Angus Cattle Research Articles

47 Effects of Sous Vide Cooking on the Tenderness of Beef Loins from Different USDA Quality Grades

Abstract The objective of this study was to determine the effects of sous vide cooking on the tenderness of beef loins from different USDA quality grades. Certified Angus Beef (CAB, n = 6), consisting of Motest0-Moderate100 marbling scores, USDA Low Choice (CH, n = 6), and USDA Select (SEL, n = 6) beef loins were purchased from a local meat purveyor and aged for 20 d with pack date set as d 0. Following aging, loins were cut into 2.54-cm-thick steaks, and every alternating steak was assigned to tenderness evaluation. Steaks were randomly assigned 1 of 3 treatments: sous vide 1 h (SV1), sous vide 2 h (SV2), and grilled (GR). Following sous vide cooking at 57°C, all treatments were grilled using the flat surface of a clamshell grill to an internal temperature of 71°C. Instrumental measurements for external cooked color (L*, a*, and b*) were recorded at 3 different locations on each steak following cooking using the HunterlLab Miniscan EX Plus spectrophotometer. Beef tenderness was evaluated using TA.XTPlus Warner-Bratzler shear (WBS) force machine after steaks chilled at 4°C for 12 – 18 h. There was no significant (P > 0.05) treatment by quality grade interactions for WBS force. GR steaks had a higher (P < 0.05) WBS force compared with SV1 and SV2 indicating a less tender product. SEL also had a higher WBS force value (P < 0.05) than CAB. Additionally, there was an increase (P < 0.05) in L* between GR, SV1, and SV2 indicating GR steaks were whiter, followed by SV1, then SV2 being the darkest. SV2 had a higher (P < 0.05) cook loss than SV1. In conclusion, there was no difference between the interactions of WBS force and treatments. Therefore, sous vide has an impact on tenderness that overpowers the quality grade differences, providing a more tender product compared to grilling.

Effects of Phragmites australis Shoot Remainder Silage on Growth Performance, Blood Biochemical Parameters, and Rumen Microbiota of Beef Cattle.

The objective of the present study was to assess the effects of replacing corn silage with Phragmites australis shoot remainder (PSR) silage on intake, growth performance, serum biochemical parameters, and rumen microbial diversity of growing-finishing beef. Fifteen Angus beef cattle with an average body weight of 253 ± 2.94 kg were randomly divided into three groups (five replicas vs. each group vs. Angus beef cattle). The three treatments were group A fed 60% PSR silage + 40% concentrate, group B fed 30% PSR silage + 30% corn silage + 40% concentrate, and group C fed 60% corn silage + 40% concentrate. The adaptation period was 15 days, and the trial period lasted for 45 days. Results showed that the ADG was significantly higher, and FCR was significantly lower both in groups A and B compared with group C. The results of serum biochemical parameters showed that the concentration of GLU was significantly lower in group B than both groups A and C. Microbial diversity results showed that the OTUs, Shannon, Chao1, and ACE indices were significantly lower in group A compared with groups B and C. At the phyla level, the relative abundances of Tenericutes and Melainabacteria had significant differences among the three groups, and the relative abundances of Papillibacter, Anaeroplasma, and Anaerovorax had significant differences among the three groups at the genus level. Additionally, Rikenellaceae was the unique biomarker among the three groups. Furthermore, the results of function prediction showed that the gene families associated with metabolism of cofactors and vitamins, cellular processes and signaling, metabolism, biosynthesis of other secondary metabolites, infectious diseases, signaling molecules and interaction, nervous system, and digestive system were significantly decreased, while lipid metabolism was dramatically increased from groups A to C at KEGG level 2. At KEGG level 3, 11 metabolic pathways were significantly influenced among the three groups. In summary, these findings indicated that PSR silage substituted the corn silage totally or partially improved the growth performance, and altered the rumen microbial composition and diversity and the corresponding change in prediction function of rumen bacteria in Angus beef cattle.

