Use of the spectrophotometric color method for the determination of the age of skin lesions on the pig carcass and its relationship with gene expression and histological and histochemical parameters.

The presence of lesions on the pig carcass is an indicator of poor animal welfare and has economic impact as it downgrades the carcass value. The assessment of the age of lesions on the carcass may help identify risk factors and ultimately prevent their occurrence. The aim of this study was to assess the age of lesions on pig carcasses through spectrophotometric color evaluation and to relate the results with gene expression and histological and histochemical parameters. A total of 96 barrows were mixed 4 times over 3 d before slaughter and 80 lesions were selected after skin lesion observations to define 4 age categories: < 7 h (T1), 7-25 h (T2), 25-30 h (T3), and 49-54 h (T4). A nonlesioned skin area was used as a control. At slaughter, 3 biopsies per lesion and control skin were taken immediately after bleeding for analyses of gene expression (, , , , , , , , , ), skin histological characteristics (inflammation, erosion or ulceration, and necrosis), and enzyme activity (alkaline phosphatase and adenosine triphosphatase). The number of lesions was counted on each carcass, and the color was assessed visually by a pictorial chart and instrumentally through a spectrophotometer. Delta values (Δ) were calculated as the difference between the value of the lesion and the value of the control for all measures, except for the histological analysis. Results indicated that visual color observation was not sufficiently accurate to discriminate lesions by time of infliction ( > 0.10), while the spectrophotometer ΔL* and Δa* values variation allowed the identification of < 7 h or > 25 h old lesions ( < 0.05). Similarly, the expression of , , , , and genes was higher ( < 0.05) in < 7 h old lesions, while gene expression was higher ( < 0.05) in < 25 h old lesions. As for the histological analysis, the severity of inflammation was correlated with the age of the lesion (lower score in < 7 h old lesions and higher score in > 25 h old lesions; < 0.05). To conclude, the spectrophotometric color assessment of the carcass lesions at slaughter appears to be a reliable method to discriminate between fresh and older lesions on the carcass at the abattoir.

Review: Effects of Ractopamine Hydrochloride (Paylean) on welfare indicators for market weight pigs.

This review summarizes the effects of ractopamine hydrochloride (RAC) dose (5, 7.5, 10, and 20 mg/kg) on market weight pig welfare indicators. Ractopamine hydrochloride (trade name Paylean) is a ß-adrenergic agonist that was initially approved in the U.S. in 1999 at doses of 5 to 20 mg/kg to improve feed efficiency and carcass leanness. However, anecdotal reports suggested that RAC increased the rate of non-ambulatory (fatigued and injured) pigs at U.S. packing plants. This led to the addition of a caution statement to the Paylean label, and a series of research studies investigating the effects of RAC on pig welfare. Early research indicated that: (1) regardless of RAC administration, fatigued (non-ambulatory, non-injured) pigs are in a state of metabolic acidosis; (2) aggressive handling increases stress responsiveness at 20 mg/kg RAC, while 5 mg/kg reduces stress responsiveness to aggressive handling. Given this information, dosage range for Paylean was changed in 2006 to 5 to 10 mg/kg in market weight pigs. Subsequent research on RAC demonstrated that: (1) RAC has minimal effects on mortality, lameness, and home pen behavior; (2) RAC fed pigs demonstrated inconsistent prevalence and intensity of aggressive behaviors; (3) RAC fed pigs may be more difficult to handle at doses above 5 mg/kg; and (4) RAC fed pigs may have increased stress responsiveness and higher rates of non-ambulatory pigs when subjected to aggressive handling, especially when 20 mg/kg of RAC is fed.

A note comparing the welfare of Zebu cattle following three stunning-slaughter methods.

The objective of this study was to assess welfare of cattle during bleeding after slaughter with or without stunning. A total of 434 bulls were distributed across three slaughter treatments: penetrating captive bolt stunning followed by chest sticking (PCB, N=279), non-penetrating captive bolt stunning followed by halal slaughter (NPCB, N=67) and shechita without previous stunning (SHE, N=88). Four measures of possible consciousness and return to sensibility were recorded 20 and 60 s after bleeding as welfare indicators. They were the frequencies of responses to nostril stimulation and tongue pinch, spontaneous eye blinking, and rhythmic breathing. All responses were absent in stunned cattle at both 20 and 60 s, and in SHE cattle 7, 4, 10, and 100% of the animals presented these responses, respectively. Repeat shots were required for 46% NPCB and 2% PCB (P<0.05). The application of religious slaughter without previous stunning may result in greater risk of cattle suffering, pain and distress at slaughter.

