The effects of breed cross on performance and meat quality of once-bred gilts in a seasonal outdoor rearing system

Abstract

This study investigated the suitability of once-bred gilts of two different breed crosses in an alternative seasonal outdoor rearing system, with slaughter of the once-bred gilts and their progeny at the end of the season. In total 38 once-bred gilts (Large White x Landrace (LW*L) and Large White x Duroc (LW*D) were housed outdoors one month before farrowing until slaughter, 2-3 weeks after weaning. Body weight, backfat thickness and litter size of the once-bred gilts, and pre-weaning mortality and growth of the piglets were recorded. Carcass quality and technological meat quality (pH u , internal and surface reflectance, water-holding capacity, processing yield and shear-force) of m. longissimus dorsi were measured. Sensory meat quality (taste panel) of oven-baked loin (m. longissimus dorsi) and cured and smoked ham (m. semimembranosus) was investigated. LW*L once-bred gilts had more piglets at weaning, whereas growth rate of LW*D progeny was higher; pre-weaning mortality and litter weight did not differ between the breeds. LW*L had higher lean meat content and lower backfat thickness. Technological meat quality and chemical composition did not considerably differ between the two breed crosses. LW*D had higher quality with regard to meat flavour and stringiness, but tended to have lower quality with regard to juiciness of cured and smoked ham, compared with LW*L.

Full text

Page 1

Arch. Tierz., Dummerstorf 48 (2005) 4, 359-371



Departments of 1Food Science, 2Animal Nutrition and Management, 3Animal Breeding and Genetics. Swedish
University of Agricultural Sciences, Uppsala, Sweden



ANKE HEYER1, KRISTINA ANDERSSON2, SARA LEUFVÉN3,
LOTTA RYDHMER3 and KERSTIN LUNDSTRÖM1



The effects of breed cross on performance and meat quality of
once-bred gilts in a seasonal outdoor rearing system



Dedicated to Prof. Dr. Dr. h.c. mult. Ernst Kalm on the occasion of his 65th birthday



Abstract
This study investigated the suitability of once-bred gilts of two different breed crosses in an alternative seasonal
outdoor rearing system, with slaughter of the once-bred gilts and their progeny at the end of the season. In total
38 once-bred gilts (Large White x Landrace (LW*L) and Large White x Duroc (LW*D) were housed outdoors
one month before farrowing until slaughter, 2-3 weeks after weaning. Body weight, backfat thickness and litter
size of the once-bred gilts, and pre-weaning mortality and growth of the piglets were recorded. Carcass quality
and technological meat quality (pHu, internal and surface reflectance, water-holding capacity, processing yield
and shear-force) of m. longissimus dorsi were measured. Sensory meat quality (taste panel) of oven-baked loin
(m. longissimus dorsi) and cured and smoked ham (m. semimembranosus) was investigated. LW*L once-bred
gilts had more piglets at weaning, whereas growth rate of LW*D progeny was higher; pre-weaning mortality and
litter weight did not differ between the breeds. LW*L had higher lean meat content and lower backfat thickness.
Technological meat quality and chemical composition did not considerably differ between the two breed crosses.
LW*D had higher quality with regard to meat flavour and stringiness, but tended to have lower quality with
regard to juiciness of cured and smoked ham, compared with LW*L.

Key Words: Duroc, Landrace, housing system, outdoor housing, carcass quality, sensory meat quality,
technological meat quality


Zusammenfassung
Titel der Arbeit: Einfluss der Rassenkreuzung auf das Leistungsvermögen und die Fleischqualität bei
Jungsauen in einem saisonalen Freilandhaltungssystem
In dieser Studie wurde die Eignung einer Freilandhaltungsform, bei der belegte Jungsauen ab dem Frühjahr im
Freien gehalten und vor dem Winter mit ihren Nachkommen geschlachtet werden, untersucht. 38 Jungsauen der
Rassenkreuzungen Large White*Schwedische Landrasse (LW*L) und Large White*Duroc (LW*D) wurden
hinsichtlich des mütterlichen Produktions- und Aufzuchtleistungsvermögens sowie der mütterlichen Schlacht-
körper- und Fleischqualität verglichen. Gewichts- und Rückenspeckentwicklung sowie Anzahl lebend geborener
und abgesetzter Ferkel wurden notiert. Schlachtkörperqualität und technologische Fleischqualität (pHu, FOP,
Farbe (Minolta), Wasserbindevermögen, Prozess-Ausbeute und Scherkraft) des m. longissimus dorsi (LD)
wurden gemessen. Sensorische Fleischqualität von im Ofen gebackenem LD und gepökelt/geräuchertem m.
semimembranosus (SMA) wurde von ausgebildeten Sensorikern ermittelt. LW*L Jungsauen hatten mehr Ferkel
beim Absetzen, wohingegen die täglichen Zuwachsraten bei den LW*D Nachkommen besser waren. Die
Ferkelsterblichkeit in der Säugeperiode unterschied sich nicht zwischen den Rassenkreuzungen. Die
Schlachtkörper von LW*L wiesen einen höheren Fleischanteil mit geringerer Speckdicke auf. Technologische
Fleischqualität und chemische Zusammensetzung zeigten keine nennenswerten Unterschiede. Im Vergleich zu
LW*L wurde das Fleisch von LW*D hinsichtlich der Eigenschaften von Fleischgeschmack und Faserigkeit als
besser eingestuft, zeigte jedoch verminderte Saftigkeit im SMA.

