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PubMed2001

Interval mapping of carcass and meat quality traits in a divergent swine cross.

An autosomal scan of the swine genome with 119 polymorphic microsatellite (ms) markers and data from 116 F2 barrows of the University of Illinois Meishan x Yorkshire Swine Resource Families identified genomic regions with effects on variance in carcass composition and meat quality at nominal significance (p-value <0.05). Marker intervals on chromosomes 1, 6, 7, 8 and 12 (SSC1, SSC6, SSC7, SSC8, SSC12) with phenotypic effects on carcass length, 10th rib backfat thickness, average backfat thickness, leaf fat, loin eye area and intramuscular fat content confirm QTL effects identified previously based on genome wide significance (p-value <0.05). Several marker intervals included nominally significant (p-value <0.05) dominance effects on leaf fat, 10th rib backfat thickness, loin eye area, muscle pH and intramuscular fat content.

Adipose Tissue↗

PubMed2002

Effects of dietary conjugated linoleic acid on fatty acid composition, lipid oxidation, color, and water-holding capacity of pork loin.

The effects of dietary conjugated linoleic acid (CLA) on fatty acid composition, lipid oxidation, and pork quality were investigated. Pigs (n = 20) were fed a diet containing 0, 1, 2.5, or 5% CLA for 4 wk and slaughtered at 105 kg. The longissimus thoracis et lumborum muscle was collected at 24 h postmortem. Pork loin chops (3 cm thick) were packaged aerobically and stored at 4 degrees C for 7 d. Samples were analyzed for ultimate pH, intramuscular fat content, fatty acid composition, thiobarbituric acid-reactive substances, color (L*, a*, b*), and water-holding capacity. Dietary CLA reduced the concentration of linoleic acid and increased CLA concentration in intramuscular fat of pork loin (P < 0.05). The concentration of CLA in muscle was increased with dietary CLA level and did not change during storage. Thiobarbituric acid-reactive substance value of control was higher than that of the CLA-fed groups (P < 0.05). Intramuscular fat content was increased by dietary CLA, and less purge loss was observed with samples from CLA-fed pigs (P < 0.05). Dietary CLA improved the color stability of pork loin during cold storage. After 7 d, lightness (L*) and yellowness (b*) of the 5% CLA-fed group were significantly lower than those of control (P < 0.05). The results indicated that the water-holding capacity of pork loin was increased with increased intramuscular fat content apparently caused by dietary CLA. Also, the data indicated that color stability of pork was improved with inhibition of lipid oxidation and changing of fatty acid composition by dietary CLA.

Animals↗

PubMed1985

Adipose tissue growth and cellularity: changes in bovine adipocyte size and number.

Forty crossbred steers of similar birth date and fed the same growing-finishing diet were used to study adipocyte changes in six fat depots during growth from 11 to 19 mo of age. Steers were slaughtered at 2-mo intervals. Adipose tissue samples were obtained from kidney, mesenteric and brisket fat and subcutaneous, intermuscular and intramuscular fat from the 10th to 12th rib section. The osmium tetroxide fixation technique was used for determination of cell size and number. Except for three brisket fat samples, distributions of adipocyte diameters from six different fat depots were monophasic during the age range considered in this study. At 17 mo of age, the mean adipocyte diameter, in decreasing order, was: kidney fat greater than mesenteric greater than subcutaneous greater than intermuscular greater than intramuscular greater than brisket fat. Fat deposition during growth to 19 mo of age occurred mainly by hypertrophy of adipocytes. An apparent cell hyperplasia occurred in the intramuscular fat depot from 11 to 15 mo and in the brisket fat depot after 15 mo of age. Based on cellularity characteristics, evidence exists to classify intramuscular and brisket fat depots as late-developing ones. Cell number/gram of intramuscular adipose tissue was a better predictor of marbling score than was fat cell diameter.

Adipose Tissue↗

PubMed2002

Feeding intensity and dietary protein level affect adipocyte cellularity and lipogenic capacity of muscle homogenates in growing pigs, without modification of the expression of sterol regulatory element binding protein.

