The effects of lairage time and handling procedure prior to slaughter on
stress and meat quality parameters in pigs
, R. Marković
Department for Food Hygiene Technology, Faculty of Veterinary Medicine, University of Belgrade, Bulevar Oslobodjenja 18, 11000 Belgrade, Serbia
Animal Welfare Subprogram, IRTA, Finca Camps i Armet, 17121 Monells, Girona, Spain
Faculty of Technology, University of Novi Sad, Bulevar Cara Lazara 1, 21000 Novi Sad, Serbia
Received 23 September 2013
Received in revised form 19 March 2014
Accepted 2 June 2014
Available online 11 June 2014
Lairage time (short —8 min to 2.7 h, n = 28 vs. long —14 to 21.5 h, n = 72) and pig handling (gentle —no use of
stick or electric prod, pig not slipping, falling, nor emitting high-pitched vocalizations vs. rough —where any of
these occurred) effects on pig stress and meat quality were measured. Blood lactate and cortisol, plus post-
mortem pH (pH
), temperature (T
), drip loss, sensory and instrumental color and meat quality
for the longissimus dorsi, pars lumbalis derived meat were determined. Carcass rigor mortis and skin damages
were measured. Lairage time signiﬁcantly affected blood lactate, carcass rigor mortis, skin damages, drip loss,
color and meat quality. Handling procedure inﬂuenced blood lactate, pH
. Long lairage was
more stressful, and was detrimental to carcass quality, but caused better meat quality compared to short lairage.
Rough handling was related to higher lactate and lower meat quality.
© 2014 Elsevier Ltd. All rights reserved.
All meat animals will experience some levelof stress prior to slaugh-
ter and this in turn, may have detrimental effects on meat quality
(Ferguson et al., 2001). After arrival in the slaughterhouse, two impor-
tant factors that may affect the level of stress in pigs, and consequently
pork quality, are lairage time and handling procedure immediately prior
Nanni Costa, Lo Fiego, Dall'Olio, Davoli, and Russo (2002) found that
lairage time was an important source of variation determining meat
quality. After overnight lairage, meat was darker, had a higher ultimate
pH, and greater water holding capacity, producing less drip during
storage, compared to lairage of two hours (Nanni Costa et al., 2002).
Compared to lairage time of less than three hours, overnight lairage
reduced carcass weight, backfat thickness and meat temperature
(Warriss, Brown, Edwards, & Knowles, 1998). In addition, the percentage
of carcasses with skin blemishes and high ultimate pH increased
progressively with longer periods of lairage (Warriss et al., 1998).
According to Warriss (2003) and Nanni Costa et al. (2002), the optimal
lairage time is between one and three hours, since lairage shorter than
one hour increases the prevalence of pale, soft and exudative (PSE)
meat, while lairage longer than three hours poses a risk for developing
dark, ﬁrm and dry (DFD) meat and skin damages.
According to Hambrecht, Eissen, Newman, Smits, den Hartog, and
Verstegen (2005), great improvement in pork quality can be achieved
by reducing stress (actually the use of electric goads), immediately be-
fore slaughter. Hemsworth, Barnett, Hofmeyr, Coleman, Dowling and
Boyce (2002) found a correlation between negative interactions that
pigs received from the stockperson immediately prior to slaughter and
meat quality deterioration. Most of these negative interactions were
prods with an electric goad. Benjamin et al. (2001) and Rabaste et al.
(2007) found that frequent use of electric prods during pig handling
leading to the stunning area led to pigs turning back, jumping, slipping
and/or falling, and also caused injuries, so the carcasses of these animals
had a higher degree of bruising and skin damages, as well as reduced
quality of meat (PSE meat). Intense stress before stunning provoked
by rough treatment increased concentrations of norepinephrine, corti-
sol and lactate (Hambrecht et al., 2004), heart rate, body temperature
(Griot, Boulard, Chevillon, & Kerisit, 2000) and percentage of carcasses
with skin damages (Rabaste et al., 2007). Furthermore, a severe stress
one minute before stunning reduced the ultimate pH and increased
drip loss of pork (Hambrecht, Eissen, Newman, Smits, den Hartog,
et al., 2005; Rabaste et al., 2007; van der Wal, Engel, & Reimert, 1999).
Overall, lairage duration and handling immediately prior to slaugh-
ter seem to be important in the management of stress in pigs and in
the resultant pork meat quality, but these interactions are likely very
complex. Therefore, the objective of this study was to evaluate effects
of two different lairage times (short, from 8 min to 2.7 h of lairage,
n = 28 vs. long, from 14 to 21.5 h of lairage, n = 72) and handling
procedures (gentle vs. rough, based on use of stick or electric prod
Meat Science 98 (2014) 220–226
⁎Correspondding author at: Departm ent for Food Hygiene Technology, Faculty of
Veterinary Medicine, University of Belgrade, Bulevar Oslobodjenja 18, 11000 Belgrade,
Serbia. Tel.: +381 11 2685936, fax: +381 11 2685936.
E-mail address: firstname.lastname@example.org (M. Dokmanović).
0309-1740/© 2014 Elsevier Ltd. All rights reserved.
Contents lists available at ScienceDirect
journal homepage: www.elsevier.com/locate/meatsci
and reaction of pigs) on selected stress indicators (lactate, cortisol
and skin damages) and meat quality parameters (initial and ultimate
pH values, temperature, rigor mortis, drip loss, instrumental and
sensory color) in pigs for slaughter.
