- Email: [email protected]
Carcass and ham quality characteristics of heavy pigs from different genetic groups intended for the production of dry-cured hams
Meat Science 86 (2010) 371–376
Contents lists available at ScienceDirect
Meat Science j o u r n a l h o m e p a g e : w w w. e l s ev i e r. c o m / l o c a t e / m e a t s c i
Carcass and ham quality characteristics of heavy pigs from different genetic groups intended for the production of dry-cured hams J.V. Peloso a, P.S. Lopes a,⁎, L.A.M. Gomide b, S.E.F. Guimarães a, P.L.S. Carneiro c a b c
Departamento de Zootecnia, Universidade Federal de Viçosa, 36570-000, Viçosa, MG, Brazil Departamento de Tecnologia de Alimentos, Universidade Federal de Viçosa, 36570-000, Viçosa, MG, Brazil Departamento de Ciências Biológicas, Universidade Estadual do Sudoeste da Bahia, 45200-000, Jequié, BA, Brazil
a r t i c l e
i n f o
Article history: Received 4 July 2009 Received in revised form 10 November 2009 Accepted 14 May 2010 Keywords: Pig Carcass characteristics Meat quality Dry-cured ham Duroc
a b s t r a c t Carcass and ham quality characteristics of pig populations divided by harvest weights — HW (130 and 160 kg) were evaluated to determine the effects of gender (barrows and gilts) and distinct genetic groups — purebred (DUDU) and crossbred Duroc (DULA, DUWI and DULL) as well as purebred Large White (WIWI) on the suitability for use in dry-cured ham production. At 130 kg, DUDU pigs yielded the highest fat thickness of the ham (P b 0.01) and an intramuscular fat content (IMF) of 3.15% in Semimembranosus muscle (SM). DUDU pigs also had a SM pHu of 5.7. This genetic group met the specifications for dry-cured ham production. No differences could be found in meat quality characteristics between genetic groups harvested at 160 kg. However at this HW, gilts produced significantly (P b 0.05) heavier and leaner hams compared to barrows. © 2010 The American Meat Science Association. Published by Elsevier Ltd. All rights reserved.
1. Introduction The pork industry in Brazil, as in other pig meat-producing countries, comprises a wide variety of product options at the retail case, ranging from unprocessed chilled or frozen cuts to ready-to-eat processed products. In order to meet the raw material quality required by packers, pig breeders are moving towards specific genetic backgrounds, nutritional standards, and harvest weights. For instance, according to Brazilian manufactures, pigs and their respective genotypes destined for dry-cured ham production shall yield hind legs with a 25 mm fat cover and an intramuscular fat (IMF) content greater than 2.5%. The relationship between the IMF content and the quality of the final product is frequently investigated in dry-cured hams due to its correlation with tenderness, juiciness, flavor, and aroma (Ruiz-Carrascal, Ventanas, Cava, Andrés, & Garcia, 2000; Russo & Costa, 1995). Furthermore, ham shall meet quality criteria, such as a final pH greater than 5.55 in the Semimembranosus muscle, in order to avoid the occurrence of pale, soft, and exudative (PSE) pork (GarcíaRey, García-Garrido, Quiles-Zafra, Tapiador, & Luque De Castro, 2004). The respect of these criteria helps protect the product against excessive dehydration, resulting in higher capacity of meat to absorb salt and spices during the drying and ripening processes. Increasing weight at harvest has been proposed to reduce operational costs in the pork production chain, especially in packing
⁎ Corresponding author. Tel.: + 55 31 3899 3319; fax: + 55 31 3899 2275. E-mail address: [email protected] (P.S. Lopes).
plants (Lebret, Juin, Noblet, & Bonneau, 2001; Weatherup, Beattie, Moss, Kilpatrick, & Walker, 1998). At the same time, harvest of heavier pigs is indicated when these animals are destined for the production of dry-cured hams (Latorre, Lázaro, Valencia, Medel, & Mateos, 2004; Virgili et al., 2003). Different genetic groups of pigs have been used to obtain fresh hams with ideal quality traits and the use of the Duroc breed and, in particular, its crossbreds often satisfies both muscle and fat quality criteria for dry-ham processing (Cilla et al., 2006; Sabbioni et al., 2004). The objective of the present study was to evaluate carcass and meat quality traits from five distinct pig genetic groups at two different harvest weights. Furthermore, this study aimed to define which group would better fulfill the specifications of the raw material for industrial processing of dry-cured hams in the Brazilian and in exporting markets.
2. Materials and methods 2.1. Experimental population A total of 1106 pigs of five genotypes (Duroc × Duroc — DUDU, Duroc × Landrace — DULA, Duroc × Large White — DUWI, Duroc × Landrace × Large White — DULL, and Large White × Large White — WIWI) and two genders (barrows and gilts) were distributed into two harvest weights (HW) (130 and 160 kg) (Table 1). The DUDU genetic group with 160 kg HW was not tested because it is inappropriate for industrial use due to its low feed efficiency on the farm, excess fat on the carcass, as well as occurrence of deep seated hair on the hams.
0309-1740/$ – see front matter © 2010 The American Meat Science Association. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.meatsci.2010.05.017
372
J.V. Peloso et al. / Meat Science 86 (2010) 371–376
Table 1 Number of pigs used in each genetic group and gender by harvest weight. Genetic group and gender by harvest weight
Number of pigs
DUDU — ♂ Duroc × ♀ Duroc — B — 130 kg DUDU — ♂ Duroc × ♀ Duroc — G — 130 kg DULL — ♂ Duroc × ♀ (Lan × LW) — B — 130 kg DULL — ♂ Duroc × ♀ (Lan × LW) — G — 130 kg DULA — ♂ Duroc × ♀ Landrace (Lan) — B — 130 kg DULA — ♂ Duroc × ♀ Landrace (Lan) — G — 130 kg DUWI — ♂ Duroc × ♀ Large White (LW) — B — 130 kg DUWI — ♂ Duroc × ♀ Large White (LW) — G — 130 kg WIWI — ♂ Large White × ♀ Large White — B — 130 kg WIWI — ♂ Large White × ♀ Large White — G — 130 kg DULL — ♂ Duroc × ♀ (Lan × LW) — B — 160 kg DULL — ♂ Duroc × ♀ (Lan × LW) — G — 160 kg DULA — ♂ Duroc × ♀ Landrace (Lan) — B — 160 kg DULA — ♂ Duroc × ♀ Landrace (Lan) — G — 160 kg DUWI — ♂ Duroc × ♀ Large White (LW) — B — 160 kg DUWI — ♂ Duroc × ♀ Large White (LW) — G — 160 kg WIWI — ♂ Large White × ♀ Large White — B — 160 kg WIWI — ♂ Large White × ♀ Large White — G — 160 kg
78 72 117 86 130 110 100 62 40 48 60 30 64 30 40 22 20 12
B = barrow; G = gilt.
For production of the DUDU, DULA, DUWI, and DULL genetic groups, seven Duroc boars were mated with 28 Durocs, 43 Landraces, 44 Large Whites, and 44 Landrace × Large Whites sows, respectively. The WIWI genetic group was produced by mating 28 Large Whites sows with eight Large White boars. Pigs were raised at a multiplier farm belonging to a vertical integrator (pig breeding and processing company) located in the Western part of the state of Santa Catarina in Southern Brazil. After weaning at 28 days of age at an average weight of 6.5 kg, the piglets were transferred weekly in batches of 20 to the nursery and growing barns and separated based on their genetic group into pens of mixed gender. The animals remained inside these facilities until they reached 83 days of age and a mean weight of 48.3 kg. The pigs were then transferred to the finishing barns. During finishing, the pigs were separated by gender into the different genetic groups and were kept in groups of 5 to 8 pigs at a density of 1.1 m2/pig per pen. All groups no matter what targeted harvest weight was, were fed ad libitum a diet of the same formulation during the first six weeks of finishing (Table 2). After this period, the group harvested at 130 kg HW was fed a second diet ad libitum (Table 2) for the remaining five and a half weeks until harvest, whereas the group harvested at 160 kg HW was fed the same second diet ad libitum for the remaining eleven weeks until harvest. The 130 kg targeted HW was reached on average at 163 days after birth, whereas the 160 kg targeted HW was reached at 202 days. Pigs were individually weighed after a 14 h on-farm fasting period. An additional 6 h fasting time occurred during transportation and lairage. Twenty-five consecutive harvests were performed (two harvests per week), in order to collect all experimental data.
level, without the use of electric prods or mixing. After electrical stunning (700 Volts, 1.25 Amperes), exsanguination and evisceration, hot carcasses were weighed head-off (HCW), and both back fat thickness (BT) and loin depth (LD) were measured using the UF 300 ultrasound grading probe (SFK Technology Inc., Herlev, Denmark) at the 10th thoracic vertebra level. Carcasses were chilled overnight at 1 °C. 2.3. Ham fabrication and quality data collection On the day after harvest, the carcasses were cut into four primals: ham, shoulder, loin, and belly. Hams were weighed and sent to the trimming room, where the fat cover of the Semimembranosus muscle (SM) (referred to as the internal fat thickness or IFT) and the fat cover of the Biceps femoris muscle (referred to as the external fat thickness or EFT) were measured using a digital caliper (Absolute™ Digimatic Series 500, Mitutoyo Co., Kanagawa, Japan). Each ham was trimmed to the standard shape required for the curing process. After trimming, hams were reweighed, and meat quality was assessed in the SM by measuring pH at 24 h (pHu) post-mortem using a pH meter fitted with a DXK-S7/25 spear-type electrode and an automatic temperature compensation probe (Mettler Toledo, MP 120 pH Meter, Schwerzenbach, Switzerland). The objective surface light reflectance (color) of the SM was also evaluated 24 h after harvest using the Opto Star™ probe (SFK Technology Inc., Herlev, Denmark) on the Göfo scale ranging from 0 to 100, where 0 = pale and 100 = dark (Van Oeckel, Warnants, & Boucqué, 1999). Before the hams were sent to salting and dehydration in the ripening chambers, 143 and 212 samples belonging respectively to the 130 kg and 160 kg HW groups were taken from the middle of SM, vacuum packed and stored at −25 °C until the extractable lipid analysis (IMF) was conducted using the Soxhlet procedure with petroleum ether (ISO 1444, 1973). 2.4. Statistical analysis To determine the effects of genetic group and gender on carcass and ham quality traits, the General Linear Model (GLM) of the Statistical Analysis System program for Windows (SAS® Institute, 2002–2003), version 9.1, was used. Analysis of variance was performed for each live weight (130 or 160 kg) using the following model: yijk = μ + GGi + SEj + GGxSEij + eijk where: observed value of the trait; mean; genetic group (i = DUDU, DULA, DUWI, DULL or WIWI); gender (j = barrow or gilt); interaction between genetic group and gender; random error associated with each observation.