Schlüsselwörter: Duroc, Landrasse, Haltungssystem, Freilandhaltung, Schlachtkörperqualität, sensorische
Fleischqualität, technologische Fleischqualität

Page 2

360
HEYER et al.: Effects of breed cross on performance and meat quality of once-bred gilts

Seasonal outdoor rearing of once-bred gilts with their progeny and slaughter of all pigs
at the end of the warm period might be a worthwhile, alternative rearing form for
organic pork production. The advantages of such a rearing system are savings for
stable and feeding costs during wintertime and a higher value of the carcass due to
larger cutting details from once-bred gilts compared with female slaughter pigs
(HÅKANSSON et al., 1982). The seasonal application of this rearing system benefits
the natural cover of soil with grass because from late autumn until early spring the
meadow has time to recover properly. An ample natural cover is important for nitrogen
uptake by the plants and thus reduced nitrogen leak in the ground water. A year-long
outdoor rearing of the pigs would require a larger area to dilute and disperse the
porcine faeces. However, outdoor rearing of once-bred gilts is a rarely used system.
This might be because of a low economic outcome, as the payment for the carcass is
reduced due to an assumed decrease in meat quality and processing properties
compared with the younger slaughter pigs.
To stimulate the seasonal production of pig meat and improve maternal performance,
carcass and meat quality characteristics of the once-bred gilts, an appropriate dam
breed has to be used. The Duroc breed and its crosses are common in outdoor
production (BLANCHARD et al., 1999) because of its robustness. This breed has
advantages in growing performance (ELLIS et al., 1999; GLODEK et al., 2004) and
meat quality (BARTON-GADE, 1988; OLIVER et al., 1994). The generally stated
higher intramuscular fat content of Duroc meat is often linked with better eating
quality and favourable sensory meat quality characteristics (BEJERHOLM and
BARTON-GADE, 1986; LAUBE et al., 2000; MLC, 1992). The Landrace breed is
known for good maternal performance and high lean meat content with good
processing abilities (GAUGLER et al., 1984; CULBERTSON et al., 1997;
TUMMARUK et al., 2000).
The objective of this study was to compare two types of breed crosses (Large White x
Duroc and Large White x Landrace) in a seasonal outdoor piglet production with once-
bred gilts regarding maternal performance, carcass quality, technological and sensory
meat quality. A comparison between maiden gilts, slaughtered at a live weight about
145 kg and these once-bred gilts has been published elsewhere (HEYER et al., 2004).


Material and methods
Animals
This study was performed at Funbo-Lövsta, Swedish University of Agricultural
Sciences (SLU), outside Uppsala on the 60th latitude. The vegetation period in this
region is between May and October. The study comprised 38 once-bred gilts during
two years. Of these, 15 were Large White (sow) x Swedish Landrace (boar) crosses,
hereafter referred to as LW*L and 23 were Large White (sow) x Duroc (boar) crosses,
referred to as LW*D. The gilts were reared indoors and given a rearing diet (Table 1)
ad libitum up to a live weight of 90 kg and thereafter restrictedly according to the
standard feeding regimen for growing/finishing pigs in Sweden (ANDERSSON et al.,
1997). They were inseminated with Hampshire semen at an average age of 251 days
(SD 19). After insemination, the gilts received a gestation diet (30 MJ ME/day) and
were housed outdoors from approximately one week before farrowing. The gilts
farrowed in farrowing huts in individual enclosures in five batches (April, May and
Introduction

Page 3

Arch. Tierz. 48 (2005) 4
361
June 1999; April and May 2000). They were moved to one large enclosure
approximately 3 weeks after farrowing, where they remained until slaughter. The
piglets were weaned at an age of 9 weeks (76 days, SD 4) and were used in a study
concerning the effect of growing/finishing raising indoor or outdoor (STERN et al.,
2003). A lactation diet (Table 1) was given in a trough according to a norm based on
litter size. The ratio was, however, increased, as the piglets started to consume large
amounts of feed. No creep feed was used in this study. After weaning, the once-bred
gilts in the first year received a rearing diet twice per day according to their voluntary
feed intake. The second year, they were fed the lactation diet restrictedly (4 kg/day).
The once-bred gilts were slaughtered two to three weeks after weaning (slaughter age
446 days, SD 25; period from weaning to slaughter 17 days, SD 3).
The gilts were weighed, and backfat was measured with ultrasound 30 days after
insemination, at start of the outdoor season, 5 weeks after farrowing, at weaning and at
slaughter. The once-bred gilts’ individual weight and backfat thickness at farrowing
were estimated by using linear regression from measurements at 30 days after
insemination and from the day they were moved outdoors (9 days before farrowing,
SD 5). Backfat was measured at the last rib of both sides, approximately 8 cm from the
middle of the back. Litter size was recorded after farrowing by inspection through the
hut window. The stable staff judged the causes when piglets were found dead. The
piglets were weighed 4 days after birth and at weaning. The animals were monitored
daily for health and all signs of disease or injury were recorded.

