P<0.01) value of tenderness. Data show that pre-slaughter lairage duration after a long transport may influence the blood parameters as well as meat quality. On the whole, the increase in lairage duration over 36h does not determine any benefit for the animal’s well-being whereas it can cause a reduction in beef quality. For very long transports, it would be better to have an adequate organisation of the facilities in order to diminish the pre-slaughter lairage duration.

Effects of mid-summer transport duration on pre- and post-slaughter performance and pork quality in Mexico

Seven hundred and fourteen pigs were monitored from transport to slaughter in July in three treatments: 8, 16 and 24 transport hours; lairage time for the three groups was of 8 h. Transport duration significantly ( P < 0.05) affected live-weight gain during the rest period. Weight gain percentages at lairage were 0.05%, 0.78% and 1.15% for treatments 1, 2 and 3, respectively. Transport to slaughter loss percentage was 2.7%, 4.3% and 6.8% for each of the treatments. Short transport periods significantly increased carcass pH below normal values. Animals transported under acute stress (8 h) showed pale carcasses (high possibilities of transforming into PSE meat). On the contrary, pigs transported for 24 h had more dark red carcasses. Transport from farm to the slaughterhouse should take no more than 16 h in order to improve carcass quality and animals’ welfare.

Effectiveness of electrolytes at alleviating dehydration and improving carcass characteristics of adult sheep in lairage

The aim of this work was to examine the effectiveness of a commercial electrolyte mixture in alleviating dehydration and improving carcass characteristics of adult sheep under commercial processing conditions. Two separate experiments were conducted to investigate this aim. Experiment 1 had 2 hydration treatments (water with and without electrolytes) and sheep commenced their treatments on their arrival at the abattoir. Animals were then slaughtered at the lairage times of 24, 48 or 72 h. Experiment 2 had the same treatments and an additional no water (no electrolyte) treatment. In the second experiment only, animals from each of the treatment groups were allocated into 2 stimulation groups, so that on the production line the carcasses were either treated with high voltage stimulation or not treated. Experiment 2 animals were grazed for 2 weeks at the abattoir prior to commencement of the treatments. Animals were slaughtered after a lairage time of 24, 48 or 72 h, except for animals on the no-water treatment: these animals had lairage times of 24 or 48 h only. It was found in both experiments that there was no difference (P&gt;0.05) between the water treatments for all carcass and meat quality traits measured. Lairage time had an effect (P&lt;0.05) on urine specific gravity in both experiments. Urine specific gravity decreased as lairage time increased in experiment 1, but an opposing trend was found in experiment 2. In experiment 1, as lairage time increased, GR (total tissue depth at the 12th rib) decreased. Electrical stimulation in experiment 2 lowered (P&lt;0.05) the initial pH and interacted with lairage time causing differences in cook loss for meat aged for 1 or 7 days, but had no impact on other traits.

Effects of lairage time and electrical stimulation on sheep meat quality

This paper describes an experiment which examined the effects of lairage time and electrical stimulation on meat quality and carcass traits in conventionally chilled sheep meat. The 120 Merino wethers used in this experiment were sourced on farm and were transported to the abattoir and held in a paddock 1 week before slaughter. The animals were then placed into 2 different pens (replicas). The sheep were killed at random either at day 1 (n = 60) or day 2 (n = 60). There were 30 animals taken from both pens 1 and 2 each day. Half of these animals were exposed to high voltage stimulation (30 stimulated) and for the other half the high voltage stimulation was turned off (30 control) each day. There was no significant (P&gt;0.05) effect of lairage time on hot carcass weight, GR, initial pH, shear force or cooking loss. However, lairage time had a significant (P&lt;0.05) effect on final pH and the temperature when the pH reached 6.0. Initial pH, final pH (21 h) and temperature at pH 6.0 were significantly different (P&lt;0.05) between stimulated and non-stimulated carcasses, but there was no effect on cook loss or shear force (P&gt;0.05). A significant (P&lt;0.05) interaction between lairage time and stimulation was found for shear force which showed that non-stimulated meat from sheep held in lairage for 2 days was tougher than that from stimulated carcasses.

