Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 221
Filter
1.
J Dairy Sci ; 2024 May 31.
Article in English | MEDLINE | ID: mdl-38825122

ABSTRACT

This study aimed to assess the impact of bulk tank milk (BTM), waste milk (WM), and pasteurized waste milk (PWM) on nutrient digestibility, ruminal and cecal fermentation, gastrointestinal tract (GIT) development, and antimicrobial resistance of fecal Escherichia coli from dairy calves at 2 periods (30 and 60 d of age). Calves were grouped according to body weight, serum protein levels, and breed composition. Three treatments were included: BTM (n = 21), WM from cows under antibiotic treatment (n = 21), and PWM (waste milk submitted to high-temperature, short-time pasteurization; n = 21). A total of 63 calves were used, of which: 18 animals (n = 6 per treatment) evaluated in the period of 4 - 30 d and 45 (n = 15 per treatment) from 4 - 60 d. During the experimental period, a daily intake of 6 L of milk was divided into 2 equal meals, with ad libitum access to water and starter. Milk and feed intakes were recorded daily. Apparent total-tract digestibility and nitrogen balance were conducted from 25 to 29 d of age (n = 6) and from 53 to 57 d of age (n = 15). Animals were euthanized at 30 ± 1 and 60 ± 1 d of age for the assessment of ruminal and cecal fermentation and GIT development. Antimicrobial susceptibility testing was conducted at 1, 30, and 60 d of age (n = 15/treatment). Statistical analysis utilized a linear mixed-effects model for continuous outcomes and generalized linear models for single measurements (R software). Treatments WM and PWM had lower rumen pH, higher ruminal acetate concentration, larger reticulorumen and liver, and a higher prevalence of fecal-resistant E. coli compared with BTM at both 30 and 60 d. Up to 60 d, both BTM and WM treatments exhibited higher digestibility of ether extract and gross energy compared with the PWM, whereas WM and PWM treatments showed increased nitrogen intake and retention compared with the BTM. These findings suggest that pasteurization of waste milk negatively affects nutrient digestibility and calf performance, while also impacting rumen development. Additionally, the use of milk containing antibiotic residue leads to the selection of resistant E. coli in the GIT over time.

2.
J Dairy Sci ; 2024 Apr 10.
Article in English | MEDLINE | ID: mdl-38608938

ABSTRACT

Our objective was to estimate the requirements of metabolizable energy (ME) and net energy for the maintenance (NEm) of lactating and dry cows, the efficiency of ME utilization for milk production (kl) and tissue gain (kg), and the use of body energy mobilization for milk production (kt) throughout the lactation of primiparous crossbred Holstein × Gyr cows, using open-circuit respiration chambers. Twenty-nine primiparous Holstein × Gyr crossbred cows with an initial BW averaging 563 ± 40.1 kg and 2.5 ± 0.09 years old were used throughout lactation and dry periods. The cows were kept non-pregnant throughout the study to eliminate possible confounding factors. Apparent digestibility assays, followed by calorimeter measurements, were performed 6 times throughout the lactation period. In the dry-off period, the cows were also evaluated but fed with restricted intake (DMI = 1.1% BW/d) to achieve heat production close to maintenance. After 21 d of diet adaptation, an apparent digestibility assay followed by calorimeter measurements was performed. Parameter estimates for lactation period were obtained by mixed models including lactation stage as repeated measures. For restricted feeding at dry-off and fasting period assays, the requirements were estimated by exponential regression. For whole lactation, the values of MEm and NEm were 0.588 and 0.395 MJ/BW0.75, respectively. The efficiencies klkgkt were 0.672, 0.771, and 0.814, respectively. However, MEm and NEm were higher in early and mid-lactation than late, while kl was higher in early than other lactation stages. Dry and non-pregnant cows had MEm of 0.434 MJ/BW0.75 and NEm of 0.351 MJ/BW0.75 for maintenance level, and MEm of 0.396 MJ/BW0.75 and NEm of 0.345 MJ/BW0.75 for fasting metabolism level and efficiency of ME utilization for maintenance was 0.80. Our findings confirmed that F1 crossbred Holstein × Gyr dairy cows have differences in energy requirement and efficiency throughout the lactation stages, suggesting the use of different values in each stage. The estimated values of energy requirement for maintenance and efficiencies for primiparous lactating crossbred Holstein × Gyr were similar to those reported in the literature in specific studies and requirements systems.

