FLEISCHWIRTSCHAFT international 3/2017

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Fleischwirtschaft international 3_2017
Research &Development
Effect of pre-slaughter fasting
and gender on pork quality
By Artur Rybarczyk, Aleksandra Łupkowska, Beata Hartuna and Anna Sulerzycka
The aim of this study was to determine the effect of pre-slaughter fasting
on the meat quality of both genders of offspring of Duroc boars at approximately
the same pre-slaughter lairage time. The carcasses of the
pigs subjected to longer pre-slaughter fasting (24 compared to 18 hours)
had better technological meat quality with asimilar weight and muscle
percentage, as evidenced by significantly higher pH, lower electrical
conductivity (EC), lower drip loss from fresh and thawed meat, lower
lightness (L*) and increased redness (a*). The length of pre-slaughter
fasting had no effect on the sensory traits nor the shear force of the meat.
Differences between sexes were visible in the higher lightness (L*) and
yellowness (b*) of the longissimus lumborum muscle of barrows compared
to gilts with similar muscle content and basic chemical composition.
The authors observed no interactions between the length of preslaughter
fasting of finishers and their sex that had an effect on the
quality of the meat.
Feed deprivation before transporting pigs (i.e. pre-slaughter fasting) is
used mainlytoreduce the risk of death during transport, especiallyin
hot weather (TARRANT,1993;WARRISS,1994; BRADSHAW et al., 1996), to improve
the quality of the meat, and also to avoid the risk of bacterial
contamination from gut contents during evisceration (MICKWITZ VON et al.,
1982; EIKELENBOOM et al., 1991;GISPERT et al., 1996; EILERT,1997).
The length of time since the final feeding before slaughter is crucial
for the concentration of pre-slaughter muscle glycogen and the incidence
of post mortem PSE meat (pale, soft, exudative) (TARRANT,1989;
EIKELENBOOM et al., 1991).Longer pre-slaughter fasting lowers post mortem
levels of muscle glycogen and lactic acid (DE SMET et al., 1996), resulting
Lean meat content
Tab. 1: Hot carcass weight and percentage lean meat determined by AutoFom
Traits Time of fasting Gender Interaction
18 h 24h Barrows Gilts
Hot carcass 85.63±2.39 85.41 ±2.74 85.85 ±2.35 85.20±2.73 n.s.
weight (kg)
Lean meat in 56.63±1.98 57.35±2.07 56.71±1.98 57.25±2.09 n.s.
carcass (%)
Lean meat in 59.88±1.99 60.34 ±2.17 59.87±2.03 60.34 ±2.13 n.s.
ham (%)
Lean meat in 53.55±2.77 54.36±3.00 53.50±2.91 54.39 ±2.86 n.s.
loin (%)
Lean meat in 57.36±1.48 57.80±1.67 57.43±1.57 57.73±1.60 n.s.
shoulder (%)
Lean meat in
belly(%)
52.91 ±2.31 53.25±2.51 52.69±2.37 53.45±2.39 n.s.
n.s.: not significant at P≤0.05 and P≤0.01.
Source: RYBARCZYK et al. FLEISCHWIRTSCHAFT international 3_2017
Keywords
» Pigs
» Feed withdrawal
» Physico-chemical traits
» Sensory properties
in ahigher pH, improved water holding capacity and darker meat (JONES et
al., 1985; RYBARCZYK et al., 2007). However, extended fasting may also lead
to an increased aggression in pigs and fights for dominance, particularly
between pigs from different farms (MURRAY et al., 2001).This may result in
adeficiency of glycogen, which increases the incidence of DFD meat
(dark, firm, dry) (WARRISS,1982;FISCHER et al., 1988; EIKELENBOOM et al., 1991;
WITTMANN et al., 1994).
In many countries, a12–15 hfasting prior to slaughter is acommon
practice, aiming to reduce the risk of microbiological contamination
during slaughter and to limit deviations from the desired level of meat
quality (EIKELENBOOM et al., 1991;BAGER et al., 1995). However, studies by
GUÀRDIA et al. (2004) and RYBARCZYK et al. (2007) suggest that the deprivation
of feed before slaughter for aperiod less than 18 hincreases
the risk of PSE, while more than 22 hmay increase the incidence of
DFD as aresult of adepletion of muscle
glycogen (EIKELENBOOM et al., 1991; GISPERT et
al., 2000; GUÀRDIA et al., 2005). Significantly,
some authors (MURRAY et al., 2001; BEATTIE
et al., 2002; MORROW et al., 2002) report a
small or negligible impact of fasting time
before slaughter on meat quality.These
discrepancies can be explained by differences
in the level of stress or activity
imposed on the pigs before slaughter, e.g.
mixing animals from different suppliers,
and the conditions of road transport
(LEHESKA et al., 2002; BERTOL et al., 2005;
FAUCITANO et al., 2006). Research by FAUCI-
TANO et al. (2010)indicated that a24-hour
period between the last feed and the
slaughter of the animals seems to be
optimal for carcass yield and good meat
quality and safety.
Therefore, the aim of this study was to
determine the effect of the duration of
pre-slaughter fasting (18 and 24 h) on the
technological and sensory quality of meat
from Duroc boar offspring, taking into account
the gender of the pigs.
Received: 30 September 2016 |reviewed:18October 2016 |revised:25October 2016 |accepted: 25 October 2016