Higher Marbling Scores Research Articles

Live and carcass production traits for progeny of an F1 USDA Prime-Yield Grade 1 carcass clone sire compared to progeny of popular beef terminal sires.

The cloning of beef carcasses that grade United States Department of Agriculture (USDA)Prime-yield grade (YG) 1 (P1) has produced a sire that ranked well against high-performing bulls from multiple breeds. An F1 (P1 × P1 - first generation offspring) sire would ideally outperform its high-performing parents. A terminal sire study was conducted comparing progeny of an F1 (P1 × P1) sire (AxG1) against progeny (heifers and steers) of four high-performing sires of varying breeds {P1 (ALPHA); Angus; Simmental; Angus × Simmental}. Production traits included morbidity and mortality frequencies, weaning weight, feedlot arrival weight, and days on feed; carcass traits included frequency of abscessed liver and lung health, quality grade and YG parameters, total carcass value (US$), and carcass value per hundredweight (CWT [45.4 kg]; US$). A completely randomized experimental design was used; data were analyzed using a mixed model with a fixed effect of sire and random effects of harvest date, sex, and pen. AxG1 sired heifers had the highest (P < 0.01) marbling score, the highest (P < 0.01) carcass value per CWT, and numerically had the lowest calculated YG and highest frequency of YG one carcass. Steers sired by AxG1 had the least (P = 0.05) backfat, lowest (P < 0.01) calculated YG, highest (P < 0.01) marbling score, highest (P < 0.01) frequency of USDA Prime carcasses, the greatest (P < 0.03) total carcass value, and greatest (P < 0.01) carcass value per CWT. Collectively, AxG1 steer and heifer carcasses exhibited the least 12th rib fat thickness and lowest USDA YG in addition to the largest longissimus muscle area, highest marbling score, and greatest frequency of USDA Prime. These data suggest that AxG1 performed comparably to other high-performing industry terminal sires in carcass quality and YG outcomes.

Meta-analysis of carcass and meat characteristics of young or super young steers and of different sexual conditions finished in confinement

The objective was to evaluate the carcass and meat characteristics of feedlot steers based on sexual condition and age at the beginning of the finishing phase, through a systematic review and meta-analysis. The selection of articles was carried out by two reviewers, who selected articles from the Google Scholar and Scielo platforms. The criteria for choosing articles followed the PICO tool. After searching for articles, they were subjected to analysis under the methodological conditions of the research. After this phase, 61 research articles carried out in Brazil remained, from which information was extracted from the material, methods and results. The data were compared according to the age of the steers: young (between 20 and 26 months of age) and super young (between 10 and 16 months of age); and depending on sexual condition: castrated or not castrated. Young steers have higher slaughter weights and higher hot and cold carcass weights. Meat from super young steers presented a higher score for tenderness when evaluated by the panel of evaluators. Uncastrated steers had higher slaughter weight, hot and cold carcass weight and rib eye area, while castrated steers demonstrated greater thickness of subcutaneous fat in the carcass and meat with higher marbling score. Slaughtering super young and castrated steers improves the quality aspects of the carcass and meat, however it reduces the amount of meat.

