Intensified tropical pasture-based beef cattle production systems and their effects on carcass traits, meat quality and methane emissions from Nellore steers

Beef cattle data from temperate (TEMP, n = 3947) and tropically (TROP, n = 4137) adapted breeds were analysed to compute estimates of genetic and phenotypic correlations between animal, abattoir carcass, and meat quality measures. Live animal traits included: liveweight (S2LWT), scanned subcutaneous rump fat depth (S2P8), scanned eye muscle area (S2EMA), flight time (S1FT), and finishing average daily gain (FADG). Carcass traits included: hot carcass weight (CWT), retail beef yield percentage (RBY), intramuscular fat percentage (IMF), subcutaneous rump fat depth (P8), eye muscle length by width (ELW), and meat colour score (MEATC). Meat quality measures taken on 2 muscles [M. longissimus thoracis et lumborum (LTL) and M. semitendinosus (ST)] included: shear force of LTL (LTL_SF) and ST (ST_SF); compression of the ST (ST_C); cooking loss % of the LTL (LTL_CL%) and ST (ST_CL%); Minolta LTL L* (LTL_L*), a* (LTL_a*), ST a* (ST_a*); and consumer-assessed LTL tenderness score (LTL_TEND). Genetic and phenotypic correlations between animal measures and related carcass traits were moderate to very high for TEMP and TROP. Genetic correlations between S2LWT and CWT were 0.89 and 0.82, between S2P8 and P8 0.80 and 0.88, and between S2EMA and ELW 0.62 and 0.68, for TEMP and TROP, respectively. Genetic correlations between animal measures and other carcass traits varied; moderate genetic correlations were estimated between S2P8 and RBY (–0.57, –0.19 for TEMP, TROP) and S2P8 and IMF (0.39, 0.23 for TEMP, TROP). Genetic correlations between animal and meat quality measures were moderate to low. For TEMP, moderate genetic correlations were estimated between S2P8 and LTL_TEND (0.38), FADG and ST_a* (–0.49), and FADG and LTL_TEND (0.45); and for TROP, S1FT and LTL_SF (–0.54), and S2EMA and LTL_L* (–0.46). Phenotypic correlations between animal and meat quality were generally low and close to zero. Several moderate to high genetic correlations existed between carcass and meat quality traits. In general, fatness measures were genetically correlated with tenderness (e.g. IMF and LTL_TEND 0.61, 0.31 for TEMP, TROP). CWT was genetically correlated with meat colour (CWT and LTL_L* 0.66, 0.60 for TEMP, TROP) and objective tenderness measures (CWT and ST_C –0.52, –0.22 for TEMP, TROP). Once again phenotypic correlations between carcass and meat quality were low, indicating that few phenotypic predictors of meat quality traits were identified. Several of the genetic correlations show that both animal and abattoir carcass traits may be of use as indirect measures for carcass and meat quality traits in multiple trait genetic evaluation systems.

Body composition, fat deposition and meat quality are important traits in chickens. Melanocortin receptor (MCR) plays an important role in central melanocortin system (CMS) and muscle cells. The purpose of the present study was to analyze association of the MC3R and the MC4R genes with chicken carcass and meat quality traits. Using eight meat-type chicken populations constructed with 5 pure lines (developed from Chinese local breeds) and 3 crossbreeds (S01×D99, S01×S05, S01×S10), the association of 3 single nucleotide polymorphisms (SNP: MC3R-A1424G, MC4R-G923T and MC4R-C944T) of MC3R and MC4R gene with carcass and meat quality traits was studied. The results showed as follows: (1) the MC3R-A1424G genotypes were significantly associated with most carcass traits except for semi-eviscerated percentage and leg muscle percentage (LMP), the MC4R-G923T genotypes were significantly associated with live weight, carcass weight, leg muscle weight (LMW) and LMP, and the MC4R-C944T genotypes were not significantly associated with most carcass traits except for LMW and LMP; (2) to meat quality, the MC3R-A1424G genotypes significantly affected muscle crude protein (GP) value, and the allele A had positive additive effects on slaughter traits. The MC4R-G923T and the MC4R-C944T sites significantly affected muscle GP value and glutamic acid (Glu) value; (3) the haplotypes based on the 2 SNP of MC4R gene were also significantly associated with meat quality traits, but had no significant associations with carcass traits. The research built the base for further analysis on relation between genetic variation of MC3R and MC4R genes and the carcass and meat quality traits, and molecular marker's application in breeding.