2. Material and methods
2.1. Animals, housing and feeding
Commercial market pigs (n = 100, comprising 31 gilts, 51 barrows
and 18 boars), six months of age and with live weights between 115
and 130 kg were studied. All animals were of the same cross-breed
(cross between Naima sows and hybrids P-76 PenArLan boars) and
originated from the same farm. Pigs were housed in the ﬁnishingfacility
on partially slatted ﬂoors, in pens with 20 animals per pen (stocking
density = 1 m
/pig). Pigs were provided with ad libitum feed and
water via one automatic feeder and two nipple drinkers in each pen.
2.2. Pre-slaughter and slaughter
Feed and water were not withdrawn from the animals before trans-
portation. The distance between pens and the transportation trailer was
about 20 m and the loading ramp wassloped downwards at 15°. All the
pigs (n = 20) from each pen were transported together as one batch of
animals at a stocking density of 0.45 m
/pig. Transport from farm to the
abattoir lasted 15 min. The surface of the trailer ﬂoor and the unloading
dock were on the same level (not sloped). During loading and
unloading, sticks and electric prods were used to move pigs. After
unloading, pigs entered a 10 m long corridor that led to the lairage
pens. During lairage, pigs were not mixed (each batch of 20 pigs was
lairaged in one pen), and stocking density was 0.70 m
per pig. In
lairage, pigs had access to water. A 5 m, single-ﬁle corridor led from
the lairage pens to the stunning area. During pig handling from lairage
pens to the stunning area, sticks and electric prods were used according
to industry practice in Serbia. After lairage, pigs were head-only electri-
cally stunned (50 Hz, 2 A and 220 V) in batches of 6 animals without
restraining. Immediately after stunning pigs were bled on the ﬂoor
and then hoisted on a rail. The time of current application was on aver-
age 3.51 ± 2.08 s and the time from stunning to sticking ranged from 1
to 10 s. Following bleeding, carcasses were processed using convention-
al industry practice.
2.3. Experimental design
One group of pigs entered the lairage in the early morning hours
(around 6 AM) and was slaughtered on the same day (short lairage,
from 8 min to 2.7h, average of1.36 h; n = 28). The other group entered
the lairage in the afternoon (around 4 PM), overnighted in the lairage
and was slaughtered the following morning (long lairage, from 14 to
21.5 h, average of 17.01 h; n = 72).
Three observers assessed handling procedures and pig behaviors for
each pig while the animals walked from the lairage pen to the stunning
area. Observers stood at three different places to record their observa-
tions: at the exit of lairage pen; next to the corridor; and in the stunning
area. Pigs were sent to slaughter in groups of 6 animals. At the back of
the group, a stock handler forced the pigs on go down the corridor
with a stick and an electric prod. Those pigs at the rear were able to
jump on pigs in front and consequently those animals involved in
these behaviors could slip, fall or vocalize. Handling and behavior
parameters were scored as present or absent, but the number of times
per animal was not recorded. Handling procedures were deﬁned as
rough or gentle. A pig was classiﬁed as roughly handled if it was hit
with the stick or prodded with the electric prod, or if it slipped, fell or
vocalized in a high pitch (Table 1). If any of these handling or behavior
parameters or their combination was present for any pig, handling of
that pig was characterized as rough. In contrast, the absence of all of
these handling and behavior parameters was classiﬁed as gentle
handling of the observed pig.
2.4. Blood sampling and determination of blood lactate and cortisol content
At slaughter, blood samples were collected into plastic tubes and a
part of this materialwas then transferred to Vacutainer tubes containing
heparin (against blood coagulation) which were placed on ice. Blood
lactate content was immediately determined using a portable lactate
analyzer (Lactate Scout, EKF Diagnostic, Magdeburg, Germany), which
was calibrated with a standard solution to ensure accuracy. After
blood collection and within 4 to 6 h, the Vacutainer tubes were centri-
fuged at 3000 rpm for 3 min to separate blood supernatant (plasma).
Plasma was transferred into microtubes and stored at −20 °C until
the determination of cortisol concentration by radioimmunoassay
(RIA-CT Cortisol, INEP, Belgrade, Serbia).
2.5. Carcass and meat quality analyses
Carcasses were clearly labeled to ensure that they originated from
the 100 live pigs studied. Meat quality measurements were carried
out 60 min, 24 and 72 h after slaughter on muscle longissimus dorsi
(LD) and pars lumbalis. Values of pH and temperature were measured
using a Testo 205 (Germany) pH-meter, calibrated with pH 4.00 and
7.00 phosphate buffer, at 60 min (pH
) and 24 h (pH
post-mortem. Skin damages were assessed on three regions of the
right carcass side (from head to back of shoulder,from back of shoulder
to hind-quarters and the region of the hind-quarters) immediately after
dressingusing scores 1 (no damage), 2 (scratches or small wounds, less
than 2 cm), 3 (bleeding wounds between 2 and 5 cm or healed wounds
of more than 5 cm) and 4 (deep and open wounds of more than 5 cm).
The ﬁnal score for each carcass was obtained by summing scores for the
three regions. The degree of rigor mortis was estimated on the right car-
cass side 3 h post-mortem by measuring the degree of angle between
body axis and foreleg (Davis, Townsend, & McCampbell, 1978). For
that purpose, photographic images of carcass sides were taken, at a dis-
tance of approximately 2 m and a height of 160 cm, parallel to the plane
in which carcass sides were hanging, and the angle was then calculated
using an AutoCAD 2010 software (Autodesk, Inc., San Francisco, USA)
(Image 1). For determination of drip loss and color, meat samples,
which were 2.5 cm thick loin chops, were taken 24 h after slaughter
from LD, between the 3rd and 4th lumbar vertebrae. Meat samples
were weighed and stored for 48 h at 4 °C in a container (Honikel,
1998). After storage, meat samples were reweighed and the percentage
Deﬁnition of handling and behavior parameters.