Muscle fat stores at slaughter partly determine the dietetic and sensory quality traits of pork meat. Nutritional strategies during the growing-finishing period are able to modify intramuscular fat content; however, the underlying mechanisms remain largely unknown. The objective of this study was to determine some of the cellular, biochemical, and molecular bases of muscle fat content variation in response to feeding regimen in pigs. Crossbred pigs of 30 kg BW were allocated to three feeding groups: free access ([C], n = 10) to a standard diet (3.25 kcal of DE/kg, 9.5 g of lysine/kg), standard diet at 75% of the spontaneous voluntary intake ([FR], n = 10), or both low protein and energy intakes ([PR], n = 10) in order to get the same growth rate as the FR pigs and the same body composition as the C pigs. At slaughter (110 kg BW), FR and PR pigs were 30 d older than C pigs (P < 0.001). In agreement with the protocol, carcass adiposity was similar in PR and reduced (P < 0.01) in FR pigs compared with C animals. Lipid content in longissimus lumborum muscle was reduced by 25% in FR pigs and increased by 40% in PR pigs compared to C pigs (P < 0.001). Commensurate variations in the diameter of muscle adipocytes were observed between the three feeding groups (P < 0.001). The muscle activities of malic enzyme and glucose-6-phosphate dehydrogenase, generating reduced nicotinamide adenine dinucleotide phosphate for fatty acid synthesis, were depressed (P < 0.05) in both FR and PR groups, compared to the C group. The expression level of the sterol regulatory element binding protein that was chosen as the putative candidate at the molecular level was not modified by the feeding regimen. No variations in the oxidative enzyme markers were denoted, whereas lactate dehydrogenase activity was reduced by 13% (P < 0.05) in PR group compared to other groups. In conclusion, moderate long-term feed restriction results in decreased lipogenic capacity of muscle adipocytes and intramuscular fat content. In contrast, the reduction of both protein and energy intakes more likely results in an imbalance between multiple aspects of muscle energy metabolism, in favor of intramuscular fat accretion.

Adipocytes↗

PubMed2006

Economic evaluations of beef bulls in an integrated supply chain.

Economic benefits from the use of expected progeny of a sample of beef bulls with genetic evaluations were calculated over an integrated supply chain for combinations of price discounts for intramuscular fat and LM area. Fixed backfat finish and marketing at the point of optimized gross margins were considered. An economic model was used to calculate average expected gross margins for a sample of bulls. Across-breed, age-constant genetic evaluations were used to predict carcass characteristics of progeny including weight, retail yield, intramuscular fat, and LM area, as well as input requirements including feed and housing as a function of time on feed. Proportion of retail cuts affected by price discounts was included in the calculations. Optimizing endpoints did not affect rankings to any extent relative to a fixed end point in this sample of bulls, as a result of fixed endpoints being similar to optimized endpoints for the economic situation considered. However, rank correlations were only 0.63 and 0.71 between rankings for no discount being applied and rankings with discounts for intramuscular fat and LM area, for fixed and optimized endpoints, respectively. We conclude that market prices are necessary considerations in choices of bulls to use in commercial beef production.

Adipose Tissue↗

PubMed1999

Economic values for meat quality traits in pigs.

The aim for this study was to derive economic values for meat quality traits. Meat quality experts from 10 slaughter and retail companies in Switzerland were asked to give an interview in which they indicated their willingness to pay different prices for carcasses from different quality classes. Economic values for the seven meat quality traits color (L*), drip loss, intramuscular fat content, iodine value, pH1 (45 min after slaughtering), pH2 (24 to 30 h after slaughtering), and proportion of premium cuts were derived from the answers. For each trait, a weighted mean of these economic values was calculated using the number of pigs slaughtered by a company per year as a weighting factor. Population mean and standard deviation of the investigated traits were taken from station test results of Swiss Large White pigs (intramuscular fat content, iodine value, pH1, pH2, and proportion of premium cuts) and from the literature (color and drip loss). Weighted means (range among companies) of economic values per slaughter pig on the basis of one phenotypic standard deviation of the trait in Swiss Francs (SFr.) were -22.92 (0 to -62.46) for color, -10.27 (0 to -43.64) for drip loss, 10.84 (0 to 29.43) for intramuscular fat content, -29.90 (-15.54 to -43.58) for iodine value, 11.50 (.67 to 19.79) for pH1, 0 (0) for pH2, and 10.92 (-2.30 to 33.67) for proportion of premium cuts.

