Carcass Quality Traits Research Articles

Animal fat and vitamin E in rabbit diets: Total tract apparent digestibility, growth performance, carcass and meat quality traits

The present study tested the effect of a dietary inclusion with vitamin E and pork lard on the apparent digestibility of the nutrients, the growth performance, the carcass traits, the physical meat quality, and the α-tocopherol content. A total of 60 hybrid rabbits were reared in individual cages from weaning (35 days of age) until slaughter (78 days of age). A control diet with no supplements, one diet supplemented with 2% pork lard, and two diets that used the aforementioned diets supplemented with an additional 200 mg/kg α-tocopheryl acetate were designed. The diets were isoprotein and isoenergy. The fat inclusion increased the crude protein (P < 0.05) and ether extract (P < 0.001) total tract apparent digestibility, and the same was observed for the vitamin E inclusion (P < 0.001 for both variables). This improved the dietary digestible protein content (P < 0.05), which increased the digestible protein to digestible energy ratio (P < 0.001). The fat × vitamin E interaction was observed for the total tract apparent digestibility of the ether extract (P < 0.001), the neutral detergent fibre (P < 0.05) and the acid detergent fibre (P < 0.01). The growth traits were unaffected, with the exception of the feed conversion ratio that improved with the vitamin E addition (P < 0.05). Similarly, the carcass traits remained unaffected, with the exception of the perirenal and total fat incidence that increased with the fat supplement (P < 0.05), and the scapular fat that was reduced with the vitamin E inclusion (P < 0.05). The meat L* (lightness), a* (redness), b* (yellowness) colour values and ultimate pH were unaffected by the experimental treatments, even though a fat × vitamin E interaction was observed for the a* and chroma values of the Longissimus thoracis et lumborum muscle (P < 0.05). Both the fat (P < 0.05) and vitamin E (P < 0.001) dietary inclusion increased the meat α-tocopherol content. Based on the results, it was concluded that the 2% dietary inclusion of animal fat did not provide more benefits for the considered parameters than the sole α-tocopheryl acetate incorporation, but contributed to the increase in the vitamin E content in the meats.

Carcass traits, meat quality, and sensory attributes of fast-growing broilers given outdoor access at different ages

This study evaluated the effect of outdoor access offered to fast-growing broilers at different ages and its impact on meat quality attributes. A total of 200 straight-run broilers were arranged according to the completed randomized design and distributed into 4 treatment groups. The treatments were replicated 5 times; each replicate consisted of 10 birds. The treatment included age at exposure to outdoor access including day 21, day 28, and day 35, and a control group in which the birds were reared at an indoor facility for up to 56 days. Taste, flavor, juiciness, and overall acceptability of breast meat were highest for broilers given outdoor access on day 21 followed by day 28, day 21 and lowest for broilers without outdoor access. Tenderness of breast meat was highest in broilers without outdoor access followed by broilers given outdoor access on day 35 and day28 and lowest for broilers given outdoor access on day 21 of age. It can be concluded that giving outdoor access to fast-growing broilers at the age of day 21 improves carcass and meat quality traits.

Genome-wide association study identifies markers associated with carcass and meat quality traits in Italian Large White pigs.

A GWAS was performed using the genotypes obtained by PorcineSNP60 v2 BeadChip and 11 phenotypic traits (carcass lean meat percentage; backfat thickness; Longissimus thoracis muscle thickness; lightness; backfat thickness measured with caliper at the midline; meat pH measured at about 1h post mortem and 24h post mortem; CIE L*, a* and b* color parameters; and water-holding capacity). Three markers were associated with three of the phenotypic traits considered: M1GA0009592 (SSC7) with backfat thickness and lean meat content, DIAS0002910 (SSC6) and ALGA0109856 (SSC6) with water-holding capacity. The marker M1GA0009592, associated with backfat thickness, lies in a QTL region near the gene JARID2, which is a transcription factor also involved in the regulation of adipose-derived stem cell pluripotency. The results seem to indicate a possible role of these genomic regions in the regulation of pig carcass fatness (i.e. backfat at last rib) and water-holding capacity.

