L. Faucitano

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 animals 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 slaughter weight on carcass composition and meat quality in pigs of two different growth rates.

Three hundred and forty (340) Duroc×(Landrace×Yorkshire) crossbred piglets were allotted to a 2×2×3 factorial design experiment. The independent variables were the growth rate (fast: around -10 days at 100kg and slow: around +2 days at 100kg), based on two different EBVs (estimated breeding value) of the sire-line for age, the sex (barrows and gilts) and the live weight at slaughter (107, 115 and 125kg). A sub-population of 119 pigs (10 carcasses per treatment) was selected for the carcass and meat quality evaluation trials. As live weight increased there were significant increases in hot carcass weight and dressing percentage (P<0.05). Lean, fat and bone proportions were not affected by weight. Gilts had higher lean proportion (P<0.05) than barrows. Furthermore, carcasses of fast growing pigs were fatter (P<0.05) than those of slower growing ones. Loin muscle pH, drip loss and reflectance values did not vary significantly with any of the treatments. Intramuscular fat was higher in barrows (P<0.05) than in gilts and soluble collagen content decreased with increasing weight (P<0.05). Muscle protein (%) increased (P<0.05) from 107 to 115kg and gilts had a higher (P<0.05) content than castrates. No evidence was found that increasing slaughter weight detracts from carcass characteristics or meat quality.

Application of computer image analysis to measure pork marbling characteristics

Sixty longissimus (L) muscle chops were selected according to marbling score in order to develop a technique for the quantitative description of marbling fat by means of computer image analysis (CIA) and study its relationship with intramuscular fat content and shear force variation in pork. L muscle samples were taken from gilts belonging to three genetic lines differing in carcass leanness, namely Large White (LW), Meishan-derived dam line (M) and Synthetic Genex 3000 (SG). SG gilts had leaner loins (P<0.001) than LW and M. However, the SG loins were more marbled (P<0.001) and had higher IMF content. In addition, CIA analysis showed that marbling fat was finer and better distributed in the SG line. CIA marbling characteristics were significantly correlated with both IMF content (P<0.001) and shear force values (P<0.05) demonstrating the reliability of this technique to assess the contribution of marbling characteristics to variations in pork eating quality.

The effect of stunning method on the incidence of PSE meat and haemorrhages in pork carcasses

Two commercial pig abattoirs (A and B) equipped with a head-only and head-to-chest electrical stunning systems, and two (C and D) equipped with compact carbon dioxide (CO(2)) stunning systems, were visited during 3 days to evaluate the effects of the stunning system on meat quality and haemorrhages. Meat quality was evaluated by measuring muscle electrical conductivity (PQM) and colour (Minolta Chromameter) at 2 and 7 h post mortem (abattoirs A and C, and B and D, respectively). PQM and colour were measured in 2486 and 2321 loins respectively. Also ultimate pH (pHu) was measured in 2395 loins at 24 h post mortem. Haemorrhages were evaluated by recording the incidence of petechiae, ecchymosis and haematomas, bone fractures were also recorded. A total of 1980 shoulders, 3943 loins, and 5438 hams were inspected. In the abattoirs equipped with the electrical stunning systems, a higher (P<0.05) incidence of potentially PSE meat (PQM>6) was found compared with the abattoirs equipped with CO(2) stunning. Likewise, the loins from electrically stunned pigs were paler than those from CO(2) stunned pigs (P<0.05). Electrical stunning increased the incidence of petechiae in the loin and the ham (P<0.05). No shoulder, loin or ham with bone fractures was found in the abattoirs studied. Therefore, CO(2) stunning reduces the incidence of PSE meat and of petechiae on muscle fascia of loins and hams, compared with electrical stunning. However, petechiae are not of great importance because they can be removed from the affected commercial cuts.