Can the monitoring of animal welfare parameters predict pork meat quality variation through the supply chain (from farm to slaughter)?

The objective of this study was to assess the relationship between the animal welfare conditions evaluated through the supply chain and pork quality variation. A total of 4,680 pigs from 12 farms-5 animal welfare improved raising system (AWIRS) and 7 conventional raising system (CON) farms-were assessed from farm to slaughter through a comprehensive audit protocol merging the European Welfare Quality, the Canadian Animal Care Assessment, and American Meat Institute audit guide criteria. At the abattoir, a subsample of 1,440 pigs (120 pigs/farm) was randomly chosen out of 24 loads (2 farms per wk) transported by 2 drivers (driver A and driver B) for the assessment of stunning effectiveness, carcass bruises, blood lactate levels, and meat quality traits. Meat quality was assessed in the longissimus lumborum (LL) muscle 24 h postmortem by measuring ultimate pH (pHu), color (L*, a*, and b*), and drip loss. Data were analyzed by the MIXED, GLIMMIX, and NAPAR1WAY procedures of SAS. Spearman correlations were calculated to determine the relationship between audit scores and meat quality traits. Better animal welfare conditions, as showed by greater final scores for good housing (GHo; = 0.001) and good health ( = 0.006) principles, were recorded at AWIRS farms. Pigs from AWIRS farms handled by driver B displayed a greater percentage of turning back ( = 0.01) and slips ( < 0.001) during unloading and a greater ( = 0.02) frequency of falls in the stunning chute. A greater ( = 0.02) reluctance to move at loading was found in CON pigs loaded by driver A compared with driver B, whereas a greater ( < 0.001) reluctance to move was found in these pigs at unloading when they were unloaded by driver B. Drip loss was higher ( = 0.003) and pale, soft, and exudative pork percentage was greater ( < 0.001) in the LL muscle of the heavier AWIRS pigs. The GHO principle was best correlated with pHu ( = -0.75, = 0.01) and Minolta L* value ( = 0.87, < 0.001) of the LL muscle. Overall, drip loss variation in the LL muscle was correlated with the frequency of slips at unloading ( = 0.63, = 0.001) and in the restrainer area ( = 0.74, < 0.001). The results of this study showed that the quality of the raising system and truck driver skills as assessed by animal welfare audit protocols are important sources of variation in the behavioral response of pigs to preslaughter handling and may affect pork quality variation. However, the different live weight between CON and AWIRS pigs may have biased the meat quality results in this study.

Effects of season, truck type, and location within truck on gastrointestinal tract temperature of market-weight pigs during transport.

Two experiments were done to assess the effects of season, truck type, and location in the truck on the gastrointestinal tract temperature (GTT) of market-weight pigs during transport. In Exp. 1, a total of 504 sentinel pigs were selected from a total load of 3,756 pigs over 12 wk in summer or winter and transported in either a double-decked (DD) hydraulic truck or a pot-belly (PB) trailer for 2 h. In Exp. 2, a total of 330 sentinel pigs were selected from a total load of 2,145 pigs over 11 wk in summer or winter and transported in a PB trailer for 8 h. In both experiments, sentinel pigs were equipped with a temperature data logger for the real-time GTT recording from the farm to slaughter. Transport was divided into 8 periods in Exp. 1 (rest, pretravel, initial travel, prearrival 1, prearrival 2, unloading, lairage 1, and lairage 2) and in Exp. 2 (rest, pretravel 1, pretravel 2, travel, prearrival 1, prearrival 2, lairage 1, and lairage 2). A delta GTT (ΔGTT) was calculated as the difference between the measured GTT at any determined event and the GTT measured at rest. In Exp. 1, the ΔGTT of pigs was greater ( < 0.001) in summer than in winter and only during the pretravel and initial travel periods. No difference was observed in the ΔGTT between the 2 truck types ( > 0.10). In summer, pigs located in the front top and rear top compartments of the PB trailer presented greater ( < 0.05) ΔGTT values than those transported in the middle top and front belly compartments during initial travel. In summer, during prearrival 1 and 2, a greater ( < 0.05) loss of GTT was found in pigs located in the rear top compartment of the DD truck compared with the rear lower compartment and in the front middle compartment compared with the rear middle compartment of the PB trailer. In Exp. 2, the ΔGTT of pigs was greater ( = 0.03) in summer than in winter during pretravel 2. Pigs in the front top compartment had a greater ( < 0.05) ΔGTT compared with pigs in the middle top, lower deck, and front belly compartments during the pretravel periods. Based on the results of the 2 experiments, modifications of the PB trailer model are recommended to limit body temperature increase due to physical stress at loading and unloading, and during transport due to inconsistent ventilation rate across vehicle locations.