Animals↗

PubMed2006

A novel nuclear-encoded mitochondrial poly(A) polymerase PAPD1 is a potential candidate gene for the extreme obesity related phenotypes in mammals.

People with obesity, especially extreme obesity, are at risk for many health problems. However, the responsible genes remain unknown in >95% of severe obesity cases. Our previous genome-wide scan of Wagyu x Limousin F2 cattle crosses with extreme phenotypes revealed a molecular marker significantly associated with intramuscular fat deposition. Characterization of this marker showed that it is orthologous to the human gene KIAA1462 located on HSA10p11.23, where a major quantitative trait locus for morbid obesity has been reported. The newly identified mitochondrial poly(A) polymerase associated domain containing 1 (PAPD1) gene, which is located near this marker, is particularly interesting because the polymerase is required for the polyadenylation and stabilization of mammalian mitochondrial mRNAs. In the present study, both cDNA and genomic DNA sequences were annotated for the bovine PAPD1 gene and ten genetic markers were detected in the promoter and exon 1 region. Among seven markers assayed on approximately 250 Wagyu x Limousin F2 animals, two single nucleotide polymorphisms (SNPs) in the promoter region were significantly associated with intramuscular fat (P<0.05). However, there was a significant interaction (P<0.05) between a third SNP, which causes an amino acid change in coding exon 1, and each of these two promoter SNPs on intramuscular fat deposition. In particular, the differences between double heterozygous animals at two polymorphic sites and the slim genotype animals exceeded 2.3 standard deviations for the trait in both cases. Our study provides evidence for a new mechanism--the involvement of compound heterosis in extreme obesity, which warrants further examination.

Adipose Tissue↗

PubMed2001

Low-fat diet alters intramuscular substrates and reduces lipolysis and fat oxidation during exercise.

We determined whether a low-fat diet reduces intramuscular triglyceride (IMTG) concentration, whole body lipolyis, total fat oxidation, and calculated nonplasma fatty acid (FA) oxidation during exercise. Seven endurance-trained cyclists were studied over a 3-wk period during which time they exercised 2 h/day at 70% of maximum O2 uptake VO(2 max) and consumed approximately 4,400 kcal/day. During the 1st wk, their fat intake provided 32% of energy. During the 2nd and 3rd wk, they were randomly assigned to eat 2 or 22% of energy from fat (2%FAT or 22%FAT). Compared with 22%FAT, 2%FAT lowered IMTG concentration and raised muscle glycogen concentration at rest (P < 0.05). Metabolism was studied during 1 h of exercise at 67% VO(2 max) performed in the fasted state. 2%FAT resulted in a 27% reduction (P < 0.05) in total fat oxidation vs. 22%FAT without altering the stable isotopically determined rates of plasma free fatty acid or glucose disappearance. Therefore, 2%FAT reduced calculated nonplasma FA oxidation by 40% in association with a 19% reduction in whole body lipolysis while increasing calculated minimal muscle glycogen oxidation compared with 22%FAT (all P < 0.05). In summary, an extremely low fat (2% of energy) and high-carbohydrate diet lowers whole body lipolysis, total fat oxidation, and nonplasma FA oxidation during exercise in the fasted state in association with a reduced concentration of intramuscular triglyceride.

Adult↗

PubMed2006

An effect of a missense mutation in the porcine melanocortin-4 receptor (MC4R) gene on production traits in Polish pig breeds is doubtful.

