Commercial Beef Production Research Articles

Development of a duplex recombinase polymerase amplification-lateral flow strip assay with 1 min of DNA extraction for simultaneous identification of pork and chicken ingredients

Meat adulteration is a challenge faced by the global food industry. However, existing protein-based methods or DNA-based polymerase chain reactions are time-consuming and require specialist devices. Therefore, a rapid and on-site assay is urgently needed for identifying meat species. In this study, we developed a duplex recombinase polymerase amplification-lateral flow strip (dRPA-LFS) assay coupled with a rapid DNA extraction method (utilizing the UiO-66 coated stick as the DNA isolation device, and the isolation can be completed in 1 minute, including lysis, washing, and desorption in three steps) for the identification of pork and chicken ingredients. Targeted genes, the pork (Porcine) mitochondrial ND2 gene and chicken (Gallus gallus) cytochrome B gene, were designed with primers and probes. The whole dRPA-LFS detection procedure can be finished within 18.5 minutes (including 1 minute of rapid DNA extraction, 15 minutes of dRPA amplification, and 2.5 minutes of LFS semi-quantitative detection by the naked eye), and the result can also be quantified by ImageJ software within 15 minutes. No positive amplification was observed in beef, lamb, duck, rabbit, goose, ostrich, and horse meat DNA. This assay is sensitive and can detect as low as 0.1 % (wt %) of pork and chicken in simulated adulterated meat mixtures. This assay was successfully applied to the authentication identification of 30 commercial beef and lamb products.

Productivity of Commercial Feedlot Beef Production Significantly Improved by <i>Asparagopsis</i> Bioactives Stabilized in Canola Oil

Productivity of Commercial Feedlot Beef Production Significantly Improved by <i>Asparagopsis</i> Bioactives Stabilized in Canola Oil

Genotypic and allelic variability of the calpain CAPN1-316 gene in the Tropical Milking criollo breed and indication of its meat tenderness

Background: Genes and their variants related to milk and beef production in cattle can be identified through molecular markers. In particular, the Calpain gene CAPN1-316 has been linked to meat tenderness. The males of the Tropical Milking Criollo cattle not assigned as breeding animals are destined for commercial beef production. Objective: To estimate the genotypic and allelic frequencies in the calpain gene CAPN1-316 and its relation to meat tenderness in the Tropical Milking criollo breed. Methods: Molecular marker microsatellites of single sequence repeats (SSR) from DNA were extracted from blood samples of 423 purebred animals from three farms to identify the variants of the CAPN1-316 gene using the polymerase chain reaction (PCR). Genotypic and Allelic frequencies within populations, genetic distance, heterozygosity, and Xi squared (X2) test were performed using Pop Gene V.4. Results: The genotypic frequencies of the whole population were CC 0.31, GG 0.18, and CG 0.51. The allelic frequencies of variant C per farm were 0.62, 0.60, and 0.52. The genotypic and allelic frequencies of the CAPN1-316 polymorphisms were in Hardy-Weinberg equilibrium (X2, p>0.05). The CC genotype showed indication of greater tenderness. Conclusion: In the Tropical Milking criollo cattle, the C variant of the CAPN1-316, favorable to meat tenderness, had a bigger frequency than the G variant.

Cadaverine as a Potential Spoilage Indicator in Skin-Packed Beef and Modified-Atmosphere-Packed Beef.

This study investigated cadaverine as a spoilage indicator in commercial beef products stored under conditions favourable for the growth of lactic acid bacteria. Samples included vacuum-skin-packed entrecotes (EB) aged up to 42 days and modified-atmosphere-packed (70% O2 + 30% CO2) minced beef (MB) stored at 5 °C. Two MB product lines were analysed: one stored aerobically two days post-slaughter before mincing and another stored for 14 days in vacuum packaging prior to mincing. Sensory assessment/evaluation and microbial analysis were performed throughout the shelf life of the products and compared to cadaverine levels measured using LC-MS/MS. Cadaverine concentrations in EB reached approximately 40,000 µg/kg on the "best before" date, while remaining below 50 µg/kg in both MB products on the corresponding date. While cadaverine concentrations in EB displayed a consistent increase, suggesting its potential as a spoilage indicator post-ageing, the low concentrations in MB, did not correlate with sensory assessments, revealing its limitations as a universal spoilage marker. In conclusion, it is necessary to conduct product-specific studies to evaluate the applicability of cadaverine as a spoilage indicator for beef products.