Stick use A hit with stick to any part of the pig's body
Electric prod use An electric prod touches any part of the pig's body
Slipping Loss of balance without the pig's body touching the ﬂoor
Falling Loss of balance in which any part of the pig's body (except legs) touches the ﬂoor
High-pitched vocalization High-pitched squeals during movement through the handling area
221M. Dokmanovićet al. / Meat Science 98 (2014) 220–226
of drip loss was calculated. Sensory and instrumental color (CIE L*a*b*;
CIE, 1976) were determined at 24 h post-mortem, after approximately
60 min of blooming time (Honikel, 1998). L*, a* and b* (CIE, 1976)
values were determinedusing a Minolta chroma meterCR-400 (Minolta
Co., Ltd., Osaka, Japan) utilizinga 65 light source and a 2° observer. Color
and drip loss were analyzed in duplicate. An analytical panel of three
trained members assessed the sensory color of meat samples by using
a1–6 scaling method (NPPC, 2000). Meat quality classes (pale, soft
and exudative —PSE; reddish-pink, soft and exudative —RSE; red,
ﬁrm and non-exudative —RFN; pale, ﬁrm and non-exudative —PFN;
and dark, ﬁrm and dry —DFD) were determined according to
Kauffman, Cassens, Scherer, and Meeker (1992), using the pH
loss after 48 h of storage and L* parameter (CIE, 1976)after24hpost-
mortem (Table 2).
2.6. Statistical analysis
Statistical analysis of the results was conducted using the software
GraphPad Prism version 5.00 for Windows (GraphPad Software, San
Diego, California USA, www.graphpad.com). All parameters were de-
scribed by descriptive statistics (mean, standard deviation, minimum
and maximum values). Student t-test was used to examine the effects
of lairage time (short vs. long) and handling procedure (gentle vs.
rough) on stress and meat quality parameters in pigs. Two-way
ANOVA with Tukey's multiple comparison test was used to test com-
bined effects of two lairage times and handling procedures on lactate
and cortisol contents. Differences between long and short lairage
times, and between gentle and rough handling for meat in the differing
quality classes (PSE, RSE, RFN, PFN and DFD) were determined by
Fisher's exact test. Values of p b0.05 were considered signiﬁcant.
3. Results and discussion
3.1. Characterization of the experimental population
Table 3 shows mean values of stress and meat quality parameters in
pigs. Blood lactate at exsanguination ranged from 1.3 to 24.6 mmol/l
which is in accordance with the results of other authors, who detected
from 1.1 to 20.6 mmol/l (Edwards, Grandin, et al., 2010), from 4.0 to
19.7 mmol/l (Edwards, Engle, et al., 2010) and from 0.11 to
20.57 mmol/l (Hemsworth et al., 2002). Blood cortisol content varied
within studies, on average from 49.5 to 80.8 ng/ml (Hambrecht et al.,
2004) and from 55.1 to 77.9 ng/ml (Hambrecht, Eissen, Newman,
Smits, den Hartog, et al., 2005), with a range from 1.70 to 300.9 ng/mg
(Foury et al., 2005), which was close to the range observed in the cur-
rent study (3 to 248 nmol/l). These large variations in cortisol content
could be due to inﬂuences of species, breed, time of day, stress, meal,
physicalor sexual activity,change of environment, individual variability
gentle handling 9.24 6.33
rough handling 13.21 15.92
long lairage short lairage
n=43 n=29 n=23 n=5
Fig. 1. Concentrations of lactate (mmol/l) in relation to the lairage time and handling
procedure (XSEM). Bars lacking a common letter differ (p b0.05).
gentle handling 53.71 64.65
rough handling 60.62 73
long lairage short lairage
n=43 n=29 n=23 n=5
Fig. 2. Concentrations of cortisol (nmol/l) in relation to the lairage time and handling
procedure (XSEM). Bars lacking a common letter differ (p b0.05).
Image 1. Determination of degree of angle between body axis and foreleg.
Assessment of meat quality classes according to Kauffman et al. (1992).
Meat quality pH
Drip loss (%) L* value
PSE b6.0 ≥5≥50
RSE b6.0 ≥542–50
RFN b6.0 b542–50
PFN b6.0 b5≥50
DFD ≥6.0 b5b42
—pH value measure d 24 h post-mo rtem; L* —lightne ss; PSE —pale, soft an d
exudative; RSE —reddish-pink, soft and exudative; RFN —red, ﬁrm and non-exudative;
PFN —pale, ﬁrm and non-exudative; and DFD —dark, ﬁrm and dry meat.
