Exploring the impact of fatty acid composition on carcass and meat quality in Bos taurus indicus influenced cattle.

The study of fatty acid (FA) and mineral content in beef is crucial for bridging health and taste. Understanding these components is essential for catering to consumer preferences for nutritious and tasty food, in line with current dietary trends and health recommendations. This holistic view of beef quality is key to helping both producers and consumers make more knowledgeable and health-oriented decisions in meat consumption. The objectives of this study were to 1) characterize the FA composition and mineral concentration of beef from Brangus cattle; 2) estimate their heritability; and 3) calculate the genetic and phenotypic correlations of carcass and meat quality traits to FA composition and mineral concentrations. Brangus steers were evaluated for meat quality and sampled for nutritional content measurements. Brangus cattle had palmitic acid levels as low as 21%, and stearic acid levels as high as 26%, which is notable since stearic acid is considered to have a neutral or potentially beneficial impact on cholesterol levels, unlike other saturated fats. Additionally, Brangus cattle had oleic acid levels as high as 53%, a beneficial monounsaturated fat, and linoleic acid concentrations as high as 12%, an essential omega-6 FA. Saturated FA showed weak negative correlations (-0.06 to -0.15) with hot carcass weight, marbling, and fat over ribeye, similar to polyunsaturated FA which had moderate negative correlations (-0.19 to -0.37) with these traits. Conversely, monounsaturated FA was positively correlated (0.16 to 0.34) with these traits, suggesting that higher levels of monounsaturated FA, particularly oleic acid, are associated with improved meat quality and consumer-desirable traits such as increased marbling. This relationship where higher marbling is linked with increased monounsaturated FA and decreased saturated FA is unique in Brangus cattle, differing from other breeds where increased intramuscular fat typically raises FA saturation levels. The variation in FA observed in Brangus cattle highlights the breed's potential to provide nutritionally enriched beef. With selective breeding, it may be possible to improve both the nutritional value and marbling of the meat, meeting consumer demand for healthier, tastier options. Overall, the study underscores the intricate relationships between FA composition, mineral content, and meat quality, with implications for breeding and nutrition strategies aimed at improving meat quality and healthfulness.

The fat composition and mineral content of beef influences both its taste and nutritional value. This study seeks to understand the relationship between meat quality and the nutritional value of beef from Brangus cattle. Animals varied greatly in their levels of essential omega-6 and monounsaturated fat. Higher levels of these fatty acids have been shown to improve the flavor of beef in addition to having a beneficial impact on cholesterol levels. Brangus cattle also exhibited a unique relationship between monounsaturated fat and meat quality, where higher levels of monounsaturated fat were associated with desirable traits such as increased marbling. Regarding mineral content, iron and zinc showed weak negative correlations with monounsaturated fat and moderate positive correlations with polyunsaturated fat. This study sheds light on the complex relations between fat profiles, mineral content, and meat quality. This understanding can inform breeding and management strategies to promote the production of meat that is not only palatable but also beneficial for consumer's health.

How does a superior quality sign guarantee the quality of lamb meat? The Label Rouge case.

Owing to the social, environmental and health changes in Europe, meat quality is becoming a critical issue for the long-term future of livestock farming. Label Rouge (LR) is a quality label owned by the French government that identifies food products produced inside or outside the European Union. This label guarantees the superior quality of a product compared with a standard product. This superior quality is guaranteed throughout the production process by specifications negotiated between the Institut National de l'Origine et de la Qualité (INAO) and operators in the sector. These specifications comprise two documents: first, common production conditions that apply to all specifications in a sector, and second, a book of specifications (BoSs). These two documents, which form the qualification mechanism, are divided into several parts: product name, product description, traceability, production method, labelling and the main control points. This study aims to understand how the LR defines lamb meat quality in the 11 existing BoSs using the seven dimensions of quality of animal-source foods (nutritional, sensory, commercial, technological, safety, convenience and image). We performed a computerised qualitative transversal analysis of the commitments associated with the production method and description of the product. This analysis was enriched by five semi-structured interviews with INAO members. We show that although LR is committed to all aspects of lamb meat quality, the sensory, image and carcass commercial quality attributes are predominant. However, the image attribute of quality is so ubiquitous that it required refinement to provide a better understanding of the construction of quality in terms of its environmental, ethical and cultural components.

Leveraging Functional Genomics for Understanding Beef Quality Complexities and Breeding Beef Cattle for Improved Meat Quality.