Table 1
Composition and calculated nutrient content of the diet (Futtermittelzusammensetzung und errechnete
Nährwerte)


Rearing
Gestation




Lactation
Post- weaning
1st year
Post- weaning
2nd year
Ingredients, %
Barley
Wheat
Oats
Wheat bran
Rye wheat
Rapeseed meal
Yellow peas
Feed fat
Limestone
NaCl
Dicalcium phosphate
L-lysine•HCl (78%)
DL-methionine (99%)
Vitamin and mineral premix 1.00

67.00
-
-
-
-
7.05
20.00
1.84
0.51
0.40
1.95
0.16
0.06

9.24
5.38
29.57
10.00
32.86
8.89
-
-
1.45
0.45
1.16
-
-
1.00

23.45
36.00
-
-
4.69
15.00
17.34
-
0.89
0.45
1.18
-
-
1.00

17.72
43.23
-
-
-
13.73
21.73
-
0.92
0.44
1.23
-
-
1.00

23.45
36.00
-
-
4.69
15.00
17.34
-
0.89
0.45
1.18
-
-
1.00
Calculated nutrient content
ME, MJ/kg
CP, %
Lysine, digestible, %


Carcass traits, technological and sensory meat quality
All animals were slaughtered at a commercial slaughterhouse, after 10 km transport
and at least 2 h of lairage in the abattoir. Cold carcass weight was measured on the
bled and eviscerated animal, with head but without tongue, front legs, hooves, genital

11.3
13.6
0.44

12.0
17.0
0.70

12.0
17.7
0.72

12.0
17.0
0.70
12.4
16.0
0.72

Page 4

362
HEYER et al.: Effects of breed cross on performance and meat quality of once-bred gilts
organs, flare fat, kidney and diaphragm. Backfat thickness was measured over the m.
longissimus dorsi (LD), just behind the last rib. Ham and loin of the right carcass half
were weighed with skin and fat then defatted and weighed again as meat and bone.
Five ham muscles (m. semimembranosus et aductor (SMA), m. semitendinosus (ST),
m. quadriceps (QUA), m. gluteus (GLU) and m. biceps femoris (BF)) were dissected
and weighed separately. Lean meat percentage was estimated according to [-49.672 +
(1.012* % ham in carcass) + (0.622* % meat and bone in ham) + (0.667* % loin in
carcass) + (0.2* % meat and bone in loin)] (I. HANSSON, pers. comm.).
Technological meat quality traits were measured on samples of LD taken at the last rib
and backwards approximately 24 h after slaughter. All measurements followed the
procedures as described in HEYER et al. (2004). The technological meat quality
measurements included ultimate pH (pHu), internal reflectance (FOP), surface
reflectance with the parameters L* (lightness), a* (redness) and b* (yellowness).
Water-holding capacity was determined as drip loss on LD and thawing loss as weight
difference of frozen and defrosted SMA. For processing yields, brine absorption
during immersion of SMA, commercial processing yield (total yield) on SMA and
laboratory processing yield (Napole yield) on LD were measured. Maximal shear force
and total work of Warner-Bratzler (WB) was determined on cooked LD. Chemical
composition of the LD was analysed as intramuscular fat (IMF), crude protein, ash and
dry matter, according to the methods as described in HEYER et al. (2004).
Sensory meat quality was determined on oven-baked LD of 20 once-bred gilts (all
animals of the first year) and cured and smoked SMA of 18 once-bred gilts (all
animals of the second year) by a trained taste panel. The meat (oven-baked LD and
cured and smoked SMA) was prepared as described in HEYER el al. (2004).
Tenderness, juiciness and fat flavour were determined on both LD and SMA, acidity
and meat flavour solely on LD and smoke flavour, stringiness and salinity solely on
SMA. The scale for the taste characteristics scored from 1= very low intensity of the
character to 100 = very high intensity.

Statistics
Statistical analyses of maternal performance, carcass quality and technological meat
quality were performed with the GLM procedure in SAS (SAS Institute Inc., Cary,
N.C., USA, versions 8.02). Data given in the tables are least square means and
standard errors. The model included breed cross (LW*D or LW*L) and year as fixed
factors. No interactions between the fixed effects were found. For litter weight and
piglet growth, age of the piglets at weighing was included as a covariate. Pre-weaning
mortality (no. weaned/no. live-born) and piglet growth were analysed with and without
the fixed effect of litter size (class: ≤6; 7-9; 10-12; ≥13 live-born piglets). Statistical
analyses of sensory meat quality were performed with the MIXED procedure in SAS.
In addition to the fixed effects described above, taste panel member and individual pig
were included in the model as random effects.


Results
Maternal performance
All 38 once-bred gilts were healthy during the whole study; no sign of illness was
observed. LW*L had significantly larger litters 4 days after birth (2.0 piglets; p=0.021)
compared to LW*D (Table 2). These once-bred gilts also had more piglets at weaning

Page 5

Arch. Tierz. 48 (2005) 4
363
(1.7 piglets) because pre-weaning mortality did not differ. The main reason for the
mortality was crushing. For LW*L, 38.5% of piglet mortality was registered as
crushing losses, compared with 48.6 % for the LW*D. No effect of breed cross on
litter weight 4 days after birth and at weaning was observed. Litters with LW*D
mothers grew faster in the period from day 4 to weaning. When litter size was included
in the model, a tendency of higher growth rate could still be seen.