A missense G-A SNP in the porcine melanocortin-4 receptor (MC4R) gene that causes an Asp-Asn substitution at position 298 of the corresponding MC4R protein is considered to be economically important, although published results on its effect are inconsistent. We analysed the association of this MC4R polymorphism with production traits in 679 gilts from two breeds, Polish Large White (PLW) and Polish Landrace (PL), as well as one synthetic line 990. The frequency of the A allele differed significantly among the breeds with frequencies of 0.76, 0.29 and 0.16 in PLW, PL and line 990 respectively. There was no evidence of an effect of this polymorphism on daily food intake, backfat thickness or abdominal fat. The A allele was correlated with higher test daily gains and lower levels of intramuscular fat in PL, and increased levels of intramuscular fat in PLW.

Animals↗

PubMed1997

Body composition determined with MR in patients with Duchenne muscular dystrophy, spinal muscular atrophy, and normal subjects.

Magnetic resonance imaging was used to determine total fat mass of patients with neuromuscular disorders, accounting for intramuscular fat. Nineteen boys aged 9 to 12 (eight with Duchenne muscular dystrophy, three with type II spinal muscular atrophy and eight control subjects) underwent whole-body magnetic resonance imaging examination and anthropometric measurements. Whole-body fat mass was deduced from automated analysis of images normalized by a reference signal. Intramuscular and subcutaneous fat masses were deduced from manual analysis of twelve reference slices. Affected children significantly differed from control subjects for higher total fat mass, mostly related to intramuscular fat mass. Shorter protocols validated from whole-body data were shown to be more accurate than fat mass estimation derived from anthropometric measurements.

Adipose Tissue↗

PubMed1985

Release of vasoactive intestinal peptide by intraduodenal infusion of HCl or fat and intramuscular injection of neostigmine in man.

A highly sensitive radioimmunoassay system for plasma vasoactive intestinal peptide (VIP) was developed to examine the effect of intraduodenal infusion of HCl or fat on the plasma VIP levels in healthy subjects, and the effect of intramuscular injection of neostigmine in patients with irritable bowel syndrome (IBS). Intraduodenal infusion of 100 ml of 0.1 N HCl or 10 g fat caused a significant rise in plasma VIP level. Neostigmine (12.5 micrograms/kg) produced a significant rise in plasma VIP level, and the plasma VIP response to neostigmine was significantly greater in the IBS group than in the normal group. These results suggest that VIP might play a role in the pathophysiology of IBS.

Adult↗

PubMed2006

Sequence characterization, tissue-specific expression and polymorphism of the porcine (Sus scrofa) liver-type fatty acid binding protein gene.

In this study, the full-length cDNA of porcine liver-type fatty acid binding protein gene (L-FABP) was obtained by the rapid amplification of cDNA ends (RACE). The nucleotide sequence and the predicted protein sequence share a high sequence identity with their mammalian counterparts. Semi-quantitative RT-PCR revealed that porcine L-FABP gene is expressed in all twelve tissues studied, but a transcript is more abundant in liver and small intestine than in other tissues. The part genomic DNA of the porcine L-FABP gene was amplified by PCR. The coding region of the pig L-FABP gene is organized in four exons and spans an approximate 2.62 kb genomic region. Comparative sequencing of four pig breeds revealed a C-->T single nucleotide polymorphism (SNP) within exon 2. The allele and genotype frequencies differed significantly between indigenous Chinese Zang, Dahe, and Yanan pigs with higher frequencies of allele C and genotype CC and Yorkshire pigs with higher frequencies of allele T and genotype TT (P < 0.01). The association analysis suggested that the C-->T polymorphism was associated with intramuscular fat content, indicating that the SNP is a potential molecular marker for intramuscular fat content.

Amino Acid Sequence↗

PubMed1990

[Fat clogging, fat cell count and fat cell size in swine in relation to age and feeding intensity].