PSIX-29 Needs Assessment for the Use of Genomic Selection Within the Commercial Beef Sector

Abstract Although purebred cattle producers have had genomic EPDs for over a decade, crossbred commercial beef cattle producers have not had the opportunity to use genomic selection for improvement of their cattle. This study aimed to identify what is needed to facilitate the adoption of genomic selection in crossbred beef herds through a survey of beef cattle associations in the western United States. Surveys were distributed electronically through state cattlemen’s associations in Arizona, Idaho, Nevada, Utah, Washington and Wyoming. Nineteen individuals completed the survey representing predominantly cow/calf operations (68%), followed by stockers (9%), feedlots (5%), raising of replacement heifers (5%), and a seedstock producer (5%). Most beef producers (74%) had heard about genomic selection, but only 26% had utilized genomic selection. Of those who had previously used genomic selection, most (60%) were cow/calf producers. Those using genomic selection had done so to identify superior animals (33%), to select replacement heifers (25%) or to identify calf parentage (17%). The use of genomic selection to reduce or manage financial risk or to choose AI bulls for mating selection could expand the value of genomic selection for the beef producer while increasing the rate of genetic improvement in their herd. Interests and concerns regarding genomic selection were also identified, which can be utilized to identify areas of extension and outreach that need to be improved for the technology to be adopted and used more effectively. Key topics needed for genomic selection to be adopted were confirming that genomic selection resulted in a positive return on investment, being able to confidently interpret genomic EPDs, learning how to fully use the genomic EPD results, and information regarding the accuracy of the genomic selection results. The potential for genomic selection within the beef industry is immense, and this survey confirmed that extension programs on genomic selection use have the opportunity to be beneficial to commercial beef producers throughout the industry to improve the genetics of their herds while reducing their financial risk.

PSXII-17 The Influence of Sire on Gestation Length and Calf Performance

Abstract The objective of this study was to determine sire effects on calf gestation length (GL), birthweight (BW), weaning weight (WW), and intermediate feedlot weight (IFW) in beef cattle. In this study, five sires (four Braunvieh and one Simmental) were used to artificially inseminate (AI) commercial cows in Northwest Arkansas resulting in crossbred calves (n = 76) being born in the Fall 2021. Dates for AI were recorded at time of service in December 2020. At parturition, the calf date of birth (DOB) and a hoof-tape BW were recorded. Calf performance data collection included WW and IFW. Calves were categorized into sire groups (n = 5) and GL groups (n = 3). Sire groups included Braunvieh sire A through D and Simmental sire E. Gestation length groups included Short GL of 26 to 278 d (SGL), Average GL of 279 to -290 d (AGL) and Long GL of 291 to 305 d (LGL). Preliminary data were analyzed using Excel. Through ANOVA, GL groups were determined to be statistically significant (P < 0.05) with means of 276.3 ± 1.8 d for SGL (n = 24), 283.2 ± 2.5 d for AGL (n = 24), and 300.5 ± 10.3 d for LGL (n = 16). When comparing sire groups, no significant differences were found for GL (P = 0.39), BW (P = 0.71), WW (P = 0.64) or IFW (P = 0.84) between sires. Descriptive statistics for GL, BW, WW and IFW were 282.0 ± 7.2 d, 36.6 ± 6.4 kg, 262.3 ± 17.4 kg and 544.2 ± 43.0 kg for Sire A, 281.7 ± 9.3 d, 36.7 ± 15.8 kg, 247.8 ± 25.8 kg and 532.0 ± 26.4 kg for Sire B, 285.6±9.8d, 35.2±14.1kg, 259.8±26.1kg and 528.4±34.4kg for Sire C, 284.5±2.1 d, 40.4 ± 0.0 kg, 249.5 ± 32.1 kg and 532.1 ± 0.0kg for Sire D and 288.5 ± 14.4d, 35.4 ± 10.3 kg, 261.7 ± 34.2 kg and 542.9 ± 36.8 kg for Sire E. Gestation length was found to have no significant differences between bull and heifer calves (P = 0.37), with bull calves averaging a greater numerical value of 2.6 d when compared with heifer calves. A significant difference was found between bull and heifer BW (P < 0.05). Means BW for bull calves were 5.43 kg heavier than heifer calves. These data suggest that GL and BW trends follow previous publications when using GL as a breeding selection tool for commercial beef production.