Consumer perception of beef is heavily influenced by overall meat quality, a critical factor in the cattle industry. Genomics has the potential to improve important beef quality traits and identify genetic markers and causal variants associated with these traits through genomic selection (GS) and genome-wide association studies (GWAS) approaches. Transcriptomics, proteomics, and metabolomics provide insights into underlying genetic mechanisms by identifying differentially expressed genes, proteins, and metabolic pathways linked to quality traits, complementing GWAS data. Leveraging these functional genomics techniques can optimize beef cattle breeding for enhanced quality traits to meet high-quality beef demand. This paper provides a comprehensive overview of the current state of applications of omics technologies in uncovering functional variants underlying beef quality complexities. By highlighting the latest findings from GWAS, GS, transcriptomics, proteomics, and metabolomics studies, this work seeks to serve as a valuable resource for fostering a deeper understanding of the complex relationships between genetics, gene expression, protein dynamics, and metabolic pathways in shaping beef quality.

ConvColor DL: Concatenated convolutional and handcrafted color features fusion for beef quality identification.

Beef is an important food product in human nutrition. The evaluation of the quality and safety of this food product is a matter that needs attention. Non-destructive determination of beef quality by image processing methods shows great potential for food safety, as it helps prevent wastage. Traditionally, beef quality determination by image processing methods has been based on handcrafted color features. It is, however, difficult to determine meat quality based on the color space model alone. This study introduces an effective beef quality classification approach by concatenating learning-based global and handcrafted color features. According to experimental results, the convVGG16 + HLS + HSV + RGB + Bi-LSTM model achieved high performance values. This model's accuracy, precision, recall, F1-score, AUC, Jaccard index, and MCC values were 0.989, 0.990, 0.989, 0.990, 0.992, 0.979, and 0.983, respectively.

Unveiling the mix-up: investigating species and unauthorized tissues in beef-based meat products.

Customers are very concerned about high-quality products whose provenance is healthy. The identification of meat authenticity is a subject of growing concern for a variety of reasons, including religious, economic, legal, and public health. Between March and April of 2023, 150 distinct marketable beef product samples from various retailers in El-Fayoum, Egypt, were gathered. There were 30 samples of each of the following: luncheon, kofta, sausage, burger, and minced meat. Every sample underwent a histological investigation as well as subjected to a standard polymerase chain reaction (PCR) analysis to identify meat types that had not been stated by Egyptian regulations. According to the obtained data, the meat products under scrutiny contained a variety of unauthorized tissues which do not match Egyptian regulations. Furthermore, the PCR results indicated that the chicken, camels, donkeys, and pigs derivatives were detected in 60%, 30%, 16%, and 8% of examined samples, respectively. In conclusion, besides displaying a variety of illegal tissues, the majority of the meat items under examination were tainted with flesh from many species. As a result, it is crucial to regularly inspect these products before they are put on the market to ensure that they comply with the law and don't mislead customers Furthermore, it is advisable for authorities to implement rigorous oversight of food manufacturing facilities to ensure the production of safe and wholesome meat.

Ageing of Australian lamb beyond 14 days does not further improve eating quality.

Limited studies are available assessing the impact of extended ageing on lamb eating quality of a wide range of cuts. From lamb (n = 153) and young mutton (n = 40) carcasses, seven cuts (eye of rack, eye of shoulder, knuckle, loin, outside, rump and topside) were collected and aged based on three ageing times (5, 14 or 21 days). Additionally, residual glycogen was determined from the loin at the corresponding ageing time. Untrained consumers assessed samples for tenderness, juiciness, flavour liking and overall liking. Increasing ageing time from 5 to 14 or 21 days significantly improved cut eating quality; however, ageing beyond 14 days showed no additional benefit. The ageing effect reduced when corrected for pH and temperature measurements, confirming ageing can improve eating quality when pH and temperature variation exists. Loin residual glycogen had no impact on eating quality at each ageing time. Our results confirm the importance of establishing optimum ageing times for cuts to ensure the highest consumer acceptability.

Genetic Markers Related to Meat Quality Properties in Fattened HF and HF x Charolaise Steers.

This study involved 45 Holstein and 60 Holstein-Charolaise steers, tailored with specific diets according to breed and rearing systems. DNA genotyping was conducted for DGAT1, LEP, SCD1, SREBF1, and TG genes to investigate their impact on carcass conformation traits, beef quality traits, and sensory quality traits. The results showed associations between the genetic variants and the analyzed traits. Specifically, DGAT1 was found to affect drip loss, meat brightness, and color saturation. The TG gene was associated with marbling and meat color. LEP influenced trim fat and pH levels, while SCD1 was linked to metabolic energy live weight gains, and pH levels. SREBF1 was related to fatness.