Hand-held lactate analyzer as a tool for the real-time measurement of physical fatigue before slaughter and pork quality prediction.

The objectives of this study were to assess the relationship between blood lactate variation measured at the plant, and pork quality variation on a large sample size and under commercial preslaughter handling conditions. A total of 600 pigs were randomly chosen on arrival at a commercial slaughter plant and blood samples taken from the ear vein at unloading (UN), after lairage (LA), in the restrainer (RE; before stunning) and at exsanguination (EX) were analysed for lactate content using a Lactate Scout Analyzer (LSA). In order to have a large range of measures, pigs were distributed into two groups; one kept in lairage overnight (G1) and the other for 2 to 3 h (G2) before slaughter. Meat quality was assessed in the Longissimus thoracis (LT), Semimembranosus (SM) and Adductor (AD) muscles by measuring the pH 30 min postmortem (pH1) and at 24 h postmortem (pHu), the colour and the drip loss. Blood lactate levels did not differ between G1 and G2 (P>0.05). A reduced muscle lactate and glucose contents (P=0.02 and P=0.004, respectively) resulting in a lower (P<0.001) glycolytic potential (GP) was observed in the LT muscle of G1 pigs when compared with G2 loins. In the LT muscle of G1 pigs, the lower GP resulted in an increased pHu (r=-0.67; P<0.001), decreased drip loss (r=0.57; P<0.001) and darker colour (r=0.50; P<0.001) compared with G2. In both G1 and G2 pigs, the lower GP was correlated to higher pHu value in the SM and AD muscles (r=-0.73; P<0.001). The greatest correlation was observed in G2 between blood lactate levels at LA and pHu value of the SM and AD muscles (r=0.46 and r=0.44, respectively; P<0.001 for both muscles). The second greatest correlation was found between blood lactate levels at EX and pH1 value in the SM muscle in both groups (r=-0.37 and r=-0.41, respectively; P<0.001 for both groups). Based on the results of this study, it appears that blood lactate levels, as measured by the LSA, reliably reflect the physiological response of pigs to perimortem stress and may help explain the variation in pork quality.

Effect of rest duration on recovery from repeated exercise in near-market-weight pigs.

The process of transportation can be seen as a succession of stressors, from which pigs may not have time to recover before slaughter. The aim of this study was to determine the extent to which the duration of the rest time given to near-market-weight pigs after an initial exposure to exercise affected their recovery from subsequent exercise. Eighteen groups of 3 gilts were exercised (Ex1) through a standard handling course, including two 19° ramps, and then were held in a holding pen for either 35 (RT35), 75 (RT75), or 150 (RT150) min (Rest Period 1, RP1). Afterward, pigs were exercised a second time (Ex2) and left to rest for 150 min. Recovery from Ex2 (Rest Period 2, RP2) was assessed using measures of heart rate (HR), respiratory rate (RR), skin temperature (ST), and posture. Repeated measures and regression analysis were used to analyze the data. For RT75 pigs, there were no detrimental effects of Ex2 on HR, RR, and handling time (P > 0.05, for all) during the exercise and recovery periods. Skin temperature during Ex2 was greater than ST during Ex1 (P < 0.001), whereas ST during RP1 did not differ from ST during RP2 (P > 0.05). Doubling the rest period did not provide any more beneficial effects in regard to RR and HR (P > 0.05 for both) during Ex2 and RP2 compared to RT75 pigs, as shown by the similar latencies to recover for these 2 variables. However, ST did not increase between exercises, and RT150 pigs required less time to complete the handling course during Ex2. The results show that a lack of rest after an initial exposure to exercise made pigs more susceptible to stress during Ex2 and RP2, as demonstrated by greater (P < 0.001 for all) HR, RR, and ST during RP2 compared to RP1 and Ex2 compared to Ex1. When given more than 35 min to rest during RP2, RT35 pigs eventually recovered. Latencies of recovery for HR, ST, RR, and posture were all greater (P < 0.05 for HR, ST, and RR and P < 0.001 for posture) than those obtained for RT75 and RT150 pigs. This study highlights that if pigs are not initially given enough rest to recover from exercise, a subsequent exposure to the same exercise will cause an increase in these physiological variables during exercise and recovery. Further research is needed to investigate factors contributing to the quality of rest, with a particular focus on conditions not allowing a proper rest on the truck or in lairage.