Table 2
Maternal and piglet performance traits for once-bred gilts of Landrace and Duroc breed crosses, least square
means (LSM) and standard errors (SE) (Leistungsvermögen von Kreuzungs-Jungsauen und Ferkeln, LS-
Mittelwerte und Standardfehler)

LW*L (n=15) LW*D (n=23)
LSM SE LSM SE p-value
Litter size
no. born total
no. live-born
no. 4 days after birth
no. at weaning
Pre-weaning mortality, %
Pre-weaning mortalitycorr

11.9
11.5
10.8
10.2
12.1
9.5

0.72
0.73
0.62
0.60
3.14
3.43

10.0
9.9
8.8
8.5
13.3
13.7

0.57
0.58
0.49
0.48
2.51
2.35

0.052
0.092
0.021
0.034
0.773
0.293
1, %
Litter weight 4 days after birth, kg
Litter weight at weaning, kg
20.8
206.9
1.09
10.81
18.6
193.2
0.87
8.65
0.136
0.334
Piglet daily weight gain, g
day 4 to weaning
day 4 to weaningcorr

298
323

10.6
9.8

340
344

8.4
6.7

0.004
0.071
2
1 Values corrected for litter size; p=0.017 for effect of litter size.
2 Values corrected for litter size; p=0.001 for effect of litter size.

From 30 days after service to slaughter, body weight of LW*D was considerably
higher than of LW*L (Figure 1). At start of the outdoor period, the difference in
weight was 16 kg (p=0.069). Five weeks after farrowing, LW*D was heavier than
LW*L (p=0.004). Also when including the effect of litter size in the statistical model a
significant difference in weight could be seen (p=0.010). During the first 5 weeks of
lactation, LW*D had a lower weight loss, compared with the LW*L. Until weaning,
both LW*D and LW*L increased in weight; the LW*D more than the LW*L (9 kg vs.
5 kg; p=0.002). At slaughter, LW*D was 32 kg heavier (p=0.001) and reached the
similar weight as at the start of the outdoor period. Backfat of LW*D was initially
significantly thicker than that of LW*L, and this difference remained during the whole
rearing period. Compared with LW*L, LW*D had thicker backfat after farrowing
(p=0.028) (with litter size included in the statistical model: p=0.032). During the first 5
weeks of lactation, LW*D lost significantly less backfat than LW*L. At slaughter,
these once-bred gilts were as fat as 30 days after service, whereas backfat of LW*L
was 4 mm thinner.

Page 6

364
HEYER et al.: Effects of breed cross on performance and meat quality of once-bred gilts
80
100
120
140
160
180
200
220
240
0 50 100 150200
Body weight, kg
10
15
20
25
30
35
40
Backfat, mm
30 d 5wfarr outwean slgh
* *
*
***
***
***
***
***
***

Fig. 1: Body weight and backfat thickness of once-bred gilts from 30 days after service to slaughter.
Measurements at time of: 30 d= 30 days after service; out= start of the outdoor period, approximately one week
before farrowing; farr = farrowing; 5w = five weeks after farrowing, wean = weaning; slgh = slaughter; X=
LW*D cross; ○= LW*L cross; Straight line= body weight; Dashed line= backfat thickness; Levels of
significance between breed cross: ***=p<0.001, *=p<0.05 (Entwicklung von Körpergewicht und
Rückenspeckdicke bei Jungsauen vom 30. Tage der Trächtigkeit bis Schlachtung)

Feed consumption during the first 10 days of lactation was 91 and 76% of the
recommended amount based on litter size for LW*D and LW*L once-bred gilts,
respectively. The total consumption of feed from farrowing until slaughter could not
be compared between breed crosses because the animals were kept in mixed groups.
On average, feed consumption was 681 kg per sow from farrowing to slaughter,
including the feed consumed by the piglets (until weaning). The last weeks of
lactation, the piglets were often observed to eat sows’ feed. The piglets were weaned at
a weight of 21.3 (SD 4.25 kg) and 24.3 kg (SD 4.39 kg) for LW*L and LW*D litters,
respectively.

Carcass quality traits
The once-bred gilts were slaughtered at an approximate age of 450 days and a carcass
weight of 146 kg. LW*D had higher carcass weight and thicker backfat than LW*L
(p<0.001; Table 3). Lean meat content and percentage of meat and bone in ham and
loin were significantly lower in LW*D than in LW*L. The proportion of loin in
carcass was higher in LW*D. However, the proportion of QUA in the ham was lower
in LW*D than in LW*L (p=0.007), whereas the proportion of ST was higher in the
LW*D (p=0.001).

