High-field 1H T1 and T2 NMR Relaxation Time Measurements of H2O in Homeopathic Preparations of Quartz, Sulfur and Copper Sulfate

Quantitative meta-analyses of randomized clinical trials investigating the specific therapeutic efficacy of homeopathic remedies yielded statistically significant differences compared to placebo. Since the remedies used contained mostly only very low concentrations of pharmacologically active compounds, these effects cannot be accounted for within the framework of current pharmacology. Theories to explain clinical effects of homeopathic remedies are partially based upon changes in diluent structure. To investigate the latter, we measured for the first time high-field (600/500 MHz) 1H T1 and T2 nuclear magnetic resonance relaxation times of H2O in homeopathic preparations with concurrent contamination control by inductively coupled plasma mass spectrometry (ICP-MS). Homeopathic preparations of quartz (10c–30c, n = 21, corresponding to iterative dilutions of 100−10–100−30), sulfur (13x–30x, n = 18, 10−13–10−30), and copper sulfate (11c–30c, n = 20, 100−11–100−30) were compared to n = 10 independent controls each (analogously agitated dilution medium) in randomized and blinded experiments. In none of the samples, the concentration of any element analyzed by ICP-MS exceeded 10 ppb. In the first measurement series (600 MHz), there was a significant increase in T1 for all samples as a function of time, and there were no significant differences between homeopathic potencies and controls. In the second measurement series (500 MHz) 1 year after preparation, we observed statistically significant increased T1 relaxation times for homeopathic sulfur preparations compared to controls. Fifteen out of 18 correlations between sample triplicates were higher for controls than for homeopathic preparations. No conclusive explanation for these phenomena can be given at present. Possible hypotheses involve differential leaching from the measurement vessel walls or a change in water molecule dynamics, i.e., in rotational correlation time and/or diffusion. Homeopathic preparations thus may exhibit specific physicochemical properties that need to be determined in detail in future investigations.

Use of EORTC Target Definition Guidelines for Dose-Intensified Salvage Radiation Therapy for Recurrent Prostate Cancer: Results of the Quality Assurance Program of the Randomized Trial SAKK 09/10

PURPOSE Different international target volume delineation guidelines exist and different treatment techniques are available for salvage radiation therapy (RT) for recurrent prostate cancer, but less is known regarding their respective applicability in clinical practice. METHODS AND MATERIALS A randomized phase III trial testing 64 Gy vs 70 Gy salvage RT was accompanied by an intense quality assurance program including a site-specific and study-specific questionnaire and a dummy run (DR). Target volume delineation was performed according to the European Organisation for the Research and Treatment of Cancer guidelines, and a DR-based treatment plan was established for 70 Gy. Major and minor protocol deviations were noted, interobserver agreement of delineated target contours was assessed, and dose-volume histogram (DVH) parameters of different treatment techniques were compared. RESULTS Thirty European centers participated, 43% of which were using 3-dimensional conformal RT (3D-CRT), with the remaining centers using intensity modulated RT (IMRT) or volumetric modulated arc technique (VMAT). The first submitted version of the DR contained major deviations in 21 of 30 (70%) centers, mostly caused by inappropriately defined or lack of prostate bed (PB). All but 5 centers completed the DR successfully with their second submitted version. The interobserver agreement of the PB was moderate and was improved by the DR review, as indicated by an increased κ value (0.59 vs 0.55), mean sensitivity (0.64 vs 0.58), volume of total agreement (3.9 vs 3.3 cm(3)), and decrease in the union volume (79.3 vs 84.2 cm(3)). Rectal and bladder wall DVH parameters of IMRT and VMAT vs 3D-CRT plans were not significantly different. CONCLUSIONS The interobserver agreement of PB delineation was moderate but was improved by the DR. Major deviations could be identified for the majority of centers. The DR has improved the acquaintance of the participating centers with the trial protocol.

Taxane-containing induction chemotherapy followed by definitive chemoradiotherapy. Outcome in patients with locally advanced head and neck cancer

