Commercial Beef Research Articles

Monitoring cattle liveweight using a mobile, in-paddock weigh platform: Validation, attendance and utility

Cattle liveweight (LW) monitoring is essential for the effective management of animal productivity and welfare, particularly in decision-making on farms. Traditional static weigh (SW) systems require animals to be moved to fixed scales, posing challenges in extensive beef systems due to labour demands, costs, stress, and weight loss during muster. This study evaluated the relationship between LW measured by a SW system and a mobile in-field weighing system, Optiweigh (OW), in 65 weaners (Angus, Shorthorn, and Angus-Shorthorn cross) grazing forage oats on a commercial beef property in north-west NSW, Australia. Over 22 weeks, cattle were weighed fortnightly using SW scales in the cattle yards while OW continuously monitored LW in the paddock. Lin's concordance correlation coefficient showed a strong association between OW and SW liveweight (CCC = 0.97; P < 0.001), with no influence of breed or sex. However, OW slightly over-predicted LW for lighter cattle (≤ 382 kg) and under-predicted for heavier cattle (> 382 kg), prompting the development of a correction. Further research is needed to understand the reasons for these discrepancies, potentially related to diet. Additionally, cattle attendance at OW was affected by size, season, and individual variation (P < 0.001). Overall, the OW system simply and accurately monitored the temporal changes in cattle LW through voluntary animal attendance in remote systems.

Seminal plasma uterine priming alters uterine transcriptomics and negatively impacts embryo growth and uterine artery resistance but not offspring liver transcriptomics in beef cattle.

Seminal plasma uterine priming is important for pregnancy and offspring phenotype in mice and swine; however, impacts on the uterus of the dam and her offspring in cattle are unknown. We sought to determine the effects of seminal plasma uterine priming at estrus on uterine transcriptomics, early gestation (d 35, 40, and 45) embryo morphometrics, mid- to late-gestation (d 140 to 220) uterine artery hemodynamics, birth morphometrics, and liver transcriptomics in offspring at 30 d of age. Multiparous Angus-based commercial beef cows were randomly assigned to receive treatment at estrus: 0.5mL pooled seminal plasma in the uterine body (n = 31, seminal plasma primed) or no treatment (n = 31, control). Seven d later a subset of cows (n = 4/treatment) underwent uterine biopsies, and the remaining cows underwent embryo transfer. Embryo crown-rump length and uterine artery hemodynamics were measured during gestation using ultrasonography. Morphometrics of the calf were collected within 24h of parturition. Liver biopsies were collected at 30 d of age. Data were analyzed by ANOVA in a completely randomized design for the effect of treatment. Myosin heavy chain I (JSP.1) was downregulated [Benjamin-Hochberg adj P (BH) <= 0.05] and ABO alpha 1-3-N-acetylgalactosaminyltransferase and alpha 1-3-galactosyltransferase (ABO) was upregulated (BH adj P <= 0.05) in the uterus of seminal plasma primed cows 7 d after treatment. Embryo crown-rump length was less (P < 0.05) in seminal plasma primed cows. Mid- to late-gestation (d 140 to 220) uterine artery resistance was increased (P < 0.05) in seminal plasma primed cows. Seminal plasma priming did not alter birth weights or curve-crown-rump length, but heart girth was increased (P < 0.05) in offspring from seminal plasma primed cows. There were no differentially expressed genes (BH adj P <= 0.05) in offspring liver at 30 d of age; however, myosin light chain, phosphorylatable, fast skeletal muscle (MYLPF) was absent in all liver samples from calves from seminal plasma primed cows. In contrast, vomeronasal 1 receptor bosTauV1R414 (BOSTAUV1R414) was present in 6 of the 7 liver samples from calves from seminal plasma primed cows. Seminal plasma uterine priming alters uterine transcriptomics, negatively impacts early gestation embryo growth and mid- to late-gestation uterine artery resistance suggesting downstream vascular anomalies. However, these in utero conditions did not impact offspring from birth to 30 d of age.