Repeated handling of pigs during rearing. II. Effect of reactivity to humans on aggression during mixing and on meat quality

The present study was designed to determine whether reactivity toward humans can be used to predict a pig's reactivity to the slaughter procedure as measured by postmortem muscle metabolism. Forty-two pigs were group-reared in six pens with straw-bedding. Pigs received regular positive (HI) or mildly negative (RC) handling training in a separate pen for 40 d before slaughter. Control pigs remained in their home pens throughout rearing. Pigs were slaughtered at a commercial packing plant, and half of each treatment group (HI, RC, or controls) was accompanied by the handler throughout mixing and transportation, as well as a portion of the lairage time and introduction to the holding pens situated before the slaughter room, whereas the other half was not accompanied by the handler. Muscle pH and temperature, objective color (L*, a*, and b* values), and drip loss were measured on the LM, biceps femoris, semimembranosus, and adductor femoris. Prior handling experience did not in itself influence ultimate meat quality (P > 0.37); however, the presence of the negative handler (RC pigs) at slaughter accelerated (P < 0.06) preslaughter glycogen breakdown in the LM. Fighting behavior during mixing explained between 13 and 32% of the variability of lightness (L* values) of the LM, biceps femoris, and semimembranosus. Visual contact with the handler at the start of the handling training and number of fights initiated explained between 31 and 42% of the variability in ultimate muscle pH. Latency to approaching the handler during human exposure tests explained 20% of the variability in initial muscle temperature of two muscles. Fighting behavior during mixing could be partly predicted from fighting during a food competition test conducted at the start of the rearing period. Results indicate that reactivity to humans and the tendency to fight determined, in part, meat quality in pigs of similar genetic and rearing backgrounds. These behavioral characteristics were, to some extent, determined early in life. Handling experience modified behavior toward the handler but correlations between behavioral characteristics and meat quality were not influenced by prior handling experience.

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 pH 24 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 m 2 per 100 kg pig during transport would increase the risk of DFD pork by 11%.

Blood serum metabolites and meat quality in crossbred pigs experiencing different lairage time

Pigs of two crosses: A (♀ Duroc × ♂Swedish Landrace) × ♂Pietrain (n=24) and B (♀ Swedish Landrace × ♂Large White) × ♂Pietrain (n=26) were used to investigate the effects of different lairage time (2 and 24 hours) on levels of stress and meat quality traits. No direct effect of lairage time on cortisol, lactate, electrolytes and meat quality parameters was observed. However, after long lairage time, pigs showed lower level of glucose and higher CK, AST and ALT activity. Crossbred B pigs exposed to short lairage time, showed higher blood lactate, sodium, and potassium level, higher drip loss and lower pHi, whereas there were no significant differences between the crossbreeds in the long lairage group. The results indicate that long lairage time decreases blood glucose level and produces signs of muscle damage. In the short lairage period, the crossbreed B showed a higher response to pre-slaughter handling affecting the meat quality.

The effect of lairage time on consumer sensory scores of the M. longissimus thoracis et lumborum from lambs and lactating ewes

The aim of this study was to determine whether lairage time influenced consumer sensory scores of the eating quality of lamb and mutton. Commercial consignments of lambs and ewes were subjected to 3 different lairage periods (slaughter on arrival, slaughter after 1 day or slaughter after 2 days in lairage) at one site in Victoria (experiment 1) and another site in Western Australia (experiment 2). In experiment 1, 3 sucker and 3 carry-over lamb consignments, each consisting of 36 lambs, were sourced from a public saleyard. In experiment 2, 3 ewe and 3 lamb consignments, each consisting of 150 animals were sourced directly from the farm of origin. There was no primary effect of lairage time on consumer sensory scores of the M. longissimus et lumborum from either lambs or ewes at the 2 locations. Sucker lambs were tenderer than carry-over lambs in experiment 1. There was an interaction between age class and lairage time for tenderness in experiment 2, such that lamb meat was tenderer than ewe meat when slaughtered after 1 day in lairage. Ewes produced loins with shorter (0.6 µm, P&lt;0.05) sarcomere length, higher (4.9%, P&lt;0.05) intramuscular fat percentage and darker (P&lt;0.05) meat colour compared with those from sucker lambs. Hue angle was higher (2°, P&lt;0.01) for meat from sheep killed after 1 day in lairage compared with meat from sheep killed on arrival or after 2 days in lairage in both experiments.

Effects of transport and lairage on mortality, liveweight loss and carcass quality in broiler chickens

RiassuntoInfluenza del trasporto e della sosta premacellazione sulla mortalità, sulla perdita di peso e sulla qualità della carcassa di pollo. Nel corso della ricerca sono stati esaminati 321 lotti di broilers macellati in condizioni industriali su cui sono stati determinati i seguenti parametri: tasso di mortalità, perdita di peso vivo, percentuale di carcasse non idonee al consumo, percentuale di ematomi in petto, cosce ed ali. Gli animali trasportati per tempi più brevi (<3,5 h) hanno fatto rilevare un tasso di mortalità inferiore rispetto a quelli trasportati per tempi medi (3,5-5 h) e lunghi (=5 h) (0,24 vs. 0,41 e 0,45%; P<0,01). La perdita di peso è risultata superiore (P<0,01) per tempi di trasporto più lunghi (2,09%) rispetto a quanto osservato per i tempi medi (1,87%) e brevi (1,27%). Negli animali sottoposti ai trasporti più brevi è stata inoltre rilevata una superiore incidenza di ventrigli con un eccessivo stato di riempimento. La durata della sosta premacellazione non ha influenzato significativamente alcuno dei parametri considerati.