Pork quality and carcass characteristics are now being integrated into swine breeding objectives because of their economic value. Understanding the genetic basis for these traits is necessary for this to be accomplished. The objective of this study was to estimate phenotypic and genetic parameters for carcass and meat quality traits in 2 Canadian swine populations. Data from a genomic selection study aimed at improving meat quality with a mating system involving hybrid Landrace × Large White and Duroc pigs were used to estimate heritabilities and phenotypic and genetic correlations among them. Data on 2,100 commercial crossbred pigs for meat quality and carcass traits were recorded with pedigrees compromising 9,439 animals over 15 generations. Significant fixed effects (company, sex, and slaughter batch), covariates (cold carcass weight and slaughter age), and random additive and common litter effects were fitted in the models. A series of pairwise bivariate analyses were implemented in ASReml to estimate phenotypic and genetic parameters. Heritability estimates (±SE) for carcass traits were moderate to high and ranged from 0.22 ± 0.08 for longissimus dorsi muscle area to 0.63 ± 0.04 for trimmed ham weight, except for firmness, which was low. Heritability estimates (±SE) for meat quality traits varied from 0.10 ± 0.04 to 0.39 ± 0.06 for the Minolta b* of ham quadriceps femoris muscle and shear force, respectively. Generally, most of the genetic correlations were significant (P < 0.05) and ranged from low (0.18 ± 0.07) to high (-0.97 ± 0.35). There were high negative genetic correlations between drip loss with pH and shear force and a positive correlation with cooking loss. Genetic correlations between carcass weight (both hot and cold) with carcass marbling were highly positive. It was concluded that selection for increasing primal and subprimal cut weights with better pork quality may be possible. Furthermore, the use of pH is confirmed as an indicator for pork water-holding capacity and cooking loss. The heritabilities of carcass and pork quality traits indicated that they can be improved using traditional breeding methods and genomic selection, respectively. The estimated genetic parameters for carcass and meat quality traits can be incorporated into the breeding programs that emphasize product quality in these Canadian swine populations.

Meat quality and carcass characteristics are becoming more relevant for the sheep breeding programs because of their economic value. Understanding the genetic basis for these traits and its relationship with standard traits is necessary for this to be accomplished. Genetic and phenotypic parameters were estimated for 33 growth, carcass and meat quality traits using a large and unique data set from a variety of terminal sire sheep breeds and composites. This is the most comprehensive study to date of genetic parameter estimates for carcass and meat quality traits in New Zealand sheep and includes many traits that are difficult or expensive to measure and novel traits such as number of rib pairs.Heritability estimates ranged from 0.01 for meat redness at 168h after display to 0.44 for ultrasonic eye muscle depth. Most genetic correlations among growth and carcass traits were favourable and moderate to high. However, some genetic antagonisms such as those between carcass fatness and carcass weight were observed indicating that selection to produce heavier carcasses would also result in fatter carcasses. The genetic correlations among meat quality traits were quite variable. Marbling and tenderness were favourably but weakly genetically correlated, indicating that indirect selection gains by selecting only for traditional traits (i.e. growth and carcass traits) would be small and it is recommended that both be included in a breeding program in order to make greater genetic progress in these traits. The genetic correlations among growth/carcass and eating quality traits were moderate to low; however, some genetic antagonisms were observed, such as carcass fatness with marbling and meat redness, indicating that a stronger emphasis on selection for leanness could affect meat quality traits and consequently consumer eating satisfaction.The heritability estimates and phenotypic variances for the carcass and meat quality traits of New Zealand sheep populations suggest that most traits, apart from pH and meat yellowness, have sufficient phenotypic and genetic variation to enable substantial genetic gains to be achieved through selection. The genetic parameters presented in this study provide a valuable reference to design and/or update a terminal sire breeding program emphasizing meat quality traits. It is important to note that unfavourable genetic correlations identified in this study were low to moderate in magnitude, making it practical to select for favourable genetic progress in all traits or at least to maintain commercially acceptable levels for some traits, if they are measured and balanced in a selection index.

