Radiographic Analysis of the Beef Cattle Digits Slaughtered after 114 Days of Confinement.

Foot disorders are responsible for up to 5% of confinement losses. Identifying the cause of lameness and applying the correct treatment are crucial measures. The possibility of determining the probable origins of digital lesions, their extension, and assistance in cases in which it was not possible to reach a definitive clinical diagnosis demonstrates that the radiographic evaluation provides information of great importance on cattle digits. Thus, this study aimed to investigate possible radiographic changes in the hoof, bone structures, and soft tissues of the digits of Nelore bulls at the end of the confinement period. Regarding the main signs, 100% (n = 24) showed proliferation of enthesophytes and osteophytes and irregular contours, 62.5% (n = 15) enlargement of vascular channels, 37.5% (n = 9) osteolysis, 33.4% (n = 8) gas content in the white line region, 20.84% (n = 5) gas content in the dorsal lamina region, and 4.16% (n = 1) presented palisade periosteal reaction. Ten (41.7%) out of 24 (100%) animals evaluated at the end of the confinement presented lameness, three animals of score three, four animals of score two, and three animals of score one. The higher the score indicating the severity of the signs observed in the visual assessment of the radiographs, the higher the internal angle values (moderate correlation of 0.5 and p < 0.05). A higher prevalence of osteo-proliferative radiographic changes was identified at the end of the 114-day confinement period in the third phalanx of Nellore cattle even in animals that had no lameness.

A veterinary cerumenomic assay for bovine laminitis identification.

Bovine laminitis disorder results in animal welfare and economic concerns in dairy and beef farms worldwide. However, the affected metabolic pathways, pathophysiologic characteristics, and inflammatory mechanisms remain unclear, hampering the development of new diagnostics. Using cerumen (earwax) as a source of volatile metabolites (cerumenomic) that carry valuable biological information has interesting implications for veterinary medicine. Nonetheless, up to now, no applications of veterinary cerumenomic assays have been made to identify bovine laminitis. This work aims to develop a veterinary cerumenomic assay for bovine laminitis identification that is non-invasive, robust, accurate, and sensitive to detecting the metabolic disturbances in bovine volatile metabolome. Twenty earwax samples (10 from healthy/control calves and 10 from laminitis calves) were collected from Nellore cattle, followed by Headspace/Gas Chromatography-Mass Spectrometry (HS/GC-MS) analysis and biomarker selection in two multivariate approaches: semiquantitative (intensity data) and semiqualitative (binary data). Following the analysis, cerumen volatile metabolites were indicated as candidate biomarkers for identifying bovine laminitis by monitoring their intensity or occurrence. In the semiquantitative strategy, the p-cresol presented the highest diagnostic figures of merit (area under the curve: 0.845, sensitivity: 0.700, and specificity: 0.900). Regarding the binary approach, a panel combining eight variables/volatiles, with formamide being the most prominent one, showed an area under the curve, sensitivity, and specificity of 0.97, 0.81, and 0.90, respectively. In summary, this work describes the first veterinary cerumenomic assay for bovine laminitis that indicates new metabolites altered during the inflammatory condition, paving the way for developing laminitis early diagnosis by monitoring the cerumen metabolites.

Apparent digestibility and ingestive behavior of Nellore bulls with low and high residual feed intake.

The objective of this study was to determine the correlation between ingestive behavior, apparent digestibility, and residual feed intake (RFI) of finishing Nellore bulls fed a high concentrate diet. One hundred and twenty Nellore bulls, housed in individual pens, were evaluated in individual performance tests. The animals were fed a high concentrate diet (23:77 roughage/concentrate ratio). The animals were classified as low RFI, medium RFI, and high RFI. Data from ten animals from each group were used. Fecal production and nutrient digestibility were calculated using indigestible neutral detergent fiber as an internal marker. The feeding behavior was evaluated over 24 h by direct observation every 5 min. The most efficient animals (low RFI, 8.58 kg DM/day) consumed 27.62% less feed than the least efficient animals (high RFI, 10.95 kg DM/day). Animals with medium efficiency (mean RFI, 9.49 kg DM/day) consumed 15.39% less than high RFI. Nutrient digestibility coefficients were similar except for ether extract (P < 0.03) which was 8% greater for the high-RFI animals. No effect was observed for ingestive behavior (P > 0.05). Animals spent, on average, 3 h 28 min feeding, 7 h 32 min ruminating, and 13 h 40 min in idle time. In the present study, ingestive behavior and dry matter digestibility were not responsible for between-animal variation in residual feed intake in Nellore bulls fed a high concentrate diet.