Application of the principal component analysis, cluster analysis, and partial least square regression on crossbreed Angus-Nellore bulls feedlot finished

Principal component analysis (PCA) and the non-hierarchical clustering analysis (K-means) were used to characterize the most important variables from carcass and meat quality traits of crossbred cattle. Additionally, partial least square (PLS) regression analysis was applied between the carcass measurements and meat quality traits on the classes defined by the cluster analysis. Ninety-seven non-castrated F1 Angus-Nellore bulls feedlot finished were used. After slaughter, hot carcass weight, carcass yield, cold carcass weight, carcass weight losses, pH, and backfat thickness (BFT) were measured. Subsequently, samples of the longissimus thoracis were collected to analyze shear force (SF), cooking loss (CL), meat color (L*, chroma, and hue), intramuscular fat, protein, collagen, moisture, and ashes. Principal component 1 (PC1) was correlated with colorimetric variables, while PC2 was correlated with carcass weights. Afterwards, three clusters (k = 3) were formed and projected in the gradient defined by PC1 and PC2 and allowed distinguishing groups with divergent values for collagen, protein, moisture, CL, SF, and BFT. Animals from high chroma group presented meat with more attractive colors and tenderness (SF = 1.97 to 4.84kg). Subsequently, the PLS regression on the three chroma groups revealed a good fitness and the coefficients are used to predict the chroma variable from the explanatory variables, which may have practical importance in attempts to predict meat color from carcass and meat quality traits. Thus, PCA, K-means, and PLS regression confirmed the relationship between meat color and tenderness.

Evaluation of Vanaraja female line chicken for growth, production, carcass and egg quality traits

Vanaraja female line (PD-2) chicken was evaluated for growth, production, carcass and egg quality traits utilizing the data generated from 3,737 chicks and 599 hens produced in pedigreed mating with 50 sires and 250 dams at ICAR-Directorate of Poultry Research, Hyderabad, Telangana. Fertility was 86.63% and the hatchability was 86.72% on fertile egg set and 72.53% on total egg set basis in PD-2 line. The least squares means (LSM) for six week body weight and shank length were 662.38±2.54 g and 71.48±0.12 mm, respectively. Sex had significant influence on live weight, thigh and wing proportions wherein cocks had heavier and stronger legs and wings. Abdominal fat was significantly higher in females. The egg production up to 40 and 52 weeks of age was 80.29±0.03 and 133.16±0.05 eggs, respectively. The egg mass up to 52 weeks of age was 7447.41±2.98 g in PD-2 line. The heritability was low up to 15% for egg production and 17% for egg mass, the primary trait of selection in PD-2 line. Egg mass and egg weights at different ages had positive association as larger and high number of eggs contributed more to the egg mass. The egg mass and egg production had a significant positive association in PD-2 line. The egg quality was reasonably fair with average shape index of 75.22 and Haugh unit of 79.0±0.62. The albumen, yolk and shell weights were 30.20±0.14, 15.8±0.09, 0.40±0.02 g, respectively. The proportion of heritability and the magnitude of association between the important traits provide requisite information for implementing the breeding program for improvement of egg production in PD-2 line.

Evaluation of Growth, Carcass and Meat Quality of a Two-way Cross Developed for Rural Poultry Farming