Muscle glycogen concentrations in commercial consignments of Australian lamb measured on farm and post-slaughter after three different lairage periods

The aim of this study was to gain an understanding of the distribution of glycogen concentrations and ultimate pH (pHu) in 2 different muscle types for lambs slaughtered under commercial conditions in Western Australia, and to compare muscle glycogen concentrations in lambs on farm and after slaughter. The study included 13 different consignments of prime lambs from a range of commercial scenarios. In each consignment, muscle glycogen concentration was measured in a group of lambs on farm and subsequently after slaughter in 3 different lairage groups. The lairage groups were: slaughter on arrival (no lairage), slaughter after 1 day, and slaughter after 2 days in lairage. Biopsies of M. semimembranosus and the M. semitendinosus were taken from live lambs on farm just before farm curfew before transport and from carcasses immediately after slaughter. There was a significant effect of consignment on muscle glycogen concentration. Muscle glycogen concentrations on farm were lower than 1 g/100 g in 4 consignments for the M. semimembranosus and 11 consignments for the M. semitendinosus. The cause of the differences between consignments was unclear as nutrition, genotype and age class were confounded between consignments. Glycogen concentrations were lower and meat pHu higher for sucker lamb compared with carry-over lamb consignments. However, lambs finished on grain-based feedlot rations had higher muscle glycogen concentrations than lambs finished on pasture and sucker lambs when finished on pastures only. Sucker lambs were only crossbred while carry-over lambs included crossbred and Merino genotypes. When data from different consignments were pooled and the effect of consignment was considered, there were no differences between muscle glycogen concentration measured on farm and muscle glycogen concentration measured after slaughter. However, there were differences between sample times within individual consignments. Glycogen concentration at slaughter was different from glycogen concentration on farm in more consignments for M. semitendinosus than M. semimembranosus, suggesting a difference between consignments for the effect caused by stress. Typically, the M. semimembranosus glycogen concentration at slaughter was lower than on farm in consignments consisting of Merino genotypes that had high muscle glycogen concentrations on farm. In the consignments in which lairage time had an effect on muscle glycogen concentration, the differences were small. In some consignments a difference occurred between lairage times for pHu without any difference occurring for muscle glycogen concentration.

Effects of transport and lairage time on some blood constituents of Friesian-cross steers in Chile

The objective of this study was to determine the effect of two transport journeys (3 and 16 h) and four lairage times at the abattoir (3, 6, 12 and 24 h) on some stress indicators in steers to validate the current Chilean legislation of a minimum lairage period of 12 h for cattle arriving at abattoirs. The study was carried out twice, 80 steers in the winter and 80 in the summer of 1999. Forty steers were transported for 3 h and 40 for 16 h. At arrival in the slaughterhouse, the 40 transported steers were randomly divided in four lairage groups. Blood samples were collected before loading at arrival at the slaughterhouse and at slaughter during exsanguination. Mixed models were used to determine the associations between the stress indicators and the independent variables while correcting for the repeated observations on animals. Lairage increased plasma cortisol and PCV values independent of the transport duration. Glucose concentrations in steers transported for 16 h further increased after 3 and 6 h of lairage but decreased after 12 and 24 h of lairage. In steers transported for 3 h, glucose concentrations only increased after 24 h of lairage. After 24 h of lairage, the steers transported for 16 h had increased βHB concentrations compared with those transported for 3 h. Plasma CK activity was increased in steers after transport but was not affected by lairage. The study shows that there is no beneficial effect on the welfare of the animals by a long lairage time at the abattoir.

Perspective of NIRS measurements early post mortem for prediction of pork quality

The potential of near-infrared spectroscopy (NIRS) measurements early post mortem was investigated to predict ultimate drip loss, colour, tenderness and intra-muscular fat of pork. Three locations (M. longissimus thoracis, M. longissimus lumborum and M. semimembranosus) in 102 pig carcasses were tested at the end of the slaughter line. A priori variation in pork quality was introduced using an experimental design covering: genotype, lairage time, pre-slaughter handling and day of slaughter. At 1 h post mortem a diode array VIS/NIR instrument (Zeiss MCS 511/522, 380–1700 nm) equipped with a surface fibre optic probe was used and at 1 day post mortem ultimate pH, drip loss, colour and shear force was measured on similar locations. Results indicated that it was possible to predict intra-muscular fat content (correlation (R2 of 0.35 with multiple linear regression), standard error of prediction (SEP)=3.6 g/kg), but the configuration has to be refined for on-line application (bigger aperture). For drip loss no correlation was achieved with the PLS method. Even extremes (low drip loss (<2.5%) or high drip loss (>4.5%)) in drip loss were not discriminated. Predicting drip loss with NIRS early post mortem is not successful, although NIRS in the slaughter line has potential as a fast predictor of intra-muscular fat. Possibilities for using the NIRS technique to get to know more about muscle metabolism and post mortem changes are promising.