2.2. Harvest and carcass grading
yijk µ GGi SEj GGxSEij eijk
Animals were harvested following the standard operational procedures of the plant, where pre-slaughter stress was kept to a minimum
Means were compared using the Student–Newman–Keuls (SNK) test at a level of significance of P b 0.05.
Table 2 Composition of experimental diets used during the finishing phase. Nutritional levels
During the first six weeks
After the first six weeks
Digestible energy (kcal/kg) Crude protein (%) Calcium (%) Phosphorus (%) Lysine (%) Methionine (%) Threonine (%) Tryptophan (%)
3400 16.00 0.70 0.30 0.90 0.27 0.59 0.16
3400 14.50 0.65 0.25 0.70 0.21 0.46 0.13
3. Results and discussion 3.1. Carcass characteristics at 130 kg HW None of the carcass traits studied were affected by interactions between genetic group and gender at this HW. While HCW, BT, and LD differed between the genetic groups, only BT and LD differed between barrows and gilts, whereas HCW was not affected by gender (Table 3). DUDU pigs exhibited the highest BT together with the lowest HCW (P b 0.05), indicating that these pigs had the lightest and fattest carcasses among genetic groups. In contrast, the carcasses of the WIWI
J.V. Peloso et al. / Meat Science 86 (2010) 371–376 Table 3 Carcass quality traits LSM⁎ of pigs harvested at 130 kg (SE⁎⁎ in parentheses). Carcass traits 1
HCW (kg) 2
BT (mm) LD3 (mm)
Genetic groups DUDU b
93.74 (0.44) 20.87a (0.46) 55.30b (0.57)
Gender
DULA ab
95.00 (0.41) 18.71b (0.34) 55.51b (0.48)
DUWI a
95.70 (0.49) 19.17b (0.43) 56.04b (0.55)
DULL
WIWI ab
95.14 (0.49) 18.30b (0.40) 56.73b (0.50)
a
96.40 (0.66) 15.93c (0.46) 59.31a (0.68)
Barrows
Gilts
94.91 (0.30) 20.06a (0.26) 55.21b (0.34)
95.19 (0.31) 17.46b (0.28) 57.47a (0.35)
a, b, c
Means within a row followed by a different letter are significantly different among genetic groups or gender (P b 0.05). ⁎ Least square means. ⁎⁎ Standard error. 1 Hot carcass weight. 2 Back fat thickness. 3 Loin muscle depth.
pigs were heavier and, at the same time, exhibited the lowest BT and highest LD in comparison to the other genetic groups. The lower BT observed in the Large White compared to Duroc pigs has been reported by others (Blanchard, Warkup, Ellis, Willis, & Avery, 1999b; Channon, Kerr, & Walker, 2004). In agreement with our study, Stoller, Zerby, Moeller, Baas, Johnson, and Watkins (2003) observed higher BT values in a group composed of 100% Duroc genetics as compared to Landrace × Large White crosses, with a mean HCW of 83 kg. Wood et al. (2004) did not observe significant differences in HCW or BT between Duroc and Large White boars harvested at 86 kg. Channon et al. (2004) also did not observe significant differences in HCW or BT between crosses of 100% Duroc, 50% Duroc × Large White, and 100% Large White when harvested at 157 days of age. In contrast to the present results, Čandek-Potokar, Monin, and Žlender (2002) demonstrated that inclusion of Duroc genetics in crosses with Large White and Landrace pigs harvested at 209 days significantly increased the HCW, with heavier carcasses in barrows compared to gilts. Conversely, Blanchard, Ellis, Warkup, Chadwick, and Willis (1999a) reported that inclusion of 50% Duroc genetics did not alter the final HW when compared to Large White × Landrace crosses without Duroc genetics. In the present work, gilts produced leaner carcasses (P b 0.01) than barrows, as demonstrated by the lower BT and higher LD, with no significant difference (P N 0.05) in HCW (Table 3). These results are in agreement with the findings of Lovato et al. (2006), who described a lower BT in gilts as compared to barrows in Duroc × (Large White × Landrace) crosses. In the swine industry, the methods most frequently used to alter the meat/fat ratio of carcasses are altering the HW and modifying the diet and/or feeding strategies. Increasing HW, and consequently HCW, enhances BT (Beattie, Weatherup, Moss, & Walker, 1999; Blanchard et al., 1999) as well as fat content in the ham, shoulder, loin, and belly (Aalhus, Jones, Robertson, Tong, & Sather, 1991; Correa et al., 2006), thus decreasing the meat/fat ratio in the carcass as a whole (Weatherup et al., 1998).
373
groups. These results differ from the findings of Latorre et al. (2004), who reported the same GW for gilts and barrows with a HCW of 97.1 kg. In contrast to the findings of Cisneros et al. (1996) and Latorre, Lázaro, Gracia, Nieto, and Mateos (2003a), trimmed ham weight (TW) observed in our study was greater (P b 0.05) in gilts than in barrows. Among the genetic groups, WIWI pigs differed from the other genotypes as they produced heavier (P b 0.05) trimmed hams. As expected, DUDU pigs exhibited a significantly higher (P b 0.01) EFT when compared to the other genetic groups. DULA pigs displayed the second highest EFT, which was significantly different (P b 0.01) from DUWI pigs, which had the lowest EFT among all of the genetic groups. In the study of Latorre et al. (2003a), no differences in EFT were found among groups consisting of 50%, 25%, and 0% Duroc genetics with a HW of 129 kg. EFT was significantly lower (P b 0.05) in gilts in comparison to barrows. Similar results have been reported by Latorre, Medel, Fuentetaja, Lázaro, and Mateos (2003b), Latorre et al. (2003a) and Latorre et al. (2004) for pigs harvested at 133 kg. Correa et al. (2006) also found significantly lower EFT in Duroc × (Landrace × Large White) gilts as compared to barrows harvested at 125 kg. No genetic group effect (P N 0.05) on IFT was detected, but IFT was significantly higher (P b 0.05) in barrows than in gilts in the present experiment. These results confirm that gilts have the ability to produce significantly leaner hams compared to barrows at a heavier HW. However, for the production of dry-cured ham, a thicker fat cover is desired. Both EFT and IFT play a relevant role during the long aging period, as they provide protection for the muscles from excessive dehydration that could lead to disproportionate shrinkage of the ham pieces. There was no effect of gender on either pHu or Göfo values, while the genetic group had a significant effect (P b 0.05) on Göfo values. Čandek-Potokar et al. (2002) also found no significant differences in the pHu of SM between crossbred Duroc × Landrace barrows and gilts. However, consistently higher pHu were shown in the SM of barrows as compared to gilts harvested at 116, 124, and 133 kg by Latorre et al. (2003a,b) and Latorre et al. (2004). The results of Latorre et al. (2004) also revealed higher pHu than those observed in the present study for both genders (Table 4). Other studies have also found no differences in pHu of the SM of barrows compared to gilts in carcasses of 86.2 kg Table 4 Ham quality traits LSM⁎ of pigs harvested at 130 kg (SE⁎⁎ in parentheses). Ham traits
GW1 (kg) TW2 (kg) EFT3 (mm) IFT4 (mm) pHu5
3.2. Ham quality traits at 130 kg HW
Göfo value6
Ham quality traits obtained from pigs harvested at 130 kg are shown in Table 4. There were also no interactions between genetic group and gender for these traits. Gross weight (GW) was significantly higher (P b 0.05) in WIWI pigs as compared to the other genetic groups. In addition, GW was lower in DUDU pigs, but did not significantly differ between the DULA and DULL groups. Despite the same HCW, gilts produced significantly (P b 0.05) heavier hams than barrows. When comparing crosses with 0 and 25% Duroc genetics, with HCW close to that of the present experiment, Cisneros, Ellis, McKeith, McCaw, and Fernando (1996) observed a higher GW in gilts as compared to barrows, without any differences among the genetic
IMF7 (%) a, b, c
Genetic groups
Gender
DUDU
DULA
DUWI
DULL
WIWI
Barrows
Gilts
14.90c (0.08) 10.69b (0.06) 29.86a (0.99) 4.55 (0.34) 5.59 (0.02) 54.47c (0.54) 3.15a (0.25)
15.16bc (0.07) 10.80b (0.05) 26.67b (0.83) 4.52 (0.26) 5.55 (0.01) 54.23c (0.36) 1.93b (0.15)
15.32b (0.11) 10.95b (0.09) 23.68c (1.14) 4.82 (0.57) 5.59 (0.02) 56.81ab (0.65) 2.09b (0.12)
15.20bc (0.08) 10.79b (0.08) 25.95bc (0.85) 4.26 (0.27) 5.58 (0.02) 55.40bc (0.66) 1.85b (0.23)
15.96a (0.14) 11.31a (0.10) 24.30bc (1.59) 3.95 (0.44) 5.58 (0.02) 58.23a (1.02) 1.81b (0.15)
15.09b (0.05) 10.70b (0.04) 28.29a (0.60) 5.36a (0.25) 5.58 (0.01) 55.00 (0.39) 2.32 (0.13)
15.34a (0.07) 11.01a (0.05) 24.25b (0.67) 3.28b (0.12) 5.57 (0.01) 56.68 (0.36) 2.02 (0.12)
Means within a row followed by a different letter are significantly different among genetic groups or gender (P b 0.05). ⁎ Least squared means. ⁎⁎ Standard error. 1 Gross weight. 2 Trimmed weight. 3 External fat thickness. 4 Internal fat thickness. 5 pH 24 h post-mortem. 6 Ranging from 0 = pale to 100 = dark. 7 Intramuscular fat.