Selection signatures of Qinchuan cattle based on whole-genome sequences

Qinchuan cattle has gradually improved in body shape and growth rate in the long-term breeding process from the draft cattle to beef cattle. As the head of the five local yellow cattle in China, the Qinchuan cattle has been designated as a specialized beef cattle breed. We investigated the selection signatures using whole genome sequencing data in Qinchuan cattle. Based on Fst, we detected hundreds of candidate genes under selection across Qinchuan, Red Angus, and Japanese Black cattle. Through protein-protein interaction analysis and functional annotation of candidate genes, the results revealed that KMT2E, LTBP1 and NIPBL were related to brain size, body characteristics, and limb development, respectively, suggesting that these potential genes may affect the growth and development traits in Qinchuan cattle. ARIH2, DACT1 and DNM2, et al. are related to meat quality. Meanwhile, TBXA2R can be used as a gene associated with reproductive function, and USH2A affect coat color. This provided a glimpse into the formation of breeds and molecular genetic breeding. Our findings will promote genome-assisted breeding to improve animal production and health.

Economic Viability Analysis of an Oral Anthelmintic Treatment for Cattle in Feedlot

The economic viability of a commercial oral anthelmintic suspension containing 10% fenbendazole was evaluated in Angus x Nelore cattle in a feedlot. Two groups of 37 animals (treated and non-treated) were formed. A random-block design was used based on initial weight, egg count per gram of feces (EPG) and carcass grade. EPG counts and the determination of weight were performed on Days 0, 42 and 122. Carcass grade and yield were determined on the day of slaughter. Economic viability was evaluated using cost-effectiveness, sensitivity and financial analyses, considering three economic scenarios: most likely (M), optimistic (O) and pessimistic (P). The anthelmintic achieved 99.89% efficacy regarding EPG reduction. The animals exhibited an increase of 20.7 kg in live weight, 20.2 kg in live weight gain and 0.166 kg in daily weight gain (p < 0.05). No effects were found on yield or carcass grade (p > 0.05). The genus Haemonchus predominated at the onset of the study, whereas only the genus Cooperia was found after treatment. A net return of 14.60 USD per animal was found in the treated group, which remained viable under O, M and P scenarios, with respective differences of 18.92%, 12.86% and 91.15% in gross profit. The treatment was financially superior under all scenarios (real, M, O and P), with reductions of 1.89, 1.04, 0.48 and 16.39 years for the recovery of the initial investment. These results demonstrate the importance of economic analysis methods in the evaluation and selection of anthelmintics.

Study on the temperament of cows of the Aberdeen Angus cattle breed

The present study examined the temperament of 699 cows of the Aberdeen Angus cattle breed, reared in 14 farms in Bulgaria. It was carried out within the period 2017–2020. The animals subject to the study were between two and eight years old. The temperament was visually evaluated following a scoring system from 1 to 5. The assessment method involved the behavioural reaction of the cows upon manipulation, passing through a chute and fixation into a cattle crush. The temperament of cows reared in two different systems – intensive and semi-intensive farming was compared. The temperament of the Aberdeen Angus cows had an average rate of 2.74 ± 0.04. The cows which had frequent contact with people had a calmer temperament. The manner of rearing (P < 0.001) as well as the age group (P < 0.001) had a significant influence on the parameter examined. The young animals were calmer and got accustomed to working in a crush more easily when they were reared together with cows of different ages.

Development of genomic predictions for Angus cattle in Brazil incorporating genotypes from related American sires.

