M A Oliver

Universitair Ziekenhuis Ghent, Gand, Flanders, Belgium

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Publications (62)90.85 Total impact

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    ABSTRACT: Boar taint is the off-odour or off flavour of cooked pork. Currently, the most common method of controlling boar taint is surgical castration. However, immunocastration has been used in some parts of the world as an alternative to surgical castration. The aim of this study was to evaluate the sensory acceptability of meat from immunocastrated pigs (IM) compared with meat from females (FE), surgically castrated (CM) and entire males (EM). Twenty animals of each type were evaluated by 201 consumers in 20 sessions. Longissimus thoracis muscle of the different animals was cooked in an oven at 180°C for 10min. Consumers scored the odour and the flavour of the meat in a 9-point category scale without an intermediate level. There were no significant differences in consumer's evaluation of meat from IM, CM, and FE. In contrast, EM meat presented a higher percentage of dissatisfied scores and was significantly (P<0.05) less accepted than meat from CM, IM and FE. Consumers' acceptability of EM meat was always lower, independently of its androstenone levels. However meat with low levels of androstenone was more accepted that meat with medium or high levels of this substance. It can be concluded that immunocastration produced pork that was accepted by the consumers, and was indistinguishable from pork from CM or FE.
    Meat Science 12/2008; 80(4):1013-8. DOI:10.1016/j.meatsci.2008.04.018 · 2.23 Impact Factor
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    ABSTRACT: A polychotomous logistic regression was used to assess the risk factors for skin damage prior to slaughter. A total of 116 deliveries (15,695 pigs) from commercial farms to five Spanish pig abattoirs were surveyed. The skin damage condition was described as an ordinal response (1: no damage; 2: very slight damage; and 3: slight or more damage). The abattoir by the season (p<0.01), the floor surface of the lorry (p=0.02), and the mixing of unfamiliar pigs at loading (p=0.01) influenced the occurrence of skin blemishes. Skin damage increased with on-farm fasting time (p<0.01), loading time (p<0.01), lairage time (p<0.01), as well as with carcass weight (p<0.01). In winter transports the risk of skin damage decreased (p<0.01) at higher space allowance in the lorry. The risk of developing PSE and DFD pork increased with the skin damage score (p<0.01). The nn genotype for the RYR1 gene was less prone to skin damage but at the same time it is more sensitive to skin damage in relation to PSE risk. It is concluded that the skin damage score can be used as a rapid indicator of animal welfare and pork quality.
    Meat Science 12/2008; 81(4):745-51. DOI:10.1016/j.meatsci.2008.11.020 · 2.23 Impact Factor
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    ABSTRACT: An excessive accumulation of androstenone (5α-androst-16-en-3-one) in pig adipose tissue is one of the two major contributors to the phenomenon of boar taint. High levels of adipose tissue androstenone have been related to a low rate of hepatic androstenone metabolism, which includes two stages: oxidative and conjugative. Sulfotransferases (SULTs), alongside with other specific enzymes, play the key role in the conjugative stage of androstenone metabolism. The present study investigated the mechanism regulating expression of sulfotransferase 2B1 (SULT2B1) immunoreactive protein using primary cultured pig hepatocytes as a model system. A specific objective was to determine whether the expression of pig hepatic SULT2B1 is regulated by the sex steroids; androstenone, testosterone and estrone sulphate. The study was performed on entire male pigs of a Large White (40%)×Landrace (40%)×Duroc (20%) cross-breed, average carcass weight 72.2 kg. The study shows that SULT2B1 immunoreactive protein expression can be induced by testosterone (final concentrations, 10 and 500 nM) and repressed by estrone sulphate (final concentration, 100 nM). Androstenone had no significant effect on SULT2B1 immunoreactive protein expression in the range of concentration, 10 nM to 1 μM. Time-courses (0 to 48 h) of steroid effects were investigated. The maximum effects of testosterone and estrone sulphate were observed in 24 h after the steroid treatments. This study provides direct evidence for involvement of sex steroids in the regulation of porcine hepatic SULTs.