374
J.V. Peloso et al. / Meat Science 86 (2010) 371–376
Table 5 Carcass quality traits LSM⁎ of pigs harvested at 160 kg (SE⁎⁎ in parentheses). Carcass traits 1
HCW (kg) BT2 (mm) LD3 (mm)
Genetic groups DULA 116.74 (0.68) 23.93a (0.58) 53.27b (0.57)
DUWI 115.41 (0.79) 24.61a (0.78) 52.70b (0.73)
Gender DULL 116.40 (0.65) 22.78a (0.57) 54.82ab (0.62)
WIWI 114.87 (1.61) 19.72b (0.95) 56.81a (1.06)
Barrows 116.20 (0.47) 24.89a (0.45) 52.59b (0.43)
Table 6 Ham quality traits LSM⁎ of pigs harvested at 160 kg (SE⁎⁎ in parentheses). Ham traits
Gilts 116.00 (0.73) 20.45b (0.45) 56.51a (0.52)
a, b
Means within a row followed by a different letter are significantly different among genetic groups or gender (P b 0.05). ⁎ Least squared means. ⁎⁎ Standard error. 1 Hot carcass weight. 2 Back fat thickness. 3 Loin muscle depth.
(García-Macías et al., 1996; Lebret et al., 2001; Sather, Jones, Tong, & Murray, 1991) and 98.5 kg (Cisneros et al., 1996). The pHu measured in chilled pig meat is largely determined by the effects of harvest day (Hambrecht, Eissen, & Verstegen, 2003), interaction between muscle energy stores at the time of harvest and the RYR1 and PRKAG3 genes (Hocquette, Ortigues-Marty, Pethick, Herpin, & Fernandez, 1998) as well as the predominant fiber type present in the muscle (Ryu & Kim, 2005). The importance of pHu in dry-cured ham production is twofold. At the beginning of processing, pHu affects curing by interfering with the diffusion of moisture after salting. At the end of processing, pHu influences the flavor and texture of finished hams (Gou, Comaposada, & Arnau, 2002). A pHu below 5.56 in the SM before salting is associated with a pasty appearance and unpleasant flavor in dry-cured hams ready for consumption (GarcíaRey et al., 2004). In the WIWI and DUWI genetic groups, the surface of the SM was significantly lighter (P b 0.05) as compared to that in all other groups except the DUWI and DULL groups, both of which presented the same Göfo values (P N 0.05). The lowest Göfo values were observed in the DUDU and DULA pigs and did not differ from those of the DULL group (Table 4). The surface color intensity of chilled pork depends on the muscle pigment content of myoglobin and hemoglobin, as well as the relative proportion of deoxy (Mb or Hb), oxy (MbO2 or HbO2), and meta (MetMb or MetHb) in these pigments. The concentration of these pigments is higher in red muscle, which consists primarily of type I or ß fibers. Oxidation of these pigments, which depends on mitochondrial oxygen uptake and a decline in the post-mortem pH, interferes with surface lightness in freshly cut muscles (Hocquette et al., 1998). A greater decline in the pH results in increased paleness and, consequently, a reduction in Göfo values. According to Van Der Wal, Olsman, Garssen, and Engel (1992) and Jones, Tong, Campbell, and Dyck (1994), IMF content also affects the color readings on pig muscles. Invariably, a high IMF content yields higher lightness or L* values as displayed by Hunter and Minolta photometers, and lower values on the Göfo scale. However, an IMF content lower than 1.6% in the SM does not influence lightness values (Lindahl, Lundström, & Tornberg, 2001). It has also been shown that heme pigment content, especially that of myoglobin and its MetMb and MbO forms, represent the parameters that most contribute to color variations in pig muscles (Warriss, Brown, & Adams, 1990). The IMF content was significantly higher (P b 0.05) in the DUDU pigs compared to the other four genetic groups, but there was no gender effect (P N 0.05) for this trait (Table 4). On crossbred pigs, IMF is a trait which is frequently measured on fresh boneless loins due to its correlation with tenderness and flavor. In the manufacturing of dry-cured hams, IMF content variations of ham muscles are more relevant than the average IMF itself. Different amounts of IMF in ham muscles influence the flavor of the ham at the end of curing due to
Genetic groups DULA
1
GW (kg) TW2 (kg) EFT3 (mm) IFT4 (mm) pHu5 Göfo value6 IMF7 (%)
18.59 (0.21) 12.92b (0.15) 24.51 (1.00) 6.88 (0.68) 5.69 (0.02) 57.40 (0.74) 2.28 (0.11)
DUWI 19.07 (0.41) 13.12b (0.29) 22.38 (1.18) 6.05 (0.84) 5.65 (0.03) 55.59 (0.89) 2.26 (0.12)
Gender DULL 18.60 (0.21) 12.82b (0.15) 22.65 (1.03) 6.46 (0.91) 5.66 (0.03) 56.56 (0.72) 2.32 (0.11)
WIWI 19.76 (0.45) 13.88a (0.42) 19.68 (2.63) 5.11 (1.09) 5.68 (0.02) 56.87 (1.23) 2.25 (0.20)
Barrows b
18.43 (0.16) 12.82b (0.12) 24.31a (0.75) 7.67a (0.67) 5.66 (0.02) 55.92b (0.54) 2.37a (0.08)
Gilts 19.25a (0.23) 13.24a (0.17) 21.36b (0.97) 4.71b (0.36) 5.68 (0.02) 57.85a (0.64) 2.10b (0.09)
a, b Means within a row followed by a different letter are significantly different among genetic groups or gender (P b 0.05). ⁎ Least squared means. ⁎⁎ Standard Error. 1 Gross weight. 2 Trimmed weight. 3 External fat thickness. 4 Internal fat thickness. 5 pH 24 h post-mortem. 6 Ranging from 0 = pale to 100 = dark. 7 Intramuscular fat.
irregular absorption of salt and are accompanied by a pasty texture which is associated with excess fat in the ready-to-eat slices. A small variation in IMF indicates better salt diffusion during muscle curing, which results in uniform flavor throughout the finished hams.
3.3. Carcass characteristics at 160 kg HW Results of the carcass traits obtained from pigs harvested at 160 kg are shown in Table 5. There was no interaction between genetic groups or gender for any of the carcass characteristics. There was also no effect (P N 0.05) of gender or the genetic group on HCW. Genetic group and gender had a significant effect (P b 0.01) on both BT and LD. The BT was lower, and the LD was significantly higher (P b 0.01), in gilts as compared to barrows, demonstrating that even when harvested at very heavy weights, gilts still possess leaner carcasses. Among the different genetic groups, only the WIWI group demonstrated a significantly (P b 0.05) lower BT. No differences in LD were observed among the WIWI and DULL pigs, nor were any differences detected among the DULA, DUWI, and DULL groups. Increasing HW to 160 kg is an uncommon practice in the pork industry. The loss of efficiency during the finishing phase due to poor feed conversion as well as the carcass and primals excess fat contributes to the fact that the ideal HW rarely exceeds 130 kg. As a consequence, studies evaluating pork and carcass quality at 160 HW are typically performed when the production of dry-cured hams is involved. Sabbioni, Superchi, Sussi, and Bonomi (2002) investigated the linear increase of the Duroc breed at rates of 0, 25%, and 50% composition of Duroc × (Large White × Landrace) crosses that were harvested at a live weight of 171.06 kg. That study observed no effect of the proportion of Duroc genetics on HCW with respect to an HCW at 135.64 kg. A trend (P = 0.09) towards a reduction in ham weight was noticed with the increased proportion of the Duroc breed in the composition of the crosses. Conversely, Lo Fiego, Santoro, Macchioni, and De Leonibus (2005) demonstrated a significant increase in the GW of Large White × Landrace pigs harvested at 151.3 and 175.6 kg respectively.
J.V. Peloso et al. / Meat Science 86 (2010) 371–376
3.4. Ham quality traits at 160 kg HW Analysis of ham quality traits from pigs harvested at 160 kg (Table 6) also revealed no interaction between genetic group and gender on any of the traits studied. Despite the same HCW, gilts produced significantly (P b 0.01) heavier hams than barrows. There were also no significant (P N 0.05) differences for GW among the genetic groups. The TW of pigs harvested at 160 kg was higher in the WIWI group and in gilts (P b 0.05). IFT and EFT were also influenced by gender, with both measurements being significantly lower (P b 0.05) in gilts. No significant differences in IFT or EFT could be found among genetic groups. The EFT values in our study were slightly lower than those reported by Bochicchio et al. (2005) for Duroc × Large White pigs harvested at 170 kg. The pHu was not influenced by the gender nor genetic group, however a significant gender effect (P b 0.01) was found for Göfo values, representing a paler SM surface in barrows compared to gilts. In contrast to the findings of Schivazappa, Degni, Nanni Costa, Russo, Buttazzoni, and Virgili (2002), who found a significantly higher IMF in Duroc pigs compared to Landrace and Large White breeds harvested at 155.6 kg, IMF was not influenced by the genetic group (P N 0.05) in the present experiment. However, IMF was significantly higher (P b 0.05) in barrows than in gilts. According to Sabbioni et al. (2002), a 10% linear inclusion of the Duroc breed had no significant effect on pHu neither lightness of the SM in pigs harvested at 171 kg, whereas Schivazappa et al. (2002) shown a significantly higher pHu in the SM of the Landrace breed. Virgili et al. (2003) found a significant reduction in pHu when pigs harvested at 143.6 kg were compared to those harvested at 181.8 kg. The higher pHu in lighter and younger pigs might be a consequence of higher glycogen consumption during the pre-harvest period. In heavier and fatter carcasses, the suppression of heat transfer during conventional chilling favors prolonged anaerobic metabolism, which is associated with a rapid decrease in the post-mortem muscle pH (Virgili et al., 2003). The Duroc breed is well known to contribute to the increased proportion of fat in the hind leg destined for the production of drycured hams. In contrast, hams possessing high lean deposition demonstrate increased moisture and polyunsaturated fatty acid content, accompanied by a reduction in pH. These characteristics are undesirable for curing because of the susceptibility of fat to oxidation, rancid flavor, and increased muscle proteolysis (Virgili and Schivazappa, 2002). According to Sellier and Monin (1994), Duroc and Large White breeds are the most appropriate genotypes for dry-cured ham production, due to the frequency of the recessive Hal allele being nearly zero in these breeds, which favors ham muscles initial and ultimate pH to be close to 6.4 and 5.7, respectively. Russo and Costa (1995) confirmed these observations and demonstrated that the hind legs approved for dry-cured Parma™ ham presented an initial pH higher than 6.2, a pHu between 5.6 and 5.8, and drip loss below 3%. Moreover, muscles possessing a pHu below 5.5 should not be used for production of cured products because of their paleness and low curing yield (Russo & Costa, 1995). 4. Conclusions Among all genetic groups harvested at 130 kg HW, DUDU pigs presented the thickest fat layer in the ham and had an IMF of 3.15%. The high IMF probably affected the lightness, as measured by Göfo readings, thus revealing lighter color of the Semimembranosus muscle surface. The pHu values were adequate for dry-cured ham production, with similar values observed among all of the genetic groups. However, the use of purebred Durocs has its limitations in industrial production due to difficulties caused by dehairing at the slaughter-line. Apart from the Durocs, a second option within the genetic groups studied is the DULA group, which also produced appropriate ham traits, such as a low EFT and high IFT. With respect to IMF, this genetic group was close to meet
375
the specifications for the production of dry-cured hams. Ham grading before salting based on pHu and IMF will contribute to diminish the quality variations before the finished dry-cured ham pieces are dispatched to market.