Using chemical intramuscular fat percentage to predict visual marbling scores in Australian beef carcasses.

Meat Standards Australia (MSA) marbling score and AUS-MEAT marbling represent key determinants of carcass value in the Australian beef industry and are well recognised traits in national and international markets. However, with the emergence of objective measurement technologies there are opportunities to grade beef carcasses using objective traits such as chemical intramuscular fat (IMF%) but abrupt changes to MSA and AUS-MEAT grading practices would cause significant disruption to the industry. Therefore, the objective of the study was to develop and validate models that transform chemical IMF% into equivalent MSA marbling scores and AUS-MEAT marbling. The second objective was to compare IMF%-derived and grader-derived MSA marbling scores when used as input values in the MSA model to generate predicted eating quality scores (MQ4). Carcasses (n = 5513) from industry experiments across 7 years (2017-2023) were graded for MSA marbling and AUS-MEAT marbling and sampled for chemical IMF%. Data were utilised to develop IMF%-derived models for MSA marbling score (IMF-MSAMB) and AUS-MEAT marbling (IMF-AUMB). Calibration performance was maintained when cross-validated and independently validated. The IMF-MSAMB model described 91% of the variation in MSA marbling score (Residual Standard Error (RSEV) = 57.9), with a slope of 0.90 and very small bias of -0.54. Similarly, IMF-AUMB described 88% of the variation in grader AUS-MEAT marbling (RSEV = 0.68) with a slope very close to 1 (0.94) and negligible bias (0.06). In addition, predicted MQ4 scores were almost equivalent irrespective of which marbling input value was used, across a suite of cut and cook combinations. Therefore, there is an opportunity for models to assist transition to the use of chemical IMF% in place of visual marbling scores. This would enable grading technologies to be calibrated and validated against chemical IMF%, whilst minimising industry disruption.

Relationships between European carcass evaluation and Meat Standards Australia grading scheme applied to young beef cattle.

The European carcass grading scheme (EUROP) places large emphasis on meat yield and therefore on quantitative traits such as carcass conformation and superficial fat coverage. However, it falls short in considering sensory properties and consumer satisfaction. In contrast, the Meat Standards Australia (MSA) grading scheme considers, among others, animals' ossification, marbling, and ultimate pH as primary indicators of beef eating quality. This study aims to characterize MSA carcass grading scheme applied to the Italian beef production system, considering its significant role in European beef market. The study involved 3204 Charolais, Limousin, and crossbred young bulls and heifers slaughtered in a commercial Italian abattoir. Data collection spanned a broad range of variables, including animal characteristics, MSA traits, and EUROP carcass grading traits. Regardless of the sex of the animal, no significant relationship was observed between MSA traits and EUROP carcass grading scores. Factors such as sex, age, and arrival season at the fattening unit significantly affected most of MSA traits. Females had significantly higher marbling score, and lower ossification score and hump height than males. Animals imported in autumn and winter had significantly lower marbling score, but similar ossification score compared to those imported in spring and summer. Older females had the highest marbling scores. While further research is needed to assess whether the MSA grading scheme can be adapted to all different European rearing systems, results of this study are a prelude to the potential benefits that the MSA grading scheme can bring to the European beef industry.

Effect on prime animal beef merit from breeding solely for lighter dairy cows.

As the proportion of prime carcasses originating from dairy herds increases, the focus is shifting to the beef merit of the progeny from dairy herds. Several dairy cow total merit indexes include a negative weight on measures of cow size. However, there is a lack of knowledge on the effect of genetic selection, solely for lighter or smaller-sized dairy cows, on the beef performance of their progeny. Therefore, the objective of this study was to quantify the genetic correlations among cow size traits (i.e., cow BW, cow carcass weight [CW]), cow BCS, cow carcass conformation (CC), and cow carcass fat cover (CF), as well as the correlations between these cow traits and a series of beef performance slaughter-related traits (i.e., CW, CC, CF, and age at slaughter [AS]) in their progeny. After data editing, there were 52,950 cow BW and BCS records, along with 57,509 cow carcass traits (i.e., CW, CC, and CF); carcass records from 346,350 prime animals along with AS records from 316,073 prime animals were also used. Heritability estimates ranged from moderate to high (0.18-0.62) for all cow and prime animal traits. The same carcass trait in cows and prime animals were strongly genetically correlated with each other (0.76-0.85), implying that they are influenced by very similar genomic variants. Selecting exclusively for cows with higher BCS (i.e., fatter) will, on average, produce more conformed prime animal carcasses, owing to a moderate genetic correlation (0.30) between both traits. Genetic correlations revealed that selecting exclusively for lighter BW or CW cows will, on average, result in lighter prime animal carcasses of poor CC, while also delaying slaughter age. Nonetheless, selective breeding through total merit indexes should be successful in breeding for smaller dairy cows and desirable prime animal carcass traits concurrently, because of the nonunity genetic correlations between the cow and prime animal traits; this will help to achieve a more ethical, environmentally sustainable, and economically viable dairy-beef industry.