    Livestock Science 11/2008; 118(3):223-230. DOI:10.1016/j.livsci.2008.01.021 · 1.10 Impact Factor
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    ABSTRACT: Eighty Hereford steers were used to evaluate the effect of finishing diet [A: pasture, B: pasture plus concentrate (0.6% live weight), C: pasture plus concentrate (1.2% live weight), D: concentrate] on consumer acceptability of Uruguayan beef in France (FR), United Kingdom (UK), Spain (ES) and Germany (DE). Consumers (200 per country) evaluated overall, tenderness and flavour acceptability of beef (8 point scale: 1 ‘dislike extremely’, 8 ‘like extremely’). FR and UK rated lower acceptability scores for beef from D compared with A, B, and C. ES showed similar results for tenderness, but flavour scores did not differ between A and D. German consumers preferred beef from B and C. Overall, low levels of supplementation on pasture produced beef with the highest consumer acceptability followed by beef from pasture-fed animals. Feeding cattle with concentrate only may not be necessary to satisfy the EU market resulting in more profitable production systems for Uruguayan producers.
    Meat Science 10/2008; DOI:10.1016/j.meatsci.2008.10.005 · 2.23 Impact Factor
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    ABSTRACT: Sensory characteristics of longissimus thoracis muscle from three local Spanish beef breed-production systems and their relationships with chemical and instrumental meat quality traits were studied. Young bulls of Bruna dels Pirineus (BP; n=69), Avileña-Negra Ibérica (A-NI; n=70) and Morucha (MO; n=70) breeds were reared in their own production systems. MO breed showed the highest water holding capacity and also the highest thawing loss and haem pigment content (P<0.001). No differences in moisture and protein contents were found among breeds. A-NI showed the highest intramuscular fat (IMF, P<0.05) and total collagen (P<0.001) contents, whereas BP showed the lowest IMF content (P<0.05) and the highest collagen solubility (P<0.001). Beef flavour, tenderness and juiciness accounted for the eating quality differences among the three breed-production systems. Meat from A-NI was rated significantly higher (P<0.01) for beef flavour and tenderness than that from BP and MO animals. Furthermore, MO showed the lowest juiciness (P<0.001) which could be due to its higher thawing loss. Within the three breeds, thawing loss was negatively correlated with juiciness and, likewise cooking loss with juiciness and tenderness (P<0.05). The canonical discriminant analysis showed that the three breeds were significantly different (P<0.05) from each other according to sensory attributes, which justifies their involvement in different protected geographical indications (PGI).
    Meat Science 05/2008; 79(1):98-104. DOI:10.1016/j.meatsci.2007.08.005 · 2.23 Impact Factor
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    ABSTRACT: SUMMARY - From 1997, the "Mallorca Black pig" is recognised as an autochthonous endangered extensive pig breed by the Spanish Ministry of Agriculture, Fisheries and Food. In the present situation, close to 80 extensive farms with more than 1300 reproducers are recovered by the "Mallorca Black Pig Association". These animals are managed in extensive conditions and the feeding regime is based on pasture, cereals, legumes, figs, almonds, acorns and Mediterranean shrubs. A continuous evaluation of new reproducers (electronic identification, DNA traceability, reproductive and productive traits recording and morphological standard appraisal) and across farms genetic exchanges (via auction sales) are basic elements of the conservation and improvement programme set up by IBABSA and IRTA. Apart from the production of piglets for consumption at a low weight ("porcella"), growing animals are slaughtered at heavy weight (120-180 kg) and are used to obtain spiced typical sausages ("sobrasada"). Production, reproduction and carcass characteristics are under investigation to improve efficiency without a reduction on meat and traditional product quality.
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    ABSTRACT: Boar taint has been associated with the pork from entire males. Sensory profiles have been carried out in several studies showing the multidimensional property of boar taint. However, no agreement on the number and kind of descriptors has been reached. The aim of this study was to describe the sensory characteristics of boar taint using a modified Free Choice Profiling technique. The pig meat samples were selected according to their different analytical levels of androstenone and skatole and were sensorially evaluated in duplicate. After selecting the discriminant descriptors for each assessor a Generalized Procrustes Analysis was carried out. Samples with the highest analytical levels of androstenone were characterized by “ urine”, “ sweat”, “ chemical” and “ rancid” odor and flavor, “ turpentine”, “ viscera”, “ pig/animal” and “ naphthalene” odor, and “ piquant” flavor. Samples with the highest analytical levels of skatole were characterized by “ sweat” odor and flavor, “ stable”, “ manure” and “ naphthalene” odor and “ pig/animal” flavor. In general the results suggested that both compounds are responsible for certain sensory defects, although the samples with a high androstenone content displayed the majority of them.