Genomic prediction has become the new standard for genetic improvement programs, and currently, there is a desire to implement this technology for the evaluation of Angus cattle in Brazil. Thus, the main objective of this study was to assess the feasibility of evaluating young Brazilian Angus (BA) bulls and heifers for 12 routinely recorded traits using single-step genomic BLUP (ssGBLUP) with and without genotypes from American Angus (AA) sires. The second objective was to obtain estimates of effective population size (Ne) and linkage disequilibrium (LD) in the Brazilian Angus population. The dataset contained phenotypic information for up to 277,661 animals belonging to the Promebo breeding program, pedigree for 362,900, of which 1,386 were genotyped for 50k, 77k, and 150k single nucleotide polymorphism (SNP) panels. After imputation and quality control, 61,666 SNPs were available for the analyses. In addition, genotypes from 332 American Angus (AA) sires widely used in Brazil were retrieved from the AA Association database to be used for genomic predictions. Bivariate animal models were used to estimate variance components, traditional EBV, and genomic EBV (GEBV). Validation was carried out with the linear regression method (LR) using young-genotyped animals born between 2013 and 2015 without phenotypes in the reduced dataset and with records in the complete dataset. Validation animals were further split into progeny of BA and AA sires to evaluate if their progenies would benefit by including genotypes from AA sires. The Ne was 254 based on pedigree and 197 based on LD, and the average LD (±SD) and distance between adjacent single nucleotide polymorphisms (SNPs) across all chromosomes were 0.27 (±0.27) and 40743.68 bp, respectively. Prediction accuracies with ssGBLUP outperformed BLUP for all traits, improving accuracies by, on average, 16% for BA young bulls and heifers. The GEBV prediction accuracies ranged from 0.37 (total maternal for weaning weight and tick count) to 0.54 (yearling precocity) across all traits, and dispersion (LR coefficients) fluctuated between 0.92 and 1.06. Inclusion of genotyped sires from the AA improved GEBV accuracies by 2%, on average, compared to using only the BA reference population. Our study indicated that genomic information could help us to improve GEBV accuracies and hence genetic progress in the Brazilian Angus population. The inclusion of genotypes from American Angus sires heavily used in Brazil just marginally increased the GEBV accuracies for selection candidates.

Red Angus cattle

This datasheet on Red Angus cattle covers Identity.

Validation of automatic systems for monitoring the licking behaviour in Angus and Brahman cattle

Monitoring feeding time in ruminants is one means to quantify feed intake. In grazing cattle offered feed supplement blocks, time spent licking can provide valuable information in estimating the level of blocks being ingested. This current study aimed to 1) assess an ear-tag accelerometer's capability to identify the licking behaviour at supplement blocks in grazing cattle and 2) evaluate the performance of the ear-tag accelerometer and radio-frequency identification (RFID) system to predict the individual time spent licking. Two breed groups of Angus (n = 7) and Brahman (n = 7) beef heifers were kept in two separate yards over 28 days. Each heifer was fitted with an ear-tag containing a tri-axial accelerometer set at 12.5 Hz frequency. Feed supplement blocks were provided through an RFID-equipped automatic supplement weighing unit within each yard, with access to the unit being given daily only from 16:00 h – 20:00 h. The accelerometer classification model developed using support vector machine (SVM) algorithm could distinguish between licking and non-licking behaviours, with an accuracy, sensitivity, F1 score, Cohen’s kappa coefficient, and Matthew’s correlation coefficient (MCC) of 86%, 93%, 0.88, 0.70, and 0.77 for Angus and 87%, 93%, 0.89, 0.73, and 0.79 for Brahman heifers. Time spent licking predicted by accelerometers were acceptable with a mean absolute error (MAE) of 22% and 11%, modelling efficiency (MEF) of 0.81 and 0.94, concordance correlation coefficient (CCC) of 0.88 and 0.96, and a ratio of root mean square prediction error (RSR) of 0.44 and 0.25, for Angus and Brahman heifers, respectively. However, the RFID system derived predictions of time spent licking in grazing heifers were unacceptable for both breeds. Overall, the ear-tag accelerometer offers the potential to predict individual time spent licking in grazing cattle to estimate block supplement intake.

Associations of digestibility with phenotypic and genetic variation in methane production in Angus cattle

Context Cattle and sheep emit methane, a potent greenhouse gas, as part of the fermentation process of feed digestion in their gut; however, the mechanisms explaining differences among animals in enteric methane production are not fully understood. Aim To investigate whether variation among animals in their ability to digest their test ration was associated with phenotypic and genetic variation in methane production. Methods The experiment used 135 Angus beef cattle measured for their phenotypic and genetic merit for methane production. The extent of digestion of the dry matter (DMD) in the test ration by individual cattle was determined using silica as a naturally present indigestible marker. Its concentration in feed consumed and faeces was determined using rapid portable X-ray fluorescence spectroscopy, from which DMD was calculated. Key results Higher daily methane-production rate (MPR), higher methane produced per unit of feed consumed (methane yield; MY) and higher methane produced than the predicted daily production (residual MPR; RMP) by animals was accompanied by higher DMD. Higher genetic merit for MPR was also accompanied by higher DMD, but DMD had no detectable association with genetic variation in the other two methane emission traits. The regression coefficients for change in MPR (g/day), MY (g/kg DMI), RMP (g/day) with change in DMD (%) were 2.6 ± 1.1 (s.e.; P < 0.05), 0.14 ± 0.07 (P < 0.1) and 0.68 ± 0.38 (P < 0.1) respectively. Conclusions Differences among animals in their DMD were found and were associated with phenotypic variation in the three methane emission traits studied, and with genetic variation in daily methane production. The results support the caution that feeding and breeding interventions seeking to reduce methane emissions can also reduce the extent of digestion of feed by cattle. Implications Feeding and breeding interventions that seek to reduce methane emissions may change rumen physiology and reduce the extent of digestion of feed by cattle, which may be undesirable.