Comparison of ultra-wide band microwave system and ultrasound in live cattle to predict beef carcase subcutaneous fatness

Ultrasound and ultrawide band microwave system (MiS) were directly compared in their ability to scan live cattle to predict carcase traits. Commercial beef cattle (n = 315) were scanned on farm 0–14 days prior to slaughter. Traits measured were subcutaneous fatness at the P8 site (over the gluteus muscle on the rump, at the intersection of a line through the pin bone parallel to the chine and perpendicular through the 3rd sacral crest) and subcutaneous fatness at the rib fat site (between 12th & 13th rib, ¾ of the length ventrally over the longissimus muscle). The precision of prediction of carcase traits was slightly better using MiS. MiS prediction of P8 fat depth had an average RMSEP of 2.48 mm and R2 of 0.65. The MiS could predict carcase rib fat with an average RMSEP of 2.28 mm and R2 of 0.56. The accuracy of prediction was very similar between the two technologies. When predicting P8, the average bias was smallest using MiS at 0.157 mm, but the average slope was smallest using ultrasound at 0.03 mm. When predicting rib fat, MiS had the smallest average bias at 0.204 mm, and smallest average slope deviation at 0.06 mm. The MiS predicted P8 and rib fat carcase traits with similar precision and accuracy as ultrasound.

PSV-16 Evaluation of upper respiratory and fecal microbiomes in neonatal beef calves

Abstract There is a critical lack of information on the timing of colonization of bovine respiratory disease-related bacteria in the upper respiratory tract, potentially affecting calf health and disease onset. The objective of this study was to evaluate the upper respiratory tract and fecal microbiomes of neonatal beef calves during the first 24 h of life compared with their dams at the time of birth. Late-gestation commercial beef cows (n = 28) were assigned to individual, soil-surfaced pens (6.25 x 2.29 m) fitted with canvas tarps on shared fences to limit contact between unrelated pairs. Left nasal (LN), right nasal (RN), fecal, and vaginal swab samples were collected from cows at a single time point promptly after parturition. Swabs of the LN, RN, and rectum were collected from calves at birth (0 h), 6, 12, and 24 h post-parturition. Samples were flash-frozen and stored at -80°C until processing. DNA was extracted from swabs using Power Soil Pro kit. Extracted DNA was used to prepare DNA libraries for full-length 16S rRNA gene sequencing on a MinION Mk1C device. Sequenced reads were classified using Centrifuge and used in microbiome analyses conducted in R to estimate the changes in the microbiome according to animal type (cow versus calf), time of collection, and sample type (nasal, fecal, or vaginal). Upper respiratory microbiomes significantly differed (P &amp;lt; 0.005) between cows and their offspring at birth. In nasal microbiomes, animal type explained 12.6% (P = 0.002) and 18.5% (P = 0.001) of variance in beta diversity in left and right cavities, respectively. Animal type explained 42.1% of the beta diversity variance in fecal microbiomes (P = 0.001). Nasal microbiomes at birth were significantly more dispersed in dams compared with their calves in both the LN (P = 0.03) and RN (P = 0.03). Similarly, fecal microbiomes of dams were significantly more dispersed (P &amp;lt; 0.0001) than those of their offspring. There was a clear transition of the microbial communities associated with calf age in the upper respiratory and fecal niches. Calf age accounted for 2% (P = 0.02), 3.5% (P = 0.001), and 28% (P = 0.001) of the variance in the beta diversity of the LN, RN, and fecal microbiomes, respectively. After adjusting for calf age, the laterality of nasal microbiomes was not significantly (P = 0.682) associated with the composition of microbial communities. In conclusion, calf microbial communities were dissimilar to that of their dam at birth. Additionally, microbial community transition was evident with each subsequent sampling time point, potentially influenced by the presence of the dam.

161 Development, deployment, and calibration of genomic selection tools to improve performance traits for Canadian beef cattle

Abstract Genomic selection has the potential to accelerate the genetic improvement rate for difficult/expensive to measure traits such as feed efficiency and fertility traits in beef cattle. To develop genomic selection tools for Canadian beef cattle, we collected or sourced phenotypic data of feed efficiency along with other traits including carcass merit, female feed intake and fertility related traits, and their genotypes from both research and commercial herds. The phenotypic data were consolidated and recorded for contemporary groups, leading to the development of data sets including 11,292 beef cattle with residual feed intake, dry matter intake, average daily gain, metabolic body weight, 7,299 to 8,081 cattle with carcass merit traits, and 1,802 to 2,792 cows with feed intake and fertility traits after quality controls. Genotype data of the animals from various single nucleotide polymorphisms (SNP) panels were merged to the same allele format of 50K, and then imputed to 770K SNPs, and eventually to whole genome sequence variants. The refined Canadian beef cattle data sets have not only allowed us to investigate genetic architectures of the beef performance traits but also enabled the development of genomic selection tools including molecular breeding values and multiple trait selection indexes with a moderate to moderately high accuracy for the traits through a cross-validation of within reference data set. The genomic selection tools have been successfully deployed to over 10,415 breeding candidates submitted by Canadian beef producers through multiple demonstration projects. The average accuracy of the molecular breeding values and multiple trait selection index of the commercial beef cattle ranged from 0.38 to 0.49 for feed efficiency and carcass merit traits, and from 0.26 to 0.38 for female feed intake and fertility traits. Current research is focusing on calibrating the genomic selection tools with larger data sets and with more advanced genomic prediction methods.