    Journal of Sensory Studies 05/2007; 15(4):393 - 409. DOI:10.1111/j.1745-459X.2000.tb00278.x · 2.58 Impact Factor
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    ABSTRACT: Fifty-four Holstein bulls were blocked by initial BW (301 +/- 7.4 kg) and randomly assigned to 6 treatments following a 3 x 2 factorial arrangement, with 3 concentrate lipid levels (5, 8, and 11% of DM) and 2 lipid sources (whole canola seed and whole linseed), with the objective of evaluating the possibility of increasing the content of n-3 fatty acids in meat. Concentrates (mostly corn meal) were isonitrogenous and isocaloric. Concentrate and straw were both fed ad libitum. Animal BW was recorded every 2 wk, and feed consumption was recorded weekly. Ruminal pH and VFA concentrations were determined monthly. Bulls were transported to the slaughterhouse when they achieved the target slaughter weight of 443 kg (after 105 +/- 4 d of fattening). After slaughter, a sample of LM from the sixth to the eighth ribs was dissected and analyzed for intramuscular fat content and fatty acid profile. Dietary lipid source did not affect overall animal performance, rumen fermentation, or carcass quality. Rumen pH was >6.0 despite consumption by the bulls of large amounts of concentrate. In bulls fed linseed, the percentage of n-3 fatty acids in LM increased linearly with lipid level, whereas in bulls fed canola seed it remained constant. The ratio of n-6:n-3 fatty acids was lower (P < 0.01) in the LM of bulls fed linseed (10.0) than in those fed canola seed (26.0). The content of cis-9, trans-11-CLA in the LM tended (P = 0.06) to be greater in the bulls fed linseed than in those fed canola seed (62.9 vs. 49.2 mg/kg of LM, respectively). Concentration of n-3 fatty acids in meat of bulls fed high-concentrate diets can be enhanced by whole linseed supplementation without affecting animal performance, ruminal fermentation, or carcass quality.
    Journal of Animal Science 12/2006; 84(11):3039-48. DOI:10.2527/jas.2005-632 · 1.92 Impact Factor
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    ABSTRACT: The acceptability of beef from Uruguay (UY), based on eating quality, was compared with beef produced in different European countries (Germany, DE, Spain, ES and United Kingdom, UK). Consumer tests were conducted in DE, ES and UK (each comprising 200 consumers) using 'Hall Tests'. In each country four samples were evaluated, two from Hereford steers from UY (finished at 2 and 3 years) and two from local meat (the same meat sample aged 7 or 20d). Consumers evaluated tenderness, flavour and overall acceptability using 8-point category scales. Hierarchical cluster analysis, highlighted the existence of different clusters of consumers. Two main clusters were identified in DE and UK. The main cluster identified in DE, was labelled as Prefer foreign-imported beef (n=128). These consumers preferred (P<0.05) the samples from UY_2y in terms of tenderness and overall acceptability. The other cluster was labelled as Prefer local beef in terms of flavour and overall acceptability (P<0.05) and comprised the majority of consumers from ES (n=176) and UK (n=153) and the cluster 2 from DE (n=69). UK, cluster 2 (n=33) that did not discriminate between origin and ageing time of beef. These results indicate that consumers did not prefer the same type of meat within the same country and it is possible that there are individual preferences that could lead to the concept of market segmentation being based on taste preferences. It would appear that Uruguayan beef would be very acceptable in Germany and to a lesser extent in Britain and Spain, although further studies are required that include labelling information.
    Meat Science 11/2006; 74(3):435-42. DOI:10.1016/j.meatsci.2006.03.010 · 2.23 Impact Factor
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    ABSTRACT: The effect of the addition of pork haem pigment on the colour, colour stability and texture of cooked hams from pale, soft and exudative meat (PSE hams) was studied. A total of 62 hams were selected at 15h post mortem on the basis of pH, electrical conductivity (EC) and L* value in semimembranosus (SM) and biceps femoris (BF) muscles. Hams were divided into three groups to be manufactured as cooked hams: group 1 (control, with normal meat quality hams, n 20), group 2 (control, with PSE hams, n 21) and group 3 (with PSE hams to which 0.04% of pork haem pigment was added, n 21). The stability of the colour (L*, a*, b*) was followed at 0, 30 and 120min after slicing. Pigment content and the instrumental texture of the hams were also evaluated. L* value after slicing was lower in group 3 than in group 2 for both muscles at all three times studied. Colour a* value (redness) was significantly higher for group 3 than for groups 1 and 2 at the three times and in the two muscles. Accordingly, there was an increase in visual redness in BF and SM of hams from group 3 with respect to groups 1 and 2. Iridescence was higher in PSE hams. The muscle pigment content showed no significant differences among groups - neither in the fresh nor in the cooked hams. No effect of the pork pigment was found on the texture properties studied. In conclusion, the addition of stabilised pork haem pigment in the processing of PSE hams resulted in cooked hams with lower L* values and higher a* values and more visual redness, whereas colour stability and texture of hams were not affected.