Nephrogenic Systemic Fibrosis in Patients with Chronic Kidney Disease after the Use of Gadolinium-Based Contrast Agents: A Review for the Cardiovascular Imager.

Gadolinium-enhanced cardiac magnetic resonance has revolutionized cardiac imaging in the last two decades and has emerged as an essential and powerful tool for the characterization and treatment guidance of a wide range of cardiovascular diseases. However, due to the high prevalence of chronic renal dysfunction in patients with cardiovascular conditions, the risk of nephrogenic systemic fibrosis (NSF) after gadolinium exposure has been a permanent concern. Even though the newer macrocyclic agents have proven to be much safer in patients with chronic kidney disease and end-stage renal failure, clinicians must fully understand the clinical characteristics and risk factors of this devastating pathology and maintain a high degree of suspicion to prevent and recognize it. This review aimed to summarize the existing evidence regarding the physiopathology, clinical manifestations, diagnosis, and prevention of NSF related to the use of gadolinium-based contrast agents.

Cost-Effectiveness of Using the Coronary Artery Calcium Score in Guiding Therapeutic Decisions in Primary Prevention in the Brazilian Population. / Custo-Efetividade do Emprego do Escore de Cálcio Coronariano na Orientação para a Decisão Terapêutica na Prevenção Primária, na População Brasileira.

BACKGROUND: The use of the coronary artery calcium score to aid cardiovascular risk stratification may be a more cost-effective tool than the conventional strategy. OBJECTIVES: Evaluation of the cost-effectiveness of the use of the calcium score in therapeutic guidance for primary cardiovascular prevention. METHODS: A microsimulation model to assess the clinical and economic consequences of atherosclerotic cardiovascular disease, comparing the prevention strategy using the calcium score and the conventional strategy. RESULTS: The results obtained demonstrated a better cost-effectiveness of the therapeutic strategy guided by the calcium score, by reducing incremental costs and increasing quality-adjusted life years (QALY), which corresponds, in number, to improving the quality of life of the individual. CONCLUSIONS: The use of the coronary artery calcium score proved to be more cost-effective than the conventional strategy, both in terms of cost and QALY, in most of the scenarios studied.

FUNDAMENTO: O emprego do escore de cálcio no auxílio da estratificação de risco cardiovascular pode ser ferramenta com melhor custo-efetividade em comparação à estratégia convencional. OBJETIVOS: Avaliação da custo-efetividade do emprego do escore de cálcio na orientação terapêutica para a prevenção primária cardiovascular. MÉTODOS: Modelo de microssimulação para avaliar as consequências clínicas e econômicas da doença cardiovascular aterosclerótica, comparando-se a estratégia de prevenção pelo uso do escore de cálcio e a estratégia convencional. RESULTADOS: Resultados obtidos demonstram melhor custo-efetividade da estratégia terapêutica guiada pelo escore de cálcio, por meio da redução do custo incremental, e aumento nos anos de vida ajustados por qualidade (QALY), que corresponde, em número, ao benefício incorporado à qualidade de vida do indivíduo. CONCLUSÕES: O emprego do escore de cálcio mostrou-se mais custo-efetivo que a estratégia convencional tanto em custo como em QALY, na maioria dos cenários estudados.

Custo-Efetividade do Emprego do Escore de Cálcio Coronariano na Orientação para a Decisão Terapêutica na Prevenção Primária, na População Brasileira / Cost-Effectiveness of Using the Coronary Artery Calcium Score in Guiding Therapeutic Decisions in Primary Prevention in the Brazilian Population