Page 7

Arch. Tierz. 48 (2005) 4
365
Table 3
Carcass quality traits and proportion of different ham muscles in once-bred gilts of Landrace and Duroc breed
crosses, least square means (LSM) and standard errors (SE) (Schlachtkörperqualität und prozentualer Anteil
verschiedener Muskeln im Schinken bei Kreuzungs-Jungsauen; LS-Mittelwerte und Standardfehler)

LW* L (n=15) LW*D (n=23)

LSM SE LSM SE p-value
Carcass weight1, kg
Lean meat content, %
Backfat, mm
137.3
56.0
16.7
3.75
0.62
1.18



153.7
54.0
22.1
2.92
0.49
0.89



0.002
0.017
0.001
Ham in carcass, %
Meat and bone in ham, %
Loin in carcass, %
Meat and bone in loin, %
SMA2 in ham, %
ST3 in ham, %
QUA4 in ham, %
GLU5 in ham, %
BF6 in ham, %
30.0
79.6
16.2
75.4
0.35
0.65
0.26
0.97




30.5
75.8
16.8
72.0
0.27
0.51
0.20
0.76




0.252
0.001
0.036
0.011
25.5
7.9
21.5
17.3
27.8
0.27
0.15
0.24
0.32
0.20





25.3
9.0
20.5
17.0
28.2
0.21
0.11
0.19
0.25
0.16





0.554
0.001
0.007
0.434
0.118
1Measured with head and without front legs; 2SMA= m. semimembranosus et aductor; 3ST= m. semitendinosus; 4QUA= m. quadriceps;
5GLU= m. gluteus; 6BF= m. biceps femoris.


Table 4
Technological meat quality and chemical composition of muscles in once-bred gilts of Landrace and Duroc
breed crosses, least square means (LSM) and standard errors (SE) (Technologische Fleischqualität und
chemische Zusammensetzung in Muskeln von Kreuzungs-Jungsauen; LS-Mittelwerte und Standardfehler)
LW*L (n=15)
LSM SE
pHu LD
5.45 0.02
FOP LD
36.0 1.74




LW*D (n=23)
LSM
5. 48
37.1





p-value
0.143
0.656
SE
0.01
1.37
Minolta valuesLD
L* (lightness)
a* (redness)
b* (yellowness)

48.1
8.4
3.5





0.63
0.36
0.29





47.5
8.4
3.7





0.49
0.28
0.23





0.479
0.921
0.709

Water holding capacityLD
Drip loss, %
Thawing loss, %

6.0
8.7




0.52
1.08




4.7
7.6




0.41
0.58




0.063
0.352
Processing yield
Brine immersionSMA, %
Total yieldSMA
Napole yieldLD

15.1
98.1
84.2





1.75
1.36
0.70





15.4
99.1
86.4





0.93
0.72
0.55





0.879
0.530
0.023
1, %
2, %
WB shear forceLD
Max shear force, N
Total work, Nmm

40.7
201.6




2.19
7.77




38.4
202.5




1.71
6.09




0.514
0.926
Chemical compositionLD
Intra muscular fat, %
Crude protein, %
Dry matter, %
Ash, %
1Commercial yield during ham production; 2Laboratory processing yield.

Technological and sensory meat quality and chemical composition
pHu, internal and surface reflectance, thawing loss, total yield (commercial processing
yield), shear force and chemical composition did not differ between the two types of
cross-bred gilts (Table 4). A tendency of lower drip loss (p=0.063) and 2.2 percentage

2.2
23.4
24.8
1.0






0.21
0.42
0.21
0.05






2.6
23.2
25.2
1.0






0.17
0.33
0.16
0.04






0.234
0.741
0.108
0.865

Page 8

366
HEYER et al.: Effects of breed cross on performance and meat quality of once-bred gilts
points higher Napole yield (laboratory processing yield; p=0.023) were found in meat
from LW*D than that from LW*L. No difference in chemical composition was found
in meat of the two breed crosses.
Oven-baked LD of LW*D and LW*L cross-bred gilts were equally scored in sensory
meat quality test, except meat flavour, where LD of LW*D scored higher (p=0.032)
(Figure 2). Cured and smoked SMA of LW*L tended to have juicier meat (p=0.084)
and had higher stringiness (p=0.005) than of LW*D, according to the test panel.

M. longissimus dorsi
n.s.
*
n.s.
n.s.
n.s.
010 2030 40 50
Acidity
Meat flavour
Fat flavour
Juiciness
Tenderness
60

M. semimembranosus
n.s.
n.s.
n.s.
n.s.
#
**
0 102030 405060 70
Salinity
Stringiness
Smoke flavour
Fat flavour
Juiciness
Tenderness


Fig. 2: Sensory meat quality of oven-baked m. longissimus dorsi (n=20) and cured and smoked m.
semimembranosus (n=18) from once-bred gilts ■ LW*D cross, □ LW*L cross; Levels of significance: n.s.=
p>0.10, #=p<0.10, *=p<0.05, **=p<0.01 (Sensorische Fleischqualität von gebackenem m. longissimus dorsi und
gepökelt/geräuchertem m. semimebranosus bei Kreuzungs-Jungsauen)


Discussion
Maternal performance
In this study once-bred LW*L gilts had larger litters than once-bred LW*D gilts. A
higher number of live-born and weaned piglets of the Landrace breed and its crosses
are widely described in the literature (CULBERTSON et al., 1997; TUMMARUK et
al., 2000). GAUGLER et al. (1984) reported that Landrace females, compared to the