Fatty acid profile and beef quality of Nellore and Angus bulls fed whole shelled corn

This study aimed to evaluate the quality traits and fatty acid profile of beef from Nellore and Angus bulls fed whole shelled corn (WSC) and ground corn plus maize silage (GC) diets. Eighteen Nellore and 18 Angus young bulls [381 ± 12 kg initial body weight (BW) and an average age of 20 ± 1.9 months] were used in a completely randomized design using a 2 × 2 factorial arrangement and were slaughtered at a final BW of 451.5 kg and 545.5 kg, respectively. Twenty–four hours after slaughter, samples of longissimus thoracis muscle were collected for the analysis of lipid oxidation, color, fatty acid profile, shear force, and cooking loss. There was no effect of diet × breed interaction on meat color, lipid oxidation, shear force, and cooking loss. Angus beef had lower shear force (p < 0.05) than Nellore beef and had a greater concentration of linoleic acid and polyunsaturated fatty acids (PUFA) (p < 0.01). Beef of bulls fed WSC tended to have greater concentration of CLA C18:2c9t11 (p = 0.09), greater concentration of CLA C18:2t10c12 (p = 0.01), and PUFA (p = 0.05), and consequently, higher oxidation levels. Angus bulls produced beef with greater tenderness and PUFA concentration. The results of fatty acid show a possible change in biohydrogenation when animals are fed the WSC diet, reducing lipogenesis, as this diet increases the C18:2t10c12 content.

Comparative analysis of intestinal microbiome of local cattle and Aberdeen Angus cattle imported to Kazakhstan

Comparative analysis of intestinal microbiome of local cattle and Aberdeen Angus cattle imported to Kazakhstan

Genomic selection in beef cattle creates additional opportunities for embryo technologies to meet industry needs.

The use of genotype information to improve the predictability of Expected Progeny Difference was first implemented in American Angus cattle in 2009 and has now grown to where over 50% of all registered calves are genotyped. Animals with only a genotype now have genetic prediction accuracy equivalent to eight or more progeny records across all traits. Reproductive technologies have also been widely adopted with approximately 50% of all calves born being the result of artificial insemination. Non-surgical embryo transfer started increasing in the mid 1990s with just over 10% of calves born being the result of embryo transfer since 2005. The number of embryos created with in vitro technologies has risen sharply since 2015 and now accounts for close to 30% of all ET calves. Genomics has enabled embryo technologies to be more impactful, as females can be selected with greater accuracy and sires can be used at earlier ages with moderate accuracy. Large numbers of females genotyped each year also increases the number of selection candidates, increasing the selection intensity. Genomics, combined with increased recording, also provides more information on females. This increases the spread in the estimated index values of current dams, identifying more elite dams for selection as embryo donors. The greater scope of female selection also contributes to better inbreeding management. Commercial animals genotyped could be targeted for oocyte harvesting at slaughter, creating opportunities for low cost high value beef embryos to be used in the beef on dairy segment of the industry.

Costs of Horn Fly (Diptera: Muscidae) Control for Cow-calf Producers in Tennessee and Texas, 2016.