222 M. Dokmanovićet al. / Meat Science 98 (2014) 220–226
and other factors (Mormede, 2007). In the current study, though, the
pigs were of the same cross-breed, reared under an identical production
regime, with similar pre-slaughter handling before entering lairage
pens, and were all slaughtered in the morning to limit the confounding
effect of diurnal cortisol ﬂuctuation (Mormede, 2007). At this time,
cortisol concentrations were likely higher than they would have been
in the afternoon or evening, although measurement of this was not an
aim of the current study. Therefore, the great variation in cortisol levels
that we have observed could be, at least partly, a consequence of indi-
vidual variability. The higher concentrations of cortisol measured in in-
dividual pigs could reﬂect exquisite sensitivity of the hypothalamic–
pituitary–adrenal axis to stressors rather than a high level of stress
(Foury, Geverink, Gil, Gispert, Hortos, Font, Furnols, Carrion, Blott,
Plastow & Mormede, 2007). Values of pH after 60 min ranged from
5.64 to 6.81, and after 24 h from 5.26 to 5.93. The highest carcass tem-
perature was 40.3 °C and the highest drip loss of meat samples was
9.50%. Rigor mortis was from 115.1 to 136.6°. Some carcasses were
without any skin blemishes (score 3), while others scored the maxi-
mum for skin blemishes (score 12). CIE parameters ranged from 35.11
to 60.22 (CIE L* value), from 4.15 to 11.83 (CIE a* value) and from
2.23 to 7.41 (CIE b* value), while sensory color scores ranged from 1.0
3.2. Lairage time
Table 4 shows stress and meat quality parameters in relation to the
short and long lairage times. Pigs undergoing long lairage had
signiﬁcantly higher (p b0.05) blood lactate content (10.86 mmol/l)
compared to short lairage (8.04 mmol/l), which may be due to higher
stress reactions of those pigs because they were more exposed to
stressful procedures in lairage, such as rough handling, ﬁghts, change
of environment and food deprivation (Bruijnzeel, Stam, Compaan, &
Wiegant, 2001; Stam, Bruijnzeel, & Wiegant, 2000; Stam, van Laar,
Akkermans, & Wiegant, 2002). Perez, Palacio, Santolaria, Del Aceña,
Chacón, Verde, Calvo, Zaragoza, Gascón and García-Belenguer (2002)
did not ﬁnd that lairage time had any signiﬁcant effect on blood lactate,
while Salajpal, Dikic, Karolyi, Sinjeri, Liker, Kostelic and Juric (2005)
determined that one group of pigs after short lairage (2 h) had higher
blood lactate levels compared to pigs in long lairage (24 h). In the
current study, there was no signiﬁcant difference between the two com-
pared cortisol concentrations (Table 4). Although Nanni Costa et al.
(2002) found lower initial and ultimate pH values after short lairage
compared to long lairage, in the current study, no differences in meat
pH were seen among pigs undergoing short or long lairage. Similarly,
no signiﬁcant difference was determined in meat temperature between
the two lairage time groups. As the degree of rigor mortis can be used to
assess stress level prior to slaughter (Knowles & Warriss, 2007; Warriss,
Brown, & Knowles, 2003), the signiﬁcantly higher (p b0.01) degree of
rigor mortis (124.1°) after a long lairage could indicate a procedure
more stressful, in accordance with lactate concentrations. The results
of the current study show that longer lairage signiﬁcantly (p b0.001)
increased skin damage score, as found by other authors (Guardia et al.,
2009; Nanni Costa et al., 2002; Warriss et al., 1998), because pigs were
more aggressive due to the prolonged period of food withdrawal.
After short lairage, drip loss (6.93%) was signiﬁcantly higher (p b0.01)
compared to long lairage (6.05%), which is in accordance with the re-
sults of other authors (Hoffman & Fisher, 2010; Salajpal et al., 2005).
Lower drip loss of meat after long lairage could be a consequence of
higher muscle glycogen degradation and higher meat pH value,
meaning meat released less water (Dalmau, Velarde, & Gispert,
2009). Signiﬁcantly (p b0.001)darkermeatcolor(lowerCIEL*
value) was found after long lairage, which was also conﬁrmed by a
signiﬁcantly (p b0.05) higher value for sensory color. Similar chang-
es in color were also found by Nanni Costa et al. (2002) and Hoffman
and Fisher (2010). After short lairage, signiﬁcantly higher CIE a*
(8.16) and CIE b* (4.78) values were found compared to long lairage
(7.53 and 3.97). In addition, lairage times had an effect on meat quality
classes (Table 5). For example, after short lairage a signiﬁcantly higher
(p b0.001) incidence of PSE (82.14%) and lower incidences of RSE
(17.86%) and RFN meat (0%) were found, compared to the group with
long lairage (30.55, 41.67 and 20.83%, respectively) (Table 5). Similarly
Perez, Palacio, Santolaria, Del Aceña, Chacón, Verde, Calvo, Zaragoza,
Gascón and García-Belenguer (2002) and Nanni Costa et al. (2002)
found that longer lairage had a positive effect in reducing the incidence
of PSE meat. Moreover, a high percentage of carcasses with PSE (45.0%)
Characterizat ion of the experimental populati on (n = 100): Stress and meat quality
Parameter XSD Min. Max.
Blood lactate (mmol/l) 10.06 ± 5.47 1.30 24.60
Plasma cortisol (nmol/l) 58.36 ± 57.46 3.00 248.00
6.33 ± 0.21 5.64 6.81
5.55 ± 0.13 5.26 5.93
(°C) 38.58 ± 0.74 37.10 40.30
Rigor mortis (°) 124.80 ± 4.62 115.10 136.60
Skin damages score 7.09 ± 2.30 3.00 12.00
Drip loss (%) 6.30 ± 1.40 3.01 9.50
CIE L* value 50.20 ± 3.02 35.11 60.22
CIE a* value 7.71 ± 1.26 4.15 11.83
CIE b* value 4.21 ± 0.96 2.23 7.41
Sensory color 2.44 ± 0.52 1.00 4.00
—pH values measured 60 min and 24 hpost-mortem;T
temperature mea sured 60 min post-mortem; L* —lightness; a* —redness; and b* —
Stress and meat quality parameters in relation to the lairage time.