275 Frequency of chronic passive congestive livers at harvest in the Texas Panhandle and the association with carcass outcomes

Abstract Chronic passive congestive (CPC) livers are reported as one of the most common clinical signs of right-sided Bovine Congestive Heart Failure (BCHF). Frequency of CPC livers at harvest and the associated loss of offal and carcass value does not appear in the literature. Our objectives were to 1) quantify the frequency of CPC livers at harvest within the Texas Panhandle, and 2) evaluate the association with offal and carcass outcomes. Audits were performed over the duration of a production week (both harvest shifts) per each large commercial beef processing facility (4 total) in the Texas Panhandle. West Texas A&amp;M University trained personnel identified CPC (large blue) livers at evisceration and documented heart score (HS; scale 1 = normal to 5 = extreme structural changes), liver weight, USDA-FSIS inspection fate (U.S. Inspected &amp; Passed; U.S. Condemned) of the liver, remaining viscera, and carcass. Other visual observations (sex, predominant black hair coat color, carcass/visceral edema, liver abscesses) were noted. 1) Frequency data were documented among cattle-type populations: sex (steers, heifers, cows, bulls), and phenotype [native, dairy-cross, dairy, category-B (Mexico-origin)]. 2) Carcass and lot identification were collected for the purpose of tracking and obtaining carcass grading data. Of carcasses deemed wholesome-U.S. Inspected &amp; Passed, USDA yield and quality metrics [hot carcass weight (HCW), 12th-rib fat thickness (FT), ribeye area (REA), marbling score (MS)] of those identified with CPC, as well as data for the balance of respective lots were collected. Carcass outcomes of those exhibiting a CPC liver were compared with the outcomes of remaining lot. Frequency data were analyzed via chi-square. Carcass data were analyzed using mixed models, where occurrence of CPC liver was the fixed effect; facility, cattle type, and sex were random effects. A total of 83,527 animals were audited, with a CPC liver frequency of 0.17% (n = 144). Frequencies among sex (steer = 0.16%; heifer = 0.17%; cow = 0.33%; P &amp;lt; 0.01) and phenotypes (native = 0.15%; category-B = 0.04%; dairy cross = 0.14%; P = 0.01) were documented. Heart scores ranged from 1 to 4, with HS 3 occurring most frequently [HS 1 (n = 2); HS 2 (n = 39); HS 3 (n = 62); HS 4 (n = 17)]. Weights of CPC livers ranged from 7.3 kg to 34.4 kg; the heaviest CPC livers were recorded in cows (mean = 17.2 kg; P &amp;lt; 0.01). Despite USDA-FSIS guidelines, 2.08% of CPC livers were U.S. Inspected &amp; Passed, along with 16.90% of viscera and 84.03% of carcasses. Cow carcasses encountered the greatest U.S. Condemn-rates (38.24%) among the sex categories. Within the fed-beef population, natives were the only category resulting in U.S. Condemned carcasses (10.64%). All carcass outcomes were decreased (P ≤ 0.01) by CPC livers.

Genetic and genomic analysis of Belgian Blue’s susceptibility for psoroptic mange

BackgroundPsoroptic mange, caused by Psoroptes ovis mites, is affecting Belgian Blue cattle’s welfare and production potential. The Belgian Blue cattle—known for its high degree of muscling, low feed conversion ratio and high beef quality—is highly susceptible for this disease.ResultsIn this study, we phenotyped 1975 Belgian Blue cattle from more than 100 different groups on commercial beef farms for their psoroptic mange susceptibility. Substantial individual differences were observed within these management groups, with lesion extent differences up to ± 15%. Animal models showed that estimated heritabilities were low for lesion extent and severe lesion extent (0.07 and 0.09, respectively) and 0.12 for the number of mites. A genome wide association study for mange susceptibility revealed signals on BTA6, BTA11, BTA15 and BTA24. In these regions, candidate genes GBA3, RAG2, and TRAF6 were identified.ConclusionsDespite the challenges in phenotyping for psoroptic mange due to the timing of screening, the continuous evolution of lesions and different management conditions, we successfully conducted a study on the genetic susceptibility to psoroptic mange in Belgian Blue cattle. Our results clearly indicate that psoroptic mange is under polygenic control and the underlying candidate genes should be studied more thoroughly. This is the first study providing candidate genes for this complex disease. These results are already valuable for Belgian Blue breeding, however, further research is needed to unravel the architecture of this disease and to identify causal mutations.