Impact of bushfires on Australian livestock health, welfare and carcase quality

The 2019/2020 Australian bushfires were unprecedented in terms of total area burned and impact on livestock and wildlife populations. However, there is currently limited literature available relating the consequences of bushfire or smoke exposure to livestock health, welfare, and carcase quality. A retrospective cross-sectional study was conducted using historical monitoring data from a Meat Standards Australia (MSA) accredited abattoir located on the mid-north coast of New South Wales, Australia. The spatiotemporal association between exposure to bushfire smoke (specifically the duration of the bushfires, distance from closest bushfire, annual bushfire season, proportion of the property of origin burned during the bushfires and time frame since exposure to bushfires) and effects on carcase meat quality metrics and pathology were measured, by building linear, generalised linear and cumulative link mixed models. Our findings indicate that hot carcase weight increased as the distance between the property of origin and the closest bushfire became greater and decreased with exposure to bushfires of longer duration or when greater proportions of the property of origin were burnt during bushfires. Subcutaneous rib fat of carcases also increased with an increasing distance of properties from the closest recorded bushfire and decreased with exposure to bushfires during the 2019/2020 season. Higher meat colour scores (darker meat colour) were associated with exposure to bushfires during the 2019/2020 season and exposure to bushfires of longer durations. There was only a weak association between increasing distance to the closest bushfire and higher marbling scores. Evidence of pneumonia in carcases was associated with exposure to bushfires of longer duration, specifically increasing risk of pneumonia was associated with fires of longer durations. Greater periods of time since exposure (i.e., >6 months) to bushfires were also associated with a higher risk of evidence of pneumonia at the time of processing. With increasing incidence of bushfires in Australia forecasted as a result of climate change, there is an urgent need to understand the impact of bushfires on livestock, to limit the effects on livestock health and mitigate the risk of significant socioeconomic impacts to the livestock industry. By providing a greater understanding of the impact of bushfires, the findings of this study can support producers to make informed decisions to mitigate the effects of bushfires on livestock health and carcase meat quality.

A Comparative Study on the Carcass and Meat Chemical Composition, and Lipid-Metabolism-Related Gene Expression in Korean Hanwoo and Brindle Chikso Cattle.

The objective of this study was to elucidate the effect of cattle breed on carcass and meat chemical composition, fatty acid profiles, and lipid-metabolism-related genes. For this study, same-age Hanwoo and Chikso steers (n = 6 per breed) reared under identical conditions were used. Immediately after slaughter, muscle tissues were collected for analysis of mRNA expression. At 24 h post-mortem, the carcasses were assessed for carcass traits (marbling score, meat yield, etc.), and meat quality and fatty acid profiles in the longissimus lumborum (LL) and semimembranosus (SM) muscles. The results showed that no differences in the slaughter weight, dressing rate, back-fat thickness, trimmed fat, and total meat yield occurred between the two breeds (p > 0.05). However, Hanwoo cattle had a higher marbling score, intramuscular fat (IMF) content, and expression level of lipid-metabolism-related genes such as lipoprotein lipase, peroxisome proliferator-activated receptor gamma, and fatty acid binding protein 4, compared with Chikso (p < 0.05). Contrastingly, Chikso had a higher total unsaturated fatty acid content and expression level of stearoyl CoA desaturase 1 (p < 0.05). It may be said that the difference in the expression levels of lipid-metabolism-related genes could be the molecular factors underlying IMF deposition and fatty acid profile differences in the beef from the two breeds.

Image feature extraction via local binary patterns for marbling score classification in beef cattle using tree-based algorithms

The objective of this study was to investigate the potential of creating a pipeline to classify the marbling score obtained from ribeye area (REA) images using computer vision and machine learning methods. Our database consisted of images and measurements (N = 2,446) from the transversal cut between the 12th and 13th ribs of the Longissimus dorsi muscle from carcasses of a beef cattle population (Bos taurus). Each sample was previously labeled by the industry using a low, medium or high marbling score. The prediction accuracies of two tree-based Machine Learning (ML) algorithms (Decision Tree - DT and Random Forest - RF) were compared, as well as different measures for extracting features from the REA images, which were used as input for the ML algorithms. In order to extract features based on detectable color patterns and textures contained in smaller parts of the grayscale image, we proposed the application of the local binary pattern (LBP) method prior to the adoption of ML methods. Mean classification accuracies for the test set ranged from 45.78% to 91.25% for different test scenarios. The results were mostly impacted by the feature extraction metrics, ML methods, potential subjectivity during the classification process by the industry, and the number of classes evaluated together. The best prediction accuracy results were achieved after performing the cross-validation (20% in each balanced group, 5 folds, and 10 repetitions), considering solely the extreme groups (low and high marbling scores) and pre-selecting from each group the 400 most visually representative samples. The RF algorithm outperformed the DT for most scenarios. After increasing the number of images to 580 samples for the same two groups, the highest testing accuracies were reduced to 83.05% for RF and 75.58% for DT. Such a decrease in the classification accuracies may be associated with the addition of erroneously classified images, due to the subjective nature of the industry evaluation. In conclusion, our preliminary studies showed the LBP method as a powerful feature extraction strategy considering a scenario where the labels were well defined. Our results revealed high accuracies for the classification of marbling extremes, but there is an evident need to improve the understanding of the biological and visual aspects that led to a sharp drop in classification accuracy after the insertion of the intermediate groups of marbling. In addition, the authors highlight the importance of an accurate labeling process for achieving better classification accuracy when applying supervised classification methods.