Parameter Short lairage (n = 28) Long lairage (n = 72)
XSD Min. Max. X SD Min. Max.
Blood lactate (mmol/l) 8.04
± 5.70 1.3 21.5 10.86
± 5.21 2.6 2 4.6
Plasma cortisol (nmol/l) 67.04 ± 63.28 5 247 54.89 ± 55.06 3 248
6.33 ± 0.21 6.03 6.74 6.33 ± 0.21 5.64 6.81
5.54 ± 0.11 5.26 5.77 5.57 ± 0.13 5.30 5.93
(°C) 38.71 ± 0.77 37.1 40.2 38.44 ± 0.70 37.2 40.3
Rigor mortis (°) 126.70
± 3.85 116.5 134.1 124.10
± 4.71 1 15.1 1 36.6
Skin damages score 5.88
± 2.41 3 12 7.57
±2.08 3 12
Drip loss (%) 6.93
± 1.08 5.03 8.97 6.05
± 1.44 3.01 9.50
CIE L* value 52.30
± 2.86 48.97 60.22 49.37
± 2.67 35.11 57.44
CIE a* value 8.16
± 1.17 5.37 10.62 7.53
± 1.25 4.15 11.83
CIE b* value 4.78
± 1.13 3.47 7.41 3.97
± 0.78 2.23 6.62
Sensory color 2.26
± 0.52 1.0 3.5 2.50
± 0.54 1.0 4.0
—pH valuesmeasured 60 min and 24 h post-mortem; T
—meat temperature measured60 min post-mortem;L* —lightness; a* —redness; and b* —yellowness;
within a row different letters indicate a signiﬁcant difference between groups (a,b —pb0.05; x,y —pb0.01; α,β—pb0.001).
223M. Dokmanovićet al. / Meat Science 98 (2014) 220–226
and RSE (35.0%) meat in the current study indicated a problem with
meat softness and exudation, which was also observed by Panella-
Riera, Gispert, Gil, Soler, Tibau, Oliver, Velarde and Fabrega (2012).In
our study, 49% of carcasses had a pale color (CIE L* ≥50) compared to
51% of carcasses with red and dark color (CIE L* b50), which is similar
to those carcasses observed by Tomović, Jokanović, Petrović, Tomović,
Tasić, Ikonić, Sumić, Sojić, Skaljac and Sošo (2013) (43.4% and 56.6%,
3.3. Handling procedure
Table 6 shows frequencies of pig handling and pig's behavior param-
eters according to which pigs were assigned to the categories of gentle
or rough handling. The group with gentle handling, in which none of
the mentioned pig handling or behavior parameters was observed,
contained 66% of pigs, while the remaining 34% of pigs were categorized
into the group with rough handling. Occurrences of slipping, falling or
being electrically prodded are negative to the animal's well-being
(Grandin, 2010) and therefore should be minimized during handling.
In our study, the use of a stick or electric prod in 17% of pigs led to
their slipping, falling and high-pitched vocalization, but also to their
jumping on pigs in front, which then exhibited a similar behavior.
Similarly, Correa et al. (2010) observed that the use of an electric prod
caused a higher incidence of slipping, falling and vocalization in pigs.
Greater heart rates and cortisol and lactate concentrations in blood of
pigs handled with an electric prod have been reported in several studies
(Brundige, Oleas, Doumit, & Zanella, 1998; Correa et al., 2010;
Hemsworth et al., 2002), conﬁrming the higher degree of stress.
Slipping and falling caused stress in animals (Cockram & Corley, 1991;
Grandin, 1998), and therefore, in the current study, pigs that slipped
(14%) or fell (13%) experienced a stressful procedure. Furthermore,
high-pitched vocalization can be an indicator of stress and negative
emotional states in pigs (Dupjan, Tuchscherer, Langbein, Schon,
Manteuffel & Puppe, 2011; Manteuffel, Puppe, & Schön, 2004; Reimert,
Bolhuis, Kemp, & Rodenburg, 2013), so the 15% of pigs in our study
with such high-pitched vocalization may have done this in response
Table 6 shows stress and meat quality parameters in relation to the
handling procedure. Blood lactate content was signiﬁcantly higher
(p b0.001) after rough handling (13.61 mmol/l) compared to after
gentle handling (8.21 mmol/l). The impact of rough procedures on
increase of blood lactate was also determined by Hambrecht et al.
(2004) and Hambrecht, Eissen, Newman, Smits, den Hartog, et al.