Tennessee and Texas cow-calf producers were surveyed to assess their 2016 expenses for horn fly control methods. Cattle producers who were members of the Texas and Southwestern Cattle Raisers Association and Tennessee cattle producers who have participated in the Tennessee Agricultural Enhancement Program participated in the survey. Average horn fly management costs in Tennessee and Texas were $9.50/head and $12.40/head, respectively. An ordinary least squares regression and quantile regression were estimated to examine how horn fly costs are influenced by producer and farm demographics, seasonality of horn flies, producer horn fly perceptions, and management practices. When controlling for these variables, Tennessee and Texas cattle producers did not spend significantly different amounts on horn fly control methods. Horn fly costs were associated with producer and farm demographics, producer perceptions of horn flies, and management practices. For example, results indicate that horn fly management costs vary depending on a producer's level of education and income. Having Angus cattle and larger herd sizes were associated with lower costs per head spent on horn fly management. Producers who did not consider horn flies to be a problem until greater quantities of flies were present on the animal spent 15% less per head on managing horn flies. In terms of horn fly control methods, feedthrough insecticides increased horn fly costs the most, followed by using ear tags. This is the first known research to estimate horn fly management costs among cattle producers.

Haplotype-Based Single-Step GWAS for Yearling Temperament in American Angus Cattle.

Behavior is a complex trait and, therefore, understanding its genetic architecture is paramount for the development of effective breeding strategies. The objective of this study was to perform traditional and weighted single-step genome-wide association studies (ssGWAS and WssGWAS, respectively) for yearling temperament (YT) in North American Angus cattle using haplotypes. Approximately 266 K YT records and 70 K animals genotyped using a 50 K single nucleotide polymorphisms (SNP) panel were used. Linkage disequilibrium thresholds (LD) of 0.15, 0.50, and 0.80 were used to create the haploblocks, and the inclusion of non-LD-clustered SNPs (NCSNP) with the haplotypes in the genomic models was also evaluated. WssGWAS did not perform better than ssGWAS. Cattle YT was found to be a highly polygenic trait, with genes and quantitative trait loci (QTL) broadly distributed across the whole genome. Association studies using LD-based haplotypes should include NCSNPs and different LD thresholds to increase the likelihood of finding the relevant genomic regions affecting the trait of interest. The main candidate genes identified, i.e., ATXN10, ADAM10, VAX2, ATP6V1B1, CRISPLD1, CAPRIN1, FA2H, SPEF2, PLXNA1, and CACNA2D3, are involved in important biological processes and metabolic pathways related to behavioral traits, social interactions, and aggressiveness in cattle. Future studies should further investigate the role of these candidate genes.

Scanning electron microscopy of the nasal skin in different animal species as a method for forensic identification.

The current study aims to provide a new method for the identification of animal species by using the scanning electron microscopic study on the nasal skin around the nostril. The reference databases for animal identification using traditional ways (i.e., hair and bone analyses) were somewhat available. This study was conducted on the nasal skin of seven different animal species: large ruminants (Saidi buffalo and frozen Angus cattle); small ruminants (Egyptian goat and Rahmani sheep); camels (one-hump dromedary camel); equines (African domestic donkey and Arabian horse); carnivores (farm domestic cat, Egyptian Baladi dog, and red fox); swine (Danish Landrace pig); and rodents (albino rat and New Zealand white rabbit). The nasal skin was divided by grooves into different shaped raised areas in some examined animals, the mean diameter of these areas and width of the grooves of each animal species were recorded. The characteristic differential features of the nasal skin of each animal species have been documented. Few openings of the nasolabial glands were demonstrated in large ruminants and swine, which were H letter-shaped in buffaloes, oval-shaped in cattle, and whirlpool-shaped with several layers of folds on their margin in pig. Moreover, the openings of the lateral nasal glands were whirlpool, ovoid, and oval shaped in goats, sheep, and camels, respectively. In conclusion, the present study proved that the skin around the nostrils plays an important role as means of identification in forensic investigations and improves the field of veterinary forensic medicine in general, which is not well-developed in comparison with human forensics.