Phenotypic and genetic correlations of pork myoglobin content with meat colour and other traits in an eight breed-crossed heterogeneous population

Meat colour is one of the most important meat quality traits affecting consumption desire. Genetic improvement for meat colour traits is not so easy because pigs can be phenotyped only after slaughter. Besides the parameters from the optical instrument, other indexes that reflect the material basis of meat colour should be measured accurately and used in the genomic analysis. Myoglobin (Mb) is the main chemical component determining meat colour. However, to what extent the Mb content contributes to meat colour, and whether it can be used as a trait for pig breeding to improve meat colour, and the correlations of Mb content with complex porcine traits are largely unknown. To address these questions, we measured the muscle Mb content in 624 pigs from the 7th generation of a specially designed eight breed-crossed pig heterogeneous population, evaluated its phenotypic and genetic correlations with longissimus thoracis colour score at 24 h after slaughter. More than that, we also systematically phenotyped more than 100 traits on these animals to evaluate the potential correlations between muscle Mb content and economically important traits. Our results showed that the average muscle Mb content in the 624 pigs was 1.00 mg/g, ranging from 0.51 to 2.17 mg/g. We found that higher Mb content usually correlated with favourable meat colour, higher marbling score, less moisture content, and less drip loss. Genetic correlation analysis between muscle Mb content and 101 traits measured in this study shows that Mb content is also significantly correlated with 31 traits, including marbling, shear force, firmness, and juiciness. To our knowledge, this is one of the largest studies about the correlations of muscle Mb content with as many as 100 various traits in a large-scale genetically diversified population. Our results showed that the Mb content could be a selection parameter for the genetic improvement of meat colour. The selection for higher Mb content will also benefit marbling, shear force, firmness, and overall liking but might not affect the growth, carcass, and fat deposition traits.

Allelic and genotypic frequencies for loci associated with meat quality in Mexican Braunvieh cattle.

The objective was to estimate allelic and genotypic frequencies for loci associated with meat quality in a Mexican population of Braunvieh cattle. Information was obtained from 300 animals genotyped with the Genomic Profile Bovine LD chip of 30K and 50K SNPs. After the final edition, including quality control, the data contained information for 12 loci of the CAPN1, CAPN3, CAPN5, CAPN14, DGAT1, DGAT2, TG, ANK1, and MADH3 genes. Allelic and genotypic frequencies and Hardy-Weinberg equilibrium were estimated with the Cervus 3.0.7 software. The studied population markers were in Hardy-Weinberg equilibrium, except for those associated with CAPN1, DGAT1, and MADH3. Frequencies higher than those reported for other breeds were found for genotypes associated with meat softness, higher marbling score, lower quantity of saturated fatty acids, and lower shear force (CAPN1 and DGAT2). There were similarities with frequencies reported for Bos taurus breeds for the CAPN3 and TG genes. For the DGAT1 and ANK1 genes, the frequencies of the desired genotypes were low. A marker for DGAT1 and another for MADH3 were monomorphic. The results of this study are encouraging in terms of the potential of the Braunvieh population studied for breeding programs aiming to increase meat quality. The breed has strengths that could be used either by crossbreeding to generate heterozygous animals or by selection to increase frequencies of valuable alleles.