Triplex-colored nucleic acid lateral flow strip and multiplex polymerase chain reaction coupled method for quantitative identification of beef, pork and chicken

Meat adulteration is one of the worldwide challenges for food quality control. Now, we developed a multiplex PCR and nucleic acid lateral flow strip (mPCR-NALFS) integrated method that employs triplex-color latex microspheres (LMs) as visual labels for simultaneous identification of beef, pork and chicken DNA. First, three primer pairs for beef, pork and chicken DNA are tailed with specific oligonucleotide sequences (anti-recognition/anti-detection/anti-control probes) as swing tags. Then, double-stranded amplicons obtained after mPCR amplification were flanked by tags. Finally, these amplicons can accurately hybridize with the pre-immobilized recognition probes on the conjugate pad, detection probes on the test lines and control probes on the control line, respectively. The LMs and recognition probe modified LMs were characterized by scanning electron microscopy, ultraviolet-visible spectroscopy and Fourier Transform Infrared spectroscopy. This strip can quantitatively detect beef, pork and chicken DNA within 10 min without compromising on accuracy compared to the electrophoresis. Specificity analysis revealed no cross-reactivity with meat derived from beef, pork, chicken, duck, mutton, rabbit, goose, ostrich, camel and horse meat. As low as 0.1 % (wt%) of beef, pork and chicken in the simulated adulterated meats were co-detected. This assay was successfully employed for adulteration identification in 28 commercial beef and lamb products.

Evaluation of commercial meat product food label conformity using multiplex PCR assay

This study evaluated the authenticity of pre-packaged processed beef products using multiplex PCR (mPCR) analysis on mtDNA. A total of 48 commercial beef products, including meatballs, burgers, corned beef, smoked beef, and sausages, were examined. They were categorized into three price groups: low (<5 USD/kg), medium (5–10 USD/kg), and high (>10 USD/kg). The DNA genome was extracted and used to amplify mtDNA 12S rRNA to identify bovine, porcine, dog, and rat ingredients, as well as mtDNA cytochrome c oxidase subunit 1 (COI) to detect bovine, chicken, and porcine ingredients. The results showed that all samples contained bovine DNA (155 bp), based on mPCR 12S rRNA. Moreover, chicken DNA was detected in 33 beef products (596 bp) based on mPCR COI. Mislabeling was detected in 56.25% of beef products. In addition, chicken DNA was detected in all three price groups. In conclusion, some products did not comply with the label composition labeling, and higher prices did not guarantee beef product originality.