Navigating the contradictory dynamics of production and social reproduction in collectively owned agricultural enterprises in South Africa's land reform

AbstractThe paper explores how beneficiaries of South Africa's land reform programme attempt to navigate the contradictory dynamics of production and social reproduction in collectively owned agricultural enterprises. The Mphuzanyoni Communal Property Association in KwaZulu‐Natal province farms with commercial beef herds and the Mayime Cooperative in the Eastern Cape province is engaged in a joint venture dairy farming scheme in partnership with an agribusiness firm. Severe tensions are evident between the social reproduction of households and the requirements of simple or expanded reproduction of agricultural enterprises. Bernstein's concept of competing ‘funds’ is used to examine struggles over production and reproduction on the farms, in which members of socially differentiated households contest divergent visions for the collective enterprises. Conflicts centre on how labour and capital should be mobilised, how income and other benefits in kind should be distributed to households and whether or not income should be invested for purposes of simple or expanded reproduction of the enterprise. Challenges of governance are rooted in these conflicts rather than in group ownership as a form of property right.

Retrospective evaluation of the causes and distribution of lameness in beef and dairy cattle evaluated by ambulatory and in-house clinical services at a North American veterinary teaching hospital

Since lameness occurs so commonly and has such significant effects on cattle productivity and farm profitability, manage­ment and prevention of lameness is essential to the design of effective health and husbandry programs. Unfortunately, the causes and distribution of lameness lesions between beef and dairy cattle, as well as the different management groups within a specific production class, can differ dramatically. A recent report analyzing data from 17 dairies found infectious condi­tions, specifically digital dermatitis and foot rot, were the most common cause of lameness in first-lactation cattle. In contrast, non-infectious lesions, namely white line disease and sole and toe ulcers, were the most common cause of lameness in cows in their second or greater lactation. A report evaluating the inci­dence of specific causes of lameness in cattle on 6 commercial beef feedlots found that the most frequently identified causes of lameness were upper limb issues and deep digital sepsis. How­ever, when characterizing different causes of lameness in beef cattle outside of feedlots, there exists a dearth of published data. Therefore, the objective of this study was to describe the different causes and distribution of lameness in beef and dairy cattle presenting to either a primary care ambulatory service or in house referral services at a veterinary teaching hospital in the southeastern United States.

Optimizing ReBreed21 II: Fertility and reproductive efficiency in different parities during a shortened breeding season in beef cattle

This study evaluated the efficiency of a rapid reinsemination program allowing timed AI (TAI) every 21d (ReBreed21) in a commercial beef cow-calf operation. Nelore females from different parities (n = 2085) were synchronized for first TAI (D0 = TAI) using an estradiol/progesterone (E2/P4) protocol and assigned to one of three reinsemination programs: Resynch33 (n = 753), traditional resynch program with second TAI at D42 after first TAI; ReBreed21 (n = 687); or ReBreed21+EC (n = 670). The ReBreed females (n = 1357) received intravaginal P4 insert on D12, on D19 P4 was removed, and a dose of equine chorionic gonadotropin (eCG) was administered, then, ReBreed21 females received 0.6 mg of EC (ReBreed21+EC) or nothing (ReBreed21) and on D21, nonpregnancy (NP) was determined using Doppler ultrasound to detect corpus luteum (CL) blood flow (BF) (NP: <25 % BF pixels of total CL area) and NP cows received immediate TAI and GnRH to induce ovulation. Pregnancy diagnosis was performed at D33 after TAI following all TAIs. Cows considered pregnant at D21, based on CL BF, but NP on D33 were designated False-Positives (FP) and false negatives (FN) were number of nonpregnant cows/heifers on d21 based on the CL BF found to subsequently be pregnant on D33 divided by the total number pregnant. Pregnancy/AI (P/AI) did not differ for the first TAI (55.1 %) among the treatments. Heifers had similar P/AI at the second AI in all groups and similar to the first AI. Primiparous had greater P/AI in ReBreed21+EC and Resynch33 at s TAI compared to ReBreed21, 51.7 %, 55.8 %, 34.2 %, respectively. Multiparous had greater P/AI at second TAI in Resynch33 (60.9 %) than ReBreed21 programs (34.7 %). The percentage FP and FN among ReBreed21 programs did not differ, 13.8 and 0.2 %, respectively. Overall accumulative pregnancies on D21 of the breeding season were greater for ReBreed21 and ReBreed21+EC than Resynch33 (69.7 %, 71.6 %, and 55.5 %, respectively). However, on D42 of the breeding season, only heifers had greater pregnancies in ReBreed21 programs than Resynch33 (73.3 %, 74.3.6 %, and 63.2 %, respectively). Average days to pregnancy were less (P = 0.01) for ReBreed21 and ReBreed21+EC than Resynch33. Thus, the ReBreed21 strategy can improve the efficiency of TAI programs in beef cattle. Of interest, ReBreed21 was particularly effective in nulliparous, somewhat effective in primiparous when EC was added to the program, but relatively ineffective in multiparous beef cattle.