3.
Braz J Biol ; 83: e275622, 2024.
Article in English | MEDLINE | ID: mdl-38422264

ABSTRACT

Citrus bergamia is a citric species known as bergamot. The species is widely used due to its derivatives, such as juices, extracts, and essential oil. Specifically, the bergamot essential oil (BEO) is of great interest, with a chemical composition rich in terpenes and esters. Considering its chemical composition, bioactivity, and great economic potential, the characterization of BEO should be studied. However, this essential oil is almost unexplored in terms of a characterization associated with colloids. Chemical characterization was carried out by gas-chromatography coupled to a mass spectrometer and by gas-chromatography coupled to a flame ionization detector. Antibacterial activity against Staphylococcus aureus and Escherichia coli was carried out to confirm the bioactivity of this important essential oil. Dynamic light scattering analysis was performed to create a pattern of droplet size distribution of BEO. Major compounds of BEO were linalyl acetate, limonene, and linalool. The BEO was active against E. coli and presented a MIC value of 2.000 µg/mL, while values of MIC and MBC higher than 2.000 µg/mL were observed for S. aureus. The dynamic light scattering analysis revealed a mean hydrodynamic diameter of 65.7 ± 2.2 nm. After a 1:10 dilution it was observed reduction of mean diameter and enhancement of the percentagem of low size droplets, resepctively 44.1 ± 1.2 nm and 14.5 ± 0.5 nm (28.8 ± 1.2%). Higher droplets and reduced polydispersity index were observed after 1:100 dilution. In the present study, the chemical characterization was in accordance with the species, as the characteristic chemical markers of the species were found. Moreover, it has presented antibacterial activity as expected for the BEO. The analysis of the colloid showed a pattern of droplet size distribution following the Ostwald ripening mechanism after dilution.


Subject(s)
Oils, Volatile , Oils, Volatile/pharmacology , Oils, Volatile/chemistry , Escherichia coli , Staphylococcus aureus , Terpenes , Anti-Bacterial Agents/pharmacology
5.
J Dairy Sci ; 106(12): 8821-8834, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37678777

ABSTRACT

We aimed to estimate the protein requirements of pregnant Holstein × Gyr cows. A total of 61 Holstein × Gyr (HG) cows were used, with an average initial body weight (BW) of 480 ± 10.1 kg and age 5 ± 0.5 yr. Cows were divided into 3 groups: pregnant (n = 43), nonpregnant (n = 12), and baseline (n = 6). Baseline animals were slaughtered before starting the experiment to estimate the initial body composition of the remaining animals. Pregnant and nonpregnant cows received 2 diets: maintenance and ad libitum. Pregnant cows were slaughtered at 139, 199, 241, and 268 gestation days (GD). First, we used data only from nonpregnant cows to determine the requirements for maintenance and growth in adult cows. The requirements of metabolizable protein for maintenance (MPm; grams of empty metabolic BW [EBW0.75] per day) were estimated using a linear regression between the metabolizable protein intake (MPI, g/d) and average daily gain (g/d), and the MPm was defined as the intercept divided by the average metabolic BW. Net protein requirements for gain (NPg; g/d) were estimated by the first derivative of the allometric equation between final crude protein in the body (kg) and the final empty BW (EBW; kg). The efficiency of use of metabolizable protein for gain (k) was calculated from the regression between the retained protein (g EBW0.75/d) and the MPI (g EBW0.75/d), and k was the slope of this regression. The MPI was estimated by combining microbial protein synthesis (purine derivatives) with the digestible rumen undegradable protein [(total protein intake - rumen-degradable protein) × intestinal digestibility]. Second, an exponential model was used to fit the protein accumulation in the gestational components in the function of GD. The first derivative of that model was considered the net requirement for gestation (NPgest). The efficiency of protein utilization for gestation (kgest) was calculated by the iterative method using the equation Δ = MPI - (MPm + NPg/kg + NPgest/kgest), where kg is efficiency of protein utilization for gain. The iteration was performed aiming at a zero deviation between observed MPI and metabolizable protein (MP) estimated by the requirements determined herein. We obtained a value of 3.88 g EBW0.75/d for MPm. The estimation of NPg can be calculated according to the following equation: NPg = 0.716 × (EBWopen-0.308) × EBGc, where EBWopen is the EBW (kg) for nonpregnant animals and EBGc is the empty body gain (kg/d) corrected for the gestational component. The k was determined as 0.347. The NPgest requirements were determined as NPgest (g/d) = 0.0008722 × exp(0.01784 × GD) × (calf weight/35). The kgest was 0.625. It is important to highlight that different methods of MP estimates should not be mixed and that the proposed method requires the estimation of microbial protein (estimated via urinary estimates), which might limit practical application. In conclusion, new studies should be conducted to validate our results and the methodology adopted to determine protein requirements for pregnancy in dairy cows. Due to the pattern of protein accumulation in the gestational components, we suggest an exponential model to describe protein requirements for pregnancy for dairy cows.