Resumo Fundamento: O emprego do escore de cálcio no auxílio da estratificação de risco cardiovascular pode ser ferramenta com melhor custo-efetividade em comparação à estratégia convencional. Objetivos: Avaliação da custo-efetividade do emprego do escore de cálcio na orientação terapêutica para a prevenção primária cardiovascular. Métodos: Modelo de microssimulação para avaliar as consequências clínicas e econômicas da doença cardiovascular aterosclerótica, comparando-se a estratégia de prevenção pelo uso do escore de cálcio e a estratégia convencional. Resultados: Resultados obtidos demonstram melhor custo-efetividade da estratégia terapêutica guiada pelo escore de cálcio, por meio da redução do custo incremental, e aumento nos anos de vida ajustados por qualidade (QALY), que corresponde, em número, ao benefício incorporado à qualidade de vida do indivíduo. Conclusões: O emprego do escore de cálcio mostrou-se mais custo-efetivo que a estratégia convencional tanto em custo como em QALY, na maioria dos cenários estudados.

Abstract Background: The use of the coronary artery calcium score to aid cardiovascular risk stratification may be a more cost-effective tool than the conventional strategy. Objectives: Evaluation of the cost-effectiveness of the use of the calcium score in therapeutic guidance for primary cardiovascular prevention. Methods: A microsimulation model to assess the clinical and economic consequences of atherosclerotic cardiovascular disease, comparing the prevention strategy using the calcium score and the conventional strategy. Results: The results obtained demonstrated a better cost-effectiveness of the therapeutic strategy guided by the calcium score, by reducing incremental costs and increasing quality-adjusted life years (QALY), which corresponds, in number, to improving the quality of life of the individual. Conclusions: The use of the coronary artery calcium score proved to be more cost-effective than the conventional strategy, both in terms of cost and QALY, in most of the scenarios studied.

Mechanistic insights into the amidolysis of a phosphate triester: the antagonistic role of water.

The breakdown of O,O-diethyl-2,4-dinitrophenyl phosphate in formamide (FMD) solutions is assessed using kinetic studies and 31P nuclear magnetic resonance (NMR) analysis. Regiospecific nucleophilic amidolysis via P-O bond cleavage is observed, leading to non-toxic diester and FMD regeneration. In the systems evaluated, water plays an antagonistic role: while it is key for the breakdown of the reaction intermediate, it inhibits the nucleophilic activity of FMD by hydrogen bonding effects.

Improving cardiovascular magnetic resonance access in low- and middle-income countries for cardiomyopathy assessment: rapid cardiovascular magnetic resonance.

AIMS: To evaluate the impact of a simplified, rapid cardiovascular magnetic resonance (CMR) protocol embedded in care and supported by a partner education programme on the management of cardiomyopathy (CMP) in low- and middle-income countries (LMICs). METHODS AND RESULTS: Rapid CMR focused particularly on CMP was implemented in 11 centres, 7 cities, 5 countries, and 3 continents linked to training courses for local professionals. Patients were followed up for 24 months to assess impact. The rate of subsequent adoption was tracked. Five CMR conferences were delivered (920 attendees-potential referrers, radiographers, reporting cardiologists, or radiologists) and five new centres starting CMR. Six hundred and one patients were scanned. Cardiovascular magnetic resonance indications were 24% non-contrast T2* scans [myocardial iron overload (MIO)] and 72% suspected/known cardiomyopathies (including ischaemic and viability). Ninety-eighty per cent of studies were of diagnostic quality. The average scan time was 22 ± 6 min (contrast) and 12 ± 4 min (non-contrast), a potential cost/throughput reduction of between 30 and 60%. Cardiovascular magnetic resonance findings impacted management in 62%, including a new diagnosis in 22% and MIO detected in 30% of non-contrast scans. Nine centres continued using rapid CMR 2 years later (typically 1-2 days per week, 30 min slots). CONCLUSIONS: Rapid CMR of diagnostic quality can be delivered using available technology in LMICs. When embedded in care and a training programme, costs are lower, care is improved, and services can be sustained over time.

Cost-Minimization Analysis for Cardiac Revascularization in 12 Health Care Systems Based on the EuroCMR/SPINS Registries.