Page 9

Arch. Tierz. 48 (2005) 4
367
breed of Duroc and Large White, are most productive in terms of litter size and litter
weight, but the authors also emphasized that significant heterosis estimates were
obtained for litter size, litter weight and piglet mortality. It has to be ‚emphasized’ that
despite the lack of access to creep feed for the piglets, they grew well and both the
piglets and the once-bred gilts were in a good condition at weaning. LW*D had higher
growth rate, compared to the LW*L pigs. For these LW*D pigs a higher growth rate
was also observed during the growing/finishing period (STERN et al., 2003).
Crushing is reported as a main factor for pre-weaning mortality of piglets, caused by
down-laying of the mother (MCGLONE and HICKS, 2000). In the present study, the
most important reason was crushing as well. The higher crushing rate for Duroc sows
might be because they are larger and heavier and thus less agile in their movements at
down-laying before suckling. The LW*L once-bred gilts had the capacity to rear their
larger litters and had consequently more piglets at weaning than the LW*D once-bred
gilts. A mortality of 12 to 13%, as found in the present study, was on an acceptable
level for an outdoor rearing system and no aggressiveness of the sows towards piglets
was observed. SPITSCHAK (1997) reported a similar mortality during the summer
months, which increased during winter with losses as high as 24%.
LW*L had higher weight loss during lactation, compared to the LW*D. This is in
accordance with CASSADY et al. (2002), who found that pure-bred Duroc sows have
lower weight loss during lactation, compared to Landrace and Large White pure-
breeds. Weight loss during lactation is strongly related to litter size and piglet growth
(WÜLBERS-MINDERMANN et al., 2002) because sows mobilise more body
reserves with greater number of piglets (NEIL et al., 1996). HARDGE et al. (1999)
considered that for pre-weaning growth, the most important factor is maternal milk
yield. Thus, the higher weight loss of LW*L might be explained by their larger
number of piglets in addition to a lower feed consumption. During the first 10 days of
lactation, when individual feed intake was recorded, LW*L once-bred gilts consumed
approximately 25% less than the recommended norm, which was based on litter size.
Less body reserves are probably mobilised during lactation in LW*D due to higher
feed consumption. The high body weight and backfat thickness of the LW*D may
indicate that these once-bred gilts are more suitable for outdoor production, especially
in colder countries.

Carcass meat quality
Higher backfat thickness and lower lean meat content of LW*D compared to LW*L
was in accordance to earlier comparisons (WOOD et al., 1988; ENFÄLT et al., 1997;
STERN et al., 2003) between Duroc crosses and other commercial breeds.
BLANCHARD et al. (1999) reported that backfat thickness increased with increasing
genetic portion of Duroc breed in the growing/finishing pig. Also the progeny of the
once-bred gilts in the present study (25% Duroc or Landrace, 25% Large White, 50%
Hampshire) showed that Duroc cross breeds had lower lean meat content, compared to
the Landrace cross breeds (STERN et al., 2003). Nowadays Duroc has an improved
carcass quality, in terms of higher lean meat content and thinner backfat thickness,
because this was effectively included in the breeding goals for Duroc boars
(NORSVIN, 2004). However, differences in these carcass traits are still present. It has
to be emphasized that the lower lean meat content in the present study was found for
LW*D once-bred gilts, which have a higher age, higher carcass weight and underwent

Page 10

368
HEYER et al.: Effects of breed cross on performance and meat quality of once-bred gilts
a whole cycle of reproduction. In comparison with growing/finishing pigs, the once-
bred gilts reach a lower price per kg meat (0.75 vs. 1.20 EUR/kg) because of their
higher body weight and backfat thickness. This disadvantage of lower economic value
per kg meat has to be taken into account when gilts are slaughtered after their first
reproduction cycle. However, the lower payment per kg meat might not be justified,
because once-bred gilts produce valuable carcasses of good quality with adequate
technological and sensory meat quality when comparing to maiden gilts, raised to a
higher slaughter weight (HEYER et al., 2004).

Technological meat quality and chemical composition
The Duroc breed is widely known for its enhanced technological meat quality traits,
e.g. decrease of WB shear force and cooking loss compared to white breeds (MLC,
1992) and is therefore often used as terminal sire breed (OLIVER et al., 1994). The
breeding company, from which the Duroc sires in the present study originated, has
technological meat quality included in the breeding goal (NORSVIN, 2004). In
accordance with other studies, pHu and FOP values did not differ between the two
breed crosses in the present study (CAMERON et al., 1990; EDWARDS et al., 1992;
ENFÄLT et al., 1997; BLANCHARD et al., 1999). ENFÄLT et al. (1997), who found
no differences in pHu between Duroc and Yorkshire breed crosses, suggested that
differences in pHu of pure breeds might be alleviated by the effect of breed cross. In
literature, Duroc meat is often mentioned as darker (OLIVER et al., 1994) and also
redder (CAMERON et al., 1990), compared to other breeds, which could be explained
by the higher content of haem in the muscle fibres of Duroc pigs (MLC, 1992).
However, in the present study, no differences in lightness or redness could be
measured, which might be due to the higher age and weight of the once-bred gilts in
comparison with the growing/finishing pigs of the cited studies.
The water-holding capacity in terms of drip and cooking losses in meat from pure
breeds and breed crosses of Duroc and white breeds are widely studied (OLIVER et
al., 1994; ENFÄLT et al., 1997; BLANCHARD et al., 1999) and generally no
differences in drip and cooking losses between the breed crosses were found.
However, in the present study, drip loss in LW*D tended to be lower, compared to
LW*L. Also Napole yield differed between the two breed crosses with a higher yield
for LW*D, whereas total yield after commercial ham processing was similar. The
discrepancy between Napole and total yield might be due to the preparation of the
meat (fresh/thawed) and/or the use of different muscles for yield determination.
Shear force values did not differ between breed crosses. BARTON-GADE (1988)
reported that shear force of meat from purebred Duroc pigs was significantly lower
than that from white races. BLANCHARD et al. (1999) considered that with
increasing portion of Duroc genes in the pig, shear force decreased. ENFÄLT et al.
(1997) found similar shear force for breed crosses with Duroc or Large White as sires.
In all named cases, the measurements were carried out on growing/finishing pigs and
as possible explanation for differences in meat toughness, differences in IMF content
and growth rate were discussed. However, in the present study once-bred gilts were
used, and differences in WB shear force between breeds might have been alleviated
due to their high age and weight.
In contrast to the general perception of higher IMF in Duroc and its breed crosses
(BARTON-GADE, 1988; OLIVER et al., 1994; LAUBE et al., 2000), no differences