Effects of transport duration on maintenance behavior, heart rate and gastrointestinal tract temperature of market-weight pigs in 2 seasons.

Welfare and meat quality of market-weight pigs may be negatively affected by transport duration and environmental temperatures, which vary considerably between seasons. This study evaluated the effects of 3 transport durations (6, 12, and 18 h) on the physiology and behavior of pigs in summer and winter in western Canada. Market-weight pigs were transported using a pot-belly trailer at an average loading density of 0.375 m(2)/100 kg. Four replicates of each transport duration were conducted during each season. Heart rate and gastrointestinal tract temperature (GTT) were monitored from loading to unloading in 16 pigs from 4 selected trailer compartments (n = 96 groups, total of 384 animals, BW = 120.8 ± 0.4 kg), namely top front (C1), top back (C4), middle front (C5), and bottom rear (C10). Behavior was recorded for pigs (948 and 924 animals, in summer and winter, respectively) in C1, C4, and C5 during transportation (standing, sitting, lying), and during 90 min in lairage (sitting, lying, drinking, latency to rest) for pigs in all 4 compartments. Transport was split into 7 periods: loading, pre-travel (PT), initial travel (IT), pre-arrival 1 (PA1) and 2 (PA2), unloading, and lairage. During IT and PA2, pigs spent less time lying in winter than summer (P < 0.05 and P < 0.05, respectively). During PA1, PA2, and unloading, a greater (P < 0.001) heart rate was found in pigs transported in winter compared with summer. During PA2, pigs subjected to the 18-h transport treatment in winter had a greater (P < 0.05) GTT than the other groups. In lairage, pigs transported for 18 h in winter drank more (P < 0.001) and took longer to rest (P < 0.01) than pigs from other groups. During PA1, pigs transported for 18 h had the greatest GTT (P < 0.001). At unloading, pigs transported for 6 h had the lowest GTT (P < 0.001). In lairage, pigs transported for 18 h spent less time lying than those transported for 6 or 12 h (P < 0.001). These results suggest that in winter, pigs increased their metabolism and were reluctant to rest on cold floors. Pigs transported for 18 h in winter showed greater evidence of thirst. It may be concluded that under western Canadian climatic conditions, long transports (18 h) in cold weather appear to be more detrimental to pig welfare.

Effects of ractopamine administration and castration method on the response to preslaughter stress and carcass and meat quality in pigs of two Piétrain genotypes.

The objective of this study was to evaluate the effects of ractopamine supplementation, castration method, and their interaction on the behavioral and physiological response to preslaughter stress and carcass and meat quality of 2 Piétrain genotypes. A total of 1,488 male pigs (115 ± 5 kg BW) were distributed according to a 2 × 2 × 2 factorial arrangement of treatments. The first factor was ractopamine supplementation with 2 groups of pigs (376 and 380 pigs each) receiving 7.5 mg/kg of ractopamine (RAC) or not (NRAC) in their diet during the last 28 d of the finishing period. The second factor was castration method, with 744 surgical castrates (SC) and 744 immunized males (IM), and the third factor was the genotype with 2 crossbreeds containing 50% (genotype A, GA; n = 744) or 25% (genotype B, GB; n = 744) Piétrain genetics. Surgical castration took place at 2 d of age, whereas immunization against gonadotropin-releasing factor (GnRF) was performed through 2 subcutaneous injections of GnRF analog (Improvest, 2 mL) at 10 and 4 wk before slaughter. At loading more vocal stimulation was needed by the handler to drive GB pigs forward through the farm alley (P = 0.01) and RAC-fed GB pigs through the ramp (P = 0.02). Feeding RAC to IM increased the number of fights in lairage compared with SC (P = 0.03). Feeding RAC shortened fighting bouts compared with NRAC pigs (P = 0.05). The SC-GA pigs showed a greater gastrointestinal tract temperature during unloading (P = 0.05) and lairage time (P = 0.03). Blood creatine kinase (CK) concentrations were greater (P = 0.04) in SC compared with IM, and no difference was found in the concentrations of stress hormones in urine collected postmortem. Dressing yield was greater (P = 0.01) in RAC and SC-GB pigs. Carcasses from RAC pigs and IM were leaner than those from NRAC and SC pigs (P < 0.001 and P = 0.002, respectively). Feeding RAC to IM increased drip loss in the LM (P = 0.05). Warner-Bratzler shear force values were slightly greater in the LM from RAC-GB pigs and from IM compared with SC (P = 0.01 and P < 0.001, respectively) and in the semimembranosus muscle of RAC pigs (P = 0.006). In conclusion, immunization against GnRF more than the use of Piétrain genotypes appears to be a viable alternative to the use of ractopamine, as it seems to promote production of lean carcasses without compromising animal welfare and pork quality.