OBJECTIVES: The aim of this study was to compare the costs of a noninvasive cardiac magnetic resonance (CMR)-guided strategy versus 2 invasive strategies with and without fractional flow reserve (FFR). BACKGROUND: Coronary artery disease (CAD) is a major contributor to the public health burden. Stress perfusion CMR has excellent accuracy to detect CAD. International guidelines recommend as a first step noninvasive testing of patients in stable condition with known or suspected CAD. However, nonadherence in routine clinical practice is high. METHODS: In the EuroCMR (European Cardiovascular Magnetic Resonance) registry (n = 3,647, 59 centers, 18 countries) and the U.S.-based SPINS (Stress-CMR Perfusion Imaging in the United States) registry (n = 2,349, 13 centers, 11 states), costs were calculated for 12 health care systems (8 in Europe, the United States, 2 in Latin America, and 1 in Asia). Costs included diagnostic examinations (CMR and x-ray coronary angiography [CXA] with and without FFR), revascularizations, and complications during 1-year follow-up. Seven subgroup analyses covered low- to high-risk cohorts. Patients with ischemia-positive CMR underwent CXA and revascularization at the treating physician's discretion (CMR+CXA strategy). In the hypothetical invasive CXA+FFR strategy, costs were calculated for initial CXA and FFR in vessels with ≥50% stenoses, assuming the same proportion of revascularizations and complications as with the CMR+CXA strategy and FFR-positive rates as given in the published research. In the CXA-only strategy, costs included CXA and revascularizations of ≥50% stenoses. RESULTS: Consistent cost savings were observed for the CMR+CXA strategy compared with the CXA+FFR strategy in all 12 health care systems, ranging from 42% ± 20% and 52% ± 15% in low-risk EuroCMR and SPINS patients with atypical chest pain, respectively, to 31% ± 16% in high-risk SPINS patients with known CAD (P < 0.0001 vs 0 in all groups). Cost savings were even higher compared with CXA only, at 63% ± 11%, 73% ± 6%, and 52% ± 9%, respectively (P < 0.0001 vs 0 in all groups). CONCLUSIONS: In 12 health care systems, a CMR+CXA strategy yielded consistent moderate to high cost savings compared with a hypothetical CXA+FFR strategy over the entire spectrum of risk. Cost savings were consistently high compared with CXA only for all risk groups.

Effects of Megasphaera elsdenii administration on performance and carcass traits of finishing Bos indicus feedlot cattle.

This study evaluated the effects of Megasphaera elsdenii administration at the beginning of the feedlot period on performance of Bos taurus indicus bulls. On d 0, 383 Nellore bulls (initial shrunk body weight 384 ± 29.2 kg; initial age = 24 ± 2 mo) were assigned to treatments in a randomized complete block design. Treatments consisted of 1) 14 d adaptation diet and transition to a finishing diet (CONT), 2) CONT plus oral administration of 20 mL of Lactipro-NXT (M. elsdenii) on d 0 of the study (MEG-14), 3) CONT diet, consisting of 6 d of adaptation diet plus oral administration of 20 mL of Lactipro-NXT on d 0 of the study (MEG-6), and 4) No adaptation diet and oral administration of 20 mL of Lactipro-NXT on d 0 of the study (MEG-0). Experimental period lasted 119 d. No treatment effects were observed for any of the performance parameters evaluated herein (P ≥ 0.15). Nonetheless, a treatment × wk interaction was observed for DM, NEm, and NEg intakes (P < 0.0001). For all these parameters, MEG-0 and MEG-6 had a reduced intake vs. MEG-14 and CONT in the first wk of the study (P ≤ 0.05). For the carcass traits, no effects were observed for HCW (P ≥ 0.24), whereas MEG-6 had a greater REA when compared with MEG-0 and MEG-14 (quadratic effect; P = 0.04) and MEG-administered bulls tended to have a greater BFT vs. CONT (P = 0.08). In summary, M. elsdenii administration at the beginning of the feedlot period did not improve performance, whereas reducing the length of the adaptation period for 6 d improved REA of finishing Bos taurus indicus bulls.

Effects of grain adaptation programs and antimicrobial feed additives on performance and nutrient digestibility of Bos indicus cattle fed whole shelled corn.