Wagyu–Angus cross improves meat tenderness compared to Angus cattle but unaffected by mild protein restriction during late gestation

For the spring-calving beef herds, late gestation coincides with winter and early spring, when cows are dependent on feed supplements with low quality hay, which is hard to meet their nutrient requirements. However, the effects of deficiencies of metabolizable protein intake during late gestation on offspring beef quality are unclear. Wagyu cattle have excellent marbling, and insemination with Wagyu vs Angus semen is a practical option for beef producers to improve beef quality. To test, Angus cows (621 ± 73 kg) were selected and randomly separated into two groups. Each group was inseminated with either Angus or Wagyu semen. During the last 90 days of gestation, cows in each group were further separated and received either a low protein diet (85% of the NRC metabolizable protein requirement), which was a low quality hay-based diet common in northwestern region of the U.S., or an adequate protein diet (108% NRC requirement). All progeny was managed together and harvested at a final BW of 576.5 ± 16.6 kg. Wagyu-sired offspring had higher marbling scores and quality grades than Angus (P < 0.01). Protein supplementation did not affect Slice Shear Force (SSF) in either breeds (P = 0.60). However, Wagyu-sired cattle had lower SSF than Angus-sired (P < 0.01). In addition, Wagyu-sired cattle had higher intramuscular fat (P < 0.05) and total collagen content (P < 0.05), but Angus-sired had greater mature collagen cross-links, as shown by higher contents of Pyridinoline (P < 0.01) and Ehrlich Chromogen (P < 0.01). Consistently, the mRNA expression of enzymes catalyzing collagen cross-linking was higher in Angus-sired offspring, including Plod 1 (P < 0.05), Plod 2 (P = 0.08), and P4Hα 2 (P < 0.01). In conclusion, Wagyu-sired cattle had greater tenderness and marbling score compared to Angus-sired, which was associated with lower collagen cross-links. Feeding mature grass hay-based diet with relatively low protein content during late gestation had no major effect on beef quality of subsequent cattle.

28 Genomic prediction for marbling score in Hanwoo cattle using sequence data

Abstract As sequence information becomes available for some livestock species, there is a question on the amount of non-redundant information that may be embedded in the extra millions of SNPs or in causative variants within sequence. The objective of this study was to assess the gain in accuracy by using imputed whole-genome and selected SNP from sequence data in a beef cattle population. The dataset consisted of marbling score phenotypes for 545K Hanwoo cattle and pedigree information for 1.3M, of which 1,160 were genotyped for 50K SNPs. Imputation was done first to 777K and then to whole-genome sequence (WGS), which comprised 11,146,536 SNPs. Additionally, differentially expressed genes (DEG) and their 321,614 harboring SNPs were identified based on RNA-seq analysis of animals with high and low marbling score. An extra scenario combined 50K with DEG SNPs. Genomic predictions were obtained using GBLUP and single-step GBLUP (ssGBLUP) with and without weights, and BayesR. The last method could not be used for the WGS data because of the large number of SNPs. Predictive ability was calculated as the correlation between phenotypes adjusted for fixed effects and GEBV for 169 young animals. For all the methods, WGS and DEG had a slightly negative impact on predictive ability. Both GBLUP and BayesR had similar performances when using 50K, DEG, and 50K+ DEG, with predictive abilities equal to 0.19, 0.16, and 0.18, respectively. Predictive ability for ssGBLUP was 0.27, 0.26, and 0.27, in the aforementioned order. Using WGS, predictive ability for GBLUP was 0.17 and for ssGBLUP was 0.26. Weighting SNP differently did not improve predictions. As ssGBLUP uses all data available, not only genotyped animals with phenotypes as the other methods, it is more robust for genomic predictions. No gain in accuracy was observed, possibly because the selected sequence variants were not causative.