Background: Rural poultry farming with improved dual purpose chicken varieties is fast growing in the country. The meat quality of cocks and its acceptance by the consumer is important for its propagation as dual purpose variety. The two way cross produced by PD-1 xPD-4 (improved Aseel) was evaluated for growth, carcass and meat quality.Metohds: The growth, carcass and meat quality traits were evaluated in a two way cross developed and propagated for rural poultry farming at ICAR-Directorate of Poultry Research, Rajendranagar, Hyderabad, Telangana. The data collected on 232 birds for growth, 40 birds for carcass and 20 birds for meat quality were utilized for the study. Result: The body weight and shank length significantly (P£0.05) differed between the sexes from six weeks onwards with higher (P£0.05) body weights and longer shanks in males. The six week body weight and shank length were 578.23±8.22g and 78.93±6.22 mm in males and 548.28±7.20 g and 76.15±5.28 mm in females, respectively. The Least squares means for body weight at 12 weeks of age in males and females were 1652.61±21.49 and 1367.86 ±14.99 g, respectively. Males had strong legs with significantly (P£0.05) high proportion of thigh meat. The effect of sex was non-significant on Dressing percentage (DP), neck, back and breast meat proportions. The DP was 71.12±0.22% in males and 72.51±0.43 % in females, respectively. The bone proportion was higher (P£0.05) in males. Abdominal fat proportion was significantly (P£0.05) higher in pullets. Feather proportion was higher (P£0.05) in males. Sex did not show any significant variation on the pH, Shear force value (SFV) and Hydroxy Proline (HP) values. The yellowness (b*) differed (P£0.05) between the sexes and it was lower in males. The fat and moisture content differed significantly (P£0.05) between the sexes. Fat proportion was higher (P£0.05) in females (3.57±0.05) than in males (2.97±0.01). Protein and ash proportions were similar in both the sexes. The sensory attributes ranged from 6.55 to 7.15 on an eight point scale in two-way cross meat indicating better consumer acceptability. The study concluded that, two-way cross with ideal growth, carcass and optimum meat quality and reasonable consumer acceptability may be a suitable variety for propagating in rural and tribal areas under free range backyard conditions.

Associations between UASMS2 polymorphism in leptin gene and growth, carcass and meat quality traits of cattle: a meta-analysis

Although numerous studies investigated the effect of UASMS2 polymorphism in leptin gene on cattle production, a consensus has not yet been reached. Therefore, we reviewed and meta-analyzed the effects of UASMS2 on cattle. We searched potentially relevant studies from seven databases (to December 25, 2019). Standard mean difference along with 95% confidence intervals was calculated to assess the strength of association through the random-effects model. Six published articles containing 1378 cattle samples were included in our meta-analysis. We found UASMS2 was not related to carcass weight, dressing percentage and loin muscle area in the recessive genetic model, but there was a significant association between UASMS2 and average daily weight gain, dry matter intake, body weight, marbling score, and backfat thickness. This meta-analysis indicated that UASMS2 was associated with growth and meat quality traits of cattle, implying that this SNP can be used reliably in beef cattle breeding. This study may provide valuable information on improving beef yield and quality in cattle production.

Non-Destructive Imaging and Spectroscopic Techniques for Assessment of Carcass and Meat Quality in Sheep and Goats: A Review.

In the last decade, there has been a significant development in rapid, non-destructive and non-invasive techniques to evaluate carcass composition and meat quality of meat species. This article aims to review the recent technological advances of non-destructive and non-invasive techniques to provide objective data to evaluate carcass composition and quality traits of sheep and goat meat. We highlight imaging and spectroscopy techniques and practical aspects, such as accuracy, reliability, cost, portability, speed and ease of use. For the imaging techniques, recent improvements in the use of dual-energy X-ray absorptiometry, computed tomography and magnetic resonance imaging to assess sheep and goat carcass and meat quality will be addressed. Optical technologies are gaining importance for monitoring and evaluating the quality and safety of carcasses and meat and, among them, those that deserve more attention are visible and infrared reflectance spectroscopy, hyperspectral imagery and Raman spectroscopy. In this work, advances in research involving these techniques in their application to sheep and goats are presented and discussed. In recent years, there has been substantial investment and research in fast, non-destructive and easy-to-use technology to raise the standards of quality and food safety in all stages of sheep and goat meat production.

Effects of A Concentrate Rich in Agro-Industrial By-Products on Productivity Results, Carcass Characteristics and Meat Quality Traits of Finishing Heifers.