The aim of this study was to evaluate the relationship between temperament in Nellore bulls with carcass and meat quality traits. In total, 1,400 bulls were studied, and temperament was assessed using two measurements: movement score (MOV) and flight speed test (FS). Both MOV and FS were measured at two time points, with background (MOVb and FSb) temperament measured at yearling age, ~550 d after birth, and the preslaughter (MOVps and FSps) temperament measured at the end of the feedlot period. The change of temperament resulting in an increase or decrease in reactivity was also used to measure meat quality. The traits used to define carcass and meat quality included carcass bruises (BRU), hot carcass weight (HCW, kg), ribeye area (REA, cm2), backfat thickness (BFT, cm), marbling score (MS), meat pH after thawing (pH), presence or absence of dark cutters, color parameters of luminosity (L*), redness (a*) and yellowness (b*), cooking loss (CL, %), and Warner-Bratzler shear force (WBSF, kg). A principal component (PC) analysis was initially applied to the carcass and meat quality traits, followed by logistic regression models and linear mixed models to evaluate the effects of temperament on carcass and meat quality. The risks of carcass bruises and dark cutters did not differ as a function of any temperament trait (P > 0.05). In turn, animals classified as high MOVb (reactive) had lower PC3 values (P = 0.05), CL (P = 0.02), and tended to have lower MS (P = 0.08). In addition, animals classified as high FSb (faster and reactive cattle) produced carcasses with smaller REA (P < 0.01), higher meat pH (P < 0.01), lower color gradients (L*, P = 0.04; b*, P < 0.01), and lower PC1 and PC4 scores (P < 0.01) when compared with the low FSb class. For preslaughter temperament, high MOVps was related to lower color a* (P = 0.04), whereas high FSps was related to lower HCW, MS, and PC2 (P < 0.01) than the calmer ones (low FSps). The reduction in MOV was related to more tender meat, and the reduction in FS to heavier carcass and brighter meat. We conclude that excitable temperament in Nellore cattle may have negative effects in some of the carcass and meat quality attributes assessed, mainly those related to muscle deposition on carcass and color gradients. Measurement of temperament before the cattle entered the feedlot was a better predictor of carcass and meat quality traits, compared with temperament assessment at the end of the feeding period.

Meat quality and carcass traits were measured for 2180 feedlot finished Brahman (BRAH) and Tropical Composite (TCOMP) steers to investigate genetic and non-genetic influences on shear force, and other meat quality traits. Genetic and phenotypic correlations were estimated between carcass and meat quality traits, and with live animal measurements collected in steers from weaning to feedlot exit, and their heifer half-sibs up to their first mating, which were managed in Australia’s tropical or subtropical environments. Left sides of carcasses were tenderstretched (hung by the aitch-bone) while right sides were conventionally hung (by the Achilles tendon). Tenderstretching reduced mean shear force by 1.04 kg, and phenotypic variance by 77% of that observed in conventionally hung sides. Genotype differences existed for carcass traits, with TCOMP carcasses significantly heavier, fatter, with greater eye muscle area, and lower retail beef yield than BRAH. TCOMP had lower shear force, and higher percent intramuscular fat. Meat quality and carcass traits were moderately heritable, with estimates for shear force and compression of 0.33 and 0.19 for BRAH and 0.32 and 0.20 for TCOMP respectively. In both genotypes, estimates of heritability for carcass traits (carcass weight, P8 and rib fat depths, eye muscle area and retail beef yield) were consistently moderate to high (0.21 to 0.56). Shear force and compression were genetically correlated with percent intramuscular fat (rg = –0.26 and –0.57, respectively), and meat colour (rg = –0.41 and –0.68, respectively). For TCOMP, lower shear force was genetically related to decreased carcass P8 fat depth (rg = 0.51). For BRAH steers and heifers measured at pasture, fatness traits and growth rates were genetically correlated with shear force, although the magnitude of these relationships varied with time of measurement. Net feed intake was significantly genetically correlated with carcass rib fat depth (rg = 0.49), eye muscle area (rg = –0.42) and retail beef yield (rg = –0.61). These results demonstrate that selection to improve production and carcass traits can impact meat quality traits in tropically adapted cattle, and that genotype specific evaluations will be necessary to accommodate different genetic relationships between meat quality, carcass and live animal traits.