Comparison between a complete preconditioning programme and conventional conduct on behaviour, health and performance of young bulls from small cow-calf herds

Bovine respiratory diseases (BRDs) have major socioeconomic impacts in the beef sector. Antimicrobials have been traditionally used to prevent the development of BRDs upon arrival in fattening units. Currently, from a “One Health and One Welfare” perspective, alternative solutions are being investigated. Preconditioning programmes that aim at reducing stress and reinforcing immune functions have been proposed to decrease BRDs incidence. In this study, we assessed the effect of a preconditioning protocol set up in nine commercial beef herds on young bulls’ behaviour, health, and performance. Preconditioned bulls (PREC) were weaned indoors 50 days before departure, and progressively fed a concentrate diet supplemented with vitamins and trace elements. They also received an anthelmintic treatment, and two doses of a trivalent vaccine against respiratory pathogens at 4-week intervals. In contrast, controls (CTRL) were kept on pasture with their dams with no vaccination or particular diets. All calves were transported together to a single sorting facility to be sorted by experimental groups, origins, and BW, forming new groups before dispatch to four fattening units. At arrival, CTRL were treated with anthelmintic drugs and received one injection of the same BRDs vaccine. No intervention was performed on PREC bulls. BRD-scores were 0.73 in PREC versus 0.07 in CTRL (P = 0.01) during the preconditioning period and 0.96 in PREC versus 0.54 in CTRL (P = 0.41) after 15 days in the fattening units. Morbidity estimates were 18% in PREC versus 1% in CTRL (P < 0.001) during the preconditioning period and 32% in PREC versus 19% (P = 0.07) in CTRL after 15 days in the fattening units. Poor housing conditions during preconditioning and a different aetiology could partly explain these results. At arrival to fattening, the average daily gain (ADG) was 1 605 g for PREC versus 1 140 g (P = 0.012) for CTRL. After fattening for 180 days, differences in BW, ADG, carcass weight and conformation were inconclusive. In Europe, preconditioning programmes including vaccination must be set up coherently with good husbandry practices and with a global adaptation of batch management of the beef sector otherwise, they may be less effective than expected.

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.

In vitro digestion of beef and vegan burgers cooked by microwave technology: Effects on protein and lipid fractions

Commercial beef burgers and vegan analogues were purchased and, after a microwave treatment, they were submitted to an in vitro digestion (INFOGEST). Vegan cooked burgers showed similar protein content (16–17 %) but lower amounts of total peptides than beef burgers. The protein digestibility was higher in beef burgers. Peptide amounts increased during in vitro digestion, reaching similar amounts in both types of products in the micellar phase (bioaccessible fraction). The fat content in cooked vegan burgers was significantly lower than in beef burgers (16.7 and 21.2 %, respectively), with a higher amount of PUFAs and being the lipolysis activity, measure by FFA, less intense both after cooking and after the gastrointestinal process. Both types of cooked samples showed high carbonyl amounts (34.18 and 25.51 nmol/mg protein in beef and vegan samples, respectively), that decreased during in vitro digestion. On the contrary, lipid oxidation increased during gastrointestinal digestion, particularly in vegan samples. The antioxidant capacity (ABTS and DPPH) showed higher values for vegan products in cooked samples, but significantly decreased during digestion, reaching similar values for both types of products.