    Food Science and Technology International 10/2006; 12(5):429-435. DOI:10.1177/1082013206070161 · 0.98 Impact Factor
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    ABSTRACT: Malic enzyme 1 (ME1) is a part of the tricarboxylate shuttle that provides NADPH and acetyl-CoA required in fatty acid biosynthesis. The pig ME1 locus maps on the proximal end of chromosome 1, where a quantitative trait loci (QTL) affecting fat deposition has been previously described. We amplified fragments of 1457 and 1459 bp that corresponded to the complete coding region and the 3'-untranslated region (UTR), respectively, of the pig ME1 gene. The sequences of these two fragments in pigs from three breeds (Landrace, Large White and Piétrain) contained five single nucleotide polymorphisms (SNP) in the 3'-UTR: C1706T, G1762T, A1807C, C1857A and T1880A. Three haplotypes were found in two generations of a selected Landrace population: H1 (C1706 G1762 A1807 C1857 A1880), H2 (C1706 G1762 A1807 C1857 T1880) and H3 (T1706 T1762 C1807 A1857 T1880). Using Bayesian association analyses, significant associations (highest posterior density at 95%) between ME1 genotype and backfat (BF) thickness at 171 days and muscular pH were found in a Landrace population.
    Animal Genetics 03/2006; 37(1):28-32. DOI:10.1111/j.1365-2052.2005.01366.x · 2.21 Impact Factor
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    ABSTRACT: In the present study German (DE), Spanish (ES) and British (UK) consumers’ acceptance of lamb from their own country compared to lamb from Uruguay (UY) was evaluated. Two-hundred consumers in each country evaluated tenderness, flavour and overall acceptability of four types of lamb, two from UY (light and heavy lambs aged 20 d) and 2 local (with two ageing times, 7 and 20 d). In each country 1.5 cm-thick slices of lamb were evaluated by previously selected consumers in controlled conditions. DE and UK consumers showed significantly (P < 0.05) different acceptability scores between samples, the lamb from heavier animals and aged 20 d being the most appreciated. On the other hand the majority of the ES consumers significantly (P < 0.05) preferred the meat from lighter lambs. Production systems, cultural aspects and consumption habits seem to affect the acceptability of the lamb to the consumers.
    Meat Science 03/2006; 72(3):545-554. DOI:10.1016/j.meatsci.2005.09.002 · 2.23 Impact Factor
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    ABSTRACT: The fatty acid composition of commercial lambs from different production systems of Spain, Germany, United Kingdom and of two types of Uruguayan lambs (heavy and light) was studied. Concentrate fed lambs, as Spanish lambs, displayed the highest proportions of linoleic acid (C18:2), while Uruguayan lambs, reared under extensive grazing conditions, showed the highest proportions of linolenic acid (C18:3), due to the great concentration of this fatty acid in grass. German and British lambs, which were fed grass and concentrate, displayed intermediate proportions of linolenic acid (C18:3). Heavy Uruguayan lambs had higher intramuscular fat content (5.92%) than German (4.25%) and British (4.32%) lambs, and this content was twofold higher than light lambs (Spanish (2.41%) and light Uruguayan (3.05%)). Heavy Uruguayan, German and British lambs had a low polyunsaturated/saturated (P/S) ratio due to their high saturated fatty acid (SFA) content and proportion. Principal component analysis was performed to study the relationship between fatty acids. Spanish lambs were clearly separated from the other types and were situated close to the proportions of short chain and n-6 fatty acids and n-6/n-3 ratio in the data plot for fatty acid proportions. Light Uruguayan lambs were located close to long chain fatty acids, and heavy Uruguayan and British lambs were placed near the antithrombotic potential (ATT), stearic acid (C18:0), SFA and conjugated linoleic acid (CLA) proportions. German lambs were located between Spanish lambs and the other types.
    Meat Science 10/2005; 71(2):256-63. DOI:10.1016/j.meatsci.2005.03.020 · 2.23 Impact Factor
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    ABSTRACT: Functional genomics, including analysis of the transcriptome and proteome, provides new opportunities for understanding the molecular processes in muscle and how these influence its conversion to meat. The Quality Pork Genes project was established to identify genes associated with variation in different aspects of raw material (muscle) quality and to then develop genetic tools that could be utilized to improve this quality. DNA polymorphisms identified in the porcine PRKAG3 and CAST genes illustrate the impact that such tools can have in improving meat quality. The resources developed in Quality Pork Genes provide the basis for identifying more of these tools.