Subject(s)
Diet , Energy Intake , Pregnancy , Female , Cattle , Animals , Nutritional Requirements , Diet/veterinary , Body Weight , Body Composition , Animal Feed/analysis
6.
Nat Phys ; 19(6): 836-844, 2023.
Article in English | MEDLINE | ID: mdl-37323805

ABSTRACT

The most direct approach for characterizing the quantum dynamics of a strongly interacting system is to measure the time evolution of its full many-body state. Despite the conceptual simplicity of this approach, it quickly becomes intractable as the system size grows. An alternate approach is to think of the many-body dynamics as generating noise, which can be measured by the decoherence of a probe qubit. Here we investigate what the decoherence dynamics of such a probe tells us about the many-body system. In particular, we utilize optically addressable probe spins to experimentally characterize both static and dynamical properties of strongly interacting magnetic dipoles. Our experimental platform consists of two types of spin defects in nitrogen delta-doped diamond: nitrogen-vacancy colour centres, which we use as probe spins, and a many-body ensemble of substitutional nitrogen impurities. We demonstrate that the many-body system's dimensionality, dynamics and disorder are naturally encoded in the probe spins' decoherence profile. Furthermore, we obtain direct control over the spectral properties of the many-body system, with potential applications in quantum sensing and simulation.

8.
Science ; 374(6574): 1474-1478, 2021 Dec 17.
Article in English | MEDLINE | ID: mdl-34735218

ABSTRACT

The discrete time crystal (DTC) is a nonequilibrium phase of matter that spontaneously breaks time-translation symmetry. Disorder-induced many-body localization can stabilize the DTC phase by breaking ergodicity and preventing thermalization. Here, we observe the hallmark signatures of the many-body­localized DTC using a quantum simulation platform based on individually controllable carbon-13 nuclear spins in diamond. We demonstrate long-lived period-doubled oscillations and confirm that they are robust for generic initial states, thus showing the characteristic time-crystalline order across the many-body spectrum. Our results are consistent with the realization of an out-of-equilibrium Floquet phase of matter and introduce a programmable quantum simulator based on solid-state spins for exploring many-body physics.

9.
Nature ; 597(7874): 45-50, 2021 09.
Article in English | MEDLINE | ID: mdl-34471276

ABSTRACT

Conventional wisdom holds that macroscopic classical phenomena naturally emerge from microscopic quantum laws1-7. However, despite this mantra, building direct connections between these two descriptions has remained an enduring scientific challenge. In particular, it is difficult to quantitatively predict the emergent 'classical' properties of a system (for example, diffusivity, viscosity and compressibility) from a generic microscopic quantum Hamiltonian7-14. Here we introduce a hybrid solid-state spin platform, where the underlying disordered, dipolar quantum Hamiltonian gives rise to the emergence of unconventional spin diffusion at nanometre length scales. In particular, the combination of positional disorder and on-site random fields leads to diffusive dynamics that are Fickian yet non-Gaussian15-20. Finally, by tuning the underlying parameters within the spin Hamiltonian via a combination of static and driven fields, we demonstrate direct control over the emergent spin diffusion coefficient. Our work enables the investigation of hydrodynamics in many-body quantum spin systems.