Simple SummaryIn geographic areas where it is not possible to finish beef cattle on pastures or preserved forages, diets are mainly based on cereals. This intensive feeding system competes for feed with other species and does not take advantage of the capacity of ruminants to digest fibrous feeds. Moreover, cereal-rich diets for ruminants cannot be considered sustainable under current policy guidelines and make no significant contribution to the circular bioeconomy. We assayed an alternative intensive finishing diet for beef heifers where agro-industrial by-products, some of them highly fibrous ones, comprised 73.5% of the concentrate. We found that there were no differences in growth performance, carcass characteristics and meat quality traits between treatments, which might be considered positive from the point of view of sustainability of beef production. We also found that instrumental measures of meat related to important sensory attributes for consumer acceptance can be improved by increasing ageing time from 7 to 21 or 28 days.Finishing diets in intensive beef production systems are mainly based on cereals, which does not take advantage of the capacity of the ruminant digestive system to digest fibrous feeds, cannot be considered sustainable and does not contribute to the circular bioeconomy. Our aim was to investigate the effects of an alternative concentrate rich in agro-industrial by-products for finishing crossbred Limousine heifers. Four pens with 12 heifers and four pens with 13 heifers were randomly allocated to one of two treatments: control (CON), a commercial concentrate with a 43.3% cereal composition, and alternative (ALT), a concentrate with a composition of 26% cereals and up to 73.5% agro-industrial by-products. Growth performance data were collected along the 91 days of the experimental period. Carcass characteristics were collected after slaughter and 24 h later. Vacuum-packaged samples from longissimus muscle were aged for 7, 21 or 28 days to study meat quality traits. Feed intake was higher and feed conversion rate was lower in the ALT treatment, but no differences were found in average daily gain and feeding costs. Treatment had no effects on any of the measured carcass traits (grading, hot and cold carcass weight, dressing out, chilling losses, subcutaneous fat depth, pH, temperature and lean and fat colour) nor on the meat quality traits (drip loss, cooking loss, shear force, oxidative stability, chromatic indices and pigment contents). Ageing time decreased drip loss and shear force, increased lightness and did not affect redness or surface colour stability. In conclusion, feeding crossbred Limousine heifers a finishing diet rich in agro-industrial by-products did not have any negative effects on performance, carcass and meat quality traits, which might be considered positive from the point of view of sustainability of beef production. Under the conditions assayed, ageing for 21 and 28 days improved tenderness of meat, without detrimental effects on oxidative stability or traits related to visual acceptability.

Transcriptome Profiling Associated with Carcass Quality of Loin Muscles in Crossbred Pigs.

Simple SummaryCarcass quality traits, such as lean depth and loin depth, are of extreme economic importance for the swine industry. This study aimed to identify the gene expression pattern related to carcass quality in crossbred pigs ((Landrace × Yorkshire) × Duroc). In total, 20 crossbred pigs were used in this study and divided into two groups based on the loin muscle quality grade. Total RNA samples extracted from the loin muscles of both groups were submitted for RNA-seq. Differentially expressed gene (DEG) analysis of the two groups revealed 282 up-regulated and 189 down-regulated genes (p ≤ 0.01), linked to tissue development, striated muscle tissue development, tissue morphogenesis, and lipid metabolic process gene ontology (GO) terms. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis highlighted genes related to the calcium signaling pathway, apelin signaling pathway, and the mammalian target of rapamycin (mTOR) signaling pathway. We constructed an expressed gene catalog, which may serve as a resource for genomic studies focused on uncovering the molecular mechanisms underlying carcass quality in crossbred pigs.Carcass quality traits, such as lean depth and loin depth, are of extreme economic importance for the swine industry. This study aimed to identify the gene expression pattern related to carcass quality in crossbred pigs ((Landrace × Yorkshire) × Duroc). In total, 20 crossbred pigs were used in this study and they were divided into two groups (class I grade, n = 10; class II grade, n = 10) based on the carcass grades. Total RNA samples extracted from the loin muscles of both groups were submitted for RNA-seq. The quality assessment of the sequencing reads resulted in 25,458 unigenes and found 12,795 candidate coding unigenes with homology to other species after annotation. Differentially expressed gene (DEG) analysis of the two groups revealed 282 up-regulated and 189 down-regulated genes (p ≤ 0.01), linked to tissue development, striated muscle tissue development, tissue morphogenesis, and lipid metabolic process gene ontology (GO) terms. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis highlighted genes related to the calcium signaling pathway, melanogenesis, the sphingolipid signaling pathway, the apelin signaling pathway, and the mTOR signaling pathway. We constructed an expressed gene profile, which may serve as a resource for genomic studies focused on uncovering the molecular mechanisms underlying carcass quality in crossbred pigs.