    Meat Science 07/2005; 70(3):409-21. DOI:10.1016/j.meatsci.2004.06.025 · 2.23 Impact Factor
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    ABSTRACT: A polychotomous logistic regression model was used to identify and assess the risk factors for pork meat becoming pale, soft and exudative (PSE). A total of 116 deliveries, comprising 15,695 commercial pigs delivered from different commercial farms to five Spanish pig commercial abattoirs were surveyed. The PSE condition was described as an ordinal response variable (normal, prone to PSE and PSE) based on measurements of electrical conductivity in the Semimembranosus muscle 1-2 h post-mortem. The RYR1 genotype, the abattoir, the season, the gender, the floor surface in the lorry, the loading system, and the stocking density during transportation influenced the risk of PSE condition, as well as on-farm fasting time, loading time, transportation and lairage times. The effect of the RYR1 gene, determined in a subsample of 1331 pigs, was due to nn stress-susceptible pigs, in which the risk of PSE meat (PQM>6 μs) increased fourfold. Abattoirs should be especially careful in summer, when the risk of PSE meat was found to be double that of winter. The risk of PSE meat decreased with the time of transportation, though its effect depended on the stocking density. Thus, our results indicate that, for transits longer than 3 h, the risk of PSE increases with stocking density during transport, while the opposite occurs for shorter transits.
    Meat Science 07/2004; 67(3):471-8. DOI:10.1016/j.meatsci.2003.11.020 · 2.23 Impact Factor
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    ABSTRACT: Seventy-four young bulls of the Bruna dels Pirineus beef cattle breed were reared in a typical production system and slaughtered at an average age of 381 days and live weight of 541 kg. The animals were evaluated for productive traits, carcass quality, meat quality, eating quality and biochemical characteristics of m. longissimus thoracis (LT). Biochemical measurements included intramuscular fat (IMF) and collagen proportion, haem pigment concentration, lactate dehydrogenase and isocitrate dehydrogenase activities and type I (MHC I) fibre percentage determined by ELISA. Bruna dels Pirineus bulls achieved high growth rates during the fattening period (1.63 kg/day) and showed good carcass quality, with a high dressing-out proportion (607 g/kg, hot carcass), a good conformation score (U; EUROP) and a moderate fatness score (3;1-5). Carcass composition was estimated from the sixth rib joint dissection (682 g/kg lean proportion, 127 g/kg total dissectable fat and 163 g/kg bone). IMF (24.3 g/kg) and MHC I (27.9%) showed high variabilities (CV>30%). Sensory analysis of LT included beef and livery odour and flavour intensity, and overall tenderness and juiciness assessment of loin samples (14-day ageing). Beef odour and flavour were slightly positively correlated with IMF and carcass fatness score (P<0.05). Fatness, MHC I, insoluble collagen and cooking losses tended to affect the livery flavour intensity positively. This variable was significantly higher in meat from bulls of lower carcass quality (i.e. lower conformation score, lower lean proportion; P<0.05) and higher type I fibre percentage. Loin overall tenderness and juiciness were not affected by the biochemical traits studied, however, they were negatively affected by cooking loss (P<0.05).
    Meat Science 02/2004; 66(2):425-36. DOI:10.1016/S0309-1740(03)00131-1 · 2.23 Impact Factor
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    ABSTRACT: The relationship between muscle biochemical traits, myosin heavy chain I and meat quality of longissimus thoracis was studied using gilts from five divergent porcine lines (A to E) (carcass weight: 83.7±8.7 kg). Intramuscular fat (IMF) and haem pigments content as well as myosin heavy chain 1 (MyHC I) percentage and the activity of lactate dehydrogenase (LDH) and isocitrate dehydrogenase (ICDH) were determined. Only group E, a well conformed line of pigs, included the halothane positive genotype. The presence of the Hal gene in this line resulted in meat of poorer quality in terms of meat of higher exudate compared to line D, also a well conformed line of predominantly Pietrain origin but being halothane gene free. Line C presented the highest IMF content (2.02%) as well as high oxidative characteristics (MyHC I, 10.0%; LDH/ICDH, 1.92 μmol nmol(-1); ICDH activity, 1.78 nmol min(-1) g(-1)) and the lowest drip losses (5.3%). According to a principal component analysis including MyHC I, biochemical traits and meat quality parameters, line C was characterized by a high IMF content and oxidative traits, and line B by a high glycolytic metabolism. Line E was distinguished by high drip losses and by low pH(45) and pH(u). In conclusion, several observed differences in muscle metabolism between lines free of the halothane gene (A, B, C and D) must be caused by other "genetic background" factors.