The Meat Standards Australia carcass grading site affects assessment of marbling and prediction of meat-eating quality in growing European beef cattle.

The lack of consumer feedback on beef eating quality contributes to reduced beef consumption in Europe. The Meat Standards Australia (MSA) grading scheme can assess the palatability of beef carcasses usually graded at the 10th thoracic vertebrae. However, the European beef industry relies on late-maturing breeds usually cut at the 5th vertebrae due to commercial reasons. Data from 55 young bulls and heifers of late-maturing breeds were collected in an Italian slaughterhouse following the MSA guidelines at both carcass grading sites and sides. Intramuscular fat levels were assessed through two scores and used with other variables to feed the MSA model, which predicts the MSA index, the meat-eating quality scores (MQ4) for 5 muscles and for each carcass grading site × side combination. The scores were analyzed using a mixed linear model. A correlation analysis was conducted to predict the variables measured at the 10th site using their correspondent at the 5th carcass grading site. A stepwise regression was conducted to understand the weight of each measured variable on marbling and MQ4 scores measured both at 5th and 10th carcass grading sites. Results showed significantly higher value for the studied traits at the 5th carcass grading site, while carcass side had no significant impact. The equations had high predictive capability and MSA marbling score played a key role in explaining the variability across carcass grading sites. The differences in marbling and MQ4 scores between the carcass grading sites suggest considering this factor if the MSA grading system will be applied to Europe.

Objective grading of rib eye traits using the Q-FOM™ camera in Australian beef carcasses.

The objective of this study was to develop calibration models against rib eye traits and independently validate the precision, accuracy, and repeatability of the Frontmatec Q-FOM™ Beef grading camera in Australian carcasses. This study compiled 12 different research datasets acquired from commercial processing facilities and were comprised of a diverse range of carcass phenotypes, graded by industry identified expert Meat Standards Australia (MSA) graders and sampled for chemical intramuscular fat (IMF%). Calibration performance was maintained when the device was independently validated. For continuous traits, the Q-FOM™ demonstrated precise (root mean squared error of prediction, RMSEP) and accurate (coefficient of determination, R2) prediction of eye muscle area (EMA) (R2 = 0.89, RMSEP = 4.3 cm2, slope = 0.96, bias = 0.7), MSA marbling (R2 = 0.95, RMSEP = 47.2, slope = 0.98, bias = -12.8) and chemical IMF% (R2 = 0.94, RMSEP = 1.56%, slope = 0.96, bias = 0.64). For categorical traits, the Q-FOM™ predicted 61%, 64.3% and 60.8% of AUS-MEAT marbling, meat colour and fat colour scores equivalent, and 95% within ±1 classes of expert grader scores. The Q-FOM™ also demonstrated very high repeatability and reproducibility across all traits.

Identification of key genes and functional enrichment pathways involved in fat deposition in Xinyang buffalo by WGCNA.