Growth comparison and model validation for growth of Shiga toxin-producing Escherichia coli (STEC) in ground beef

The aim of this study was to compare the growth of non-O157 Shiga toxin-producing Escherichia coli (STEC) with E. coli O157:H7 in ground beef and modified Tryptic Soy Broth (TSB). Additionally, the performance of three available models (ComBase, Huang et al. model, and Cepeda et al. model), for predicting STEC growth in ground beef was evaluated. To achieve this, eleven groups of STEC, including E. coli O157:H7, were inoculated into irradiated ground beef (7% or 27% fat) or modified TSB, and then subjected to programmed water baths to follow time-varying sinusoidal temperature profiles for 300 h (low temperature, 5–15 °C) and 25 h (high temperature, 10–40 °C). The growth data of STEC in ground beef were fitted to the three models, and model performance indices such as mean relative percentage error (MRPE), mean absolute relative error (MARE), root mean squared error (RMSE), bias factor (BF) and accuracy factor (AF) were calculated to assess their accuracy in predicting STEC growth. The study found that the growth of non-O157 STEC was similar to that of E. coli O157:H7, indicating that growth models for E. coli O157:H7 can be used to predict the growth of non-O157 STEC. The fat content did not significantly affect STEC growth in ground beef. Among the three models tested, the Huang et al. model underestimated the growth of all STEC in ground beef, with an RMSE of up to 2.14 log CFU/g. The ComBase model also under-predicted STEC growth in ground beef at high temperatures (10–40 °C) and could not predict growth at temperatures below 10 °C, where STEC might grow slowly. In contrast, the Cepeda et al. model accurately predicted STEC growth in ground beef and is considered an conservative growth model for STEC in commercial ground beef products. In summary, this study provides important insights into the growth of non-O157 STEC and E. coli O157:H7 in ground beef and their modeling, which can aid in predicting the safety of commercial ground beef products.

Environmental performance of commercial beef production systems utilizing conventional productivity-enhancing technologies.

The objective of this study was to evaluate the effects of using conventional productivity-enhancing technologies (PETs) with or without other natural PETs on the growth performance, carcass traits, and environmental impacts of feedlot cattle. A total of 768 cross-bred yearling steers (499 ± 28.6 kg; n = 384) and heifers (390 ± 34.9 kg; n = 384) were offered a barley grain-based basal diet and divided into implanted or non-implanted groups. Steers were then allocated to diets that contained either: (i) no additive (control); natural feed additives including (ii) fibrolytic enzymes (Enz), (iii) essential oil (Oleo), (iv) direct-fed microbial (DFM), (v) DFM + Enz + Oleo combination; conventional feed additives including (vi) Conv (monensin, tylosin, and beta-adrenergic agonists [βAA]); or Conv with natural feed additives including (vii) Conv + DFM + Enz; (viii) Conv + DFM + Enz + Oleo. Heifers received one of the first three dietary treatments or the following: (iv) probiotic (Citr); (v) Oleo + Citr; (vi) Melengesterol acetate (MGA) + Oleo + βAA; (vii) Conv (monensin, tylosin, βAA, and MGA); or (viii) Conv + Oleo (ConvOleo). Data were used to estimate greenhouse gas (GHG) and ammonia (NH3) emissions, as well as land and water use. Implant and Conv-treated cattle exhibited improvements in growth and carcass traits as compared to the other treatments (P < 0.05). Improvements in the performance of Conv-cattle illustrated that replacing conventional feed additives with natural feed additives would increase both the land and water required to satisfy the feed demand of steers and heifers by 7.9% and 10.5%, respectively. Further, GHG emission intensity for steers and heifers increased by 5.8% and 6.7%, and NH3 emission intensity by 4.3% and 6.7%, respectively. Eliminating the use of implants in cattle increased both land and water use by 14.6% and 19.5%, GHG emission intensity by 10.5% and 15.8%, and NH3 emission intensity by 3.4% and 11.0% for heifers and steers, respectively. These results demonstrate that the use of conventional PETs increases animal performance while reducing the environmental impacts of beef production. Restricting use would increase the environmental footprint of beef produced for both domestic and international markets.