Combining Embryo Transfer and Artificial Insemination to Achieve Twinning in Beef Cattle, and Effects of Different Twin Calf-Raising Methods on Neonatal Behavior and Growth

As the beef industry moves towards efficient animal production to improve sustainability in agriculture, new production and management approaches are emerging. Among the many facets of the beef industry, cow–calf operations have the most opportunity for efficiency improvement, including improvements in fertility. This project accounts for measures and methods of (1) twinning reproductive technologies and (2) twin calf perinatal care and pre-weaning rearing. The overall objective was to produce twin calves using two reproductive technologies—embryo transfer and artificial insemination. The subobjectives were to determine accuracy of twin pregnancies embryo/fetal losses using ultrasonography, evaluate parturition and dystocia, and determine the effects of different twin-raising methods on neonatal behavior and growth. A fixed-time artificial insemination (FTAI) protocol was applied to 77 multiparous Angus-cross cows from a commercial beef herd in northcentral South Dakota during the summer of 2019. Cows were assigned to two different treatments groups: only artificially inseminated (AI) or received an embryo transfer following artificial insemination (ET + AI). They were estrous-synchronized, artificially inseminated (AI) with black Angus semen at day 0, and received and embryo transfer (ET) at day 7. Ultrasound examination detected 56% pregnancy risk for both groups, with sensitivity, specificity, and accuracy of 75%, 100%, and 90.5%, respectively, for bilateral twin detection. Calves were born during spring 2020. Twin calves (n = 34) and singleton calves (n = 11) were assigned to one of three raising methods: (1) twin born and twin raised (TT; n = 16), (2) twin born and single raised (TS; n = 18), and (3) single born and single raised (S; n = 11). Neonatal nursing behavior and birth weights were recorded, and adjusted day 200 and day 280 were calculated measures of vitality and growth. Blood samples were collected at age 24 h for colostrum intake measures (total serum protein, IgG1, and IgM). Twin calves were born 20% (p &lt; 0.05) lighter in body weight than singletons; however, weights did not differ at day 280 between TT and S calves. TS calves had the shortest average latency to stand, but immunoglobulin concentrations did not differ among treatments. At weaning, cows that had birthed and raised twins produced more kilograms of live weight per pregnancy than cows birthing and raising singletons. Using ET + AI proved to increase twinning rate, and growth was maintained when raising both twins with their dam.

Impact of binary mixtures of natural waxes in mechanical properties and microstructure of oleogels.

Solid fats are critical to obtaining a wide range of food texture and quality characteristics, but their consumption is strongly associated with higher cardiovascular disease risks. Structuring unsaturated oils with natural waxes into oleogels (OG) is an innovative solution to develop fat mimics with a healthier profile. Soy wax (SW), beeswax (BW) and carnauba wax (CW), have been used in binary mixtures of waxes, aiming to understand their interactions and influence on OG quality properties and microstructural characteristics. In the present study, OGs were produced using binary wax mixtures and analyzed for texture, color, smoke point, microstructure, Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). Wax combinations led to antagonistic (mixtures with SW) and synergistic interactions (BW/CW) based on their mechanical properties. At the microstructural level BW/CW blends showed a reduction in crystal size and with a more compact structure. XRD and FTIR spectra revealed a packing of orthorhombic perpendicular subcell for most OGs, whereas SW produced samples with an arrangement with β' crystals, characteristic of edible solid fats. Additionally, when compared to commercial beef fat, BW/CW mixtures showed similar quality attributes indicating that they could act as fat mimic. The combined analysis of microstructure, spectroscopic and mechanical properties enhanced the understanding of how the nature of the interactions between waxes and lipid phases impact in the final quality of the structured oils. The study's insights indicate that binary wax combinations can efficiently replace solid fats, offering healthier alternatives at the same time as preserving desired sensory characteristics. © 2024 Society of Chemical Industry.

13 Effects of an acclimation protocol during the handling events of the 7 d CO-synch + CIDR protocol on temperament and reproductive performance of Bos taurus commercial beef heifers