Leptin, the hormone product of the obese gene, is secreted predominately from white adipose tissue and regulates feed intake, energy metabolism and body composition. It has been considered a candidate gene for performance, carcass and meat quality traits in beef cattle. The objective of this study was to identify SNPs in the promoter region of the leptin gene and to evaluate the possible association of the SNP genotypes with carcass and meat quality traits in Korean cattle. We identified a total of 25 SNPs in the promoter region (1,208-3,049 bp upstream from the transcription start site) of the leptin gene, eleven (g.1508C>G, g.1540G>A, g.1545G>A, g.1551C>T, g.1746T>G, g.1798ins(G), g.1932del(T), g.1933del(T), g.1934del(T), g.1993C>T and g.2033C>T) of which have not been reported previously. Their sequences were deposited in GenBank database with accession number DQ202319. Genotyping of the SNPs located at positions g.2418C>G and g.2423G>A within the promoter region was performed by direct sequencing and PCR-SSCP method to investigate the effects of SNP genotypes on carcass and meat quality traits in Korean cattle. The SNP and SSCP genotypes from the two mutations of the leptin promoter were shown to be associated with the BF trait. The average BF value of animals with heterozygous SNP genotype was significantly greater than that of animals with the homozygous SNP genotypes for the g.2418C>G and g.2423G>A SNPs (p<0.05). Analysis of the combined genotype effect in both SNPs showed that animals with the AC SSCP genotype had higher BF value than animals with BB or AA SSCP genotypes (p<0.05). These results suggest that SNP of the leptin promoter region may be useful markers for selection of economic traits in Korean cattle.

Growth, meat quality, and carcass traits are of economic importance in swine breeding. Understanding their genetic basis in commercial crossbred pigs and purebred-crossbred genetic correlations are necessary for a successful breeding program. The objectives of this study were to 1) estimate genetic parameters for growth, meat quality and carcass traits in a purebred sire line and related commercial crossbred pigs and 2) estimate the corresponding genetic correlations between purebreds and crossbreds (rpc). We analyzed 115266, 10927 and 43057 purebred records for growth, meat quality (n = 4) and carcass traits (n = 7), respectively. For crossbreds, there were 2000 pigs with growth records, with 900 of them having meat quality and carcass data. A series of univariate and bivariate analyses were used to estimate genetic parameters and rpc. Growth showed moderate heritability (0.20 ± 0.10 to 0.25 ± 0.01) in both purebreds and crossbreds. Heritability estimates for meat quality traits ranged from 0.21 ± 0.03 to 0.42 ± 0.04 in purebreds and from 0.17 ± 0.14 to 0.47 ± 0.15 in crossbreds. Carcass traits had higher heritability estimates in purebreds compared to crossbreds, except for hot carcass weight (0.10 ± 0.02 vs. 0.24 ± 0.16). Genetic correlations among meat quality traits were variable in both populations, whereas genetic correlations among carcass traits were similar in purebreds and crossbreds. Estimates of rpc were high for growth (0.99 ± 0.5) and for meat quality traits (0.94 ± 0.39 to 0.99 ± 0.2), except for Minolta color (-0.48 ± 0.56). Carcass traits had moderate to high estimates of rpc (0.64 ± 0.4 to 0.92 ± 0.3). Carcass fat had a negative estimate of rpc (-0.1 ± 0.5). However, ultrasound fat as an indicator trait for carcass fat had a high positive estimate of rpc (0.88 ± 0.14). Our results indicate that selection in purebreds can be efficient to improve these traits in both purebreds and crossbreds but for some traits, genetic gain can be improved by applying combined crossbred and purebred selection. Funding provided by Genome Canada and the National Research Council.

Carcass and meat quality are two important attributes for the beef industry because they drive profitability and consumer demand. These traits are of even greater importance in crossbred cattle used in subtropical and tropical regions for their superior adaptability because they tend to underperform compared to their purebred counterparts. Many of these traits are challenging and expensive to measure and unavailable until late in life or after the animal is harvested, hence unrealistic to improve through traditional phenotypic selection, but perfect candidates for genomic selection. Before genomic selection can be implemented in crossbred populations, it is important to explore if pleiotropic effects exist between carcass and meat quality traits. Therefore, the objective of this study was to identify genomic regions with pleiotropic effects on carcass and meat quality traits in a multibreed Angus–Brahman population that included purebred and crossbred animals. Data included phenotypes for 10 carcass and meat quality traits from 2,384 steers, of which 1,038 were genotyped with the GGP Bovine F-250. Single-trait genome-wide association studies were first used to investigate the relevance of direct additive genetic effects on each carcass, sensory and visual meat quality traits. A second analysis for each trait included all other phenotypes as covariates to correct for direct causal effects from identified genomic regions with pure direct effects on the trait under analysis. Five genomic windows on chromosomes BTA5, BTA7, BTA18, and BTA29 explained more than 1% of additive genetic variance of two or more traits. Moreover, three suggestive pleiotropic regions were identified on BTA10 and BTA19. The 317 genes uncovered in pleiotropic regions included anchoring and cytoskeletal proteins, key players in cell growth, muscle development, lipid metabolism and fat deposition, and important factors in muscle proteolysis. A functional analysis of these genes revealed GO terms directly related to carcass quality, meat quality, and tenderness in beef cattle, including calcium-related processes, cell signaling, and modulation of cell–cell adhesion. These results contribute with novel information about the complex genetic architecture and pleiotropic effects of carcass and meat quality traits in crossbred beef cattle.