10.
Carcinogenesis ; 42(11): 1380-1389, 2021 11 12.
Article in English | MEDLINE | ID: mdl-34447990

ABSTRACT

XPC deficiency is associated with mitochondrial dysfunction, increased mitochondrial H2O2 production and sensitivity to the Complex III inhibitor antimycin A (AA), through a yet unclear mechanism. We found an imbalanced expression of several proteins that participate in important mitochondrial function and increased expression and phosphorylation of the tumor suppressor p53 in Xeroderma pigmentosum complementation group C (XP-C) (XPC-null) cells compared with an isogenic line corrected in locus with wild-type XPC (XPC-wt). Interestingly, inhibition of p53 nuclear import reversed the overexpression of mitochondrial proteins, whereas AA treatment increased p53 expression more strongly in the XP-C cells. However, inhibition of p53 substantially increased XP-C cellular sensitivity to AA treatment, suggesting that p53 is a critical factor mediating the cellular response to mitochondrial stress. On the other hand, treatment with the antioxidant N-acetylcysteine increased glutathione concentration and decreased basal H2O2 production, p53 levels and sensitivity to AA treatment in the XPC-null back to the levels found in XPC-wt cells. Thus, the results suggest a critical role for mitochondrially generated H2O2 in the regulation of p53 expression, which in turn modulates XP-C sensitivity to agents that cause mitochondrial stress.


Subject(s)
DNA-Binding Proteins/genetics , Hydrogen Peroxide/metabolism , Mitochondria/physiology , Tumor Suppressor Protein p53/metabolism , Cell Line, Transformed , Humans
11.
Science ; 372(6547): 1192-1196, 2021 06 11.
Article in English | MEDLINE | ID: mdl-34112691

ABSTRACT

Extending the framework of statistical physics to the nonequilibrium setting has led to the discovery of previously unidentified phases of matter, often catalyzed by periodic driving. However, preventing the runaway heating that is associated with driving a strongly interacting quantum system remains a challenge in the investigation of these newly discovered phases. In this work, we utilize a trapped-ion quantum simulator to observe the signatures of a nonequilibrium driven phase without disorder-the prethermal discrete time crystal. Here, the heating problem is circumvented not by disorder-induced many-body localization, but rather by high-frequency driving, which leads to an expansive time window where nonequilibrium phases can emerge. Floquet prethermalization is thus presented as a general strategy for creating, stabilizing, and studying intrinsically out-of-equilibrium phases of matter.

12.
J Appl Physiol (1985) ; 131(2): 589-600, 2021 08 01.
Article in English | MEDLINE | ID: mdl-34138649

ABSTRACT

To determine the association between quadriceps muscle strength (QMS) and endurance (QME) and exercise capacity in patients with COPD after stratification for sex and resting lung function (LF). Data were collected from 3,246 patients with COPD (60% men, 64 ± 9 yr), including measures of exercise capacity [peak aerobic capacity (peakV̇o2), 6-min walk distance (6MWD)] and isokinetic QMS and QME. Patients were stratified for sex, forced expiratory volume in 1 s (>50/≤50% predicted), single breath carbon monoxide diffusing capacity (>50/≤50% predicted), and residual volume (>140/≤140% predicted). After stratification for resting LF, QMS and QME were significantly associated with peakV̇o2 (r range: 0.47-0.61 and 0.49-0.65 for men and 0.53-0.66 and 0.48-0.67 for women, respectively) and 6MWD (r range: 0.29-0.42 and 0.44-0.55 for men and 0.25-0.54 and 0.34-0.55 for women, respectively) (P < 0.001). Regression models demonstrated that QMS and QME were significant determinants of peakV̇o2 (explained variance R2 range: 35.6%-48.8% for men and 36.8%-49.0% for women) and 6MWD (R2 range: 24.3%-43.3% for men and 28.4%-40.3% for women), independent of age and fat-free mass. Quadriceps muscle function was significantly associated with peakV̇o2 and 6MWD in male and female patients with COPD after stratification for resting LF, in which QME appear to be a more important determinant than QMS. This underlines the importance of systematically evaluating both quadriceps muscle strength and endurance in in all patients with COPD.NEW & NOTEWORTHY Our findings identified quadriceps muscle function as an important determinant of exercise capacity across a wide spectrum of lung function. Quadriceps muscle endurance appears to be a more important determinant than quadriceps muscle strength, underlining the importance of including both the measurement of quadriceps muscle strength and endurance in routine assessment for all patient with COPD.