(2005). Inadequate pre-slaughter handling operations often elevate
blood cortisol levels (Bradshaw et al., 1996). However, no signiﬁcant
differences were found in blood cortisol between the two handling
procedures in the current study. Effects of lairage time and handling
procedure on blood lactate and cortisol content are shown in Figs. 1
and 2.Signiﬁcantly higher (p b0.05) lactate values were measured
after rough handling compared to gentle handling, regardless of
lairage duration. In terms of blood cortisol, there were no signiﬁcant
differences between the compared groups. After pigs were gently
handled prior to slaughter, the initial meat pH value (6.37) was
signiﬁcantly higher (p b0.01) compared to that of meat from pigs
exposed to rough handling (6.26), which is in accordance with the
results of most authors (Hambrecht, Eissen, Newman, Smits,
Verstegen & den Hartog, 2005; Hambrecht et al., 2004; Rabaste
et al., 2007; Stoier, Aaslyng, Olsen, & Henckel, 2001). In fact, rough
treatment immediately prior to slaughter causes release of stress
hormones that speed up metabolism in muscles and post-mortem
glycogen degradation which leads to lower initial pH values of
meat (Lambooij, 2000). This is conﬁrmed by signiﬁcantly higher
(p b0.001) meat temperature after rough handling (38.92 °C)
compared to that after gentle handling (38.40 °C). In the current
study, ultimate pH values did not differ after rough (5.55) or gentle
handling (5.54), while other authors found higher ultimate pH
values after rough handling compared to after gentle handling
(Carr, Newman, Rentfrow, Keisler, & Berg, 2008; Hambrecht,
Eissen, Newman, Smits, Verstegen, et.al., 2005; Hambrecht et al.,
2004). Contrary to the ﬁndings of most authors who measured
darker meat color after rough handling (Hambrecht, Eissen,
Newman, Smits, Verstegen, et.al., 2005; Stoier et al., 2001;
Terlouw & Rybarczyk, 2008), in the current study, no signiﬁcant
difference was found in the color of meat from pigs handled gently
compared to those handled roughly. No signiﬁcant differences
were found between the two handling procedures in the incidences
The effect of lairage time on incidences of meat quality classes (n = 100).
Lairage Total PSE RSE RFN PFN DFD
n % n% n% n% n% n%
Short 28 100 23 82.14
Long 72 100 22 30.55
4 5.55 1 1.4
Total 1001004545 3535 1515 44 11
PSE —pale, soft and exudative; RSE —reddish-pink, soft and exudative; RFN —red, ﬁrm
and non-exudative; PFN —pale, ﬁrm and non-exudative; and DFD —dark, ﬁrm and dry
meat; within a column different letters indicate signiﬁcant difference between groups
(a,b —pb0.05; x,y —pb0.01; α,β—pb0.001).
Stress and meat quality parameters in relation to the handling procedure.
Parameter Gentle handling (n = 66) Rough handling (n = 34)
XSD Min. Max. X SD Min. Max.
Blood lactate (mmol/l) 8.21
± 4.25 1.3 17.5 13.61
± 5.84 2.8 24.6
Plasma cortisol (nmol/l) 57.08 ± 58.64 3 248 63.53 ± 56.94 4 221
± 0.18 6.01 6.81 6.26
± 0.23 5.64 6.67
5.54 ± 0.14 5.26 5.93 5.55 ± 0.13 5.32 5.77
± 0.67 37.1 39.9 38.92
± 0.76 37.5 40.3
Rigor mortis (°) 125.00 ± 4.54 115.1 136.6 124.40 ± 4.83 116.3 135.4
Skin damage score 6.82 ± 2.23 3 12 7.47 ± 2.48 3 12
Drip loss (%) 6.41 ± 1.41 3.01 9.49 6.08 ± 1.38 3.73 8.82
CIE L* value 49.91 ± 2.92 35.11 55.19 50.78 ± 3.17 46.64 60.22
CIE a* value 7.67 ± 1.17 4.15 10.62 7.80 ± 1.43 6.03 11.83
CIE b* value 4.19 ± 0.84 2.23 6.78 4.24 ± 1.18 2.70 7.41
Sensory color 2.45 ± 0.54 1.0 4.0 2.39 ± 0.54 1.0 3.5
—pH valuesmeasured 60 min and 24 h post-mortem; T
—meat temperature measured60 min post-mortem;L* —lightness; a* —redness; and b* —yellowness;
within a row different letters indicate a signiﬁcant difference between groups (x,y —pb0.01; α,β—pb0.001).
224 M. Dokmanovićet al. / Meat Science 98 (2014) 220–226
of meat quality classes (Table 7). Carr, Newman, Rentfrow, Keisler
and Berg (2008) found that on-farm handling procedures did not
have any signiﬁcant inﬂuence on incidence of PSE and DFD meat.
Long lairage proved to be a more stressful procedure (higher blood
lactate content and higher degree of rigor mortis and skin damages),
and had a detrimental effect on carcass quality (higher degree of skin
damages), but resulted in better meat quality (lower drip loss and
darker color) compared to short lairage. After short lairage (from
8 min to 2.7 h) a higher incidence of PSE meat and lower incidence of
RFN meat (normal quality) were observed compared to the group
with long lairage (from 14 to 21.5 h). Rough handling was related to
higher blood lactate and lower meat quality (lower pH
This paper was supported by the Ministry of Education and Science,
Republic of Serbia, through the funding of the Project “Selected biolog-
ical hazards to the safety/quality of food of animal origin and the control
measures from farm to consumer”(31034). The authors wish to express
their sincere gratitude to Dr. Sheryl Avery andProfessor Sava Buncic for
their linguistic and scientiﬁc comments.
Benjamin, M. E., Gonyou, H. W., Ivers, D. J., Richcardson, L. F., Jones, D. J., Wagner, J. R.,
Seneriz, R., & Anderson, D. B. (20 01). Effects of animal handling method on the
incidence of stress responses in market swine in a model system. Journal of Animal
Bradshaw, R. H., Parrott, R. F., Goode, J. A., Lloyd, D.M., Rodway, R. G., & Broom, D.M.
(1996). Behavioural and hormonal responses of pigs during transport: Effect of
mixing and duration of journey. Animal Science Journal,62,547–554.
Bruijnzeel, A. W. , Stam, R., Compaan, J. C., & Wiegant, V. M . (2001). Stress-induced
sensitization of CRH-ir but not P-CREB-ir responsivity in the rat central nervous
system. Brain Research,908,187–196.