Salmonella Carriage in Peripheral Lymph Nodes and Feces of Cattle at Slaughter Is Affected by Cattle Type, Region, and Season

Salmonella is a significant food safety concern in commercial beef production, and some contamination is thought to occur by inclusion of Salmonella-infected peripheral lymph nodes (LN) in ground beef and through fecal contamination. Surveillance in processing plants assists packers in risk management of Salmonella by understanding seasonal trends and risks associated with different cattle types. Approximately 25 fecal samples and 20 LN were collected from animals representing each of five cattle types (cull beef cattle, cull dairy cows, conventional feedlot cattle, all-natural feedlot cattle raised without pharmaceuticals, and grass-finished cattle) and each of five climate regions (mixed-temperatures and dry, mixed-temperatures and humid, hot and humid, hot and dry, cold) during each of three seasons (summer, fall, winter) to better characterize Salmonella inputs into a commercial cattle processing facility. In total, 1,840 fecal samples and 1,550 LN samples were collected. Fecal samples and LN were cultured for Salmonella, and select isolates were serogrouped and screened for antimicrobial resistance. Conventional feedlot cattle had the highest LN Salmonella concentrations (1.17 log10 CFU/g LN) in this data set, while cull dairy cows had the highest fecal Salmonella concentrations (1.96 log10 CFU/g feces). Conventional feedlot cattle and cull dairy cows had the greatest Salmonella prevalence in both LN (32 and 18%, respectively) and feces (37 and 49%, respectively), while all-natural feedlot cattle had the lowest prevalence in the LN (3%) and feces (7%). As expected, Salmonella prevalence and concentration was lowest for all cattle types during winter compared to warmer seasons. When examined by climate region, a greater Salmonella prevalence in both feces and LN was observed in climate region 4 (hot-dry), than the other regions. Only 21 of 50 Salmonella isolates examined for antimicrobial susceptibility were identified as multidrug resistant (MDR); cull dairy cows were responsible for 48% of MDR isolates, cull beef cattle were responsible for 38%, and conventional feedlot, grass-fed, and all-natural feedlot cattle were each responsible for 4.8%. These results indicate that different production schemes, season, and climate region may influence which cattle are most likely to introduce Salmonella to the abattoir, allowing for greater risk awareness during the slaughter process.

A Farm-to-Fork Quantitative Microbial Exposure Assessment of β-Lactam-Resistant Escherichia coli among U.S. Beef Consumers.

Integrated quantitative descriptions of the transmission of β-lactam-resistant Escherichia coli (BR-EC) from commercial beef products to consumers are not available. Here, a quantitative microbial exposure assessment model was established to simulate the fate of BR-EC in a farm-to-fork continuum and provide an estimate of BR-EC exposure among beef consumers in the U.S. The model compared the per-serving exposures from the consumption of intact beef cuts, non-intact beef cuts, and ground beef. Additionally, scenario analysis was performed to evaluate the relative contribution of antibiotic use during beef cattle production to the level of human exposure to BR-EC. The model predicted mean numbers of BR-EC of 1.7 × 10−4, 8.7 × 10−4, and 6.9 × 10−1 CFU/serving for intact beef cuts, non-intact beef cuts, and ground beef, respectively, at the time of consumption. Sensitivity analyses using the baseline model suggested that factors related to sectors along the supply chain, i.e., feedlots, processing plants, retailers, and consumers, were all important for controlling human exposure to BR-EC. Interventions at the processing and post-processing stages are expected to be most effective. Simulation results showed that a decrease in antibiotic use among beef cattle might be associated with a reduction in exposure to BR-EC from beef consumption. However, the absolute reduction was moderate, indicating that the effectiveness of restricting antibiotic use as a standalone strategy for mitigating human exposure to BR-EC through beef consumption is still uncertain. Good cooking and hygiene practices at home and advanced safety management practices in the beef processing and post-processing continuum are more powerful approaches for reducing human exposure to antibiotic-resistant bacteria in beef products.