Subject(s)
Pulmonary Disease, Chronic Obstructive , Quadriceps Muscle , Exercise , Exercise Test , Exercise Tolerance , Female , Forced Expiratory Volume , Humans , Male , Muscle Strength
13.
Animal ; 15(6): 100224, 2021 Jun.
Article in English | MEDLINE | ID: mdl-34049108

ABSTRACT

It remains unknown whether dairy cows with more reactive temperament produce more enteric methane (CH4) and are less bioenergetically efficient than the calmer ones. The objectives of this study were (a) to evaluate the relationship between cattle temperament assessed by traditionally used tests with energetic metabolism and enteric CH4 emissions by crossbred dairy cows; (b) to assess how cows' restlessness in respiration chambers affects energetic metabolism and enteric CH4 emissions. Temperament indicators were evaluated for 28 primiparous F1 Holstein-Gyr cows tested singly in the handling corral (entrance time, crush score, flight speed, and flight distance) and during milking (steps, kicks, defecation, rumination, and kick the milking cluster off). Cows' behaviors within respiration chambers were also recorded for each individual kept singly. Digestibility and calorimetry trials were performed to obtain energy partitioning and CH4 measures. Cows with more reactive temperament in milking (the ones that kicked the milking cluster off more frequently) spent 25.24% less net energy on lactation (P = 0.04) and emitted 36.77% more enteric CH4/kg of milk (P = 0.03). Furthermore, cows that showed a higher frequency of rumination at milking parlor allocated 57.93% more net energy for milk production (P < 0.01), spent 50.00% more metabolizable energy for milk production (P < 0.01) and 37.10% less CH4/kg of milk (P = 0.04). Regarding the handling temperament, most reactive cows according to flight speed, lost 29.16% less energy as urine (P = 0.05) and tended to have 14.30% more enteric CH4 production (P = 0.08), as well as cows with a lower entrance time (most reactive) that also lost 13.29% more energy as enteric CH4 (P = 0.04). Temperament and restless behavior of Holstein-Gyr cows were related to metabolic efficiency and enteric CH4 emissions. Cows' reactivity and rumination in the milking parlor, in addition to flight speed and entrance time in the squeeze chute during handling in the corral, could be useful measures to predict animals more prone to metabolic inefficiency, which could negatively affect the sustainability of dairy systems.


Subject(s)
Methane , Temperament , Animals , Cattle , Diet , Female , Lactation , Milk
14.
Int Endod J ; 54(1): 61-73, 2021 Jan.
Article in English | MEDLINE | ID: mdl-32896000

ABSTRACT

AIM: To investigate the presence of resolvins E1 (RvE1) and D2 (RvD2) in teeth with primary endodontic infections and apical periodontitis, and to assess the influence of calcium hydroxide medication [Ca(OH)2 ], in association with 2% chlorhexidine gel (2% CHX gel), and N-acetylcysteine (NAC) on the levels of RvE1 and RvD2 in periapical tissues. METHODOLOGY: Thirty-six single-rooted teeth with primary endodontic infections and apical periodontitis were selected and randomly divided into three groups according to the medication: [Ca(OH)2 ] + saline solution (SSL) [Ca(OH)2  + SSL group] (n = 12), Ca(OH)2  + 2% chlorhexidine gel [Ca(OH)2  + 2% CHX gel group] (n = 12) and NAC [NAC group] (n = 12). Samples were collected from the periapical interstitial fluid at two different sampling times: before (S1) and after 14 days of intracanal medications (S2). Resolvins were measured using the enzyme-linked immunosorbent assay. Data were analysed using paired t-test, Wilcoxon test and Kruskal-Wallis test, followed by Dunn's post hoc test; all statistical tests were performed at a significance level of 5%. RESULTS: RvE1 and RvD2 were detected in 100% of the samples (36/36) at S1 and S2. Ca(OH)2 medication did not increase the levels of RvE1 or RvD2 (both P > 0.05); however, NAC significantly increased the levels of RvE1 and RvD2 after 14 days of treatment (P < 0.05). CONCLUSIONS: RvE1 and RvD2 were detected in periapical tissues from teeth with root canal infections. Moreover, calcium hydroxide medication did not increase the levels of resolvins in apical periodontitis. In contrast, the use of NAC intracanal medication significantly increased the levels of RvE1 and RvD2 after 14 days of treatment.