Effect of ramp configuration on easiness of handling, heart rate, and behavior of near-market weight pigs at unloading.

Three experiments, each using 280 pigs, were conducted in a simulated compartment to test the effect of angle of entrance (AOE) to the ramp (90°, 60°, 30°, or 0°), ramp slope (0°, 16°, 21°, or 26°), and an initial 20-cm step associated with 16° or 21° ramp slopes on the ease of handling, heart rate (HR), and behavior of near market-weight pigs during unloading. Heart rate (pigs and handler), unloading time, interventions of the handler, and reactions of the pigs were monitored. The results of the first experiment show that using a 90° AOE had detrimental effects on ease of handling (P < 0.05), HR of the pig (P < 0.05), and behavior (P < 0.05). The 0° and 30° AOE appeared to improve the ease of unloading, whereas the 60° AOE had an intermediate effect. The 30° AOE appeared to be preferable, because pigs moved at this angle balked less frequently (P < 0.01) and required less manipulation (P < 0.05) than pigs moved with a 0° AOE. The results of the second experiment show that the use of a flat ramp led to the easiest unloading, as demonstrated by the lower number of balks (P < 0.001) when pigs were moved to the ramp and less frequent use of paddle (P = 0.001) or voice (P < 0.001) on the ramp, compared with the other treatments. However, the flat ramp did not differ from the 21° ramp in many of the variables reflecting ease of handling, which may be explained by the difference in configuration between the ramps. The results also show that the use of the steepest ramp slope had the most detrimental effect on balking and backing up behavior of pigs (P < 0.001), and handling (touches, slaps, and pushes; P < 0.05 for all) when moved to the ramp and on unloading time (P < 0.01). No differences in pig HR (P < 0.05) and ease of handling on the ramp (P < 0.05) were found between a 26° and 16° ramp slope, suggesting that the length of the ramp may be one of the factors that make unloading more difficult. The results of the last experiment show that an initial step made unloading physically more demanding for the handler (P < 0.001) and pigs on the ramp (P < 0.05) as demonstrated by their greater HR. The greater difficulty of handling (P < 0.01) and reluctance to move (P < 0.05) of pigs moved toward the 16° ramp with a step suggest that pigs perceived this ramp as more psychologically challenging. Making a few changes in terms of the design of the ramp could improve the efficiency of handling and reduce stress in pigs.

Transportation of market-weight pigs: II. effect of season and location within truck on behavior with an eight-hour transport.

Transportation of pigs to slaughter has the potential to negatively impact animal welfare, particularly in hot temperatures and over long transport durations. The objective of this experiment was to determine if season and location within vehicle influenced the behavior of market-weight pigs during loading, transit, unloading, and lairage after a long-distance trip to slaughter. On a pot-belly truck, 1,170 pigs were transported (n = 195 pigs/wk in 7 experimental compartments) for 8 h to a commercial abattoir in summer (6 wk) and winter (5 wk). Pig behavior was observed at loading, in transit, at unloading, and in lairage. Handler intervention at loading was observed, and the time to load and unload was recorded. Although season did not (P = 0.91) affect loading time, more prods (P = 0.014) were necessary to load pigs in summer than winter. Loading in winter also tended to be longer (P = 0.071) into compartments involving internal ramps. In transit, more pigs (P = 0.025) were standing in winter compared with summer. Unloading took longer (P < 0.006) in winter than in summer and from compartments where pigs had to negotiate ramps and 180° turns. Furthermore, pigs in summer experienced more slipping (P = 0.032), falling (P = 0.004), overlapping (P < 0.001), and walking backward (P < 0.001) than pigs in winter. Pigs unloading from compartments with internal ramps slipped more (P < 0.0001) than other pigs. Season influenced latency to rest in lairage, with those transported in summer resting sooner (P < 0.0001) than those in winter. In conclusion, season and location within trucks differentially affect pig behavior before, during, and after long-distance transportation. Differences in lighting and temperature between seasons and the inclusion of internal ramps within vehicles may play important roles in the welfare of pigs transported to slaughter.