Acknowledgements We thank the CNPq (National Council of Research and Development) and FAPEMIG (Minas Gerais State Research Foundation) for financial support.
References Aalhus, J. L., Jones, S. D. M., Robertson, W. M., Tong, A. K. W., & Sather, A. P. (1991). Growth characteristics and carcass composition of pigs with known genotypes for stress susceptibility over a weight range of 70 to 120 kg. Animal Production, 52, 347−353. Beattie, V. E., Weatherup, R. N., Moss, B. W., & Walker, N. (1999). The effect of increasing carcass weight of finishing boars and gilts on joint composition and meat quality. Meat Science, 52(2), 205−211. Blanchard, P. J., Ellis, M., Warkup, C. C., Chadwick, J. P., & Willis, M. B. (1999). The influence of sex (boars and gilts) on growth, carcass and pork eating quality characteristics. Animal Science, 68, 487−493. Blanchard, P. J., Warkup, C. C., Ellis, M., Willis, M. B., & Avery, P. (1999). The influence of the proportion of Duroc genes on growth, carcass and pork eating quality characteristics. Animal Science, 68, 495−501. Bochicchio, D., Faeti, V., Marchetto, G., Poletti, E., Maranesi, M., Mordenti, A. L., et al. (2005). Effect of feeding partially hydrogenated lard on trans-fatty acid content of muscle and backfat of heavy pigs. Meat Science, 71(4), 651−656. Čandek-Potokar, M., Monin, G., & Žlender, B. (2002). Pork quality, processing, and sensory characteristics of dry-cured hams as influenced by Duroc crossing and sex. Journal of Animal Science, 80(4), 988−996. Channon, H. A., Kerr, M. G., & Walker, P. J. (2004). Effect of Duroc content, sex and ageing period on meat and eating quality attributes of pork loin. Meat Science, 66(4), 881−888. Cilla, I., Altarriba, J., Guerrero, L., Gispert, M., Martínez, L., Moreno, C., et al. (2006). Effect of different Duroc line sires on carcass composition, meat quality and dry-cured ham acceptability. Meat Science, 72(2), 252−260. Cisneros, F., Ellis, M., McKeith, F. K., McCaw, J., & Fernando, R. L. (1996). Influence of slaughter weight on growth and carcass characteristics, commercial cutting and curing yields, and meat quality of barrows and gilts from two genotypes. Journal of Animal Science, 74(5), 925−933. Correa, J. A., Faucitano, L., Laforest, J. P., Rivest, J., Marcoux, M., & Gariépy, C. (2006). Effects of slaughter weight on carcass composition and meat quality in pigs of two different growth rates. Meat Science, 72(1), 91−99. García-Macías, J. A., Gispert, M., Oliver, M. A., Diestre, A., Alonso, P., Muñoz-Luna, A., et al. (1996). The effects of cross, slaughter weight and halothane genotype on leanness and meat and fat quality in pig carcasses. Animal Science, 63, 487−496. García-Rey, R. M., García-Garrido, J. A., Quiles-Zafra, R., Tapiador, J., & Luque De Castro, M. D. (2004). Relationship between pH before salting and dry-cured ham quality. Meat Science, 67(4), 625−632. Gou, P., Comaposada, J., & Arnau, J. (2002). Meat pH and meat fibre direction effects on moisture diffusion in salted ham muscles dried at 5 °C. Meat Science, 61(1), 25−31. Hambrecht, E., Eissen, J. J., & Verstegen, M. W. A. (2003). Effect of processing plant on pork quality. Meat Science, 64(2), 125−131. Hocquette, J. -F., Ortigues-Marty, I., Pethick, D., Herpin, P., & Fernandez, X. (1998). Nutritional and hormonal regulation of energy metabolism in skeletal muscles of meat-producing animals. Livestock Production Science, 56(2), 115−143. ISO 1444 (1973). Determination of free fat content in meat and meat products. Geneva: International Organization for Standardization. Jones, S. D. M., Tong, A. K. W., Campbell, C., & Dyck, R. (1994). The effects of fat thickness and degree of marbling on pork colour and structure. Canadian Journal of Animal Science, 74(1), 155−157. Latorre, M. A., Lázaro, R., Gracia, M. I., Nieto, M., & Mateos, G. G. (2003). Effect of sex and terminal sire genotype on performance, carcass characteristics, and meat quality of pigs slaughtered at 117 kg body weight. Meat Science, 65(4), 1369−1377. Latorre, M. A., Lázaro, R., Valencia, D. G., Medel, P., & Mateos, G. G. (2004). The effects of gender and slaughter weight on the growth performance, carcass traits, and meat quality characteristics of heavy pigs. Journal of Animal Science, 82(2), 526−533. Latorre, M. A., Medel, P., Fuentetaja, A., Lázaro, R., & Mateos, G. G. (2003). Effect of gender, terminal sire line and age at slaughter on performance, carcass characteristics and meat quality of heavy pigs. Animal Science, 77, 33−45. Lebret, B., Juin, H., Noblet, J., & Bonneau, M. (2001). The effects of two methods of increasing age at slaughter on carcass and muscle traits and meat sensory quality in pigs. Animal Science, 72, 87−94. Lindahl, G., Lundström, K., & Tornberg, E. (2001). Contribution of pigment content, myoglobin forms and internal reflectance to the colour of pork loin and ham from pure breed pigs. Meat Science, 59(2), 141−151. Lo Fiego, D. P., Santoro, P., Macchioni, P., & De Leonibus, E. (2005). Influence of genetic type, live weight at slaughter and carcass fatness on fatty acid composition of subcutaneous adipose tissue of raw ham in the heavy pig. Meat Science, 69(1), 107−114.
376
J.V. Peloso et al. / Meat Science 86 (2010) 371–376
Lovato, P. A., Vielmo, H., Oliveira, V., Hauschild, L., Antocheviez, R. F., Carvalho, A. A., et al. (2006). Características de carcaças de suínos alimentados do desmame ao abate em comedouro de acesso único equipado ou não com bebedouro. Ciência Rural, 36(1), 229−233. Ruiz-Carrascal, J., Ventanas, J., Cava, R., Andrés, A. I., & Garcia, C. (2000). Texture and appearance of dry cured ham as affected by fat content and fatty acid composition. Food Research International, 33(2), 91−95. Russo, V., & Costa, L. N. (1995). Suitability of pig meat for salting and the production of quality processed products. Pig News and Information, 16(1), 17N−26N. Ryu, Y. C., & Kim, B. C. (2005). The relationship between muscle fiber characteristics, postmortem metabolic rate, and meat quality of pig longissimus dorsi muscle. Meat Science, 71(2), 351−357. Sabbioni, A., Beretti, V., Zanon, A., Superchi, P., Sussi, C., & Bonomi, A. (2004). Effect of the proportion of Duroc genes in crosses with Large White and Landrace pigs on the characteristics of seasoned Parma ham. Italian Journal of Animal Science, 3, 31−39. Sabbioni, A., Superchi, P., Sussi, C., & Bonomi, A. (2002). Effect of Duroc genes proportion on growth performance and on carcass and meat quality characteristics in heavy pigs. Italian Journal of Animal Science, 1, 17−24. SAS for Windows release 9.1. SAS Institute. Cary, North Caroline, USA, 2002–2003. Sather, A. P., Jones, S. D. M., Tong, A. K. W., & Murray, A. C. (1991). Halothane genotype by weight interactions on pig meat quality. Canadian Journal of Animal Science, 71(3), 645−658. Schivazappa, C., Degni, M., Nanni Costa, L., Russo, V., Buttazzoni, L., & Virgili, R. (2002). Analysis of raw meat to predict proteolysis in Parma ham. Meat Science, 60(1), 77−83.
Sellier, P., & Monin, G. (1994). Genetics of pig meat quality: A review. Journal of Muscle Foods, 5(2), 187−219. Stoller, G. M., Zerby, H. N., Moeller, S. J., Baas, T. J., Johnson, C., & Watkins, L. E. (2003). The effect of feeding ractopamine (Paylean) on muscle quality and sensory characteristics in three diverse genetic lines of swine. Journal of Animal Science, 81(6), 1508−1516. Van Der Wal, P. G., Olsman, W. J., Garssen, G. J., & Engel, B. (1992). Marbling, intramuscular fat and meat colour of Dutch pork. Meat Science, 32(3), 351−355. Van Oeckel, M. J., Warnants, N., & Boucqué, Ch. V. (1999). Measurement and prediction of pork colour. Meat Science, 52(4), 347−354. Virgili, R., Degni, M., Schivazappa, C., Faeti, V., Poletti, E., Marchetto, G., et al. (2003). Effect of age at slaughter on carcass traits and meat quality of Italian heavy pigs. Journal of Animal Science, 81(10), 2448−2456. Virgili, R., & Schivazappa, C. (2002). Muscle traits for long matured dried meats. Meat Science, 62(3), 331−343. Warriss, P. D., Brown, S. N., & Adams, S. J. M. (1990). Variation in haem pigment concentration and colour in meat from British pigs. Meat Science, 28(4), 321−329. Weatherup, R. N., Beattie, V. E., Moss, B. W., Kilpatrick, D. J., & Walker, N. (1998). The effect of increasing slaughter weight on the production performance and meat quality of finishing pigs. Animal Science, 67, 591−600. Wood, J. D., Nute, G. R., Richardson, R. I., Whittington, F. M., Southwood, O., Plastow, G., et al. (2004). Effects of breed, diet and muscle on fat deposition and eating quality in pigs. Meat Science, 67(4), 651−667.