Page 11

Arch. Tierz. 48 (2005) 4
369
between LW*D and LW*L once-bred gilts in IMF and other chemical components
were found. This might be because the once-bred gilts underwent a whole
reproduction cycle, including gestation and lactation. During lactation, fat reserves
were depleted by the suckling progeny and could not be recovered during the short
post-weaning fattening period. Even when the backfat thickness of the Duroc breed
cross was higher post-weaning, the IMF content was similar.

Sensory meat quality
The general consistency of sensory meat quality between breed crosses in the present
study is contrary to findings from several authors (BARTON-GADE, 1988;
CAMERON et al., 1990; BLANCHARD et al., 1999), who found higher tenderness
and juiciness of Duroc and its crosses, compared to other breeds. Sensory meat quality
characteristics i.e. tenderness and juiciness are, related to IMF, pH value and shear
force (WOOD et al., 1986; EIKELENBOOM et al., 1996a, b; ENFÄLT et al., 1997;
ELLIS et al., 1999; OLSSON et al., 2003). In the present study, pHu, IMF and shear
force did not differ between the breed crosses and therefore did not affect tenderness
and juiciness (in LD) to a greater extent. The tendency of juicier SMA of LW*L pigs
might be an effect of the lower water-holding capacity of this breed cross.
HULLBERG et al. (2005) described that a lower water-holding capacity, in that study
determined as lower processing yield, resulted in higher juiciness. An explanation
might be that meat with low water-holding capacity binds the water less strongly and
releases water more easy during chewing.



References
ANDERSSON, K.; SCHAUB, A.; LUNDSTRÖM, K.; THOMKE, S.; HANSSON, I.:
The effects of feeding system, lysine level and gilt contact on performance, skatole levels and economy
of entire male pigs. Livestock Production Science 51 (1997), 131-140
BARTON-GADE, P.:
The effect of breed on meat quality characteristics in pigs. In proceedings of 34th International
Congress of Meat Science and Technology, Brisbane, Australia. (1988), 568-570
BEJERHOLM, C.; BARTON-GADE, P.:
Effect of intramuscular fat level on eating quality of pig meat. In proceedings of 32nd European
Meeting. Meat Research Workers, Ghent. (1986), 389-391.
BLANCHARD, P.J.; WARKUP, C.C.; ELLIS, M.; WILLIS, M.B.; AVERY, P.:
The influence of the proportion of Duroc genes on growth, carcass and pork eating quality
characteristics. Animal Science 68 (1999), 495-501
CAMERON, N.D.; WARRISS, P.D.; PORTER, S.J.; ENSER, M.B.:
Comparison of Duroc and British Landrace pigs for meat and eating quality. Meat Science 27 (1990),
227-247
CASSADY, J.P.; YOUNG, L.D.; LEYMASTER, K.A.:
Heterosis and recombination effects on pig reproductive traits. Journal of Animal Science 80 (2002),
2303-2315
CULBERTSON, M.S.; MABRY, J.W.; BERTRAND, J.K.; NELSON, A.H.:
Breed-specific adjustment factors for reproductive traits in Duroc, Hampshire, Landrace, and Yorkshire
swine. Journal of Animal Science 75 (1997), 2362-2367
EDWARDS, S.A.; WOOD, J.D.; MONCRIEFF, C.B.; PORTER, S.J.:
Comparison of the Duroc and Large White as terminal sire breeds and their effect on pig meat quality.
Animal Production 54 (1992), 289-297
EIKELENBOOM, G.; HOVING-BOLINK, A.H.; VAN DER WAL, P.G.:
The eating quality of pork.1. The influence of ultimate pH. Fleischwirtschaft 76 (1996a), 405-406
EIKELENBOOM, G.; HOVING-BOLINK, A.H.; VAN DER WAL, P.G.:
The eating quality of pork. 2. The influence of intramuscular fat. Fleischwirtschaft 76 (1996b), 559-560