Effects of forage finishing methods with alfalfa on cattle growth performance and beef carcass characteristics, eating quality, and nutrient composition

Over 2 yr, yearling steers (n = 200) were used to evaluate growth performance, carcass, meat quality, and nutrient composition traits as affected by management regimen comparing three methods of forage finishing (alfalfa pasture, hay, and silage) versus a high corn diet. Management regimen × year interactions (P < 0.01) for average daily gain, dry matter intake, gain-to-feed, carcass weight, and grade fat were due to lower performance for hay-fed cattle in years 1 vs. 2. Carcass, meat quality, and taste panel traits were generally similar (P > 0.10) across method of forage finishing. Trained taste panels found longissimus muscle from grain-fed beef to be more (P < 0.01) tender, juicy, and flavourful than forage finished beef, with lower (P ≤ 0.05) ratings for tenderness and juiciness for hay- vs. silage-finished beef. Corn finished beef contained greater amounts of oleic and monounsaturated fatty acids and lower amounts of omega-3 and polyunsaturated fatty acids than forage finished beef (P ≤ 0.04). Although the method of forage finishing may not affect most performance, carcass, and meat quality (pH, colour, intramuscular fat content, and shear force) traits, there may be concerns with tenderness and juiciness for beef from cattle finished on alfalfa hay.

Egg Yolk IgY: A Novel Trend of Feed Additives to Limit Drugs and to Improve Poultry Meat Quality.

Drugs that are commonly used in poultry farms can potentially cause a detrimental effect on meat consumers as a result of chemical residues. Therefore, seeking a natural alternative is crucial for the health of the consumers. The egg yolk immunoglobulin Y (IgY) is a promising natural replacement for antibiotics in the broilers' diet. There is a scarce focus on the influence of probiotics and IgY on the quality and the nutritive values of broiler meat and whether it can efficiently displace the anti-microbial power of antibiotics. Herein we used 40 Ross chicks (1.2 ± 0.43 days old) and separated them into four groups with variant feed additives (basal diet “control,” probiotic, IgY, and probiotic + IgY). Our findings showed that the combination of probiotic and IgY supplementation enhanced the carcass quality traits and decreased the pH values that could retard spoilage due to bacteria and improve shelf life and meat quality. The same group also achieved a significant reduction in thiobarbituric acid value, indicating an improvement of meat quality. Moreover, color, shear force, water holding capacity, and cooking loss were most acceptable in broiler meat supplemented with IgY, which confirmed the highest carcass quality. Notably, the weight gain in the combination group has been greatly increased. Also, the protein percentage was the highest (22.26 ± 0.29, P < 0.001) in this combined supplementation group, which revealed the highest nutritive values. Staphylococcus aureus and Escherichia coli could not be detected in the meat of the probiotics group and/or in the combined treatment group. Interestingly, the IgY group showed an evidence of the killing power (log colony-forming units per milliliter) of S. aureus and Listeria monocytogenes at 1,500 μg/ml. Our findings, in vitro as well as in vivo, revealed that the combination group had antimicrobial bioactivity and enhanced the chickens' immunity. Therefore, IgY, a novel trend of feed additives, can be used to limit drugs. Additionally, the mortality percentage recorded was zero in all groups that received feed supplementation, while the combination group reached the best financial advantages. We concluded that feeding IgY powder with probiotic is a frontier to improve the productivity, immunity, and meat quality of broilers.

Polymorphism of the PLIN1 gene and its association with body measures and ultrasound carcass traits in Qinchuan beef cattle.