Growth dependent changes of fat gain, the number of fat cells in the cutlet muscle and the size of the fat cells in the bacon of the back were studied in dependence on feeding intensity with a total of 145 male castrates of the genotype (L X E) XSF. Between their 5th and 32nd weeks of life the animals were butchered at intervals of 3 weeks and the parameters were determined. The gain of fat and the intramuscular fat content were highest in the high-level variant (daily weight gain 720 g) and lowest in the low-level variant (daily weight gain 530 g). The diameter of the fat cells in the middle layer of the bacon of the back increased up to an age of 26 weeks and then remained constant. Differences between the feeding groups were registered; the animals of the high-level group had the biggest fat cells from the 14th week onwards. A nutrition-caused difference between the number of fat cells per mm2 of the cutlet muscle could not be found. The calculated total number of fat cells in the cutlet muscle increased due to growth up to an age of 26 weeks. The results provided basic knowledge of fat gain and influences on it in pigs and they indicate possibilities of making statements on fat retention determining the microstructure of the fat tissue of the living animal by means of biopsy.

Adipose Tissue↗

PubMed2003

Effects of L-carnitine on growth performance, carcass composition, and metabolism of lipids in male broilers.

We studied the effects of L-carnitine on growth performance, carcass composition, and lipid metabolism in male broilers. Six hundred male commercial broilers were allotted to five groups, each of which included three replicates (40 birds per replicate). The groups received the same basal diet supplemented with 0, 25, 50, 75, or 100 mg/kg L-carnitine, respectively. The feeding trial showed that L-carnitine had no significant effect on daily gain or feed conversion. Supplementation with L-carnitine (above 25 mg/kg) in the diet increased breast muscle yield (P < 0.05) and crude fat content of the muscles and decreased abdominal fat content (P < 0.05). Addition of 50, 75, or 100 mg/kg L-carnitine to the diet decreased total activities of glucose-6-phosphate dehydrogenase, malic dehydrogenase, isocitrate dehydrogenase, and lipoprotein lipase (P < 0.05) in the subcutaneous fat and total activity of carnitine palmitoyltransferase-I (P < 0.05) in breast muscles. The results of this study indicate that L-carnitine could reduce the deposit of subcutaneous fat by decreasing total activities of enzymes in the fat and enhance intramuscular fat by decreasing the activity of carnitine palmitoyltransferase-I in breast muscles.

Adipose Tissue↗

PubMed2006

The bovine QTL viewer: a web accessible database of bovine Quantitative Trait Loci.

BACKGROUND: Many important agricultural traits such as weight gain, milk fat content and intramuscular fat (marbling) in cattle are quantitative traits. Most of the information on these traits has not previously been integrated into a genomic context. Without such integration application of these data to agricultural enterprises will remain slow and inefficient. Our goal was to populate a genomic database with data mined from the bovine quantitative trait literature and to make these data available in a genomic context to researchers via a user friendly query interface. DESCRIPTION: The QTL (Quantitative Trait Locus) data and related information for bovine QTL are gathered from published work and from existing databases. An integrated database schema was designed and the database (MySQL) populated with the gathered data. The bovine QTL Viewer was developed for the integration of QTL data available for cattle. The tool consists of an integrated database of bovine QTL and the QTL viewer to display QTL and their chromosomal position. CONCLUSION: We present a web accessible, integrated database of bovine (dairy and beef cattle) QTL for use by animal geneticists. The viewer and database are of general applicability to any livestock species for which there are public QTL data. The viewer can be accessed at http://bovineqtl.tamu.edu.

Animals↗

PubMed1998

Different periods of feed restriction before compensatory growth in Belgian Blue bulls: I. animal performance, nitrogen balance, meat characteristics, and fat composition.