Two experiments were conducted to evaluate the effects of feed additives [monensin (MON); 30 mg/kg of dry matter (DM), and virginiamycin (VM); 25 mg/kg DM] and grain adaptation programs [adding roughage (ROU; sugarcane bagasse) or not (NO-ROU) during the 20-d adaptation period] on performance, carcass characteristics, and nutrient digestibility of Bos indicus cattle fed finishing diets containing 85% whole shelled corn and 15% of a pelleted protein-mineral-vitamin supplement. In Exp.1, 105 Nellore bulls [initial body weight (BW) = 368 ± 25 kg] were used in a complete randomized block design with a 2 × 2 factorial arrangement of treatments, consisting of two feed additives (MON and VM) associated with two adaptation programs (ROU or NO-ROU during the 20-d adaptation period). Effects of feed additives × adaptation programs were not detected (P ≥ 0.13). Feed additives did not affect dry matter intake (DMI), average daily gain (ADG), and feed efficiency (G:F) during the 20-d adaptation period (P ≥ 0.35). During the total feeding period (105 d), feeding MON decreased DMI (P ≤ 0.03) compared to VM. Adding sugarcane bagasse to finishing diets during the 20-d adaptation period (ROU) increased ADG (P = 0.05) and G:F (P = 0.03), and tended to increase BW (P = 0.09) compared to NO-ROU. In Exp. 2, 10 ruminally cannulated Nellore steers (BW = 268 ± 38 kg) were used in a completely randomized design to evaluate the effects of the two feed additives used in the Exp. 1 (MON and VM; 5 steers/treatment) on DMI, total apparent digestibility of nutrients, and ruminal fermentation characteristics. No differences in DMI, total tract apparent digestibility of nutrients, and ruminal fermentation characteristics were observed between MON and VM (P ≥ 0.32). An effect of sampling day (P < 0.001) was observed for ruminal pH, which was greater on day 0 compared to day 7, 14, and 21 of the experimental period (P ≤ 0.05). In summary, supplementing monensin and virginiamycin for finishing Nellore bulls fed whole shelled corn diets, resulted in similar growth performance and carcass characteristics. Including sugarcane bagasse to adapt finishing bulls to no-roughage diets containing whole shelled corn is an alternative to increase growth performance.

Cardiovascular magnetic resonance in women with cardiovascular disease: position statement from the Society for Cardiovascular Magnetic Resonance (SCMR).

This document is a position statement from the Society for Cardiovascular Magnetic Resonance (SCMR) on recommendations for clinical utilization of cardiovascular magnetic resonance (CMR) in women with cardiovascular disease. The document was prepared by the SCMR Consensus Group on CMR Imaging for Female Patients with Cardiovascular Disease and endorsed by the SCMR Publications Committee and SCMR Executive Committee. The goals of this document are to (1) guide the informed selection of cardiovascular imaging methods, (2) inform clinical decision-making, (3) educate stakeholders on the advantages of CMR in specific clinical scenarios, and (4) empower patients with clinical evidence to participate in their clinical care. The statements of clinical utility presented in the current document pertain to the following clinical scenarios: acute coronary syndrome, stable ischemic heart disease, peripartum cardiomyopathy, cancer therapy-related cardiac dysfunction, aortic syndrome and congenital heart disease in pregnancy, bicuspid aortic valve and aortopathies, systemic rheumatic diseases and collagen vascular disorders, and cardiomyopathy-causing mutations. The authors cite published evidence when available and provide expert consensus otherwise. Most of the evidence available pertains to translational studies involving subjects of both sexes. However, the authors have prioritized review of data obtained from female patients, and direct comparison of CMR between women and men. This position statement does not consider CMR accessibility or availability of local expertise, but instead highlights the optimal utilization of CMR in women with known or suspected cardiovascular disease. Finally, the ultimate goal of this position statement is to improve the health of female patients with cardiovascular disease by providing specific recommendations on the use of CMR.

Effects of plant extracts from Stryphnodendron adstringens (mart.) coville, Lafoensia pacari a. st.-hil, copaifera spp., and Pterodon emarginatus Vogel on in vitro rumen fermentation.