Biochemical and histological indicators of blood and m. longissimus dorsi of young bulls of Kazakh white-headed breed of different genotypes by the CAPN1 and GH genes

The use of molecular genetic markers for productivity is one of the modern approaches in breeding beef cattle. The article presents the results of the studies on the influence of genotypes by the calpain (CAPN1) and growth hormone (GH) genes on live weight, fatty acid composition of blood plasma, quantitative and qualitative indicators of meat of young cattle of Kazakh white-headed breed. It was established that animals of the homozygous geno-types СС–CAPN1 and VV-GH had a larger live weight and its average daily gain on the 240th and 365th days. Their superiority over the GG and LL genotypes was 13.8% (P&lt;0.05) and 6.9%; 14.6% (P&lt;0.05) and 6.9%, respectively. The carriers of the desirable alleles in the homozygous state had the sum of unsaturated fatty acids higher by 6.3% and 7.1%, respectively, than the young bulls, in which genotypes they were absent. The predominance of unsaturated fatty acids over saturated fatty acids also determined lower values of lipid me-tabolism direction index (0.92 and 1.00) in the animals with the desirable genotype. Muscle tissue of animals of the СС and VV genotypes was characterized by a higher level of protein, fat by 0.28–2.13 abs. per cent, energy value, and the quantity of muscle fibers with a smaller diameter per unit area compared to the GG and LL genotypes by on average 8.7% and 25.5% (P&lt;0.01). Due to the greater number of interfiber fat inclusions, muscle tissue of the desirable genotypes received higher marbling scores. The obtained data testify to the prospects of replication of animals, which genotype has the desirable alleles for further improvement of traits of meat productivity of Kazakh white-headed breed.

Breed difference and regulatory role of CRTC3 in porcine intramuscular adipocyte.

The cAMP responsive element binding protein (CREB)-regulated transcription coactivator 3 (CRTC3) is a member of the CRTC protein family and plays an important role in energy metabolism. The aim of this study was to determine if the expression of porcine CRTC3 is related to intramuscular fat (IMF) deposition and meat quality in Heigai pigs (a local fatty breed in China) and Duroc×Landrace×Yorkshire (DLY) pigs (a lean crossbred pig widely cultured in China). In addition, the effect of ectopic expression of CRTC3 on gene expression in porcine IMF adipocytes was also examined. Our results showed that Heigai pigs had lower lean percentage, thicker back fat thickness and smaller loin muscle area than DLY pigs. Compared with DLY pigs, Heigai pigs had higher marbling scores, better meat color and higher IMF contents and triglyceride concentrations. Higher levels of oxidative metabolic enzyme and expression of the slow oxidative muscle fiber-related genes were observed in longissimus dorsi muscle and psoas major muscle (P<0.05) from Heigai pigs. Notably, CRTC3 and adipocyte-specific marker genes were highly expressed in muscle tissues of Heigai pigs. The expression of lipolysis-related genes ATGL and HSL were lower in Heigai muscles. Moreover, forced expression of CRTC3 promoted lipid accumulation and increased the expression of PPARγ, C/EBPα, leptin and FABP4 (P<0.05), whereas it decreased the expression of ATGL and HSL in IMF adipocytes. These results suggest that CRTC3 expression is associated with lipid accumulation and IMF deposition in pigs.

The Outcome and Economic Viability of Embryo Production Using IVF and SOV Techniques in the Wagyu Breed of Cattle.