Contents lists available at ScienceDirect
Meat Science j o u r n a l h o m e p a g e : w w w. e l s ev i e r. c o m / l o c a t e / m e a t s c i
Carcass and ham quality characteristics of heavy pigs from different genetic groups intended for the production of dry-cured hams J.V. Peloso a, P.S. Lopes a,⁎, L.A.M. Gomide b, S.E.F. Guimarães a, P.L.S. Carneiro c a b c
Departamento de Zootecnia, Universidade Federal de Viçosa, 36570-000, Viçosa, MG, Brazil Departamento de Tecnologia de Alimentos, Universidade Federal de Viçosa, 36570-000, Viçosa, MG, Brazil Departamento de Ciências Biológicas, Universidade Estadual do Sudoeste da Bahia, 45200-000, Jequié, BA, Brazil
a r t i c l e
i n f o
Article history: Received 4 July 2009 Received in revised form 10 November 2009 Accepted 14 May 2010 Keywords: Pig Carcass characteristics Meat quality Dry-cured ham Duroc
a b s t r a c t Carcass and ham quality characteristics of pig populations divided by harvest weights — HW (130 and 160 kg) were evaluated to determine the effects of gender (barrows and gilts) and distinct genetic groups — purebred (DUDU) and crossbred Duroc (DULA, DUWI and DULL) as well as purebred Large White (WIWI) on the suitability for use in dry-cured ham production. At 130 kg, DUDU pigs yielded the highest fat thickness of the ham (P b 0.01) and an intramuscular fat content (IMF) of 3.15% in Semimembranosus muscle (SM). DUDU pigs also had a SM pHu of 5.7. This genetic group met the specifications for dry-cured ham production. No differences could be found in meat quality characteristics between genetic groups harvested at 160 kg. However at this HW, gilts produced significantly (P b 0.05) heavier and leaner hams compared to barrows. © 2010 The American Meat Science Association. Published by Elsevier Ltd. All rights reserved.
1. Introduction The pork industry in Brazil, as in other pig meat-producing countries, comprises a wide variety of product options at the retail case, ranging from unprocessed chilled or frozen cuts to ready-to-eat processed products. In order to meet the raw material quality required by packers, pig breeders are moving towards specific genetic backgrounds, nutritional standards, and harvest weights. For instance, according to Brazilian manufactures, pigs and their respective genotypes destined for dry-cured ham production shall yield hind legs with a 25 mm fat cover and an intramuscular fat (IMF) content greater than 2.5%. The relationship between the IMF content and the quality of the final product is frequently investigated in dry-cured hams due to its correlation with tenderness, juiciness, flavor, and aroma (Ruiz-Carrascal, Ventanas, Cava, Andrés, & Garcia, 2000; Russo & Costa, 1995). Furthermore, ham shall meet quality criteria, such as a final pH greater than 5.55 in the Semimembranosus muscle, in order to avoid the occurrence of pale, soft, and exudative (PSE) pork (GarcíaRey, García-Garrido, Quiles-Zafra, Tapiador, & Luque De Castro, 2004). The respect of these criteria helps protect the product against excessive dehydration, resulting in higher capacity of meat to absorb salt and spices during the drying and ripening processes. Increasing weight at harvest has been proposed to reduce operational costs in the pork production chain, especially in packing
⁎ Corresponding author. Tel.: + 55 31 3899 3319; fax: + 55 31 3899 2275. E-mail address: [email protected] (P.S. Lopes).
plants (Lebret, Juin, Noblet, & Bonneau, 2001; Weatherup, Beattie, Moss, Kilpatrick, & Walker, 1998). At the same time, harvest of heavier pigs is indicated when these animals are destined for the production of dry-cured hams (Latorre, Lázaro, Valencia, Medel, & Mateos, 2004; Virgili et al., 2003). Different genetic groups of pigs have been used to obtain fresh hams with ideal quality traits and the use of the Duroc breed and, in particular, its crossbreds often satisfies both muscle and fat quality criteria for dry-ham processing (Cilla et al., 2006; Sabbioni et al., 2004). The objective of the present study was to evaluate carcass and meat quality traits from five distinct pig genetic groups at two different harvest weights. Furthermore, this study aimed to define which group would better fulfill the specifications of the raw material for industrial processing of dry-cured hams in the Brazilian and in exporting markets.
2. Materials and methods 2.1. Experimental population A total of 1106 pigs of five genotypes (Duroc × Duroc — DUDU, Duroc × Landrace — DULA, Duroc × Large White — DUWI, Duroc × Landrace × Large White — DULL, and Large White × Large White — WIWI) and two genders (barrows and gilts) were distributed into two harvest weights (HW) (130 and 160 kg) (Table 1). The DUDU genetic group with 160 kg HW was not tested because it is inappropriate for industrial use due to its low feed efficiency on the farm, excess fat on the carcass, as well as occurrence of deep seated hair on the hams.
0309-1740/$ – see front matter © 2010 The American Meat Science Association. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.meatsci.2010.05.017
372
J.V. Peloso et al. / Meat Science 86 (2010) 371–376
Table 1 Number of pigs used in each genetic group and gender by harvest weight. Genetic group and gender by harvest weight
Number of pigs
DUDU — ♂ Duroc × ♀ Duroc — B — 130 kg DUDU — ♂ Duroc × ♀ Duroc — G — 130 kg DULL — ♂ Duroc × ♀ (Lan × LW) — B — 130 kg DULL — ♂ Duroc × ♀ (Lan × LW) — G — 130 kg DULA — ♂ Duroc × ♀ Landrace (Lan) — B — 130 kg DULA — ♂ Duroc × ♀ Landrace (Lan) — G — 130 kg DUWI — ♂ Duroc × ♀ Large White (LW) — B — 130 kg DUWI — ♂ Duroc × ♀ Large White (LW) — G — 130 kg WIWI — ♂ Large White × ♀ Large White — B — 130 kg WIWI — ♂ Large White × ♀ Large White — G — 130 kg DULL — ♂ Duroc × ♀ (Lan × LW) — B — 160 kg DULL — ♂ Duroc × ♀ (Lan × LW) — G — 160 kg DULA — ♂ Duroc × ♀ Landrace (Lan) — B — 160 kg DULA — ♂ Duroc × ♀ Landrace (Lan) — G — 160 kg DUWI — ♂ Duroc × ♀ Large White (LW) — B — 160 kg DUWI — ♂ Duroc × ♀ Large White (LW) — G — 160 kg WIWI — ♂ Large White × ♀ Large White — B — 160 kg WIWI — ♂ Large White × ♀ Large White — G — 160 kg
78 72 117 86 130 110 100 62 40 48 60 30 64 30 40 22 20 12
B = barrow; G = gilt.
For production of the DUDU, DULA, DUWI, and DULL genetic groups, seven Duroc boars were mated with 28 Durocs, 43 Landraces, 44 Large Whites, and 44 Landrace × Large Whites sows, respectively. The WIWI genetic group was produced by mating 28 Large Whites sows with eight Large White boars. Pigs were raised at a multiplier farm belonging to a vertical integrator (pig breeding and processing company) located in the Western part of the state of Santa Catarina in Southern Brazil. After weaning at 28 days of age at an average weight of 6.5 kg, the piglets were transferred weekly in batches of 20 to the nursery and growing barns and separated based on their genetic group into pens of mixed gender. The animals remained inside these facilities until they reached 83 days of age and a mean weight of 48.3 kg. The pigs were then transferred to the finishing barns. During finishing, the pigs were separated by gender into the different genetic groups and were kept in groups of 5 to 8 pigs at a density of 1.1 m2/pig per pen. All groups no matter what targeted harvest weight was, were fed ad libitum a diet of the same formulation during the first six weeks of finishing (Table 2). After this period, the group harvested at 130 kg HW was fed a second diet ad libitum (Table 2) for the remaining five and a half weeks until harvest, whereas the group harvested at 160 kg HW was fed the same second diet ad libitum for the remaining eleven weeks until harvest. The 130 kg targeted HW was reached on average at 163 days after birth, whereas the 160 kg targeted HW was reached at 202 days. Pigs were individually weighed after a 14 h on-farm fasting period. An additional 6 h fasting time occurred during transportation and lairage. Twenty-five consecutive harvests were performed (two harvests per week), in order to collect all experimental data.
level, without the use of electric prods or mixing. After electrical stunning (700 Volts, 1.25 Amperes), exsanguination and evisceration, hot carcasses were weighed head-off (HCW), and both back fat thickness (BT) and loin depth (LD) were measured using the UF 300 ultrasound grading probe (SFK Technology Inc., Herlev, Denmark) at the 10th thoracic vertebra level. Carcasses were chilled overnight at 1 °C. 2.3. Ham fabrication and quality data collection On the day after harvest, the carcasses were cut into four primals: ham, shoulder, loin, and belly. Hams were weighed and sent to the trimming room, where the fat cover of the Semimembranosus muscle (SM) (referred to as the internal fat thickness or IFT) and the fat cover of the Biceps femoris muscle (referred to as the external fat thickness or EFT) were measured using a digital caliper (Absolute™ Digimatic Series 500, Mitutoyo Co., Kanagawa, Japan). Each ham was trimmed to the standard shape required for the curing process. After trimming, hams were reweighed, and meat quality was assessed in the SM by measuring pH at 24 h (pHu) post-mortem using a pH meter fitted with a DXK-S7/25 spear-type electrode and an automatic temperature compensation probe (Mettler Toledo, MP 120 pH Meter, Schwerzenbach, Switzerland). The objective surface light reflectance (color) of the SM was also evaluated 24 h after harvest using the Opto Star™ probe (SFK Technology Inc., Herlev, Denmark) on the Göfo scale ranging from 0 to 100, where 0 = pale and 100 = dark (Van Oeckel, Warnants, & Boucqué, 1999). Before the hams were sent to salting and dehydration in the ripening chambers, 143 and 212 samples belonging respectively to the 130 kg and 160 kg HW groups were taken from the middle of SM, vacuum packed and stored at −25 °C until the extractable lipid analysis (IMF) was conducted using the Soxhlet procedure with petroleum ether (ISO 1444, 1973). 2.4. Statistical analysis To determine the effects of genetic group and gender on carcass and ham quality traits, the General Linear Model (GLM) of the Statistical Analysis System program for Windows (SAS® Institute, 2002–2003), version 9.1, was used. Analysis of variance was performed for each live weight (130 or 160 kg) using the following model: yijk = μ + GGi + SEj + GGxSEij + eijk where: observed value of the trait; mean; genetic group (i = DUDU, DULA, DUWI, DULL or WIWI); gender (j = barrow or gilt); interaction between genetic group and gender; random error associated with each observation.