    Meat Science 11/2003; 65(3):1063-70. DOI:10.1016/S0309-1740(02)00324-8 · 2.23 Impact Factor
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    ABSTRACT: Sensitivity of the consumers to androstenone, evaluated as the degree of smell (strong/weak) perceived by smelling the pure compound, is important in determining their acceptability of pork with different levels of androstenone and skatole. However, 8% (3.3% women and 16.2% men) of highly sensitive consumers like this odour, and 12.7% (9.1% women and 15.9% men) of mildly sensitive/insensitive consumers dislike it. The effect of the appreciation (like/dislike) of the smell in the acceptability of pork samples has not been reported previously. The aim of this paper is to ascertain if this liking for androstenone odour affects pork acceptability as well as the gender, age, and culinary habits of the consumers. Consumers evaluated the flavour and odour of five cooked and reheated samples, and recorded their acceptability on a 7-step scale. Results showed that acceptability of pork increases when the frequency of cooking and eating fresh pork are higher. The acceptability also differed depending on the sensitivity of the consumer within each age group. Appreciability of androstenone odour discriminates more than sensitivity in consumers' acceptance of pork.
    Meat Science 08/2003; 64(4):433-40. DOI:10.1016/S0309-1740(02)00212-7 · 2.23 Impact Factor
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    ABSTRACT: An experimental F2 cross between Iberian and Landrace pig strains was performed to map quantitative trait loci (QTL) for diverse productive traits. Here we report results for meat quality traits from 369 F2 animals with records for pH 24 h postmortem (pH 24 h), muscle color Minolta measurements L* (lightness), a* (redness), and b* (yellowness), H* (hue angle), C* (chroma), intramuscular fat (IMF) and haematin pigment content measured in the longissimus thoracis. Pigs were genotyped for 92 markers covering the 18 porcine autosomes (SSC). Results of the genome scan show evidence for QTL for IMF (SSC6; F = 27.16), pH 24 h (SSC3; F = 7.73), haematin pigments (SSC4 and SSC7; F = 8.68 and 9.47 respectively) and Minolta color measurements L* (SSC4 and SSC7; F =16.42 and 7.17 respectively), and a* (SSC4 and SSC8; F = 8.05 and 7.36 respectively). No QTL were observed for the color measurements b*, H*, and C*. Alternative models fitting epistasis between QTL were also tested, but detected epistatic interactions were not significant at a genome-wise level. In this work we identify genomic regions related with meat quality traits. Improvement by traditional selection methods is complicated, and finer mapping would be required for their application in introgression programs.
    Journal of Animal Science 12/2002; 80(11):2801-8. · 1.92 Impact Factor
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    ABSTRACT: Three Iberian boars were bred to 31 Landrace sows to produce 79 F1 pigs. Six F1 boars were mated to 73 F1 sows. The F2 progeny from 33 full-sib families (250 individuals) were genotyped for seven microsatellites spanning the length of chromosome 4. Least squares procedures for interval mapping were used to detect quantitative trait loci (QTL). A permutation test was used to establish nominal significance levels associated with QTL effects, and resulting probability levels were corrected to a genomewide basis. Observed QTL effects were (genomewide significance, position of maximum significance in centimorgans): percentage of linoleic acid in subcutaneous adipose tissue (< 0.01, 81); backfat thickness (< 0.01, 83); backfat weight (< 0.01, 80); longissimus muscle area (0.02, 83); live weight (0.19, 88); and percentage of oleic acid in subcutaneous adipose tissue (0.25, 81). Gene action was primarily additive. The Iberian genotypes were fatter, slower growing, and had lower linoleic and higher oleic acid contents than Landrace genotypes. The interval from 80 to 83 cM contains the FAT1 and A-FABP loci that have been shown previously to affect fat deposition in pigs. This is the first report of a QTL affecting fatty acid composition of subcutaneous adipose tissue in pigs and provides a guide for the metabolic pathways affected by candidate genes described in this region of chromosome 4.
    Journal of Animal Science 11/2000; 78(10):2525-31. · 1.92 Impact Factor