The effects of doses CTL (0 mg), 30, 300 and 3000 mg/L of extracts from Stryphnodendron adstringens (Mart.) Coville (SA), Lafoensia pacari A. St.-Hil (LP), Copaifera spp. (CO) and Pterodon emarginatus Vogel (PE) on ruminal fermentation were investigated in eight experiments conducted in randomized complete block designs. The in vitro system contained four fermentation vessels. Each treatment was allocated in one vessel in each run. Incubation was run four and five times with diets 50:50 and 10:90 (roughage to concentrate ratio) respectively. Incubation vessel was the experimental unit, and each incubation run was a block. All plant extracts negatively affected DM degradation at 3000 mg/L. In diet 50:50, SA-3000 increased the molar proportion of propionate (p < 0.05), yet it decreased the concentration of fermentation products (p < 0.05); LP-300 reduced ruminal ammonia nitrogen (NH3 -N; 98 vs. 120 mg/dl for LP-300 and average of CTL and LP-30, respectively) and isobutyrate (p < 0.05); CO-300 reduced (p < 0.05) NH3 -N (98 vs. 123 mg/dl for CO-300 and average of CTL and CO-30, respectively); and P. emarginatus had no positive effects on rumen fermentation (p > 0.05). In diet 10:90, SA-300 reduced (p < 0.001) NH3 -N and total volatile fatty acids (VFA); LP-30 increased (p < 0.05) total VFA (85 vs. 63 mM for LP-30 and CTL, respectively), molar proportions of acetate and propionate, and had lower C2 :C3 than CTL (3.6 vs. 4.3, respectively); CO-300 decreased acetate and increased propionate, reducing C2 :C3 (p < 0.001; 2.8 vs. 3.6 for CO-300 and average of other doses, respectively); PE-30 and PE-300 reduced NH3 -N by 14% and increased total VFA by 29% compared with CTL (p < 0.05). Further in vivo investigations may consider L. pacari (LP-30), Copaifera spp. (CO-300) oleoresin and P. emarginatus oleoresin (PE-30 and PE-300) in diets with high inclusion of concentrate.

Amlodipine as adjuvant therapy to current chelating agents for reducing iron overload in thalassaemia major: a systematic review, meta-analysis and simulation of future studies.

BACKGROUND AND OBJECTIVES: Iron overload in thalassaemia is a crucial prognostic factor and a major cause of death due to heart failure or arrhythmia. Therefore, previous research has recommended amlodipine as an auxiliary treatment to current chelating agents for reducing iron overload in thalassaemia patients. MATERIALS AND METHODS: A systematic review and meta-analysis of the results of three randomized clinical trials evaluating the use of amlodipine in thalassaemia patients through 12 databases were carried out. RESULTS: Our final cohort included 130 patients. Insignificant difference in decreasing liver iron concentrations was found between amlodipine and control groups {weighted mean difference = -0·2, [95% confidence interval = (-0·55-0·15), P = 0·26]}. As regards serum ferritin, our analysis also showed no significant difference in serum ferritin between amlodipine and control groups {weighted mean difference [95% confidence interval = -0·16 (-0·51-0·19), P = 0·36]}. Similarly, there was insignificant difference in cardiac T2* between amlodipine and control groups {weighted mean difference [95% confidence interval = 0·34 (-0·01-0·69), P = 0·06]}. CONCLUSIONS: Despite the growing evidence supporting the role of amlodipine in reducing iron overload in thalassaemia patients, our meta-analysis did not find that evidence collectively significant. The results of our simulation suggest that when more data are available, a meta-analysis with more randomized clinical trials could provide more conclusive insights.

Degradation of Organophosphates Promoted by 1,2,4-Triazole Anion: Exploring Scaffolds for Efficient Catalytic Systems.

Organophosphate (OP) pesticides are responsible for numerous human deaths every year. Nucleophilic substitution is an important method to mitigate the toxicity of obsolete stocks of OPs. Herein, the degradation of O,O-diethyl-2,4-dinitrophenyl phosphate (DEDNPP) and pesticide diethyl-4-nitrophenyl phosphate (Paraoxon) promoted by 1,2,4-triazole (TAZ) was investigated by means of kinetic studies, nuclear magnetic resonance (NMR) analyses, and theoretical calculations. Results showed fast degradation of OPs is promoted by the anionic form of the nucleophile (TAZ(-)) in pH > 8.5 (optimal at pH = 11). Rate enhancements of 106 and 105-fold in relation to neutral hydrolysis of DEDNPP and Paraoxon were observed, respectively, consistent with alpha-nucleophiles reactivity. TAZ(-) regioselectively promotes the degradation of DEDNPP via P-O bond break, forming a quickly hydrolyzable phosphorylated intermediate, regenerating the nucleophile. Calculations using M06-2X/6-311++G(d,p) level of theory revealed that the equivalent nitrogen atoms of TAZ(-) are the main nucleophilic center of the molecule. This study expands the knowledge on the reactivity of iminic compounds as detoxificant agents of OPs, indicating the efficiency and selectivity of TAZ(-) in aqueous medium, encouraging the design of novel TAZ-based catalysts.