The Xinyang buffalo is a valuable and endangered domestic heritage resource in the Dabie Mountain region in China. With the increasing mechanization of agriculture, the Xinyang buffalo, mainly used for labor, faces unprecedented challenges. One of the feasible approaches to conserve and expand the species is to transfer Xinyang buffalo from service-use to meat-use, but the main hindrance to this transformation is the inferior meat quality of Xinyang buffalo, which is not popular with consumers. Based on the above, this study was conducted to evaluate the growth performance (n = 120) and slaughter performance (n = 3) of Xinyang buffalo and to measure the amino acid levels of the eye muscle (EM), and assess the meat quality. Later, transcriptome sequencing was performed on the subcutaneous fat of the back at six (n = 3) and 30 months of age (n = 3), together with the excavation of candidate genes associated with fat deposition using the weighted co-expression network analysis (WGCNA) method. The results showed that the slaughter rate of Xinyang buffalo was 43.09%, net meat percentage was 33.04%, the ocular area was 59.16 ± 7.58, the backfat thickness was 1.03 ± 0.16, and meat bone ratio was 3.29. The total amino acid contents were 0.63 g per gram of beef, which contained 0.05 g of essential amino acids, and the three most abundant amino acids were Ser (447.17 mg/g), Asp (29.8 mg/g), and Pro (27.24 mg/g). The WGCNA results showed that six phenotypes measured were significantly correlated with the turquoise module (r > 0.97, P < 0.001), and the genes in these modules were significantly enriched in the pathways related to substance metabolism and energy metabolisms, such as metabolic pathways, citrate cycle, and fatty acid metabolism. Meanwhile, six key candidate genes (FH, MECR, GPI, PANK3, ATP6V1A, PHYH) were identified, which were associated with growth and development, fat deposition, and intra-muscular amino acid levels (P < 0.05). In short, this study provides another feasible way to preserve buffalo and enriches the theory of its molecular genetic breeding.

Quality and Safety of Fresh Beef in Retail: A Review.

ABSTRACT: This study aimed to review the scientific literature on the quality and safety of beef sold in retail, methodologies used for quality evaluation, and proposed interventions for the sector. Bibliographical research was performed to identify scientific articles using the electronic databases Ovid, PubMed, Scielo, LILACS, Scopus, and Embase. Thirty-three articles were included in the review. Given the different dimensions of the studies, the results were organized into three categories, according to the following approaches: food, environment, and handlers; consumers and selection criteria; and intervention strategies for the retail sector. The applied methodological strategies revealed inadequate conditions and neglect in several processing and operation stages that are fundamental to the maintenance of quality standards. The results confirm a worrying scenario and the presence of risks to consumers. Based on the studies evaluated, it is necessary to emphasize consumer concern about the importance of the integrated information chain-all stages involved in the production process and meat distribution for retail meat stores. The reported conditions from different studies indicate the need for interventions with a view to prevention of health risks, continued training of food handlers, and transformation of evidenced realities. In this context, it is possible to point out the predominance of diagnostic studies, in contrast with interventional studies focused on the training and qualification of food handlers.

Visual Image Analysis for a new classification method of bovine carcasses according to EU legislation criteria.

In the European Community, conformation and fat cover of bovine carcasses is assessed using the SEUROP grading system. In this study we pursued the development of an application software (App) based on Visual Image Analysis, useful for SEUROP and Fat Cover grading of bovine carcasses using a smartphone. The App was trained using 500 bovine carcasses. Carcass conformation and Fat Cover classes were assessed in parallel by expert evaluators and by App. Overall, a high correspondence was found between the measurements of carcasses parameters by operators and by the App, as high as 84.2% for SEUROP and 86.4% for the Fat Cover. In the 15.8% of samples with discordant SEUROP evaluation, and in the 13.6% of samples with discordant Fat Cover evaluation, the operators' and App measurements deviated by only one class. All values also aligned with the requirements expected by the current legislation for the use of automated and/or semi-automated systems able to determine the market value of carcasses.

Ageing as a method to increase bloom depth and improve retail colour in beef graded AUS-MEAT colour 4.

Meat colour is an important attribute for consumer acceptance but there is an interval between colour grading and retail display. This experiment investigates the effect of time post-slaughter (5, 14 and 40 days) on colour and bloom depth (after 1 and 24 h) for beef carcasses graded AUS-MEAT colour 4 (MC 4). Sixteen carcasses were selected at grading, 8 carcasses were graded MC 4 and 8 as compliant colour (AUS-MEAT score 2 or 3). At 5 days post-slaughter, compliant loins had greater overall bloom depth and were more red than MC 4 loins. Bloom depth (24 h) increased with ageing time but reached maximum bloom at 14 days for both treatments. After ageing for 14 and 40 days, the bloom depth of MC 4 loin was no different to the 5 day aged compliant loins after 24 h on display. Colour at grading may not be a reliable measure of retail colour considering the changes post slaughter.

Effects of Green Tea Powder, Pomegranate Peel Powder, Epicatechin and Punicalagin Additives on Antimicrobial, Antioxidant Potential and Quality Properties of Raw Meatballs.