Factors influencing bruises and mortality of broilers during catching, transport, and lairage

A multilevel analysis was performed to identify and quantify risk factors associated with mortality and bruises occurring between catching and slaughter of broiler flocks. The effect of each factor in the final model was expressed as an odds ratio (OR). Data included 1,907 Dutch and German broiler flocks slaughtered in 2000 and 2001 at a Dutch processing plant. The mean dead on arrival (DOA) percentage was 0.46. Percentage of bruises was corrected for economic value. The mean corrected bruises percentage was 2.20. Factors associated with corrected bruises percentage were season, moment of transport, and ambient temperature. Unfortunately, these factors are quite difficult to manipulate. Factors associated with DOA percentage were ambient temperature, moment of transport, catching company, breed, flock size, mean BW, mean compartment stocking density, transport time, lairage time, and the interaction term transport time x ambient temperature. The most important factors that influence DOA percentage, and which can be reduced relatively easily, were compartment stocking density (OR = 1.09 for each additional bird in a compartment), transport time (OR = 1.06 for each additional 15 min), and lairage time (OR = 1.03 for each additional 15 min). In particular, reduction of transport and lairage times might have a major influence due to their large variations. Reducing or removing these factors will reduce DOA percentage. Consequently, profitability and animal welfare will increase.

Impact of the Salmonella status of market-age pigs and the pre-slaughter process on Salmonella caecal contamination at slaughter.

The aim of this study was to evaluate the impact of the pre-slaughter process on Salmonella caecal contamination of pigs at slaughter. An observational study was carried out in 2001 on 101 conventional farrow-to-finish pig farms. On each farm, one batch of contemporary pigs was followed from the end of the fattening period until slaughter. The Salmonella bacteriological status of the batches was assessed by environmental samples of faecal material. The serological Salmonella status was obtained on 30 individually identified market-age pigs using an indirect ELISA test. At the slaughterhouse, 25 g of caecal contents were taken from 10 of the identified pigs. Faecal and caecal material were analysed according to a classical bacteriological method. A questionnaire was designed to obtain information about the type of feeding during the fattening period (dry versus wet), the duration of fasting on the farm before leaving for the slaughterhouse, the duration of transport between the farm and the slaughterhouse, the holding time in lairage at the slaughterhouse and loading and unloading conditions on the farm and at the slaughterhouse. To assess the relationships between these factors and the Salmonella caecal status of the pigs and the batches, two logistic models were fitted at the individual and at the batch level, respectively. The first analysis was performed using a random effects logistic regression model. The second analysis was based on a cumulative logit model with a positive caecal rate classified into three classes as the outcome variable. The results showed that the Salmonella status of market-age pigs assessed on the farm either by serological or bacteriological examinations and the time spent in lairage before slaughtering played a crucial role on caecal contamination. In the light of these results, actions should be considered both on the farm and at the slaughterhouse to decrease the risk of Salmonella contamination of the caecal contents.

Risk assessment of PSE condition due to pre-slaughter conditions and RYR1 gene in pigs

A polychotomous logistic regression model was used to identify and assess the risk factors for pork meat becoming pale, soft and exudative (PSE). A total of 116 deliveries, comprising 15,695 commercial pigs delivered from different commercial farms to five Spanish pig commercial abattoirs were surveyed. The PSE condition was described as an ordinal response variable (normal, prone to PSE and PSE) based on measurements of electrical conductivity in the Semimembranosus muscle 1–2 h post-mortem. The RYR1 genotype, the abattoir, the season, the gender, the floor surface in the lorry, the loading system, and the stocking density during transportation influenced the risk of PSE condition, as well as on-farm fasting time, loading time, transportation and lairage times. The effect of the RYR1 gene, determined in a subsample of 1331 pigs, was due to nn stress-susceptible pigs, in which the risk of PSE meat (PQM>6 μs) increased fourfold. Abattoirs should be especially careful in summer, when the risk of PSE meat was found to be double that of winter. The risk of PSE meat decreased with the time of transportation, though its effect depended on the stocking density. Thus, our results indicate that, for transits longer than 3 h, the risk of PSE increases with stocking density during transport, while the opposite occurs for shorter transits.