Abstract It has been previously reported that cattle temperament significantly impacts fertility to estrous synchronization (ES) protocols. In addition, enrolling heifers to acclimation protocols following weaning resulted in improved reproductive parameters with an increased proportion of acclimated heifers reaching puberty earlier when compared with non-acclimated cohorts. The objective of the present experiment was to assess the effects of an acclimation protocol during the handling events of an ES on changes in temperament and fertility to the ES protocol in Bos taurus commercial beef heifers. A total of 361 Angus-influenced commercial heifers from 5 different locations were enrolled in the experiment. Before enrolling heifers in the 7-d CO-Synch + CIDR protocol (d -10), individual heifers were evaluated for reproductive tract score (RTS), and chute score (CS) and stratified to receive acclimation (TRT) or to serve as control (CTRL). On d -10, heifers from TRT and CTRL groups received ear tags of different colors and individuals from CTRL and TRT were kept together in their pastures. Before each handling event of the ES (d 0,7,10), TRT heifers were sorted from CTRL and submitted to acclimation, which consisted of running heifers through the handling facilities without catching individuals in the restraining chute. Treatment heifers were then comingled with CTRL heifers, and all heifers were brought to the handling facilities for the ES event. Individual CS and exit velocities (EV) were recorded for all animals at all days (-10,0,7,10). Chute scores were recorded in a 1 to 5 scale, where 1 = calm, no movement; 2 = restless movements; 3 = frequent movement, vocalization; 4 = constant moving, vocalization, shaking of the chute; 5 = violent, continuous struggling. Individual estrus detection patch scores were assessed at the day of fixed-time artificial insemination (FTAI) based on percentage of activation, where 0 = lost; 1 = less than 25% activated, 2 = less than 50% activated, 3 = less than 75% activated, 4 = more than 75% activated. Pregnancy status was determined by rectal ultrasonography approximately 40 d after FTAI. Estrus detection patch scores did not differ between CTRL and TRT heifers (P = 0.1906). In addition, pregnancy rates to FTAI did not differ between TRT and CTRL heifers (56.81% and 52.74%; P = 0.3563). Reproductive tract scores (P = 0.777), EV (P = 0.9607) and CS (P = 0.990) did not differ between CTRL and TRT on d -10. However, CS, but not EV was decreased on d 7 (P = 0.001) and 10 (P = 0.0002) for TRT heifers when compared with CTRL. We conclude that enrolling heifers to an acclimation protocol during the handling events of the ES protocol was effective at decreasing excitability of heifers by the day of FTAI, as evidenced by decreased CS observed for TRT heifers on d 7, and 10 but did not support an increase in fertility to the ES protocol.

Observational longitudinal study on Toxoplasma gondii infection in fattening beef cattle: serology and associated haematological findings

Toxoplasmosis, caused by the protozoan parasite Toxoplasma gondii, is a globally distributed zoonotic infection with significant implications for human and animal health. This study investigated the prevalence of T. gondii infection in a population of beef cattle at three different stages of their productive lifespan and examined the impact of T. gondii serological status on blood parameters. A commercial beef fattening unit in Italy was the setting for this research, which involved a biosecurity assessment upon cattle arrival, blood sampling at three time points and Toxoplasma-specific serological testing using indirect fluorescent antibody tests (IFAT). Results revealed a dynamic pattern of T. gondii seropositivity in cattle, with an initial prevalence of 30.6% at arrival (T0) that increased to 44.6% at 14 days (T1) and then decreased slightly to 39.3% at slaughter after 5 months (T2). Interestingly, seroconversion was observed during the study, indicating ongoing infections, and antibody waning occurred in some animals. In terms of blood parameters, seropositive cattle exhibited significantly lower mean corpuscular volume (MCV) and a higher neutrophil–lymphocyte (N/L) ratio, suggesting an activation of the innate immune response. Furthermore, cattle with higher antibody titres displayed higher neutrophil counts. However, all blood parameters with a statistical significance were within the reference range. This study provides for the first time a longitudinal investigation on the serological status for T. gondii in naturally exposed beef cattle. These findings provide valuable insights into the clinico-pathological aspects of natural T. gondii exposure in cattle and underscore the importance of monitoring and managing T. gondii infection in livestock production systems.

Application of bacteriophage MS2 in preliminary simulation of inactivation rate of pathogenic viruses in commercial beef and chicken packaging

SummaryIn response to the growing concern of transmitting pathogenic viruses through food, this research aimed to assess the impact of various factors on the commercial packaging of meat (chicken and beef) on the inactivation of bacteriophage MS2 which was scrutinised by examining the influence of packaging type, bacteriophage spiking levels, temperature, as well as the meat shape and type. The findings revealed that the recovery of bacteriophage MS2 from minced beef was lower in modified atmosphere packaging (MAP) compared with air packaging (AP) at both storage times, spiking levels, and freezing and refrigerating temperatures. On the other hand, the recovery of the bacteriophage from chopped beef was lower in AP than in MAP in refrigerating conditions at both spiking levels during the 3 days of storage. According to our findings, the recovery levels of bacteriophage MS2 from chicken had statistically significant differences in both packaging types at different spiking levels. Storage conditions and packaging type were the most essential parameters in bacteriophage MS2 viability. The lowest bacteriophage viability belonged to MAP.