Most QTL detection studies in pigs have been carried out in experimental F(2) populations. However, segregation of a QTL must be confirmed within a purebred population for successful implementation of marker-assisted selection. Previously, QTL for meat quality and carcass traits were detected on SSC 7 in a Duroc purebred population. The objectives of the present study were to carry out a whole-genome QTL analysis (except for SSC 7) for meat production, meat quality, and carcass traits and to confirm the presence of segregating QTL in a Duroc purebred population. One thousand and four Duroc pigs were studied from base to seventh generation; the pigs comprised 1 closed population of a complex multigenerational pedigree such that all individuals were related. The pigs were evaluated for 6 growth traits, 7 body size traits, 8 carcass traits, 2 physiological traits, and 11 meat quality traits, and the number of pigs with phenotypes ranged from 421 to 953. A total of 119 markers were genotyped and then used for QTL analysis. We utilized a pedigree-based, multipoint variance components approach to test for linkage between QTL and the phenotypic values using a maximum likelihood method; the logarithm of odds score and QTL genotypic heritability were estimated. A total of 42 QTL with suggestive linkages and 3 QTL with significant linkages for 26 traits were detected. These included selection traits such as daily BW gain, backfat thickness, loin eye muscle area, and intramuscular fat content as well as correlated traits such as body size and meat quality traits. The present study disclosed QTL affecting growth, body size, and carcass, physiological, and meat quality traits in a Duroc purebred population.

Transcriptome analysis in comparing carcass and meat quality traits of Jiaxing Black Pig and Duroc×Duroc×Berkshire×Jiaxing Black Pig crosses.

Carcass and meat quality traits of Nellore young bulls and steers throughout fattening

Genes involved in the physiological control of energy and triglyceride synthesis, such as malic enzyme 1, NADP(+)-dependent, cytosolic (ME1) and nuclear receptor subfamily 0, group B, member 2 (NR0B2), are key candidates that may have effects on meat and carcass quality traits. These genes were sequenced in Aberdeen Angus beef cattle, and the possibility of associations between SNPs and economically important carcass and meat quality traits was tested. Six novel SNPs, five in ME1 and one in NR0B2, were identified. A SNP in exon eight of ME1 resulted in a non-synonymous amino acid change from valine to isoleucine. Phenotypic data were recorded on 536 commercial Aberdeen Angus-cross beef cattle, which comprised 28 carcass quality, tenderness and sensory traits. The majority of the SNPs were associated with at least one of these traits, including an association between the NR0B2 SNP and fat class, and associations between at least one of the ME1 SNPs and eye muscle area, sirloin weight before maturation, sirloin steak tail length, and juiciness.

Combined GWAS and LDLA approaches to improve genome-wide quantitative trait loci detection affecting carcass and meat quality traits in pig

Moringa oleifera is a plant that has a very high composition of nutrients, including vitamins, minerals, amino acids and fatty acids, in its leaves and seeds, and has shown a potential to improve growth performance in poultry species when added as a supplement in their diet. This study investigated the supplementation of different levels of Moringa oleifera leaf powder and its effect on growth performance, carcass, skin and meat quality traits in Japanese quails. A total of 480-days-old quails were used in this study. The birds were randomly divided into four experimental groups which consisted of quails fed a conventional diet (control, M-0) or a conventional diet supplemented with 2% (M-2), 4% (M-4) and 6% (M-6) Moringa oleifera leaf powder. The results revealed that body weight and average body weight gain at 2 weeks of age were higher in M-2 quails than in quails in the other experimental groups (p < 0.05). The body weight and average body weight gain at 1, 3, 4 and 5 weeks of age were similar among the quails in the various experimental groups (p > 0.05). In addition, the feed intake, feed conversion ratio per bird, carcass, meat and skin quality traits did not vary among the quails in the various experimental groups (p > 0.05). The findings of the current study indicate that adding Moringa oleifera to quails' diets may have the potential to enhance the growth performance of quails without having an adverse effect on their carcass and meat quality traits. Nevertheless, in order to ensure a long-lasting impact of Moringa on growth, carcass and meat quality, the amount of Moringa that is added to the diet must be carefully considered.