Effects of Silage-Based Diets and Cattle Efficiency Type on Performance, Profitability, and Predicted CH4 Emission of Backgrounding Steers

Feed costs are the largest expense in commercial beef production. Increasing cattle (Bos taurus) feed efficiency should reduce feed costs and increase beef profitability. This study used data from two years of a backgrounding trial conducted in Lacombe, Alberta, Canada. The evaluation looked at economic and predicted CH4 emission impacts of diet quality and cattle efficiency type in backgrounding systems. The hypothesis was that diet quality from use of barley (Hordeum vulgare c.v. Canmore) or triticale (xTriticosecale c.v. Bunker) silage-based diets and cattle efficiency type defined by residual feed intake would interact to affect profitability and CH4 emissions. Effects of diet and cattle efficiency type on profitability and CO2e emissions were assessed using statistical and stochastic risk simulation. The profitability of beef backgrounding was affected by cattle efficiency type and diet quality with higher quality barley silage also lowering CO2e emissions. The difference in certainty equivalent (CAD~30 steer−1) of efficient steers on barley silage and inefficient steers on barley silage or efficient or inefficient steers on triticale silage supports a beef backgrounding producer focus on diet quality and cattle efficiency type. This study did not address potential agronomic differences, including yield, which could provide nuance to forage choice.

Connecting Heat Tolerance and Tenderness in Bos indicus Influenced Cattle.

Simple SummaryBos indicus (also known as zebu or humped) cattle are heat tolerant and parasite resistant, which is advantageous in hot, humid climates. However, Bos indicus cattle are also known for excitable temperaments, slower growth, and variation in meat quality characteristics. The relationships between thermotolerance, temperament, and meat production traits are poorly understood. Due to its contribution to body weight, muscle may play an important role in determining the thermoregulatory capacity of Bos indicus cattle. Ultimately, defining relationships between muscle metabolism and heat tolerance are necessary in order to enhance tenderness, without sacrificing heat tolerance of Bos indicus breeds.Bos indicus cattle are widely utilized in tropical and subtropical climates. Their heat tolerance and parasite resistance are integral for beef production in these regions; however, a reputation for excitable temperaments, slower growth, and variation in tenderness has limited their use in commercial beef production. This suggests that there is antagonism between heat tolerance and meat production traits. Meat quality characteristics are determined by the properties of skeletal muscle as well as conditions during slaughter and processing. Thus, it is possible that adaptations related to heat tolerance in the living animal affect tenderness and other meat quality attributes. Since muscle represents a large proportion of body mass, relatively small changes at the cellular level could impact overall heat production of the animal. Specifically, protein degradation and mitochondria function are aspects of organ and cellular metabolism that may help limit heat production and also have a connection to tenderness. Protein degradation postmortem is critical to structural changes that enhance tenderness whereas mitochondria may influence tenderness through their roles in energy metabolism, calcium regulation, cell death signaling, and oxidative stress. This review explores potential relationships between cellular metabolism in vivo and beef quality development in Bos indicus and Bos indicus influenced cattle.

Direct lysis-multiplex polymerase chain reaction assay for beef fraud substitution with chicken, pork and duck

Since the "Horsemeat Scandal" in Europe has aroused people's attention to adulteration of meat, real-time PCR method was used as gold standard to detect single animal species. However, real-time PCR requires expensive equipment, professional personnel, and fluorescent probes with specific modifications in addition to primers, which limit the practical application of this technology for multiple fraud identification. Therefore, the rapid, economical, multiple detection technology for the authenticity of animal-derived ingredients is in urgent need. In this study, a novel direct lysis-multiplex polymerase chain reaction (DL-mPCR) method is reported to simultaneously identify pork, chicken and duck adulterated in beef products within 90 min for the first time. A novel direct lysis (DL) method is employed to obtain sample DNA in a more convenient way without a high-speed centrifuge. The sample preparation step is greatly simplified compared to commercial kit method and can be completed within 15 min. Four pairs of high-specificity primers for the mitochondrial D-loop region of cattle, pig, chicken and duck were designed. The highly specific and sensitivity mPCR assay with optimal primer ratio was constructed, which could detect pork, chicken and duck down to 0.1% (w/w) in meat mixtures treated with freezing, heating and autoclaving, respectively. It was found that 27.8% of 79 commercial beef products collected in local markets contained pork or chicken to varying degrees. The accuracy of the results had been verified by standard real-time PCR. This novel approach (DL-mPCR) proved to be very reliable, time-saving and practical, especially suitable for low-resource front-line detection of meat authentication.