Subject(s)
Calcium Hydroxide , Periapical Periodontitis , Acetylcysteine , Chlorhexidine , Dental Pulp Cavity , Humans , Periapical Periodontitis/drug therapy , Root Canal Irrigants , Root Canal Preparation
15.
Intensive Care Med ; 46(11): 1977-1986, 2020 11.
Article in English | MEDLINE | ID: mdl-33104824

ABSTRACT

The aim of this Intensive Care Medicine Rapid Practice Guideline (ICM-RPG) is to formulate an evidence-based guidance for the use of neuromuscular blocking agents (NMBA) in adults with acute respiratory distress syndrome (ARDS). The panel comprised 20 international clinical experts from 12 countries, and 2 patient representatives. We adhered to the methodology for trustworthy clinical practice guidelines and followed a strict conflict of interest policy. We convened panelists through teleconferences and web-based discussions. Guideline experts from the guidelines in intensive care, development, and evaluation Group provided methodological support. Two content experts provided input and shared their expertise with the panel but did not participate in drafting the final recommendations. We followed the Grading of Recommendations Assessment, Development, and Evaluation approach to assess the certainty of evidence and grade recommendations and suggestions. We used the evidence to decision framework to generate recommendations. The panel provided input on guideline implementation and monitoring, and suggested future research priorities. The overall certainty in the evidence was low. The ICM-RPG panel issued one recommendation and two suggestions regarding the use of NMBAs in adults with ARDS. Current evidence does not support the early routine use of an NMBA infusion in adults with ARDS of any severity. It favours avoiding a continuous infusion of NMBA for patients who are ventilated using a lighter sedation strategy. However, for patients who require deep sedation to facilitate lung protective ventilation or prone positioning, and require neuromuscular blockade, an infusion of an NMBA for 48 h is a reasonable option.


Subject(s)
Neuromuscular Blockade , Neuromuscular Blocking Agents , Respiratory Distress Syndrome , Adult , Critical Care , Humans , Respiration, Artificial , Respiratory Distress Syndrome/drug therapy
16.
Animal ; 14(S3): s438-s452, 2020 Sep.
Article in English | MEDLINE | ID: mdl-32778195

ABSTRACT

Accurate estimates of methane (CH4) production by cattle in different contexts are essential to developing mitigation strategies in different regions. We aimed to: (i) compile a database of CH4 emissions from Brazilian cattle studies, (ii) evaluate prediction precision and accuracy of extant proposed equations for cattle and (iii) develop specialized equations for predicting CH4 emissions from cattle in tropical conditions. Data of nutrient intake, diet composition and CH4 emissions were compiled from in vivo studies using open-circuit respiratory chambers, SF6 technique or the GreenFeed® system. A final dataset containing intake, diet composition, digestibility and CH4 emissions (677 individual animal observations, 40 treatment means) obtained from 38 studies conducted in Brazil was used. The dataset was divided into three groups: all animals (GEN), lactating dairy cows (LAC) and growing cattle and non-lactating dairy cows (GCNL). A total of 54 prediction equations available in the literature were evaluated. A total of 96 multiple linear models were developed for predicting CH4 production (MJ/day). The predictor variables were DM intake (DMI), gross energy (GE) intake, BW, DMI as proportion of BW, NDF concentration, ether extract (EE) concentration, dietary proportion of concentrate and GE digestibility. Model selection criteria were significance (P < 0.05) and variance inflation factor lower than three for all predictors. Each model performance was evaluated by leave-one-out cross-validation. The Intergovernmental Panel on Climate Change (2006) Tier 2 method performed better for GEN and GCNL than LAC and overpredicted CH4 production for all datasets. Increasing complexity of the newly developed models resulted in greater performance. The GCNL had a greater number of equations with expanded possibilities to correct for diet characteristics such as EE and NDF concentrations and dietary proportion of concentrate. For the LAC dataset, equations based on intake and animal characteristics were developed. The equations developed in the present study can be useful for accurate and precise estimation of CH4 emissions from cattle in tropical conditions. These equations could improve accuracy of greenhouse gas inventories for tropical countries. The results provide a better understanding of the dietary and animal characteristics that influence the production of enteric CH4 in tropical production systems.