Brundige, L., Oleas, T., Doumit, M., & Zanella, A. J. (1998). Loading techniques and their
effect on behavioral and physiological responses of market weight pigs. Journal of
Animal Science,76, 99 (Abstr.).
Carr, C. C., Newman, D. J., Rentfrow, G. K., Keisler, D. H., & Berg, E. P. (2008). 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. Professional Animal Scientist,24(3), 208–218.
CIE (1976).International Commission on Illumination, Colorimetry: Ofﬁcial Recommendation
of the International Commission on Illumination Publication CIE No. (E-1. 31). Paris,
France: Bureau Central de la CIE.
Cockram, M. S., & Corley,K. T. T. (1991). Effectof pre-slaughter handling on the behaviour
and blood composition of beef cattle. British Veterinary Journal,147,444–454.
Correa, J. A., Torrey, S., Devillers, N., Laforest, J. P., Gonyou, H. W., & Faucitano, L. (2010).
Effects of different moving devices at loading on stress response and meat quality
in pigs. Journal of Animal Science,88, 4086–4093.
Dalmau, A., Velarde, A., & Gispert, M. (2009). Standardisation of the measure “mea t
quality”to assess the welfa re of pigs at slaughter. In B. Forkm an, & L. Keeling
(Eds.), Assessment of animal welfare measures for sows, piglets and fattening pigs
(pp. 117–124). Uppsala, Sweden: School of City and Regional Planning, Cardiff
University, SLU Service/Reproenheten.
Davis, C. E., Townsend, W. E., & McCampbell, H. C. (1978). Early rigor detection in pork
carcasses by foreleg position. Journal of Animal Science,46,376–383.
Dupjan, S., Tuchscherer, A., Langbein, J., Schon, P. C., Manteuffel, G., & Puppe, B. (2011).
Behavioural and cardiac responses towards conspeciﬁc distress calls in domestic
pigs (Sus scrofa). Physiology & Behavior,103,445–452.
Edwards, L. M., Engle, T. E., Correa, J. A., Paradis, M.A., Grandin, T., & Anderson, D. B.
(2010). The relationship between exsanguination blood lactate concentration and
carcass quality in slaughter. Meat Science,85(3), 435–440.
Edwards, L. N., Grandin, T., Engle, T. E., Ritter, M. J., Sosnicki, A. A., Carlson, B.A., &
Anderson, D. B. (2010). The effects of pre-slaughter pig management from the farm
to the processing plant on pork quality. Meat Science,86(4), 938–944.
Ferguson, D.M., Bruce, H. L., Thompson, J. M., Egan, A. F., Perry, D., & Shorthose, W. R.
(2001). Factors affecting beef palatability —Farmgate to chilled carcass. Australian
Journal of Experimental Agriculture,41,879–891.
Foury, A., Devillers, N., Sanchez, M. P., Griffon, H., Le Roy, P., & Mormède, P. (2005). Stress
hormones, carcass composition and meat quality in large white × duroc pigs. Meat
Foury, A., Geverink, N. A., Gil, M., Gispert, M., Hortos, M., Font, M., Furnols, I., Carrion, D.,
Blott, S.C., Plastow, G. S., & Mormede, P. (2007). Stress neuroendocrine proﬁles in
ﬁve pig breeding lines and the relationship with carcass composition. Animal,1(7),
Grandin, T. (1998). Objective scoring of animal handling and stunning practices in
slaughter plants. Journal of the American Veterinary Medical Association,212,36–93.
Grandin, T. (2010). Recommended animal handling guidelines and audit guide. Washington,
DC: American Meat Institute Foundation.
Griot, B., Boulard, J., Chevillon, P., & Kerisit, R. (2000). Des restrainers a bande pour le bien
etre et la qualite de la viande. Viandes et Produits Carnes,3,91–97.
Guardia, M.D., Estany, J., Balasch, S., Oliver, M.A., Gispert, M., & Diestre, A. (2009). Risk as-
sessmentof skin damage due to pre-slaughter conditions and RYRIgene in pigs. Meat
Verstegen, M. W. A. (2005). Negative effects of stress immediately before
slaughter on pork quality are aggravated by suboptimal transport and lairage
conditions. Journal of Animal Science,83,440–448.
Hambrecht, E. J., Eissen, J., Newman, D. J., Smits, C. H. M., Verstegen, M. W., & den Hartog,
L. A. (2005). Preslaughter handling effects on pork quality and glycolytic potential in
two muscles differing in ﬁber type composition. Journal of Animal Science,83, 900–907.
Hambrecht, E., Eissen, J., Nooijen, I. J., Ducr o, B. J., Smits, C. H. M., den Hartog, L. A., &
Verstegen, M. W. (2004). Preslaughter stress and muscle energy largely determine
pork quality at tw o commercial pr ocessing plant. JournalofAnimalScience,82,
Hemsworth, P. H., Barnett,J. L., Hofmeyr, C., Coleman, G. J., Dowling, S., & Boyce, J. (2002).
The effects of fear of humans and preslaughter handling on the meat quality of pigs.
Australian Journal of Agricultural Research,53,493–501.
Hoffman, L. C., & Fisher, P. (2010). Comparison of the effects of different transport condi-
tions andlairage times in a Mediterranean climate in South Africa on the meatquality
of commercially crossbred large white × landrace pigs. Journal of the South African
Veterinary Association,81(4), 225–227.