Investigation of pork meat in chicken- and beef-based commercial products by ELISA and real-time PCR sold at retail in Kosovo

Food adulteration and fraudulent practices are widely observed in the food industry worldwide and are of great concern for Balkan countries. This study aims at investigating the level of undeclared pork meat in commercial beef and chicken meat products sold in Kosovo by implying one commercial enzyme-linked immunosorbent assay (ELISA) and two confirmatory real-time polymerase chain reaction (PCR) approaches [ready-to-use real-time PCR and real-time PCR with primers specific for pork mitochondrial deoxyribonucleic acid (DNA)]. In supermarkets in the capital city, Prishtina, 62 meat products were randomly sampled, and the three methods were applied. Additionally, these three approaches were evaluated for their practicability, reproducibility, and cost. The results showed that pork was present in 32% of beef- and 8% chicken-based products. ELISA and real-time PCR with pork specific primers showed 100% of reproducibility for beef- and chicken-based products. In contrast, the ready-to-use real-time PCR kit showed 100% reproducibility in chicken-, but only 75% in beef-based samples. ELISA was more rapid than both real-time PCR approaches, but it was more challenging when large numbers of samples were processed. The real-time PCR approach with pork specific primers was the cheapest, while the ready-to-use real-time PCR was the most practical method. Commercial ELISA, in combination with real-time PCR with pork specific primers, provides a reliable and affordable testing methodology that can be implemented for rapid detection and monitoring of pork adulteration in diverse commercial foods.

FUZZY LOGIC MODELING OF THE OCULAR TEMPERATURE OF CATTLE IN THERMAL STRESS CONDITIONS

This study proposes a fuzzy logic model capable of predicting the ocular temperature (OT) of beef cattle by means of infrared thermography. The goal of this study is to establish a methodology for making decisions related to animal welfare. The experiment was carried out at a commercial beef production farm, located in the south of Minas Gerais state, where twenty-eight Brahman cattle (Bos Taurus Indicus) raised in extensive production systems were evaluated. Thermal images of the entire head of the animal were collected in order to measure the ocular temperature (OT). Concurrently, the variables air dry bulb temperature (DBT) and relative humidity (RH) were recorded. The fuzzy logic model was developed using the Mandani inference method, based on the input variables DBT and RH and the output variable OT, and using the experimental data as reference. The proposed fuzzy logic system allows the estimation of the ocular temperature of beef cattle with an error of 1.71% and a coefficient of determination R 2 of 0.8749. These values validate the proposed fuzzy logic system for helping to make decisions for better animal welfare.

Using Genomics to Measure Phenomics: Repeatability of Bull Prolificacy in Multiple-Bull Pastures

Phenotypes are necessary for genomic evaluations and management. Sometimes genomics can be used to measure phenotypes when other methods are difficult or expensive. Prolificacy of bulls used in multiple-bull pastures for commercial beef production is an example. A retrospective study of 79 bulls aged 2 and older used 141 times in 4–5 pastures across 4 years was used to estimate repeatability from variance components. Traits available before each season’s use were tested for predictive ability. Sires were matched to calves using individual genotypes and evaluating exclusions. A lower-cost method of measuring prolificacy was simulated for five pastures using the bulls’ genotypes and pooled genotypes to estimate average allele frequencies of calves and of cows. Repeatability of prolificacy was 0.62 ± 0.09. A combination of age-class and scrotal circumference accounted for less than 5% of variation. Simulated estimation of prolificacy by pooling DNA of calves was accurate. Adding pooling of cow DNA or actual genotypes both increased accuracy about the same. Knowing a bull’s prior prolificacy would help predict future prolificacy for management purposes and could be used in genomic evaluations and research with coordination of breeders and commercial beef producers.