Enhancing muscle fatty acid profile by pasture finishing within a dairy-origin calf-to-steer beef production system and its potential to authenticate the dietary history of the cattle

The influence of modifying a traditional 24-mo dairy steer calf to beef production system on the fatty acid composition of the longissimus muscle and its potential to authenticate beef provenance was examined. Fifty-four male calves (n = 18 per sire breed), progeny of Holstein-Friesian cows mated with Holstein-Friesian (HF), Aberdeen Angus (AA) and Belgian Blue (BB) bulls were at pasture from March until August of their second year when they were assigned to a 3 (breed types) × 3 (finishing strategies) factorial experiment. The three finishing strategies were (i) pasture only for a further 94 d prior to slaughter (21 mo of age) (Grass), (ii) concentrates ad libitum indoors for 94 d prior to slaughter (21 mo of age) (EC) and (iii) pasture only for a further 94 d followed by concentrates ad libitum indoors for 98 d prior to slaughter (24 mo of age) (LC). Compared to EC, muscle from Grass had a lower intramuscular fat concentration and omega-6: omega-3 polyunsaturated fatty acid (PUFA) ratio and higher proportion of conjugated linoleic acid. A longer period at pasture pre-concentrate finishing increased the concentration of omega-3 PUFA which was still lower than in Grass. To maximise the omega-3 PUFA concentration, a late-maturing breed is more appropriate while to maximise conjugated linoleic acid, an early-maturing breed is more appropriate and both should be finished on grass. Chemometric analysis confirmed that the fatty acid profile can authenticate “Grass-Finished” beef per se and has potential to distinguish “Concentrate-Finished” beef based on the length of grazing prior to finishing, but not distinguish between sire breeds.

Composition of Fecal Microbiota in Grazing and Feedlot Angus Beef Cattle

Simple SummaryThis study is to investigate the difference of bovine fecal microbiota between grazing and feedlot Angus cattle. The fecal bacterial community was analyzed by high-throughput sequencing of 16S rRNA gene from six Angus cattle grazed on grassland and six Angus cattle fed on a feedlot. A total of 775 OTUs were taxonomically assigned to bacterial 12 phyla, 19 classes, 25 orders, 54 families, 141 genera, and 145 species. The dominant phyla were Firmicutes and Bacteroidetes. There was similar species richness between grazing and feedlot Angus beef, while species diversity was higher in feedlot Angus beef. The relative abundance of Firmicutes, Cyanobacteria, Elusimicrobia and Patescibacteria was significantly different between grazing and feedlot Angus beef (p < 0.05). At the genus level, five microbiotas were significantly different microbiotas between the two groups and all belonged to the Firmicutes phylum. These significant differences in microbiota composition between grazing and feedlot Angus beef may have an impact on the meat quality of Angus beef.This study is to investigate the difference in bovine fecal microbiota between grazing and feedlot Angus cattle. Fecal samples were collected from six Angus cattle grazed on grassland and six Angus cattle fed on a feedlot. The fecal bacterial community was analyzed by high-throughput sequencing of 16S rRNA gene. Sequencing of the V3–V4 region totally produced 1,113,170 effective tages that were computationally clustered into 775 operational taxonomic units (OTUs). These 775 OTUs were taxonomically assigned to bacterial 12 phyla, 19 classes, 25 orders, 54 families, 141 genera, and 145 species. The dominant phyla were Firmicutes and Bacteroidetes. There was similar species richness between grazing and feedlot Angus beef, while higher species diversity was observed in feedlot Angus beef. The relative abundance of Firmicutes, Cyanobacteria, Elusimicrobia and Patescibacteria was significantly different between grazing and feedlot Angus beef (p < 0.05). At a genus level, five microbiotas were significantly different between the two groups and all belonged to the Firmicutes phylum. These significant differences in microbiota composition between grazing and feedlot Angus beef may have an impact on the meat quality of Angus beef.

Genetic parameter estimates for feet and leg traits in Red Angus cattle.