Causes of skin damage to pig carcasses

Damage to the surface of the carcass after dehairing is a serious commercial problem, since it decreases the grade and subsequently the value of the carcass. In many countries, the incidence of skin damage on the carcass has not been considered to be a problem with high priority, as it seems to be easily solved by just trimming off the skin. However, the presence of an haematoma in the underlying tissue and its negative influence on meat quality must be taken into account. Some European Union (EU) countries are aiming at reducing the incidence of blemished carcasses in order to safeguard the image of the national pork sector for both domestic and exporting markets. Major factors responsible for the incidence of skin damage on the carcass are fighting among mixed groups of pigs and poor handling during the preslaughter stages. Recognition of the economical impact of these two factors on the slaughter pigs may lead to more welfare-friendly handling systems and to reduction in the practice of preslaughter mi...

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.

Effects of the stunning procedure and the halothane genotype on meat quality and incidence of haemorrhages in pigs

A total of 313 pigs (127 halothane-free, NN, and 186 heterozygous halothane, Nn) were slaughtered in four batches at two commercial abattoirs with two different stunning systems, an automatically head-only followed by head-to-chest electrical stunner and a compact carbon dioxide (CO(2)) stunning unit. Meat quality on the loin muscle was assessed by measuring electrical conductivity (PQM) and colour (Minolta CR 200) at 7 h post mortem, and ultimate pH. Loins showing PQM >6.0 μs were classified as clearly pale, soft and exudative (PSE) meat. The incidence of petechiae, ecchymosis and haematomas in the shoulders, loins and hams was also evaluated. In the abattoir equipped with the electrical stunning system, a higher incidence of potentially PSE meat was found compared with the abattoir equipped with CO(2) stunning (35.6 vs. 4.5%). Likewise, electrical stunning increased significatively the incidence of petechiae in the loins, shoulders and hams, and ecchymosis in the loins and hams. Also, the incidence of PSE meat was higher in the Nn pigs compared with NN pigs (24.7 vs. 7.9%). It is suggested that for improving meat quality and reducing incidence of haemorrhages electrical stunning should be avoided. Further improvements in meat quality can be achieved by eliminating the halothane gene specially in CO(2)-stunned pigs.

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.

Distribution of intramuscular fat content and marbling within the longissimus muscle of pigs

A better knowledge of intramuscular fat (IMF) content distribution would allow the identification of a predictive site on the longissimus muscle to assess the total IMF content. For this purpose, 50 commercial crossbred pigs of both genders were selected live with ultrasound equipment at the 3rd/4th last rib in order to provide backfat differences varying from 10 to 34.7 mm. Left longissimus muscles were deboned and sliced every 2 cm from the posterior (3rd last lumbar vertebra) to the anterior (5th thoracic rib) end. In all, 14 locations on the longissimus muscle were established and labeled as T5-T14 (thoracic region) and L1-L4 (lumbar region). The slices were used for subjective marbling evaluation and for intramuscular fat content (IMF) measurement. The results showed that total IMF content and marbling scores were correlated (r = 0.86) and followed a similar pattern, with highest values being obtained in the middle section of the thoracic region and in the middle-caudal section of the lumbar area. In...

The relationship between different pork carcass lean yield definitions and the market carcass value

Cutout and dissection data from 265 carcasses were used to study the impact of the lean yield definition on their ability to discriminate lean carcasses from fat carcasses. The same data were used to evaluate the relationship between the various definitions of lean yield, such as the lean yield predicted by the Destron optical probe (LYDESTRON), the saleable meat yield (SMY), the Canadian lean yield (LY2000) and the lean meat percentage (TVM), and the market carcass value. Based on the highest number of carcasses assigned to the extreme grades (leaner and fatter), the TVM had the greatest discriminating capability based on carcass leanness. The correlation coefficients obtained between market carcass value and LYDESTRON, SMY, LY2000 and TVM were 0.14, 0.54, 0.36 and 0.23, respectively. These weak correlations demonstrate that lean yield alone does not adequately explain the variation in market value between carcasses. Lean yield therefore cannot be used to estimate market value independently of the definition used.