Beef production from cull dairy cows: a review from culling to consumption.

Although more than 3 million head of dairy cows enter the food supply chain in the U.S. every year, research on this topic remains limited and scarce. Meat production from dairy cows is a significant component of beef production, accounting for almost 10% of U.S. commercial beef production. Thus, the purpose of this review is to demonstrate the importance of dairy cows as a beef source, and to provide an overview on topics from farm to meat product-culling, marketing, transportation, welfare, body composition and its relationship with lactation particularities, carcass characteristics, meat quality, and traceability. Current scientific evidence has shown that culling a dairy cow at an appropriate time has beneficial effects on cow welfare and, consequently, cow value. During marketing the dairy cow is visually evaluated for health and factors associated with its expected carcass value; thus, marketing a well-conditioned cow will ensure that the animal is fit for transportation and provides high carcass yield. However, limitations such as low body condition score, lameness or mobility problems, and visual defects remain persistent. Even though beef harvest plants accommodate cows in all body composition states, the current carcass grade system does not reflect the mature cow industry needs. Therefore, improvement of the grading system could maximize carcass utilization and increase cow carcass value by recognizing subprimal cuts that could be merchandised as whole muscle cuts. Lastly, implementation of a traceability system would unify information from the farm to harvest assisting the industry in making further advancements.

Development of Angus SteerSELECT: a genomic-based tool to identify performance differences of Australian Angus steers during feedlot finishing: Phase 1 validation

Context Genomic-based technologies are allowing commercial beef producers to predict the genetic merit of individual animals of unknown pedigree with increased ease and accuracy. Genomic selection tools that can accurately predict the feedlot and carcass performance of steers have the potential to improve profitability for the beef supply chain. Aims To validate the ability of the Angus SteerSELECT genomic product to predict differences in performance of Australian Angus steers, in terms of carcass weight, marbling score, ossification score and carcass value, using a short-fed (100 days) or long-fed (270 days) finishing protocol at a commercial feedlot. Methods A reference population of 2763 Australian Angus steers was used to generate genomic prediction equations for three carcass traits, namely, carcass weight, marbling score and ossification. The accuracy and bias of genomic predictions of breeding values were then evaluated using a validation population of 522 Angus steers, either short- or long-fed at a commercial feedlot, by comparing breeding values to measured phenotypes. The potential economic benefits for feedlot operators when using Angus SteerSELECT were estimated on the basis of the ability of the tool to predict the carcass value of steers in the validation population. Key results The accuracy of genomic predictions of breeding values for carcass weight, marbling score and ossification score were 0.752, 0.723 and 0.734 respectively. When steers were ranked in quartiles for predicted carcass value, calculated using genomic predictions of breeding values for carcass weight and marbling score, the least-square mean carcass value for steers in each quartile, from bottom 25% predicted performers to top 25% predicted performers, were estimated at A$1794, A$1977, A$2021 and A$2148 for short-fed steers and A$3546, A$3780, A$3864 and A$4258 for long-fed steers. Differences in the carcass value least-squares mean between the bottom and top quartile were highly significant (P &lt; 0.001) for both short-fed and long-fed steers. Conclusions Genomic prediction equations used in Angus SteerSELECT can predict differences in carcass weight, marbling score, ossification score and carcass value in both short-fed and long-fed Australian Angus steers. Implications Genomic selection tools that can predict differences in performance, in terms of growth and carcass characteristics, of commercial feedlot cattle have the potential to significantly increase profitability for the beef supply chain by improving the quality and consistency of the beef products they produce.