The Japanese black cattle breed (Wagyu) has an improved metabolism, which allows them to have a higher marbling score when compared with other cattle breeds. However, this may affect other aspects of the animal’s physiology, including hormone secretion and their reproductive success, such as their response to synchronization protocols and embryo production. Therefore, the objectives of this study were to test a superovulation protocol (SOV) developed with low doses of FSH and to evaluate the outcome and economic viability of embryo production using the SOV and in vitro fertilization (IVF) approaches in the Wagyu cattle breed. For that, ten Wagyu cows were submitted to five SOVs over a period of 15 months using a standard protocol: CIDR + 3 mg estradiol benzoate (D0), 35 mg FSH (Folltropin®) a.m. and p.m. (D4), 35 mg Folltropin® a.m. and 20 mg p.m. (D5), 20 mg Folltropin® a.m. and 10 mg p.m. (D6), 10 mg Folltropin® and 0.5 mg cloprostenol, both a.m. and p.m., + CIDR removal (D7), 0.05 mg GnRH + insemination 12 and 24 h after (D8) and embryo collection + 0.5 mg of cloprostenol (D16). Thirty days after each SOV, a follicular aspiration was conducted to produce IVF embryos without any pre-synchronization using standard semen in the same group of animals. The average number of embryos produced was 7.63 ± 5.61 (SOV) and 4.52 ± 2.44 (IVF) (p = 0.303). There was no significant correlation between the number of embryos produced by the different techniques (SOV and IVF), indicating that cows that respond well to SOV did not respond well to IVF and vice versa (r = 0.379, p = 0.529). The total cost of each embryo produced by SOV was R$215.00 and R$410.00 for IVF. Therefore, cows that produce less than five embryos by SOV are not economically viable due their lack of response to FSH, and the use of IVF in those animals may be more effective.

PSIV-19 Live and carcass production traits for progeny of an F1 USDA Prime – yield grade 1 carcass clone sire in comparison with progeny of popular reference sires

Abstract The cloning of beef carcasses that grade USDA Prime – Yield Grade 1 (P1) has produced a sire that ranked well against high performing bulls from multiple breeds. An F1 (P1 x P1) sire would ideally exhibit heterosis and outperform its high performing parents. A terminal sire study was conducted comparing progeny of an F1 (P1 x P1) sire (AxG1) against progeny (heifers and steers) of four high performing sires of varying breeds {P1 (Alpha); Angus; Simmental; Angus x Simmental}. Production traits included morbidity and mortality frequencies, weaning weight, and feedlot arrival weight; carcass traits included edible liver and normal lung frequencies, hot carcass weight, longissimus muscle area, 12th rib fat thickness, and marbling score. A completely randomized experimental design was used; data was analyzed using a mixed model with a fixed effect of sire and random effects of harvest date, sex, and pen. Feedlot arrival weight, frequencies of morbidity and mortality, 12th rib fat thickness, and frequency of grading Certified Angus Beef or USDA Select did not differ (P ≥ 0.16) between sires. Weaning weight and frequency of normal lungs tended (P ≤ 0.08) to differ amongst sires. Differences in hot carcass weight (P &amp;lt; 0.01), longissimus muscle area (P &amp;lt; 0.01), marbling score (P &amp;lt; 0.01), and frequencies of normal lungs (P &amp;lt; 0.01) was detected among sires. Additionally, sire differences in USDA yield grade (P &amp;lt; 0.01), and frequencies of carcasses grading USDA Prime (P &amp;lt; 0.01) and USDA Choice (P &amp;lt; 0.01) were observed. AxG1 progeny exhibited the least 12th rib fat thickness and lowest USDA yield grade in addition to the largest longissimus muscle area, highest marbling score, and greatest frequency of USDA Prime. These data suggest that AxG1 competed extremely well against other high performing industry sires.

Gender status effect on carcass and meat quality traits of feedlot Angus×Nellore cattle.

The study evaluated the effect of gender status on carcass and meat quality of feedlot Angus×Nellore cattle. A total of 176 cattle, 20 months old, were confined for 190-days and assigned to four treatments: bulls, immunocastrated, steers, and heifers. Bulls had greater rib eye area and HCW (p=0.0001). Heifers had increased fat thickness (p=0.0001). Steers and heifers had higher marbling scores (p=0.0001). There was interaction between gender and aging time for Warner-Bratzler Shear Force (p=0.0002), L* (p=0.0118), and b* (p=0.0113) values of beef. The sensory panel results showed that beef from bulls had the lowest consumer overall acceptance (p=0.0278). Especially, regardless tenderness, steers and immunocastrated beef were considered tender, independent of aging time. Beef produced by heifers, steers, and immunocastrated is considered to be of higher quality than bulls. Thus, it is may be an interesting alternative to produce high-quality beef than bulls, to attend the consumer demand for high-quality products. Additionally, the low fatty acids n6 levels and low n6:n3 ratio, high levels of CLA, MUFAs, and oleic acid suggests that the heifer meat is favorable for human health.