The PLIN1 gene produces a phosphorylated protein wrapped in lipid droplets in adipocytes. This phosphorylation assists the mobilization of fat into adipose tissue. The purpose of the experiment was to study the polymorphism of the PLIN1 gene and its relationship with the body and carcass characteristics of Qinchuan cattle to find molecular genetic markers that can be used for breeding. The expression level of the PLIN1 gene was determined in various tissues by qRT-PCR. The results showed that the highest level of PLN1 expression was found in subcutaneous fat, followed by the heart and longissimus muscle, and the lowest level was found in the kidney. Five SNP loci of the PLIN1 gene were identified in 510 Qinchuan cattle, including g.3580T>C (SNP1), g.3898G>A (SNP2), g.8333G>A (SNP3), g.10517T>C (SNP4), and g.10538G>T (SNP5). The results show that SNP1, SNP2, SNP3, and SNP4 were moderately polymorphic (0.25 < PIC < 0.5), while SNP5 was minimally polymorphic (PIC < 0.25). SNP2, SNP3, and SNP5 were within Hardy-Weinberg equilibrium (P > 0.05), but SNP1 and SNP4 were not (P < 0.05). Correlation analysis showed that the five SNPs of the PLIN1 gene were correlated with back-fat depth, intramuscular fat, and chest depth of Qinchuan cattle. The double haplotype H2H4 in Qinchuan beef was associated with body and carcass traits. We conclude that variants mapped within PLIN1 can be used in marker-assisted selection for carcass quality and body traits in breed improvement programs for Qinchuan cattle.

The effect of gender status on the growth performance, carcass and meat quality traits of young crossbred Holstein-Friesian×Limousin cattle.

ObjectiveThe objective of this study was to compare growth performance, carcass traits and meat quality in young bulls, steers and heifers produced by crossing Limousin bulls with Holstein-Friesian cows, fattened semi-intensively and slaughtered at 18 months of age.MethodsThirty-one young calves were reared in a conventional production system, and were fed milk replacer, hay and concentrate. At 6 months of age, the animals were divided into groups based on gender, and were fed a total mixed ration composed of grass silage, concentrates I and II in a semi-intensive production system. At the end of the fattening period (18 months), the animals were slaughtered, carcass quality was evaluated, and samples of musculus longissimus thoracis were collected to determine the proximate composition and quality of meat.ResultsBulls were characterized by the highest percentage share of the most valuable cuts in the carcass, and three-rib sections from bull carcasses had the highest lean meat content with low intramuscular fat content (0.93%). No significant differences in carcass conformation, dressing percentage or the percentage share of round in the right half-carcass were found between bulls vs. steers and heifers. Heifers and steers had higher carcass fat content than bulls, which had a positive influence on the sensory properties of beef. In comparison with the meat of bulls, the meat of steers and heifers was characterized by more desirable physical properties and sensory attributes (water-holding capacity, shear force, color lightness, aroma, juiciness, tenderness, flavor).ConclusionUnder the semi-intensive production system, heifers and steers had higher carcass fat content than bulls, which had a positive effect on the sensory properties of beef. Bulls are better suited for intensive systems, which contribute to improving the quality of their meat. The results of this study may encourage producers to breed steers and heifers for beef.

Correlations between single nucleotide polymorphisms in FABP4 and meat quality and lipid metabolism gene expression in Yanbian yellow cattle.

FABP4 is a candidate gene for carcass and meat quality traits in livestock and poultry. However, the effects of FABP4 have not been examined in the Yanbian yellow cattle, an economically important local cattle breed in China. In this study, we characterized single nucleotide polymorphisms (SNPs) in FABP4 in this cattle breed and their associations with meat quality traits. Six SNPs (referred to as SNP1-6) were identified in FABP4 by direct sequencing and polymerase chain reaction-restriction fragment length polymorphism. The six SNPs were significantly correlated with meat quality traits. In particular, the GG and GA genotypes of SNP1 were significantly associated with water and fat contents and GG and AA genotypes of SNP1 were significantly associated with protein contents (P < 0.05). The fat content and marbling in heterozygous individuals at SNP2-6 were significantly higher than those in wild-type or mutant individuals (P < 0.05), while protein content was significantly higher in wild-type and mutant individuals than in heterozygous individuals (P < 0.05). A gene expression analysis indicated that the lipid metabolism-related genes FABP4, PPARγ, ANGPTL4, and LPL show similar expression patterns with respect to FABP4 genotypes, with the highest levels in wild-type individuals and the lowest levels in mutants. In conclusion, FABP4 SNPs can be used for marker-assisted selection in Yanbian yellow cattle breeding.