2.2. Harvest and carcass grading
yijk µ GGi SEj GGxSEij eijk
Animals were harvested following the standard operational procedures of the plant, where pre-slaughter stress was kept to a minimum
Means were compared using the Student–Newman–Keuls (SNK) test at a level of significance of P b 0.05.
Table 2 Composition of experimental diets used during the finishing phase. Nutritional levels
During the first six weeks
After the first six weeks
Digestible energy (kcal/kg) Crude protein (%) Calcium (%) Phosphorus (%) Lysine (%) Methionine (%) Threonine (%) Tryptophan (%)
3400 16.00 0.70 0.30 0.90 0.27 0.59 0.16
3400 14.50 0.65 0.25 0.70 0.21 0.46 0.13
3. Results and discussion 3.1. Carcass characteristics at 130 kg HW None of the carcass traits studied were affected by interactions between genetic group and gender at this HW. While HCW, BT, and LD differed between the genetic groups, only BT and LD differed between barrows and gilts, whereas HCW was not affected by gender (Table 3). DUDU pigs exhibited the highest BT together with the lowest HCW (P b 0.05), indicating that these pigs had the lightest and fattest carcasses among genetic groups. In contrast, the carcasses of the WIWI
J.V. Peloso et al. / Meat Science 86 (2010) 371–376 Table 3 Carcass quality traits LSM⁎ of pigs harvested at 130 kg (SE⁎⁎ in parentheses). Carcass traits 1
HCW (kg) 2
BT (mm) LD3 (mm)
Genetic groups DUDU b
93.74 (0.44) 20.87a (0.46) 55.30b (0.57)
Gender
DULA ab
95.00 (0.41) 18.71b (0.34) 55.51b (0.48)
DUWI a
95.70 (0.49) 19.17b (0.43) 56.04b (0.55)
DULL
WIWI ab
95.14 (0.49) 18.30b (0.40) 56.73b (0.50)
a
96.40 (0.66) 15.93c (0.46) 59.31a (0.68)
Barrows
Gilts
94.91 (0.30) 20.06a (0.26) 55.21b (0.34)
95.19 (0.31) 17.46b (0.28) 57.47a (0.35)
a, b, c
Means within a row followed by a different letter are significantly different among genetic groups or gender (P b 0.05). ⁎ Least square means. ⁎⁎ Standard error. 1 Hot carcass weight. 2 Back fat thickness. 3 Loin muscle depth.
pigs were heavier and, at the same time, exhibited the lowest BT and highest LD in comparison to the other genetic groups. The lower BT observed in the Large White compared to Duroc pigs has been reported by others (Blanchard, Warkup, Ellis, Willis, & Avery, 1999b; Channon, Kerr, & Walker, 2004). In agreement with our study, Stoller, Zerby, Moeller, Baas, Johnson, and Watkins (2003) observed higher BT values in a group composed of 100% Duroc genetics as compared to Landrace × Large White crosses, with a mean HCW of 83 kg. Wood et al. (2004) did not observe significant differences in HCW or BT between Duroc and Large White boars harvested at 86 kg. Channon et al. (2004) also did not observe significant differences in HCW or BT between crosses of 100% Duroc, 50% Duroc × Large White, and 100% Large White when harvested at 157 days of age. In contrast to the present results, Čandek-Potokar, Monin, and Žlender (2002) demonstrated that inclusion of Duroc genetics in crosses with Large White and Landrace pigs harvested at 209 days significantly increased the HCW, with heavier carcasses in barrows compared to gilts. Conversely, Blanchard, Ellis, Warkup, Chadwick, and Willis (1999a) reported that inclusion of 50% Duroc genetics did not alter the final HW when compared to Large White × Landrace crosses without Duroc genetics. In the present work, gilts produced leaner carcasses (P b 0.01) than barrows, as demonstrated by the lower BT and higher LD, with no significant difference (P N 0.05) in HCW (Table 3). These results are in agreement with the findings of Lovato et al. (2006), who described a lower BT in gilts as compared to barrows in Duroc × (Large White × Landrace) crosses. In the swine industry, the methods most frequently used to alter the meat/fat ratio of carcasses are altering the HW and modifying the diet and/or feeding strategies. Increasing HW, and consequently HCW, enhances BT (Beattie, Weatherup, Moss, & Walker, 1999; Blanchard et al., 1999) as well as fat content in the ham, shoulder, loin, and belly (Aalhus, Jones, Robertson, Tong, & Sather, 1991; Correa et al., 2006), thus decreasing the meat/fat ratio in the carcass as a whole (Weatherup et al., 1998).
373
groups. These results differ from the findings of Latorre et al. (2004), who reported the same GW for gilts and barrows with a HCW of 97.1 kg. In contrast to the findings of Cisneros et al. (1996) and Latorre, Lázaro, Gracia, Nieto, and Mateos (2003a), trimmed ham weight (TW) observed in our study was greater (P b 0.05) in gilts than in barrows. Among the genetic groups, WIWI pigs differed from the other genotypes as they produced heavier (P b 0.05) trimmed hams. As expected, DUDU pigs exhibited a significantly higher (P b 0.01) EFT when compared to the other genetic groups. DULA pigs displayed the second highest EFT, which was significantly different (P b 0.01) from DUWI pigs, which had the lowest EFT among all of the genetic groups. In the study of Latorre et al. (2003a), no differences in EFT were found among groups consisting of 50%, 25%, and 0% Duroc genetics with a HW of 129 kg. EFT was significantly lower (P b 0.05) in gilts in comparison to barrows. Similar results have been reported by Latorre, Medel, Fuentetaja, Lázaro, and Mateos (2003b), Latorre et al. (2003a) and Latorre et al. (2004) for pigs harvested at 133 kg. Correa et al. (2006) also found significantly lower EFT in Duroc × (Landrace × Large White) gilts as compared to barrows harvested at 125 kg. No genetic group effect (P N 0.05) on IFT was detected, but IFT was significantly higher (P b 0.05) in barrows than in gilts in the present experiment. These results confirm that gilts have the ability to produce significantly leaner hams compared to barrows at a heavier HW. However, for the production of dry-cured ham, a thicker fat cover is desired. Both EFT and IFT play a relevant role during the long aging period, as they provide protection for the muscles from excessive dehydration that could lead to disproportionate shrinkage of the ham pieces. There was no effect of gender on either pHu or Göfo values, while the genetic group had a significant effect (P b 0.05) on Göfo values. Čandek-Potokar et al. (2002) also found no significant differences in the pHu of SM between crossbred Duroc × Landrace barrows and gilts. However, consistently higher pHu were shown in the SM of barrows as compared to gilts harvested at 116, 124, and 133 kg by Latorre et al. (2003a,b) and Latorre et al. (2004). The results of Latorre et al. (2004) also revealed higher pHu than those observed in the present study for both genders (Table 4). Other studies have also found no differences in pHu of the SM of barrows compared to gilts in carcasses of 86.2 kg Table 4 Ham quality traits LSM⁎ of pigs harvested at 130 kg (SE⁎⁎ in parentheses). Ham traits
GW1 (kg) TW2 (kg) EFT3 (mm) IFT4 (mm) pHu5
3.2. Ham quality traits at 130 kg HW
Göfo value6
Ham quality traits obtained from pigs harvested at 130 kg are shown in Table 4. There were also no interactions between genetic group and gender for these traits. Gross weight (GW) was significantly higher (P b 0.05) in WIWI pigs as compared to the other genetic groups. In addition, GW was lower in DUDU pigs, but did not significantly differ between the DULA and DULL groups. Despite the same HCW, gilts produced significantly (P b 0.05) heavier hams than barrows. When comparing crosses with 0 and 25% Duroc genetics, with HCW close to that of the present experiment, Cisneros, Ellis, McKeith, McCaw, and Fernando (1996) observed a higher GW in gilts as compared to barrows, without any differences among the genetic
IMF7 (%) a, b, c
Genetic groups
Gender
DUDU
DULA
DUWI
DULL
WIWI
Barrows
Gilts
14.90c (0.08) 10.69b (0.06) 29.86a (0.99) 4.55 (0.34) 5.59 (0.02) 54.47c (0.54) 3.15a (0.25)
15.16bc (0.07) 10.80b (0.05) 26.67b (0.83) 4.52 (0.26) 5.55 (0.01) 54.23c (0.36) 1.93b (0.15)
15.32b (0.11) 10.95b (0.09) 23.68c (1.14) 4.82 (0.57) 5.59 (0.02) 56.81ab (0.65) 2.09b (0.12)
15.20bc (0.08) 10.79b (0.08) 25.95bc (0.85) 4.26 (0.27) 5.58 (0.02) 55.40bc (0.66) 1.85b (0.23)
15.96a (0.14) 11.31a (0.10) 24.30bc (1.59) 3.95 (0.44) 5.58 (0.02) 58.23a (1.02) 1.81b (0.15)
15.09b (0.05) 10.70b (0.04) 28.29a (0.60) 5.36a (0.25) 5.58 (0.01) 55.00 (0.39) 2.32 (0.13)
15.34a (0.07) 11.01a (0.05) 24.25b (0.67) 3.28b (0.12) 5.57 (0.01) 56.68 (0.36) 2.02 (0.12)
Means within a row followed by a different letter are significantly different among genetic groups or gender (P b 0.05). ⁎ Least squared means. ⁎⁎ Standard error. 1 Gross weight. 2 Trimmed weight. 3 External fat thickness. 4 Internal fat thickness. 5 pH 24 h post-mortem. 6 Ranging from 0 = pale to 100 = dark. 7 Intramuscular fat.