Transportation of market-weight pigs: I. effect of season, truck type, and location within truck on behavior with a two-hour transport.

There is evidence that season and truck/trailer design play important roles in pig welfare during transportation although little is known about their interaction and effect on pig behavior. This experiment was designed to examine the influence of season and truck/trailer design on the behavior during loading, transit, unloading, and lairage of market-weight pigs transported to slaughter. A total of 3,756 pigs were transported on either a 3-deck pot-belly trailer (PB; n = 181 pigs/wk in 8 experimental compartments) or a double-decker hydraulic truck (DD; n = 85 pigs/wk in 4 compartments) for 2 h to a commercial abattoir in summer and winter (6 wk in each season). Density on both vehicles was 0.40 m(2)/pig. Accounting for the number of pigs, loading took longer (P = 0.033) onto the DD than the PB, but season did not (P = 0.571) influence loading time. Pigs loaded onto the PB moved backward more (P = 0.003) frequently than those loaded onto the DD. The frequency of tapping by handler was the lone handling intervention affected by truck type, with more (P = 0.014) tapping needed to move pigs on and off DD than PB. During loading, pigs made more (P < 0.001) slips and falls, overlaps, 180° turns, underlaps, and vocalizations in winter compared with summer. On truck, more (P < 0.001) pigs were standing on the DD at the farm and in transit than on the PB whereas more (P = 0.012) pigs were lying in transit in summer than in winter. Pigs took longer to unload (P < 0.001) from the PB than the DD, but no difference between vehicles (P = 0.473) in latency to rest in lairage was found. Pigs slipped and fell more (P < 0.001) during unloading, took longer (P < 0.001) to unload, and had a shorter (P = 0.006) latency to rest in lairage in winter than summer. Vehicle design, in particular the presence of ramps, influenced pig behavior before, during, and after transportation, regardless of the season. Season affected loading and unloading behavior, especially in terms of slips and falls on the ramp, and differences in truck/trailer designs were also partly to blame for unloading times and lairage behavior. Ramps and changes in direction during unloading appear to slow down the handling process.

Effects of trailer design on animal welfare parameters and carcass and meat quality of three Pietrain crosses being transported over a long distance.

This study aimed at evaluating the effects of trailer design on stress responses and meat quality traits of 3 different pig crosses: 50% Pietrain breeding with halothane (HAL)(Nn) (50Nn); 50% Pietrain breeding with HAL(NN) (50NN); and 25% Pietrain breeding with HAL(NN) genotype (25NN). Over a 6-wk period, pigs (120 pigs/crossbreed) were transported for 7 h in either a pot-belly (PB) or flat-deck (FD) trailer (10 pigs/crossbreed(-1)·trailer(-1)·wk(-1)). Temperature (T) and relative humidity (RH) were monitored in each trailer. Behaviors during loading and unloading, time to load and unload, and latency to rest in lairage were recorded, whereas a sub-population of pigs (4 pigs/crossbreed(-1)·trailer(-1)·wk(-1)) was equipped with gastro-intestinal tract (GIT) temperature monitors. Blood samples were collected at exsanguination for measurement of cortisol, creatine kinase (CK), lactate, haptoglobin, and Pig-MAP concentrations. Meat quality data were collected at 24 h postmortem from the LM and semimembranosus (SM) and adductor (AD) muscles of all 360 pigs. Greater T were recorded in the PB trailer during transportation (P = 0.006) and unloading (P < 0.001). Delta GIT temperature was greater (P = 0.01) in pigs unloaded from the PB. At loading, pigs tended to move backwards more (P = 0.06) when loaded on the FD than the PB trailer. At unloading, an interaction was found between trailer type and crossbreed type, with a greater (P < 0.01) frequency of overlaps in 50NN and 25NN pigs and slips/falls in 50Nn and 50NN pigs from the FD than the PB trailer. Cortisol concentrations at slaughter were greater (P = 0.02) in pigs transported in the PB than FD trailer. Greater lactate concentrations were found in 50Nn and 50NN pigs (P = 0.003) and greater CK concentrations (P < 0.001) in 50Nn pigs. As expected, 50Nn pigs produced leaner (P < 0.001) carcasses, with greater (P = 0.01) dressing percentages, as well as lower (P < 0.001) ultimate pH values and greater (P < 0.001) drip loss percentages in the LM and greater (P = 0.002) drip losses and a paler color (greater L* values, P = 0.02) in the SM than 50NN pigs. When used for long distance transportation under controlled conditions, the PB trailer produced no detrimental effects on animal welfare or pork quality. Pigs with 50% Pietrain crossbreeding appear to be more responsive to transport stress, having the potential to produce acceptable carcass and pork quality, provided pigs are free of the HAL gene.