Page 12

370
HEYER et al.: Effects of breed cross on performance and meat quality of once-bred gilts
ELLIS, M.; MCKEITH, F.K.; MILLER, K.D.:
The effects of genetic and nutritional factors on pork quality - Review. Asian-Australasian Journal of
Animal Sciences 12 (1999), 261-270
ENFÄLT, A.C.; LUNDSTRÖM, K.; HANSSON, I.; LUNDEHEIM, N.; NYSTRÖM, P.E.:
Effects of outdoor rearing and sire breed (Duroc or Yorkshire) on carcass composition and sensory and
technological meat quality. Meat Science 45 (1997), 1-15
GAUGLER, H.R.; BUCHANAN, D.S.; HINTZ, R.L.; JOHNSON, R.K.:
Sow productivity comparisons for four breeds of swine: purebred and crossbred litters. Journal of
Animal Science 59 (1984), 941-947
GLODEK, P.; KRATZ, R.; SCHULZ, E.; FLACHOWSKY, G.:
Effect of sire breeds in commercial pig crosses on growth, carcass composition, meat and fat quality.
Arch. Tierz., Dummerstorf 47 (2004), 59-74
HARDGE, T.; KOEPKE, K.; REISSMANN, M.; WIMMERS, K.:
Maternal influences on litter size and growth in reciprocal crossed Miniature pigs and Durocs. Arch.
Tierz., Dummerstorf 42 (1999), 83-92
HEYER, A.; ANDERSSON, H.K.; RYDHMER, L.; LUNDSTRÖM, K.:
Carcass quality and technological and sensory meat quality of once-bred gilts in a seasonal outdoor
rearing system. Acta Agriculturae Scandinavica Section a-Animal Science 54 (2004), 103-111
HULLBERG, A.; JOHANSSON, L.; LUNDSTRÖM, K.:
Sensory perception of cured-smoked pork loin from carriers and non-carriers of the RN¯ allele and its
relationship with technological meat quality. Journal of Muscle Foods 16 (2005), 54-76
HÅKANSSON, J.; FRÖHLICH, A.; HANSSON, I.; ERIKSSON, S.:
Meat and piglet production by farrowing gilts. In Swedish. Sogylteproduktion-en alternativ griskötts-
och smågrisproduktion. Animal Husbandry. Uppsala. 1982
LAUBE, S.; HENNING, M.; BRANDT, H.; KALLWEIT, E.; GLODEK, P.:
Meat quality in pig crosses with special quality characteristics as compared to present standard and
brand pork supply. Arch. Tierz., Dummerstorf 43 (2000), 463-476
MCGLONE, J.J.; HICKS, T.A.:
Farrowing hut design and sow genotype (Camborough-15 vs 25% Meishan) effects on outdoor sow and
litter productivity. Journal of Animal Science 78 (2000), 2832-2835
MLC:
Stotfold pig development unit. Second trail results. Milton Keynes, U.K.Meat and Livestock
Commission, 1992
NEIL, M.; OGLE, B.; ANNÉR, K.:
A two-diet system and ad libitum lactation feeding of the sow .1. Sow performance. Animal Science 62
(1996), 337-347
NORSVIN:
Slaktekvalitet og slaktesammensetning. http://www.norsvin.no/vedlegg/slaktekvalitet.pdf, accessed
07.06.2004
OLIVER, M.A.; GOU, P.; GISPERT, M.; DIESTRE, A.; ARNAU, J.; NOGUERA, J.L.; BLASCO, A.:
Comparison of 5 types of pig crosses. 2. Fresh meat quality and sensory characteristics of dry-cured
ham. Livestock Production Science 40 (1994), 179-185
OLSSON, V.; ANDERSSON, K.; HANSSON, I.; LUNDSTRÖM, K.:
Differences in meat quality between organically and conventionally produced pigs. Meat Science 64
(2003), 287-297
SPITSCHAK, K.:
Fertility and rearing performances of sows with piglets in outdoor keeping. (German language) Arch.
Tierz., Dummerstorf 40 (1997) 2, 123-134
STERN, S.; HEYER, A.; ANDERSSON, H.K.; RYDHMER, L.; LUNDSTRÖM, K.:
Production results and technological meat quality for pigs in indoor and outdoor rearing systems. Acta
Agriculturae Scandinavica Section a-Animal Science 53 (2003), 166-174
TUMMARUK, P.; LUNDEHEIM, N.; EINARSSON, S.; DALIN, A.M.:
Reproductive performance of purebred Swedish Landrace and Swedish Yorkshire sows: I. Seasonal
variation and parity influence. Acta Agriculturae Scandinavica Section a-Animal Science 50 (2000),
205-216
WOOD, J.D.; EDWARDS, S.A.; BICHARD, M.:
Influence of the Duroc breed on pig meat quality. In proceedings of 34th International Congress of Meat
Science and Technology, Brisbane, Australia. (1988) 571-572
WOOD, J.D.; JONES, R.C.D.; FRANCOMBE, M.A.; WHELEHAN, O.P.:
The effects of fat thickness and sex on pig meat quality with special reference to the problems
associated with overleanness. 2. Laboratory and trained taste panel results. Animal Production 43
(1986), 535-544

Page 13

Arch. Tierz. 48 (2005) 4
371
WÜLBERS-MINDERMANN, M.; ALGERS, B.; BERG, C.; LUNDEHEIM, N.; SIGVARDSSON, J.:
Primiparous and multiparous maternal ability in sows in relation to indoor and outdoor farrowing
systems. Livestock Production Science 73 (2002), 285-297


Received: 2004-12-14

Accepted: 2005-06-23


Corresponding Author
KERSTIN LUNDSTRÖM, Professor
Department of Food Science
Swedish University of Agricultural Sciences
Box 7051,
S-75007 UPPSALA
SWEDEN

E-mail: Kerstin.Lundstrom@lmv.slu.se