374
J.V. Peloso et al. / Meat Science 86 (2010) 371–376
Table 5 Carcass quality traits LSM⁎ of pigs harvested at 160 kg (SE⁎⁎ in parentheses). Carcass traits 1
HCW (kg) BT2 (mm) LD3 (mm)
Genetic groups DULA 116.74 (0.68) 23.93a (0.58) 53.27b (0.57)
DUWI 115.41 (0.79) 24.61a (0.78) 52.70b (0.73)
Gender DULL 116.40 (0.65) 22.78a (0.57) 54.82ab (0.62)
WIWI 114.87 (1.61) 19.72b (0.95) 56.81a (1.06)
Barrows 116.20 (0.47) 24.89a (0.45) 52.59b (0.43)
Table 6 Ham quality traits LSM⁎ of pigs harvested at 160 kg (SE⁎⁎ in parentheses). Ham traits
Gilts 116.00 (0.73) 20.45b (0.45) 56.51a (0.52)
a, b
Means within a row followed by a different letter are significantly different among genetic groups or gender (P b 0.05). ⁎ Least squared means. ⁎⁎ Standard error. 1 Hot carcass weight. 2 Back fat thickness. 3 Loin muscle depth.
(García-Macías et al., 1996; Lebret et al., 2001; Sather, Jones, Tong, & Murray, 1991) and 98.5 kg (Cisneros et al., 1996). The pHu measured in chilled pig meat is largely determined by the effects of harvest day (Hambrecht, Eissen, & Verstegen, 2003), interaction between muscle energy stores at the time of harvest and the RYR1 and PRKAG3 genes (Hocquette, Ortigues-Marty, Pethick, Herpin, & Fernandez, 1998) as well as the predominant fiber type present in the muscle (Ryu & Kim, 2005). The importance of pHu in dry-cured ham production is twofold. At the beginning of processing, pHu affects curing by interfering with the diffusion of moisture after salting. At the end of processing, pHu influences the flavor and texture of finished hams (Gou, Comaposada, & Arnau, 2002). A pHu below 5.56 in the SM before salting is associated with a pasty appearance and unpleasant flavor in dry-cured hams ready for consumption (GarcíaRey et al., 2004). In the WIWI and DUWI genetic groups, the surface of the SM was significantly lighter (P b 0.05) as compared to that in all other groups except the DUWI and DULL groups, both of which presented the same Göfo values (P N 0.05). The lowest Göfo values were observed in the DUDU and DULA pigs and did not differ from those of the DULL group (Table 4). The surface color intensity of chilled pork depends on the muscle pigment content of myoglobin and hemoglobin, as well as the relative proportion of deoxy (Mb or Hb), oxy (MbO2 or HbO2), and meta (MetMb or MetHb) in these pigments. The concentration of these pigments is higher in red muscle, which consists primarily of type I or ß fibers. Oxidation of these pigments, which depends on mitochondrial oxygen uptake and a decline in the post-mortem pH, interferes with surface lightness in freshly cut muscles (Hocquette et al., 1998). A greater decline in the pH results in increased paleness and, consequently, a reduction in Göfo values. According to Van Der Wal, Olsman, Garssen, and Engel (1992) and Jones, Tong, Campbell, and Dyck (1994), IMF content also affects the color readings on pig muscles. Invariably, a high IMF content yields higher lightness or L* values as displayed by Hunter and Minolta photometers, and lower values on the Göfo scale. However, an IMF content lower than 1.6% in the SM does not influence lightness values (Lindahl, Lundström, & Tornberg, 2001). It has also been shown that heme pigment content, especially that of myoglobin and its MetMb and MbO forms, represent the parameters that most contribute to color variations in pig muscles (Warriss, Brown, & Adams, 1990). The IMF content was significantly higher (P b 0.05) in the DUDU pigs compared to the other four genetic groups, but there was no gender effect (P N 0.05) for this trait (Table 4). On crossbred pigs, IMF is a trait which is frequently measured on fresh boneless loins due to its correlation with tenderness and flavor. In the manufacturing of dry-cured hams, IMF content variations of ham muscles are more relevant than the average IMF itself. Different amounts of IMF in ham muscles influence the flavor of the ham at the end of curing due to
Genetic groups DULA
1
GW (kg) TW2 (kg) EFT3 (mm) IFT4 (mm) pHu5 Göfo value6 IMF7 (%)
18.59 (0.21) 12.92b (0.15) 24.51 (1.00) 6.88 (0.68) 5.69 (0.02) 57.40 (0.74) 2.28 (0.11)
DUWI 19.07 (0.41) 13.12b (0.29) 22.38 (1.18) 6.05 (0.84) 5.65 (0.03) 55.59 (0.89) 2.26 (0.12)
Gender DULL 18.60 (0.21) 12.82b (0.15) 22.65 (1.03) 6.46 (0.91) 5.66 (0.03) 56.56 (0.72) 2.32 (0.11)
WIWI 19.76 (0.45) 13.88a (0.42) 19.68 (2.63) 5.11 (1.09) 5.68 (0.02) 56.87 (1.23) 2.25 (0.20)
Barrows b
18.43 (0.16) 12.82b (0.12) 24.31a (0.75) 7.67a (0.67) 5.66 (0.02) 55.92b (0.54) 2.37a (0.08)
Gilts 19.25a (0.23) 13.24a (0.17) 21.36b (0.97) 4.71b (0.36) 5.68 (0.02) 57.85a (0.64) 2.10b (0.09)
a, b Means within a row followed by a different letter are significantly different among genetic groups or gender (P b 0.05). ⁎ Least squared means. ⁎⁎ Standard Error. 1 Gross weight. 2 Trimmed weight. 3 External fat thickness. 4 Internal fat thickness. 5 pH 24 h post-mortem. 6 Ranging from 0 = pale to 100 = dark. 7 Intramuscular fat.
irregular absorption of salt and are accompanied by a pasty texture which is associated with excess fat in the ready-to-eat slices. A small variation in IMF indicates better salt diffusion during muscle curing, which results in uniform flavor throughout the finished hams.
3.3. Carcass characteristics at 160 kg HW Results of the carcass traits obtained from pigs harvested at 160 kg are shown in Table 5. There was no interaction between genetic groups or gender for any of the carcass characteristics. There was also no effect (P N 0.05) of gender or the genetic group on HCW. Genetic group and gender had a significant effect (P b 0.01) on both BT and LD. The BT was lower, and the LD was significantly higher (P b 0.01), in gilts as compared to barrows, demonstrating that even when harvested at very heavy weights, gilts still possess leaner carcasses. Among the different genetic groups, only the WIWI group demonstrated a significantly (P b 0.05) lower BT. No differences in LD were observed among the WIWI and DULL pigs, nor were any differences detected among the DULA, DUWI, and DULL groups. Increasing HW to 160 kg is an uncommon practice in the pork industry. The loss of efficiency during the finishing phase due to poor feed conversion as well as the carcass and primals excess fat contributes to the fact that the ideal HW rarely exceeds 130 kg. As a consequence, studies evaluating pork and carcass quality at 160 HW are typically performed when the production of dry-cured hams is involved. Sabbioni, Superchi, Sussi, and Bonomi (2002) investigated the linear increase of the Duroc breed at rates of 0, 25%, and 50% composition of Duroc × (Large White × Landrace) crosses that were harvested at a live weight of 171.06 kg. That study observed no effect of the proportion of Duroc genetics on HCW with respect to an HCW at 135.64 kg. A trend (P = 0.09) towards a reduction in ham weight was noticed with the increased proportion of the Duroc breed in the composition of the crosses. Conversely, Lo Fiego, Santoro, Macchioni, and De Leonibus (2005) demonstrated a significant increase in the GW of Large White × Landrace pigs harvested at 151.3 and 175.6 kg respectively.
J.V. Peloso et al. / Meat Science 86 (2010) 371–376
3.4. Ham quality traits at 160 kg HW Analysis of ham quality traits from pigs harvested at 160 kg (Table 6) also revealed no interaction between genetic group and gender on any of the traits studied. Despite the same HCW, gilts produced significantly (P b 0.01) heavier hams than barrows. There were also no significant (P N 0.05) differences for GW among the genetic groups. The TW of pigs harvested at 160 kg was higher in the WIWI group and in gilts (P b 0.05). IFT and EFT were also influenced by gender, with both measurements being significantly lower (P b 0.05) in gilts. No significant differences in IFT or EFT could be found among genetic groups. The EFT values in our study were slightly lower than those reported by Bochicchio et al. (2005) for Duroc × Large White pigs harvested at 170 kg. The pHu was not influenced by the gender nor genetic group, however a significant gender effect (P b 0.01) was found for Göfo values, representing a paler SM surface in barrows compared to gilts. In contrast to the findings of Schivazappa, Degni, Nanni Costa, Russo, Buttazzoni, and Virgili (2002), who found a significantly higher IMF in Duroc pigs compared to Landrace and Large White breeds harvested at 155.6 kg, IMF was not influenced by the genetic group (P N 0.05) in the present experiment. However, IMF was significantly higher (P b 0.05) in barrows than in gilts. According to Sabbioni et al. (2002), a 10% linear inclusion of the Duroc breed had no significant effect on pHu neither lightness of the SM in pigs harvested at 171 kg, whereas Schivazappa et al. (2002) shown a significantly higher pHu in the SM of the Landrace breed. Virgili et al. (2003) found a significant reduction in pHu when pigs harvested at 143.6 kg were compared to those harvested at 181.8 kg. The higher pHu in lighter and younger pigs might be a consequence of higher glycogen consumption during the pre-harvest period. In heavier and fatter carcasses, the suppression of heat transfer during conventional chilling favors prolonged anaerobic metabolism, which is associated with a rapid decrease in the post-mortem muscle pH (Virgili et al., 2003). The Duroc breed is well known to contribute to the increased proportion of fat in the hind leg destined for the production of drycured hams. In contrast, hams possessing high lean deposition demonstrate increased moisture and polyunsaturated fatty acid content, accompanied by a reduction in pH. These characteristics are undesirable for curing because of the susceptibility of fat to oxidation, rancid flavor, and increased muscle proteolysis (Virgili and Schivazappa, 2002). According to Sellier and Monin (1994), Duroc and Large White breeds are the most appropriate genotypes for dry-cured ham production, due to the frequency of the recessive Hal allele being nearly zero in these breeds, which favors ham muscles initial and ultimate pH to be close to 6.4 and 5.7, respectively. Russo and Costa (1995) confirmed these observations and demonstrated that the hind legs approved for dry-cured Parma™ ham presented an initial pH higher than 6.2, a pHu between 5.6 and 5.8, and drip loss below 3%. Moreover, muscles possessing a pHu below 5.5 should not be used for production of cured products because of their paleness and low curing yield (Russo & Costa, 1995). 4. Conclusions Among all genetic groups harvested at 130 kg HW, DUDU pigs presented the thickest fat layer in the ham and had an IMF of 3.15%. The high IMF probably affected the lightness, as measured by Göfo readings, thus revealing lighter color of the Semimembranosus muscle surface. The pHu values were adequate for dry-cured ham production, with similar values observed among all of the genetic groups. However, the use of purebred Durocs has its limitations in industrial production due to difficulties caused by dehairing at the slaughter-line. Apart from the Durocs, a second option within the genetic groups studied is the DULA group, which also produced appropriate ham traits, such as a low EFT and high IFT. With respect to IMF, this genetic group was close to meet
375
the specifications for the production of dry-cured hams. Ham grading before salting based on pHu and IMF will contribute to diminish the quality variations before the finished dry-cured ham pieces are dispatched to market.