Road transport of cattle, swine and poultry in North America and its impact on animal welfare, carcass and meat quality: a review.

This paper reviews the effects of road transport on the welfare, carcass and meat quality of cattle, swine and poultry in North America (NA). The main effects of loading density, trailer microclimate, transport duration, animal size and condition, management factors including bedding, ventilation, handling, facilities, and vehicle design are summarized by species. The main effects listed above all have impacts on welfare (stress, health, injury, fatigue, dehydration, core body temperature, mortality and morbidity) and carcass and meat quality (shrink, bruising, pH, color defects and water losses) to varying degrees. It is clear that the effect of road transport is a multi-factorial problem where a combination of stressors rather than a single factor is responsible for the animal's well-being and meat quality post transport. Animals least fit for transport suffer the greatest losses in terms of welfare and meat quality while market ready animals (in particular cattle and pigs) in good condition appear to have fewer issues. More research is needed to identify the factors or combination of factors with the greatest negative impacts on welfare and meat quality relative to the species, and their size, age and condition under extreme environmental conditions. Future research needs to focus on controlled scientific assessments, under NA conditions, of varying loading densities, trailer design, microclimate, and handling quality during the transport process. Achieving optimal animal well-being, carcass and meat quality will entirely depend on the quality of the animal transport process.

Effects of corn grain particle size and treated soybean meal on carcass and meat quality characteristics of beef steers finished on a corn silage diet.

Thirty-nine steers were distributed into a 2 x 2 factorial arrangement of treatments to determine the effect of corn grain particle size (cracked [CC] vs ground [GC] corn) and soybean meal treatment (solvent extracted soybean meal [SS] vs lignosulfonate treated soybean meal Soypass™ [SP]) on carcass and meat quality traits. When CC diet was supplemented with SS carcass quality grade score tended to decrease (P=0.09). GC had no effect on meat quality, while SP only increased the intramuscular fat content when added to CC (P=0.01). The CC diet supplemented with SP increased the proportion of saturated fatty acids (P=0.01). Despite the positive effects on carcass quality, the lack of improvement in meat quality and the more saturated fatty acid profile would not justify the use of processed corn or treated soybean meal in the finishing diet of steers.

Effects of different moving devices at loading on stress response and meat quality in pigs.

Although there is increasing evidence regarding the negative welfare and meat quality implications of electric prod use for slaughter-weight pigs, this handling tool continues to be used. Therefore, the behavioral and physiological response and carcass and meat quality of 360 pigs being loaded onto a truck for transportation to slaughter according to 3 handling procedures were studied. The 3 handling procedures were 1) moving with an electric prod and board from the finishing pen to the truck (EP); 2) moving with a board and a paddle from the finishing pen to the truck (PAD); 3) moving with a board and a paddle from the finishing pen and using a compressed air prod in the ramp before going into the truck (CAP). A subpopulation of 144 pigs (48 pigs/treatment) was equipped with heart rate monitors. Blood samples were collected from the same animals at exsanguination for the analysis of creatine phosphokinase and lactate. Data were analyzed using an ANOVA for factorial design, with the animal as the experimental unit. Behavior was analyzed with MIXED model procedure with treatment as a fixed effect. During loading, EP pigs slipped and fell (P < 0.001) and overlapped (P = 0.03) more often, but stopped (P < 0.001) and attempted turns (P = 0.01) less often than CAP or PAD. With CAP, pigs made more 180° turns (P = 0.01) than with PAD or EP. Loading with EP led to more and longer vocalizations (P = 0.02 and P = 0.001, respectively) than loading with CAP or PAD. Loading took longest with CAP and was quickest with EP (P = 0.01). Pigs handled with EP had a greater heart rate than those moved with PAD and CAP at loading (P < 0.001), wait at loading (P < 0.001), at unloading (P = 0.05), and in lairage (P = 0.02). Pigs loaded with EP had greater (P = 0.05) lactate concentrations in blood at exsanguination compared with pigs handled with CAP, with pigs loaded with PAD being intermediate. Furthermore, ultimate pH values in the semimembranosus and adductor muscles of EP pigs were greater (P = 0.002 and P = 0.004, respectively) compared with those from PAD and CAP pigs. Greater (P = 0.04) incidence of blood-splashed hams was found in EP pigs compared with PAD and CAP pigs. Therefore, considering animal welfare, carcass bruising, and blood splashes standpoints, EP should be replaced with PAD or CAP. However, additional research is necessary to identify methods that improve the loading efficiencies of PAD and CAP without adversely affecting animal welfare parameters.