Alternative technologies, which have been developed in order to meet the consumers' demand for nourishing and healthy meat and meat products, are followed by the food industry. In the present study, it was determined, using the HPLC method, that green tea contains a high level of epicatechin (EP) under optimal conditions and that pomegranate peel contains a high level of punicalagin (PN). Green tea, pomegranate peel, EP and PN were added to meatballs at different concentrations in eight groups. The antioxidant capacities of extracts were measured. The antimicrobial activity was examined for 72 h using three different food pathogens. The highest level of antimicrobial activity was achieved in the 1% punicalagin group, whereas the minimum inhibition concentration (L. monocytogenes, S. typhimurium) was found to be 1.87 mg/mL. A statistically significant decrease was found in FFA, POV and TBARS levels of meatballs on different days of storage (p < 0.05). When compared to the control group, the bioactive compounds preserved the microbiological and chemical properties of meatballs during storage at +4 °C (14 days). It was concluded that the extracts with high EP and PN concentrations can be used as bio-preservative agents for meat and meat products.

Long-range linkage disequilibrium in French beef cattle breeds.

BACKGROUND: Linkage disequilibrium (LD) is a key parameter to study the history of populations and to identify and fine map quantitative trait loci (QTL) and it has been studied for many years in animal populations. The advent of new genotyping technologies has allowed whole-genome LD studies in most cattle populations. However, to date, long-range LD (LRLD) between distant variants on the genome has not been investigated in detail in cattle. Here, we present the first comprehensive study of LRLD in French beef cattle by analysing data on 672 Charolais (CHA), 462 Limousine (LIM) and 326 Blonde d'Aquitaine (BLA) individuals that were genotyped on the Illumina BovineHD Beadchip. Furthermore, whole-genome LD and haplotype block structure were analysed in these three breeds. RESULTS: We computed linkage disequilibrium (r2) values for 5.9, 5.6 and 6.0 billion pairs of SNPs on the 29 autosomes of CHA, LIM and BLA, respectively. Mean r2 values drop to less than 0.1 for distances between SNPs greater than 120 kb. However, for the first time, we detected the existence of LRLD in the three main French beef breeds. In total, 598, 266, and 795 LRLD events (r2 ≥ 0.6) were detected in CHA, LIM and BLA, respectively. Each breed had predominantly population-specific LRLD interactions, although shared LRLD events occurred in a number of regions (55 LRLD events were shared between two breeds and nine between the three breeds). Examples of possible functional gene interactions and QTL co-location were observed with some of these LRLD events, which suggests epistatic selection. CONCLUSIONS: We identified long-range linkage disequilibrium for the first time in French beef cattle populations. Epistatic selection may be the main source of the observed LRLD events, but other forces may also be involved. LRLD information should be accounted for in genome-wide association studies.

Trends in genetic diversity and the effect of inbreeding in American Angus cattle under genomic selection.

BACKGROUND: While the adoption of genomic evaluations in livestock has increased genetic gain rates, its effects on genetic diversity and accumulation of inbreeding have raised concerns in cattle populations. Increased inbreeding may affect fitness and decrease the mean performance for economically important traits, such as fertility and growth in beef cattle, with the age of inbreeding having a possible effect on the magnitude of inbreeding depression. The purpose of this study was to determine changes in genetic diversity as a result of the implementation of genomic selection in Angus cattle and quantify potential inbreeding depression effects of total pedigree and genomic inbreeding, and also to investigate the impact of recent and ancient inbreeding. RESULTS: We found that the yearly rate of inbreeding accumulation remained similar in sires and decreased significantly in dams since the implementation of genomic selection. Other measures such as effective population size and the effective number of chromosome segments show little evidence of a detrimental effect of using genomic selection strategies on the genetic diversity of beef cattle. We also quantified pedigree and genomic inbreeding depression for fertility and growth. While inbreeding did not affect fertility, an increase in pedigree or genomic inbreeding was associated with decreased birth weight, weaning weight, and post-weaning gain in both sexes. We also measured the impact of the age of inbreeding and found that recent inbreeding had a larger depressive effect on growth than ancient inbreeding. CONCLUSIONS: In this study, we sought to quantify and understand the possible consequences of genomic selection on the genetic diversity of American Angus cattle. In both sires and dams, we found that, generally, genomic selection resulted in decreased rates of pedigree and genomic inbreeding accumulation and increased or sustained effective population sizes and number of independently segregating chromosome segments. We also found significant depressive effects of inbreeding accumulation on economically important growth traits, particularly with genomic and recent inbreeding.