Temperament and performance of Nellore bulls classified for residual feed intake in a feedlot system.

This study aimed to evaluate the performance in feedlot and temperament of Nellore bulls classified by residual feed intake. The residual feed intake was calculated as the difference between the observed and predicted dry matter intake. Bulls classified as low residual feed intake had lower dry matter intake (kg day-1) and dry matter intake (g kg-1 d-1) of body weight, and were more efficient in feed conversion ratio than those classified as medium and high. The average daily gain didn't differ among residual feed intake classes and was 1.69 kg day-1, 1.82 kg day-1 and 1.71 kg day-1 for bulls classified as low, medium, or high, respectively. The residual feed intake was positively associated with dry matter intake, feed conversion ratio and subcutaneous fat thickness. The subcutaneous fat thickness was lower in bulls classified as low residual feed intake than in those with medium and high. No differences were observed in flight speed and reactivity score among residual feed intake classes. Overall, we concluded that bulls classified as low residual feed intake consumed less dry matter than high, with no differences in average daily gain, temperamentand had better feed efficiency, albeit their subcutaneous fat thickness was lower.

Effects of monensin source on in vitro rumen fermentation characteristics and performance of Bos indicus beef bulls offered a high-concentrate diet.

In Exp. 1, Brachiaria ruziziensis (11.1 % CP) was inoculated or not with two sources of monensin, resulting in three treatments: 1) no monensin inoculation (CONT), 2) 20 mg of monensin sodium-A/kg of DM (Elanco Animal Health; MON-A), and 3) 20 mg of monensin sodium-B/kg of DM (Shandong Qilu King-Phar Pharmaceutical Co. Ltd.; MON-B). Three rumen-fistulated Jersey steers were offered a cool-season forage-based diet and were used as the rumen inoculum donors. Volatile fatty acids concentrations were evaluated at 0, 6, 12, 24, 30, and 48 h after treatment inoculation. Overall, acetate and butyrate concentrations were reduced in MON-A vs. CONT (P ≤ 0.02), whereas both monensin products reduced Ac:Pr ratio vs. CONT (P ≤ 0.01); however, MON-A also (P = 0.05) reduced the Ac:Pr ratio vs. MON-B. A treatment × hour interaction was detected for rumen propionate concentration (P = 0.01), primarily because MON-A resulted in greater propionate than CONT and MON-B at 24 and 48 h (P ≤ 0.03), but no differences were observed between CONT vs. MON-B (P ≥ 0.27). In Exp. 2, 240 Nellore bulls (initial BW = 363.2 ± 40.9 kg) were ranked and blocked according to initial BW, and within blocks animals were allotted into pens (n = 10 pens/treatment). Pens were randomly assigned into one of three treatments: 1) corn-based diet with no monensin (CONT), 2) CONT plus 28 mg of MON-A/kg of DM, and 3) CONT plus 28 mg of MON-B/kg of DM. The CONT diet was composed of sugarcane bagasse, ground corn, DDGS, urea, and a mineral-vitamin mix. The experimental period lasted 106 d and was divided into a 21-d adaptation period and an 85-d finishing phase. During the adaptation phase, both monensin sources increased (P ≤ 0.01) BW change, ADG, and F:G, as well as reduced DMI variation (P = 0.02). When the entire experimental period was evaluated, no treatment effects were detected for final BW, DMI, and ADG (P ≥ 0.26). Nonetheless, DMI variation was reduced as monensin was included (P = 0.01) and only MON-A improved the efficiency by reducing F:G vs. CONT (P = 0.05) and biological efficiency vs. MON-B (P = 0.05). Additionally, carcass ADG tended (P = 0.10) to be greater for MON-A vs. MON-B, whereas no other differences in the carcass characteristics were observed (P ≥ 0.53). In summary, the source of monensin inoculated in vitro and offered to Nellore bulls during the feedlot phase significantly affected the energetic efficiency and the performance of the animals.