Shelf life of pork from five different quality classes.

A total of 117 loins were selected on the cutting line at 24h post-mortem to study the long term shelf life (35 days, 4 degrees C) of vacuum packaged pork from five different quality classes (PSE: pale, soft, exudative; PFN: pale, firm, non-exudative; RSE: red, soft, exudative; RFN: red, firm, non-exudative; and DFD: dark, firm, dry). The microbial load at 0 d was not significantly different (P>0.05) among the pork quality classes, indicating that the initial microflora was influenced by the dressing conditions at the plant, not by the meat quality class. But after 35 d of storage, total aerobic mesophilic and presumptive lactic acid bacteria counts were higher (P<0.05) in DFD pork due to its higher ultimate pH. RSE was the second quality class most susceptible to spoilage, whereas PFN, RFN and PSE pork had similar microbial loads. Further research is needed to elucidate the causes of the shorter shelf life in RSE pork.

Comparison of alternative beef production systems based on forage finishing or grain-forage diets with or without growth promotants: 2. Meat quality, fatty acid composition, and overall palatability.

Five beef cattle management regimens were evaluated for their effect on meat quality, fatty acid composition, and overall palatability of the longis-simus dorsi (LD) muscle in Angus cross steers. A 98-d growing phase was conducted using grass silage with or without supplementation of growth promotants (Revalor G and Rumensin) or soybean meal. Dietary treatments in the finishing phase were developed with or without supplementation of growth promotants based on exclusive feeding of forages with no grain supplementation, or the feeding of grain:forage (70:30) diets. Growth promotants increased (P < 0.01) shear force and tended (P = 0.06) to increase toughness of the LD muscle due to limited postmortem proteolytic activity (lower myofibrillar fragmentation index value; P = 0.02). Grain feeding increased DM and intramuscular fat content (P = 0.03 and P = 0.05, respectively) in the LD but decreased the sensory panel tenderness score (P = 0.01). Growth promotants increased (P

Effects of growth rate, sex and slaughter weight on fat characteristics of pork bellies.

A total of 119 Duroc×(Landrace×Yorkshire) commercial pigs were used to investigate the effect of growth rate (fast vs slow), sex (barrows vs gilts) and slaughter liveweight (107, 115 and 125kg) on the fat characteristics of bellies. Backfat thickness increased with weight (P<0.01). Fat firmness score was only affected by sex (P<0.05), with gilts showing softer bellies than barrows. Fat from gilts and slow growing pigs showed a lower proportion of saturated fatty acids (SFA; P<0.001 and P<0.01, respectively), a higher proportion of linoleic fatty acid (C18:2 n-6; P<0.01), a higher proportion of total polyunsaturated fatty acids (PUFA; P<0.001 and P<0.01, respectively), and an increased iodine value (P<0.001). Consequently, the fat from these bellies had higher PUFA:SFA ratios (P<0.001) and n-6:n-3 ratios (P<0.01 and P<0.001, respectively) than that from the bellies of barrows and fast growing pigs. The belly fat from barrows and fast growing pigs had higher stearic fatty acid (C18:0; P<0.01) and SFA proportions (P<0.001 and P<0.01, respectively) than that from gilts and slow growing pigs. The belly fat from gilts and slow growing pigs would better meet the health requirements of consumers, but it is more prone to rancidity during storage leading to a potentially reduced bacon shelf-life.