Thirty double-muscled Belgian Blue bulls were maintained at a rate of gain of .5 kg/d during four periods of time, 115 (G2), 239 (G3), or 411 (G4) d (low growth period, LGP), before fattening (rapid growth period, RGP). Ten control animals (CG) were fed a diet rich in energy and protein. The G2, G3, and G4 were fed a diet low in energy and protein and the same diet as CG during RGP. Live weight was recorded biweekly, feed intake (FI) daily, and nitrogen balance at three times for each group. At the slaughterhouse, the 7, 8, and 9th ribs were removed to determine carcass composition, meat quality, and meat and fat composition. Compensatory growth reached a maximum 2 mo after refeeding and then decreased rapidly, leading to a sharp increase in the feed conversion ratio. Nitrogen balance was higher in compensating groups ( P < .05). Compensating animals had higher carcass connective and adipose tissue contents (P < .05) but lower meat fat content (P < .05). Cattle exhibiting compensatory growth had higher redness, yellowness, cooking losses, and drip losses, but had lower Warner-Bratzler peak shear force values. The saturated fatty acid content of the fat decreased with the duration of the LGP. During the first 2 mo after refeeding, compensatory growth in double-muscled bulls was ascribed to one or more of the following mechanisms: higher FI, lower maintenance requirements, or better efficiency of lean meat production. Compensatory growth at the expense of higher FI increased peripheral fat but decreased intramuscular fat deposition.

Abattoirs↗

PubMed2006

[Study of single nucleotide polymorphism of A-FABP gene and its association with fatness traits in chicken].

In this experiment, Beijing-You chicken was used to detect single nucleotide polymorphisms (SNPs) in A-FBAP gene and to study the correlation between its genotype and the trait of fat accumulation. The first exon of the gene was amplified by one pair of primers, and SNPs were detected by the technique of single strand conformation polymorphism (SSCP) and finally confirmed by sequencing. Results of analysis of variance showed that a significant difference existed among abdominal fat percentage, subcutaneous fat thickness and intramuscular fat contents in breast musculature with different genotypes (P<0.01). It implied that A-FABP gene could be a major effector gene or could be linked to gene(s) which significantly affect fat metabolism in chicken.

Adipocytes↗

PubMed2000

Genetic analyses of live-animal ultrasound and abattoir carcass traits in Australian Angus and Hereford cattle.

In order to estimate genetic parameters, abattoir carcass data on 1,713 Angus and 1,007 Hereford steers and heifers were combined with yearling live-animal ultrasound measurements on 8,196 Angus and 3,405 Hereford individuals from seedstock herds. Abattoir measures included carcass weight (CWT), percentage of retail beefyield (RBY), near-infrared measured intramuscular fat percentage (CIMF), preslaughter scanned eye muscle area (CEMA), and subcutaneous fat depth at the 12th rib (CRIB) and at the P8 site (CP8). Ultrasound scans on yearling animals included 12th-rib fat depth (SRIB), rump fat depth at the P8 site (SP8), eye muscle area (SEMA), and percentage of intramuscular fat (SIMF). Records on CWT were adjusted to 650-d slaughter age, and the remaining abattoir traits were adjusted to 300-kg CWT. Scan data were analyzed treating records on males and females as different traits. Multivariate analyses were performed on a variety of trait combinations using animal model and REML algorithm. Heritability (h2) estimates for CWT, RBY, CIMF, CP8, CRIB, and CEMA were .31, .68, .43, .44, .28, and .26, respectively, for Angus and .54, .36, .36, .08, .27, .38, respectively, for Hereford. Pooled across sexes, h2 estimates for SIMF, SP8, SRIB, and SEMA were .33, .55, .51, and .42, respectively, for Angus and .20, .31, .18, and .38, respectively, for Hereford. Genetic correlations (r(g)) between the same pair of carcass traits measured at yearling through scanning and directly at the abattoir were moderate to strongly positive, suggesting that selection using yearling ultrasound measurements of seedstock cattle should result in predictable genetic improvement for abattoir carcass characteristics. Estimates of r(g) between the scanned fat measurements and RBY were negative, ranging from -.85 for Angus heifers to -.05 for Hereford heifers. Also, the estimates of r(g) between SEMA and the fat records measured at the abattoir were negative and ranged from -.94 in Hereford heifers to -.02 in Angus heifers.

Adipose Tissue↗