Honikel, K. O. (1998). Reference methods for the assessment of physical characteristics of
meat. Meat Science,49,447–457.
Kauffman, R. G., Cassens, R. G., Scherer, A., & Meeker, D. L. (1992). Va riations in pork
quality. Des Moines, IA: National Pork Producers Council.
Knowles, T., & Warriss, P. D. (2007). Stress physiology during transport. In T. Grandin
(Ed.), Livestock handling and transport (p p. 312–328). Wallingford, UK: CAB International.
Lambooij, E. (2000). Transport of pigs. In T. Grandin (Ed.), Livestock handlingand transport
(pp. 275–296). New York, NY: CABI Publishing.
Manteuffel, G., Puppe, B., & Schön, P. C. (2004). Vocalization of farm animals as a measure
of welfare. Applied Animal Behaviour Science,88,163–182.
Mormede, P. (2007). Assessment of pig welfare. In L. Faucitano, & A. L. Schaefer (Eds.),
Welfare of pigs from birth to slaughter (pp. 33–64). Wageningen Academic Publishers
& Edition Quae.
Nanni Costa, L., Lo Fiego, D. P., Dall'Olio, S., Davoli, R., & Russo, V. (2002).Combined effects
of preslaughter treatments and lairage time on carcass and meat quality in pigs with
different halothane genotype. Meat Science,61,41–47.
NPPC (National Pork Producers Council) (2000). In E. Berg (Ed.), Pork composition and
qualityassessment procedures (pp. 1–38). Iowa, USA:National Pork ProducersCouncil,
Panella-Riera, N., Gispert, M., Gil,M., Soler, J., Tibau, J., Oliver, M.A., Velarde, A., & Fabrega,
E. (2012). Effect of feed deprivation and lairage time on carcass and meat quality
traits on pigs under minimal stressful conditions. Livestock Science,146(1), 29–37.
Zaragoza,M.P.,Gascón,M.,&García-Belenguer,S.(2002).Inﬂuence of lairage
time on some welfare and meat quality parameters in pigs. Veterinary Research,
Rabaste, C., Faucitano, L., Saucier, L., Mormède, P., Correa, J. A., Giguère, A., & Bergeron, R.
(2007). The effects of handling and group size on welfare of pigs in lairage and their
inﬂuence on stomach weight, carcas s microbial contamination and meat quality.
Canadian Journal of Animal Science,87,3–12.
Reimert, I., Bolhuis, J. E., Kemp, B., & Rodenburg, T. B. (2013). Indicators of positive and
negative emotions and emotional contagion in pigs. Physiology & Behavior,109,42–50.
Salajpal, K., Dikic, M., Karolyi, D., Sinjeri, Z., Liker, B., Kostelic, A., & Juric, I. (2005). Blood
serum metabolites and meat quality in crossbred pigs experiencing different lairage
time. Italian Journal of Animal Science,4,119–121.
Stam, R., Bruijnzeel, A. W., & Wiegant, V. (2000). Long-lasting stress sensitisation.
European Journal of Pharmacology,405,217–224.
Stam, R., van Laar, T. J., Akkermans, L. M., & Wiegant, V. M. (2002). Variability factors in
the expression of stress-induced behavioural sensi tisation. Beh avioural Brain
Stoier, S., Aaslyng, M.D., Olsen, E. V., & Henckel, P. (2001). The effec t of stress during
lairage and stunning on muscle metabolism and drip loss in Danish pork. Meat
The effect of handling procedure on incidences of meat quality classes (n = 100).
Handling Total PSE RSE RFN PFN DFD
n % n% n% n% n% n%
Gentle 66 100 30 45.45 25 37.88 10 15.15 1 1.52 0 0
Rough 34 100 15 44.12 10 29.41 5 14.71 3 8.82 1 2.94
Total 100 100 45 45 35 35 15 15 4 4 1 1
PSE —pale, soft and exudative; RSE —reddish-pink, soft, exudative; RFN —red, ﬁrm and
non-exudative; PFN —pale, ﬁrm, non-exudative; and DFD —dark, ﬁrm and dry meat.
225M. Dokmanovićet al. / Meat Science 98 (2014) 220–226
Terlouw, E. M. C., & Rybarczyk, P. (2008). Explaining and predicting differences in meat
quality through stress reactions at slaughter: The case of large white and duroc
pigs. Meat Science,79,795–805.
Tomović, V. M., Jokanović, M. R., Petrović, Lj. S., Tomović, M. S., Tasić, T. A., Ikonić, P.M.,
Sumić, Z. M., Sojić, B. V., Skaljac, S. B., & Sošo, M. M. (2013). Sensory, physical and
chemicalcharacteristicsof cooked ham manufactured from rapidly chilled and earlier
deboned M. semimembranosus. Meat Science,93,46–52.
van der Wal,P. G., Engel, B., & Reimert, H. G. M. (1999). The effect of stress, applied imme-
diately before stunning, on pork quality. Meat Science,53,101–106.
Warriss, P. D. (2003). Optimal lairage times and conditions for slaughter pigs: A review.
Warriss,P. D., Brown, S. N., Edwards, J. E., & Knowles, T. G. (1998). Effect of lairage time on
levels of stress and meat quality in pigs. Animal Science,66, 255-26.
Warriss,P. D., Brown, S. N., & Knowles, T. G. (2003). Measurements of the degree of devel-
opment of rigor mortis as an indicator of stress in slaughtered pigs. Veterinary Record,
226 M. Dokmanovićet al. / Meat Science 98 (2014) 220–226