Effects of active immunization against porcine Sox6 on meat quality and myosin heavy chain isoform expression in growing-finishing pigs

A feeding trial for 91 days was conducted to investigate effects of active immunization against porcine Sox6 (pSox6) on meat quality and myosin heavy chain (MyHC) isoform expression in growing-finishing pigs. Twenty-four castrated Duroc × Landrace × Yarkshire pigs were randomly divided into three groups: (1) Control group; (2) 1 mg/head pSox6 active immunity group; (3) 4 mg/head pSox6 active immunity group (4 mg/head group). The results showed that pigs in 4 mg/head group had a greater a* (Redness) and a higher marbling score, while no significant effect was observed in L* (Lightness), b* (Yellowness), intramuscular fat and cooking loss. Muscle succinic dehydrogenase activity in pSox6 active immunization groups was significantly increased, and muscle lactate dehydrogenase activity was significantly reduced. Meanwhile, active immunization against pSox6 upregulated the mRNA expression of MyHC I, while no effect was observed on the mRNA expressions of MyHC IIa, MyHC IIx, MyHC IIb. In addition, pigs in the 4 mg/head group exhibited lower Sox6 mRNA level and higher MyHC I protein level, while no significant influence was observed on MyHC IIb protein level. Together, our data imply that active immunization against pSox6 could improve the pork quality and promote the MyHC I expression in growing-finishing pigs.

Meat quality traits of M. longissimus lumborum from White Mangalica and (Duroc × White Mangalica) × White Mangalica pigs reared under intensive conditions and slaughtered at about 180-kg live weight

The objective of the study was to evaluate the meat quality of the Serbian autochthonous White Mangalica pure bred pig and its crossbreed with Duroc. A total of 24 pigs [White Mangalica – WM, n = 12, and (Duroc × White Mangalica) × White Mangalica) – (DWM)WM, n = 12)] were slaughtered on average 638 and 509 d of age, respectively. Colour and marbling score, and all physical (pH, instrumental colour and water holding capacity) and chemical (proximate and mineral composition and fatty acids profile) analyses were performed on M. longissimus lumborum. Pork from WM had higher marbling score and intramuscular fat content and was redder in colour than from (DWM)WM; while opposite was determined for moisture content. In intramuscular fat, WM had higher content of oleic acid as well as total monounsaturated fatty acids than (DWM)WM, while (DWM)WM had higher linoleic and arachidonic acids as well as total polyunsaturated fatty acids content. Inclusion of 25% Duroc gave pork with lower content of iron, copper and manganese. In summary, irrespective of differences in some particular traits White Mangalica crossbreds can represent a good alternative to pure White Mangalica without worsening the meat quality.

Effects of gender of dairy or beef cattle and the number of pair of permanent incisors on carcass traits

Effects of group of cattle (gender of dairy or beef cattle) and number of pair of permanent incisors (0-4 pairs) on carcass traits were investigated. Data collected from 2,059 carcasses were obtained from beef cattle cooperative in 2016. Carcass traits included slaughter weight (wt.), hot carcass wt., percentage of hot or chilled carcass wt., chilling loss, skin wt., and marbling score. Factors included group of cattle and number of pair of permanent incisors observed in each cattle group, while slaughter wt. was a co-variable in the statistical model. Descriptive statistics were used to analyze marbling score. Results showed that group of cattle affected slaughter wt., hot carcass wt., percentage of hot or chilled carcass wt., skin wt. (P&lt;0.0001), and chilling loss (P&lt;0.05). Number of pair of permanent incisors within each cattle group affected all carcass traits (p&lt;0.05), except chilling loss (p&gt;0.05). Female and male beef cattle in all ages had higher hot carcass wt. and percentage of hot or chilled carcass wt. than female and male dairy cattle. The highest marbling score of 5 was found in female and male beef and female dairy cattle with 4 pairs of permanent incisors. However, majority of cattle had marbling score 2.