Acknowledgements We thank the CNPq (National Council of Research and Development) and FAPEMIG (Minas Gerais State Research Foundation) for financial support.
References Aalhus, J. L., Jones, S. D. M., Robertson, W. M., Tong, A. K. W., & Sather, A. P. (1991). Growth characteristics and carcass composition of pigs with known genotypes for stress susceptibility over a weight range of 70 to 120 kg. Animal Production, 52, 347−353. Beattie, V. E., Weatherup, R. N., Moss, B. W., & Walker, N. (1999). The effect of increasing carcass weight of finishing boars and gilts on joint composition and meat quality. Meat Science, 52(2), 205−211. Blanchard, P. J., Ellis, M., Warkup, C. C., Chadwick, J. P., & Willis, M. B. (1999). The influence of sex (boars and gilts) on growth, carcass and pork eating quality characteristics. Animal Science, 68, 487−493. Blanchard, P. J., Warkup, C. C., Ellis, M., Willis, M. B., & Avery, P. (1999). The influence of the proportion of Duroc genes on growth, carcass and pork eating quality characteristics. Animal Science, 68, 495−501. Bochicchio, D., Faeti, V., Marchetto, G., Poletti, E., Maranesi, M., Mordenti, A. L., et al. (2005). Effect of feeding partially hydrogenated lard on trans-fatty acid content of muscle and backfat of heavy pigs. Meat Science, 71(4), 651−656. Čandek-Potokar, M., Monin, G., & Žlender, B. (2002). Pork quality, processing, and sensory characteristics of dry-cured hams as influenced by Duroc crossing and sex. Journal of Animal Science, 80(4), 988−996. Channon, H. A., Kerr, M. G., & Walker, P. J. (2004). Effect of Duroc content, sex and ageing period on meat and eating quality attributes of pork loin. Meat Science, 66(4), 881−888. Cilla, I., Altarriba, J., Guerrero, L., Gispert, M., Martínez, L., Moreno, C., et al. (2006). Effect of different Duroc line sires on carcass composition, meat quality and dry-cured ham acceptability. Meat Science, 72(2), 252−260. Cisneros, F., Ellis, M., McKeith, F. K., McCaw, J., & Fernando, R. L. (1996). Influence of slaughter weight on growth and carcass characteristics, commercial cutting and curing yields, and meat quality of barrows and gilts from two genotypes. Journal of Animal Science, 74(5), 925−933. Correa, J. A., Faucitano, L., Laforest, J. P., Rivest, J., Marcoux, M., & Gariépy, C. (2006). Effects of slaughter weight on carcass composition and meat quality in pigs of two different growth rates. Meat Science, 72(1), 91−99. García-Macías, J. A., Gispert, M., Oliver, M. A., Diestre, A., Alonso, P., Muñoz-Luna, A., et al. (1996). The effects of cross, slaughter weight and halothane genotype on leanness and meat and fat quality in pig carcasses. Animal Science, 63, 487−496. García-Rey, R. M., García-Garrido, J. A., Quiles-Zafra, R., Tapiador, J., & Luque De Castro, M. D. (2004). Relationship between pH before salting and dry-cured ham quality. Meat Science, 67(4), 625−632. Gou, P., Comaposada, J., & Arnau, J. (2002). Meat pH and meat fibre direction effects on moisture diffusion in salted ham muscles dried at 5 °C. Meat Science, 61(1), 25−31. Hambrecht, E., Eissen, J. J., & Verstegen, M. W. A. (2003). Effect of processing plant on pork quality. Meat Science, 64(2), 125−131. Hocquette, J. -F., Ortigues-Marty, I., Pethick, D., Herpin, P., & Fernandez, X. (1998). Nutritional and hormonal regulation of energy metabolism in skeletal muscles of meat-producing animals. Livestock Production Science, 56(2), 115−143. ISO 1444 (1973). Determination of free fat content in meat and meat products. Geneva: International Organization for Standardization. Jones, S. D. M., Tong, A. K. W., Campbell, C., & Dyck, R. (1994). The effects of fat thickness and degree of marbling on pork colour and structure. Canadian Journal of Animal Science, 74(1), 155−157. Latorre, M. A., Lázaro, R., Gracia, M. I., Nieto, M., & Mateos, G. G. (2003). Effect of sex and terminal sire genotype on performance, carcass characteristics, and meat quality of pigs slaughtered at 117 kg body weight. Meat Science, 65(4), 1369−1377. Latorre, M. A., Lázaro, R., Valencia, D. G., Medel, P., & Mateos, G. G. (2004). The effects of gender and slaughter weight on the growth performance, carcass traits, and meat quality characteristics of heavy pigs. Journal of Animal Science, 82(2), 526−533. Latorre, M. A., Medel, P., Fuentetaja, A., Lázaro, R., & Mateos, G. G. (2003). Effect of gender, terminal sire line and age at slaughter on performance, carcass characteristics and meat quality of heavy pigs. Animal Science, 77, 33−45. Lebret, B., Juin, H., Noblet, J., & Bonneau, M. (2001). The effects of two methods of increasing age at slaughter on carcass and muscle traits and meat sensory quality in pigs. Animal Science, 72, 87−94. Lindahl, G., Lundström, K., & Tornberg, E. (2001). Contribution of pigment content, myoglobin forms and internal reflectance to the colour of pork loin and ham from pure breed pigs. Meat Science, 59(2), 141−151. Lo Fiego, D. P., Santoro, P., Macchioni, P., & De Leonibus, E. (2005). Influence of genetic type, live weight at slaughter and carcass fatness on fatty acid composition of subcutaneous adipose tissue of raw ham in the heavy pig. Meat Science, 69(1), 107−114.
376
J.V. Peloso et al. / Meat Science 86 (2010) 371–376
Lovato, P. A., Vielmo, H., Oliveira, V., Hauschild, L., Antocheviez, R. F., Carvalho, A. A., et al. (2006). Características de carcaças de suínos alimentados do desmame ao abate em comedouro de acesso único equipado ou não com bebedouro. Ciência Rural, 36(1), 229−233. Ruiz-Carrascal, J., Ventanas, J., Cava, R., Andrés, A. I., & Garcia, C. (2000). Texture and appearance of dry cured ham as affected by fat content and fatty acid composition. Food Research International, 33(2), 91−95. Russo, V., & Costa, L. N. (1995). Suitability of pig meat for salting and the production of quality processed products. Pig News and Information, 16(1), 17N−26N. Ryu, Y. C., & Kim, B. C. (2005). The relationship between muscle fiber characteristics, postmortem metabolic rate, and meat quality of pig longissimus dorsi muscle. Meat Science, 71(2), 351−357. Sabbioni, A., Beretti, V., Zanon, A., Superchi, P., Sussi, C., & Bonomi, A. (2004). Effect of the proportion of Duroc genes in crosses with Large White and Landrace pigs on the characteristics of seasoned Parma ham. Italian Journal of Animal Science, 3, 31−39. Sabbioni, A., Superchi, P., Sussi, C., & Bonomi, A. (2002). Effect of Duroc genes proportion on growth performance and on carcass and meat quality characteristics in heavy pigs. Italian Journal of Animal Science, 1, 17−24. SAS for Windows release 9.1. SAS Institute. Cary, North Caroline, USA, 2002–2003. Sather, A. P., Jones, S. D. M., Tong, A. K. W., & Murray, A. C. (1991). Halothane genotype by weight interactions on pig meat quality. Canadian Journal of Animal Science, 71(3), 645−658. Schivazappa, C., Degni, M., Nanni Costa, L., Russo, V., Buttazzoni, L., & Virgili, R. (2002). Analysis of raw meat to predict proteolysis in Parma ham. Meat Science, 60(1), 77−83.
Sellier, P., & Monin, G. (1994). Genetics of pig meat quality: A review. Journal of Muscle Foods, 5(2), 187−219. Stoller, G. M., Zerby, H. N., Moeller, S. J., Baas, T. J., Johnson, C., & Watkins, L. E. (2003). The effect of feeding ractopamine (Paylean) on muscle quality and sensory characteristics in three diverse genetic lines of swine. Journal of Animal Science, 81(6), 1508−1516. Van Der Wal, P. G., Olsman, W. J., Garssen, G. J., & Engel, B. (1992). Marbling, intramuscular fat and meat colour of Dutch pork. Meat Science, 32(3), 351−355. Van Oeckel, M. J., Warnants, N., & Boucqué, Ch. V. (1999). Measurement and prediction of pork colour. Meat Science, 52(4), 347−354. Virgili, R., Degni, M., Schivazappa, C., Faeti, V., Poletti, E., Marchetto, G., et al. (2003). Effect of age at slaughter on carcass traits and meat quality of Italian heavy pigs. Journal of Animal Science, 81(10), 2448−2456. Virgili, R., & Schivazappa, C. (2002). Muscle traits for long matured dried meats. Meat Science, 62(3), 331−343. Warriss, P. D., Brown, S. N., & Adams, S. J. M. (1990). Variation in haem pigment concentration and colour in meat from British pigs. Meat Science, 28(4), 321−329. Weatherup, R. N., Beattie, V. E., Moss, B. W., Kilpatrick, D. J., & Walker, N. (1998). The effect of increasing slaughter weight on the production performance and meat quality of finishing pigs. Animal Science, 67, 591−600. Wood, J. D., Nute, G. R., Richardson, R. I., Whittington, F. M., Southwood, O., Plastow, G., et al. (2004). Effects of breed, diet and muscle on fat deposition and eating quality in pigs. Meat Science, 67(4), 651−667.