Microbiota associated with commercial dry-aged beef in France

Meat dry aging consists in storing unpackaged meat in a cold room, and at a specific and controlled relative humidity (RH), for a period of 1 to 5 weeks or more. This practice has become widespread in recent years due to its positive effect on the tenderness of the meat but also on other organoleptic characteristics and therefore its market value. The objective of this work was to study the bacterial and fungal microbiota of dry-aged beef at the commercial stage by both culture-dependent and -independent approaches. Fifty-eight samples of dry-aged meat from different producer types (meat processing plants, artisanal and supermarket butchers) were studied. The dry-aging conditions (temperature, RH) of the meats, as well as the surface pH and aw, were measured. The main microbial groups were enumerated by culture on various dedicated media. Concerning fungi, isolates of yeasts and molds (n = 257) were identified after dereplication by FTIR spectroscopy and/or sequencing of taxonomically relevant genes (26S rDNA, ITS, β-tubulin, actin). Metagenetic analyzes targeting the V3-V4 regions of 16S rDNA and ITS2 were also performed. Overall, ripening practices were diversified with temperatures and RH between 0.5 and 2.8 °C (median = 2 °C) and 47 and 88 % (median = 70 %), respectively. The aerobic colony count varied between 1.97 and 10.91 log10 CFU/g (median = 8.32 log10 CFU/g) and was similar to that of Pseudomonas spp., indicating that this bacterial group was dominant. Yeast populations varied between <2 and 9.41 log10 CFU/g, while molds showed abundances between <2 and 7.7 log10 TFU/g, the highest values being found in meats matured with a high RH. Bacterial and mold counts were positively correlated with the dry-aging RH and, to a lesser extent, temperature. The main yeast species were Candida zeylanoides and Yarrowia alimentaria as well as Itersonilia pannonica (identified only in metagenetics). The dominant mold species were psychrophilic or psychrotrophic species, namely Mucor complex flavus and Helycostylum elegans/pulchrum that have already been shown to be associated with dry-aged beef meat. This study has identified the main microorganisms associated with dry-aged meat in France, which raises the question of their role in the organoleptic quality of these higher value products.

Dose effects of encapsulated butyric acid and zinc on beef feedlot steer growth performance, dietary net energy utilization, rumen morphometrics, small intestine histology, and carcass characteristics.

The objective of this study was to determine the effects that increasing doses of encapsulated butyric acid and zinc (BZ) have on feedlot steer growth performance, rumen morphometrics and small intestine histology (data not statistically analyzed), dietary net energy utilization, and carcass characteristics. Steers [n = 272; shrunk body weight (BW) = 360 kg ± 74 kg] were assigned to dietary treatments [0 (CON), 1, 2, or 3g BZ/kg diet dry matter] in a randomized complete block design (RCBD) with pen (n = 32 total; n = 8 per treatment) as experimental unit. Pens were blocked by cattle source and location within the feedyard. Cattle were fed until visually assessed to have 1.27cm rib-fat and were shipped for harvest at a commercial beef abattoir. Carcass and liver health data were recorded. A subset of steers (n = 8 total; n = 2 per treatment) was harvested at the SDSU Meat Laboratory to collect empty body measurements, rumen samples for morphometric analysis, and duodenal and ileal samples for histological analysis to provide context to feeding trial outcomes. Feedlot growth performance data was calculated on a carcass-adjusted basis: hot carcass weight (HCW)/0.625. Data were analyzed as a RCBD with fixed effects of BZ inclusion level and block was considered a random effect; pre-planned contrasts for CON vs. BZ, plus linear, and quadratic responses were tested. No differences (P ≥ 0.11) were observed for final BW, dry matter intake, average daily gain (ADG), feed conversion efficiency (G:F), performance calculated dietary net energy, HCW, ribeye area, rib-fat thickness, marbling score, estimated empty body fat, or distribution of USDA yield grade (YG) 1, 3, 4, 5, and USDA quality grade among treatments. A tendency (P = 0.10) was observed for CON vs. BZ for calculated YG. Tendencies were detected for USDA YG 2 carcass distribution (linear; P = 0.07) and for normal and abscessed liver prevalence (quadratic; P = 0.08). Dressed yield tended to be greater (P = 0.08) for BZ vs. CON and increased with dose (linear; P = 0.05). Receiving period shrunk BW, ADG, and G:F was improved (P ≤ 0.02) for BZ-supplemented steers compared to CON. Data from this study suggests that the addition of BZ to feedlot finishing diets to improve receiving period growth performance and decreasing the prevalence of abscessed livers should be further investigated.