Effect of mixed hay supplementation during fattening on carcass traits and meat quality of Hanwoo steers

BackgroundThis study was aim to observe the effects of feeding mixed local hay (MH) consisted of 55% orchard grass (Dactylis glomerata L.), 35% tall fescue (Festuca arundinacea) and 10% red clover (Trifolium pratense) to Hanwoo steers on performance, carcass characteristics and meat quality (longissimus thoracis) compared with feeding imported timothy hay (TH) and local rice straw (RS).ResultsAlthough no significant effects were found on animal performance and carcass yield grade, the carcasses of MH group had higher marbling score and quality grade than those of RS and TH group (P < 0.05). Therefore, higher fat content (P < 0.001), lower shear force and hardness value in the beef of MH group than that of other groups were observed. Furthermore, the beef of MH group had higher CIE a* value (redness) than that of other groups and feeding MH to Hanwoo steers lowered n-6 to n-3 fatty acids ratio in beef.ConclusionsMixed hay provided benefits on meat quality and could be used for Hanwoo fattening program.

Bovine lipid metabolism related gene GPAM: Molecular characterization, function identification, and association analysis with fat deposition traits

Glycerol-3-phosphate acyltransferase mitochondrial (GPAM) is the enzyme that catalyzes the initial and committed step of glycerolipid synthesis in animal lipometabolism related pathway. In the present study, the correlation of GPAM expression level with adipogenesis was examined in vitro by RNAi and gene expression to silencing and over-expression of GPAM gene in BEF cells. And then, 2 novel polymorphisms were identified within key functional domain of bovine GPAM gene by sequencing and the relationship between variants of GPAM gene with fat deposition traits of Chinese Simmental-cross steers was analyzed using statistical methods. The result showed that the knockdown of GPAM expression significantly reduced the synthesis of triglycerides and expression of lipid metabolism-related gene in BEF cells (p<0.05), and the over-expression of GPAM could significantly increased the levels of triglyceride and expression of lipid metabolism-related gene (p<0.05). The results of the correlation analysis also showed that cattle with TC genotype of GPAM E20-2823C>T was significantly associated with fatty acid composition of intramuscular fat (had higher content of arachidic acid, eicosenoic acid, and arachidonic acid), individuals with A-allele homozygotes and AG-allele heterozygotes of E20-3386G>A both had higher content of myristic acid, α-linolenic acid, and linoleic acid in intramuscular fat than those with G-allele homozygotes (p<0.05). The individuals with AA genotype of E20-3386G>A was significantly associated with higher marbling score, and the individuals with CC homozygotes of E20-2823C>T had higher GFW and omasum fat weight in beef cattle population. GPAM play a pivotal role in the regulation of cellular triacylglycerol and phospholipid levels, and its mutations could serve as a useful molecular marker used for marker assisted selection in beef cattle breeding process.

Identification of differentially expressed genes between high and low marbling score grades of the longissimus lumborum muscle in Hanwoo (Korean cattle)

We conducted DD-RT-PCR analysis to identify differentially expressed genes between high and low marbling score groups with extremely different IMF content of the longissimus lumborum muscles in Hanwoo. We detected 137 DEGs between two marbling score groups. Of these DEGs, 41 DEGs were highly expressed in the high marbling score group, whereas 96 DEGs showed a higher expression in the low marbling score group. Among them, we selected eight DEGs exhibiting the greatest differential expression levels between two marbling score groups. These genes could be classified as five candidate genes according to homology to known genes and biological functions. The expression of four DEGs except for ATP6 gene was confirmed by qRT-PCR. The TPI1 gene was significantly higher expressed at the high marbling group, whereas ACTA1, TNNT1 and MDH2 genes were significantly higher expressed at the low marbling group. Therefore, the TPI1 gene was up-regulated, suggesting that this gene may have an important function related to IMF deposition.