A Genome-Wide Association Study Identifying Genetic Variants Associated with Growth, Carcass and Meat Quality Traits in Rabbits.

Growth, carcass characteristics and meat quality are the most important traits used in the rabbit industry. Identification of the candidate markers and genes significantly associated with these traits will be beneficial in rabbit breeding. In this study, we enrolled 465 rabbits, including 16 male Californian rabbits and 17 female Kangda5 line rabbits as the parental generation, along with their offspring (232 male and 200 female), in a genome-wide association study (GWAS) based on SLAF-seq technology. Bodyweight at 35, 42, 49, 56, 63 and 70 d was recorded for growth traits; and slaughter liveweight (84 d) and dressing out percentage were measured as carcass traits; and cooking loss and drip loss were measured as meat quality traits. A total of 5,223,720 SLAF markers were obtained by digesting the rabbit genome using RsaI + EcoRV-HF® restriction enzymes. After quality control, a subset of 317,503 annotated single-nucleotide polymorphisms (SNPs) was retained for subsequent analysis. A total of 28, 81 and 10 SNPs for growth, carcass and meat quality traits, respectively, were identified based on genome-wide significance (p < 3.16 × 10-7). Additionally, 16, 71 and 9 candidate genes were identified within 100 kb upstream or downstream of these SNPs. Further analysis is required to determine the biological roles of these candidate genes in determining rabbit growth, carcass traits and meat quality.

The genetic polymorphisms of melanocortin-4 receptor gene are associated with carcass quality traits in a Chinese indigenous beef cattle breed

Melanocortin-4 receptor (MC4R) was considered as an essential modifiers in feelings intake, the regulation of metabolism and body weight. This study aimed at identifying polymorphisms in MC4R gene that might associate with carcass quality traits in Chinese indigenous beef cattle breed. qPCR analysis showed that the MC4R gene was widely expressed in various tissues, with predominantly expression levels in heart. Three single-nucleotide polymorphisms (SNPs) were identified, including a mutation (g.85A > G) in 5’untranslated regions (UTR) and two mutations (g.927C > T and g.1069C > G) in exon 1. Based on the χ2 test, both g.927C > T and g.1069C > G loci fitted with Hardy-Weinberg equilibrium (P > .05). Population genetic analysis showed that except for g.85A > G, the other detected SNPs strongly affected the bovine back fat thickness and intramuscular fat content (P < .05). The individuals with Hap1/4 diplotypes (ACC-ATG) were highly significantly associated with carcass quality traits than the other diplotypes (P < .01 or P < .05). Results indicated that the bovine MC4R gene polymorphisms were implicated as genetic markers of potential importance in marker-assisted selection (MAS) strategies to improve carcass quality in Chinese Qinchuan cattle.

The value of incorporating carcass trait phenotypes in terminal sire selection indexes to improve carcass weight and quality of heavy lambs