Subject(s)
Diet , Lactation , Methane , Animal Feed/analysis , Animals , Brazil , Cattle , Diet/veterinary , Energy Intake , Female , Methane/analysis , Milk/chemistry
17.
Arq. bras. med. vet. zootec. (Online) ; 72(4): 1093-1101, July-Aug. 2020. tab
Article in Portuguese | LILACS, VETINDEX | ID: biblio-1131520

ABSTRACT

A relação da eficiência nutricional com a idade e o peso à puberdade e as características reprodutivas foram estudadas em 35 novilhas F1 Holandês x Gir, em ensaios usando o consumo alimentar residual (CAR) nos períodos pós-desaleitamento (PD) e pós-puberdade (PP). Novilhas PD (P<0,0001) e PP (P<0,001) foram ranqueadas como de alta, intermediária e baixa eficiências e apresentaram CAR de -0,259 -0,014 e 0,346kg/dia e -0,848 -0,096 e 0,842kg/dia, respectivamente. Novilhas PD diferiram (P<0,05) na idade à puberdade entre ranques de alta, intermediária e baixa eficiências, em média, aos 339,7; 346,4; 315,3 dias, respectivamente. Os pesos à puberdade de novilhas PD com alta, intermediária e baixa eficiências foram, em média, de 321±28,1kg e não diferiram (P>0,05) entre CAR. Não foi verificada correlação entre diâmetro folicular, taxa de crescimento do folículo, número de ondas foliculares no ciclo estral e taxa de gestação à primeira IA com o CARPD ou CARPP. Novilhas F1HG selecionadas para CAR com baixa eficiência podem ter idade à puberdade 10 dias a mais, quando comparadas às novilhas de alta eficiência para CAR. Não foi verificado que novilhas selecionadas para alta ou baixa eficiências alimentares, usando CAR, tivessem algum impacto negativo sobre características reprodutivas avaliadas.(AU)


The relationship between nutritional efficiency and age and weight at puberty and reproductive traits was studied in 35 F1 Holstein x Gyr heifers, in trials using residual food consumption (CAR) in the post-weaning (PW) and post-pubertal (PP) periods. PD heifers (P<0.0001) and PP (P<0.001) were classified as high, intermediate and low efficiencies and presented CAR of -0.259 -0.014 and 0.346kg/day and -0.848 -0.096 and 0.842kg/day, respectively. PD heifers differed (P<0.05) in age at puberty between high, intermediate and low efficiencies, on average, at 339.7, 346.4 and 315.3 days, respectively. The weight at puberty of PD heifers with high, intermediate and low efficiencies were, on average, 321±28.1kg and did not differ (P>0.05) between CAR. No correlation was found between follicular diameter, follicle growth rate, number of follicular waves in the estrous cycle and pregnancy rate at 1st AI with the CARPD or CARPP. F1HG heifers selected for CAR with low efficiency can be aged at puberty 10 days longer when compared to high-efficiency heifers for CAR. These results did not show that heifers selected for high or low food efficiency, using CAR, had negative impact on the reproductive characteristics evaluated.(AU)


Subject(s)
Animals , Female , Cattle , Phenotype , Weight Gain , Estrous Cycle , Feeding Behavior , Body Weights and Measures/veterinary , Pregnancy Rate
18.
PLoS One ; 15(7): e0236118, 2020.
Article in English | MEDLINE | ID: mdl-32667943