The objective of this study was to estimate genetic parameters for feet and leg traits, relationships within feet and leg traits, and relationships between feet and leg traits and production traits in Red Angus cattle. Subjective scores for 14 traits including body condition score (BCS), front hoof angle (FHA), front heel depth (FHD), front claw shape (FCS), rear hoof angle (RHA), rear heel depth (RHD), rear claw shape (RCS), size of hoof (SIZE), front side view (FSV), knee orientation (KNEE), front hoof orientation (FHO), rear side view (RSV), rear view (RV), and a composite score (COMP) were collected by trained evaluators on 1,720 Red Angus cattle. All traits except COMP were scored as intermediate optimum traits. Performance data, and EPD were obtained on all animals measured and a three-generation pedigree was obtained from the Red Angus Association of America (RAAA) that contained 13,306 animals. Data were modeled using a linear bivariate animal model with random additive genetic and residual effects, and fixed effects of age and contemporary group (herd-year) implemented in ASREML 4.0. Heritability estimates of BCS, FHA, FHD, FCS, RHA, RHD, RCS, SIZE, FSV, KNEE, FHO, RSV, RV, and COMP were 0.11, 0.20, 0.17, 0.09, 0.19, 0.25, 0.17, 0.36, 0.16, 0.17, 0.17, 0.30, 0.14, and 0.12, respectively. These results demonstrate feet and leg traits are lowly to moderately heritable. Strong, positive genetic correlations were observed between FHA and FHD (0.89), FHA and RHA (0.88), FHD and RHA (0.85), FHA and RHD (0.85), FHD and RHD (0.94), and FHO and KNEE (0.95), indicating these traits were highly related to each other. Strong and negative genetic correlations were observed between KNEE and FSV (-0.59) and FHO and FSV (-0.75). The strongest Pearson correlation between front limb traits (FHA, FHD, FSV, FHO, KNEE, and COMP) and Stayability EPD (STAY) was FSV (r = 0.16) and for rear limb traits (RHA, RHD, RCS, RSV, RV, and COMP) and STAY was RCS (r = -0.12). This suggests cattle with more slope to the angle of the shoulder and cattle with less evidence of hoof curl may stay in the herd longer. Further investigation into the economic viability of feet and leg trait genetic prediction with a larger population of animals is required to help validate these findings.

Selection of candidate genes for differences in fat metabolism between cattle subcutaneous and perirenal adipose tissue based on RNA-seq

The site of fat deposition plays an important role in meat quality and body health. Biologically, the perirenal visceral fat (PF) and back subcutaneous fat (BF) are distinct. Angus and Simmental cattle (Bos taurus) were used as models. HE staining, triglyceride assay kit and RNA-seq were used to analyze the differences in tissue morphology and lipid accumulation, co-genes, and differentially expressed genes (DEGs) between the two tissues. According to the findings, BF has a smaller cell area and greater lipid deposition ability than PF. RNA-seq generated approximately 10.99 Gb of data in each library, and 23,472 genes were identified. The genes FABP4, ADIRF, and SCD that are related to adipose deposition were highly expressed in four tissues. There were 1678 DEGs and 1955 DEGs between BF and PF in Angus and Simmental cattle respectively. Gene Ontology function analysis identified several DEGs involved in metabolism. KEGG pathway analysis showed that four pathways related to fat metabolism were enriched. In the BF, seven genes (COL1A1, COL1A2, COL3A1, COL2A1, RXRA, C1QTNF7, and MOGAT2) were up-regulated. Five genes (ADRB3, ABHD5, CPT1B, CD36, LPIN1) were down-regulated. This study identified candidate genes that led to differences in fat metabolism, which could be useful in cattle breeding.

46 Footprints of Selection in Angus and Hanwoo Beef Cattle Using Imputed Whole Genome Sequence Data

Abstract In this study, we detected genome wide footprints of selection in Hanwoo and Angus beef cattle using different allele frequency and haplotype-based methods based on imputed whole genome sequence data. Our dataset included 13,202 Angus and 10,437 Hanwoo animals with 10,057,633 and 13,241,550 imputed SNPs, respectively. A subset of data with 6,873,624 common SNPs between the two populations was used to estimate signatures of selection parameters, both within (runs of homozygosity and extended haplotype homozygosity) and between (allele fixation index, extended haplotype homozygosity) the breeds in order to infer evidence of selection. We observed that correlations between various measures of selection ranged between 0.01 to 0.42. Assuming these parameters were complementary to each other, we combined them into a composite selection signal to identify regions under selection in both beef breeds. The composite signal was based on the average of fractional ranks of individual selection measures for every SNP. We identified some selection signatures that were common between the breeds while others were independent. We also observed that more genomic regions were selected in Angus as compared to Hanwoo. Candidate genes within significant genomic regions may help explain mechanisms of adaptation, domestication history and loci for important traits in Angus and Hanwoo cattle. In the future, we will use the top SNPs under selection for genomic prediction of carcass traits in both breeds.