Genetic selection for carcass traits is paramount to maximize the profitability and long-term sustainability of any meat-producing livestock species. The main objectives of this research were to evaluate the efficiency of indicator traits for the genetic improvement of lamb carcass traits and to determine the value of including carcass traits into terminal sire selection indexes for the Canadian sheep industry. The carcass traits included hot carcass weight (HCW), fat depth at the GR site (FATGR) and average carcass conformation score (AVGCONF), and were measured on heavy lambs (slaughter age less than 365days and HCWgreater than 16.3kg) in commercial abattoirs. Growth traits were found to be moderately efficient indicator traits for the genetic improvement of HCW but selection on ultrasound traits was necessary to substantially improve the carcass quality traits (FATGR and AVGCONF). Economic selection indexes were designed by adding various combinations of carcass traits into the Canadian Sheep Genetic Evaluation System terminal indexes. Records measured on individuals and progeny were assumed to be the sources of information for live animal and carcass traits, respectively. The changes in index accuracy, efficiency and expected correlated response were used to assess the value of their inclusion. HCW was found to have a large economic value, and its inclusion into terminal selection indexes was expected to substantially increase their accuracy (0.08-0.12 points) and efficiency (20%-30%). However, further including FATGR (measured 110mm from the carcass midline over the 12th rib) and AVGCONF had little impact on the accuracy (≤0.03) and efficiency (1%-7%) of the proposed indexes. Thus, the inclusion of carcass traits into the existing terminal selection indexes could be beneficial for the genetic improvement of HCW, but further research is needed to determine optimal methods of increasing carcass fatness and muscularity.

Candidate gene markers associated with production, carcass and meat quality traits in Italian Large White pigs identified using a selective genotyping approach

Italian heavy pig selection programs are based on production (average daily gain, ADG; feed gain ratio, FGR), carcass (weight of lean cuts, LC; ham weight, HW; backfat thickness, BFT) and meat quality traits of the green hams (ham weight loss at first salting, HWLFS; and visible intermuscular fat, VIF). In this study, we evaluated whether a selective genotyping approach previously designed for BFT could identify markers associated with other traits (ADG, FGR, HW, HWLFS, LC and VIF), most of which correlated with BFT. Italian Large White gilts were chosen according to their extreme estimated breeding values for BFT (275 with the most negative and 278 with the most positive EBVs) within a population of about 12,000 sib-tested pigs. A total of 736 single nucleotide polymorphisms (SNPs) in candidate genes for fat deposition and/or related traits were genotyped. After filtering, a total of 279 SNPs in 234 genes remained for association analyses that were carried out using random residuals (RRs) for the six mentioned traits. Four SNPs in three candidate genes were associated with some of the considered traits. A SNP in the exosome component 1 (EXOSC1) gene and a SNP in the glycogen phosphorylase L (PYGL) gene were associated with HWLFS RRs. Two SNPs within the TBC1 (tre-2/USP6, BUB2, cdc16) domain family, member 1 (TBC1D1) gene were associated with LC RRs and suggestively associated with other performance, carcass and meat traits. Association analysis using six TBC1D1 haplotypes, inferred from four genotyped SNPs within this gene, confirmed the results of the single-marker association study.This study contributes to dissect the biological mechanisms underlying the genetic correlations among BFT, HWLFS and LC, which are critical for the sustainable implementation of tailored selection programs in heavy pigs.

Polymorphism of L-FABP (SNP g. 1593 C&gt;T) Gene and Its Association with Fatty Acid Composition, Carcass, and Meat Quality in Cihateup Duck

Fatty acid composition, carcass, and meat quality are quantitative traits which are controlled by several genes or polygenic. One of the genes that plays important role in the fatty acid in meat quality and fatty acid composition is liver-type fatty acid-binding protein (L-FABP). The aims of this study were to identify single nucleotide polymorphism (SNP) of liver-fatty acid binding protein (L-FABP) gene and its association with fatty acid, carcass, and meat quality traits in cihateup duck. Cihateup ducks were originated from Tasikmalaya, West Java, Indonesia. The study used a total of 98 ducks aged of 12 weeks old with the average body size of 1.4±0.12 kg for PCR-RFLP analyses and 76 ducks for the association analyses. Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) was used to identify SNP g. 1593 (C>T) of L-FABP gene. The associations of L-FABP genotypes with fatty acid, carcass, and meat quality traits were performed using T-test procedures. The result showed that the SNP of L-FABP gene was polymorphic with three genotypes (CC, CT, and TT). The Chi-square test revealed that the locus of L-FABP (g. 1593 C>T) was in Hardy - Weinberg equilibrium. L-FABP gene was significantly associated (p T) of L-FABP gene may be a useful marker for selecting and producing duck meat having desirable fatty acids and carcass and meat quality.