ABSTRACT

The objective of this study was to evaluate whether pre-weaning heifer calves divergent for residual feed intake (RFI) or residual feed intake and body weight gain (RIG) exhibit differences in thermography, blood, and ruminal parameters. Thirty-two Gyr heifer calves were enrolled in a 63-d trial and classified into 2 feed efficiency (FE) groups based on RFI and RIG (mean ± 0.5 SD). The groups were classified as high efficiency (HE) RFI (HE RFI, n = 9), HE RIG (HE RIG, n = 10), low efficiency (LE) RFI (LE RFI, n = 10), and LE RIG (LE RIG, n = 11). The amount of whole milk provided for each calf was calculated based on their metabolic weight at birth (42% x BW0.75). The liquid diet was divided into two meals at 0700 and 1400 h. The total solid diet (TSD) was composed of 92% concentrate and 8% of Tifton 85 hay chopped in 5-cm lengths, as fed. Intake was measured daily. Blood concentrations of insulin, beta hydroxybutyrate, urea, and glucose, and ruminal pH, N-NH3, and volatile fatty acids (VFA) were evaluated at 14, 28, 42, 56, and 70 days of age. Thermal images of the calves were taken with an infrared camera (FLIR T420, FLIR Systems Inc., Wilsonville, OR) on d 56 (±3) at 0600 h, before the morning feeding. Total VFA concentration and propionate as % of total VFA were 24.2% and 22.2% lower in HE RFI compared to LE RFI calves, respectively. On the other hand, acetate as % of total VFA was 10.6% greater in HE RFI than LE RFI calves. Blood urea concentration tended to be greater in LE RFI than HE RFI calves. High efficiency HE RIG tended to have 6.8% greater acetate and 15.4% lower propionate as % of total VFA than LE RIG. Blood insulin concentration was greater and blood glucose tended to be greater for LE RIG than HE RIG group. Low efficiency RIG group had greater left rib, left flank, and anus surface temperature measured by infrared thermography than the HE RIG group. Differences in ruminal fermentation do not seem to be associated with pre-weaning calves efficiency, while differences in protein metabolism seem to affect RFI during this phase. Infrared thermography appears to be correlated to RIG in pre-weaning heifer calves.


Subject(s)
Animal Feed/analysis , Diet/veterinary , Feeding Behavior/physiology , Thermogenesis , Weaning , Weight Gain , Animals , Blood Cells/metabolism , Cattle , Energy Intake , Ruminants/metabolism , Thermography
19.
J Phys Condens Matter ; 32(10): 105803, 2020 Mar 06.
Article in English | MEDLINE | ID: mdl-31747650

ABSTRACT

The magnetic properties of the double perovskites Sm2Mn1+x Co1-x O6 (x = 0, 0.05, 0.12 and 0.26) were investigated. It was found that the Curie temperature, the lattice parameters and the net magnetic moments increased for increasing amounts of Co. An irreversible behavior was observed by measuring the magnetization after cooling the sample with and without applied magnetic fields (H). The temperature below which the irreversibility was observed is H dependent and the data were nicely fit to de Almeida-Thouless lines. The ac magnetic susceptibility was measured for frequencies f  in the range 0.03-10 kHz yielding [Formula: see text] for the shifting in the freezing temperature per decade of f . The spin-dynamics were found to follow a power-law with a product of the critical exponents [Formula: see text] of about 4.99. The overall results are understood within a framework where the variation in the bonding angle associated to the super-exchange interactions are taken into consideration.

20.
Science ; 366(6471): 1349-1354, 2019 12 13.
Article in English | MEDLINE | ID: mdl-31831662

ABSTRACT

Pressure alters the physical, chemical, and electronic properties of matter. The diamond anvil cell enables tabletop experiments to investigate a diverse landscape of high-pressure phenomena. Here, we introduce and use a nanoscale sensing platform that integrates nitrogen-vacancy (NV) color centers directly into the culet of diamond anvils. We demonstrate the versatility of this platform by performing diffraction-limited imaging of both stress fields and magnetism as a function of pressure and temperature. We quantify all normal and shear stress components and demonstrate vector magnetic field imaging, enabling measurement of the pressure-driven [Formula: see text] phase transition in iron and the complex pressure-temperature phase diagram of gadolinium. A complementary NV-sensing modality using noise spectroscopy enables the characterization of phase transitions even in the absence of static magnetic signatures.

SELECTION OF CITATIONS
SEARCH DETAIL
...