BACKGROUND Induction chemotherapy followed by definitive chemoradiotherapy is an intensified treatment approach for locally advanced squamous cell carcinoma of the head and neck (HNSCC) that might be associated with high rates of toxicity. MATERIALS AND METHODS The data of 40 consecutive patients who underwent induction chemotherapy with docetaxel-containing regimens followed by intensity-modulated radiotherapy (IMRT) and concomitant systemic therapy for unresectable locally advanced HNSCC were retrospectively analyzed. Primary objectives were RT-related acute and late toxicity. Secondary objectives were response to induction chemotherapy, locoregional recurrence-free survival (LRRFS), overall survival (OS), and influencing factors for LRRFS and OS. RESULTS The median follow-up for surviving patients was 21 months (range, 2-53 months). Patients received a median of three cycles of induction chemotherapy followed by IMRT to 72 Gy. Three patients died during induction chemotherapy and one during chemoradiotherapy. Acute RT-related toxicity was of grade 3 and 4 in 72 and 3 % of patients, respectively, mainly dysphagia and dermatitis. Late RT-related toxicity was mainly xerostomia and bone/cartilage necrosis and was of grade 3 and 4 in 15 % of patients. One- and 2-year LRRFS and OS were 72 and 49 % and 77 and 71 %, respectively. CONCLUSION Induction chemotherapy followed by chemoradiotherapy using IMRT was associated with a high rate of severe acute and late RT-related toxicities in this selected patient cohort. Four patients were lost because of fatal complications. Induction chemotherapy did not compromise the delivery of full-dose RT; however, the use of three cycles of concomitant cisplatin was impaired.

Measurement and meaning of head movements in everyday face-to-face communicative interaction

Methodological approaches in which data on nonverbal behavior are collected usually involve interpretive methods in which raters must identify a set of defined categories of behavior. However, present knowledge about the qualitative aspects of head movement behavior calls for recording detailed transcriptions of behavior. These records are a prerequisite for investigating the function and meaning of head movement patterns. A method for directly collecting data on head movement behavior is introduced. Using small ultrasonic transducers, which are attached to various parts of an index person's body (head and shoulders), a microcomputer defines receiver-transducers distances. Three-dimensional positions are calculated by triangulation. These data are used for further calculations concerning the angular orientation of the head and the direction, size, and speed of head movements (in rotational, lateral, and sagittal dimensions).

Comfort of two shoulder actuation mechanisms for arm therapy exoskeletons: a comparative study in healthy subjects

Robotic exoskeletons can be used to study and treat patients with neurological impairments. They can guide and support the human limb over a large range of motion, which requires that the movement trajectory of the exoskeleton coincide with the one of the human arm. This is straightforward to achieve for rather simple joints like the elbow, but very challenging for complex joints like the human shoulder, which is comprised by several bones and can exhibit a movement with multiple rotational and translational degrees of freedom. Thus, several research groups have developed different shoulder actuation mechanism. However, there are no experimental studies that directly compare the comfort of two different shoulder actuation mechanisms. In this study, the comfort and the naturalness of the new shoulder actuation mechanism of the ARMin III exoskeleton are compared to a ball-and-socket-type shoulder actuation. The study was conducted in 20 healthy subjects using questionnaires and 3D-motion records to assess comfort and naturalness. The results indicate that the new shoulder actuation is slightly better than a ball-and-socket-type actuation. However, the differences are small, and under the tested conditions, the comfort and the naturalness of the two tested shoulder actuations do not differ a lot.

Quantification of Popliteal Artery Deformation During Leg Flexion in Subjects With Peripheral Artery Disease: A Pilot Study

Purpose: To quantify the in vivo deformations of the popliteal artery during leg flexion in subjects with clinically relevant peripheral artery disease (PAD). Methods: Five patients (4 men; mean age 69 years, range 56–79) with varying calcification levels of the popliteal artery undergoing endovascular revascularization underwent 3-dimensional (3D) rotational angiography. Image acquisition was performed with the leg straight and with a flexion of 70°/20° in the knee/hip joints. The arterial centerline and the corresponding branches in both positions were segmented to create 3D reconstructions of the arterial trees. Axial deformation, twisting, and curvatures were quantified. Furthermore, the relationships between the calcification levels and the deformations were investigated. Results: An average shortening of 5.9%±2.5% and twist rate of 3.8±2.2°/cm in the popliteal artery were observed. Maximal curvatures in the straight and flexed positions were 0.12±0.04 cm−1 and 0.24±0.09 cm−1, respectively. As the severity of calcification increased, the maximal curvature in the straight position increased from 0.08 to 0.17 cm−1, while an increase from 0.17 to 0.39 cm−1 was observed for the flexed position. Axial elongations and arterial twisting were not affected by the calcification levels. Conclusion: The popliteal artery of patients with symptomatic PAD is exposed to significant deformations during flexion of the knee joint. The severity of calcification directly affects curvature, but not arterial length or twisting angles. This pilot study also showed the ability of rotational angiography to quantify the 3D deformations of the popliteal artery in patients with various levels of calcification.

Extracortical plate fixation with new plate inserts and cerclage wires for the treatment of periprosthetic hip fractures

PURPOSE Fixation of periprosthetic hip fractures with intracortical anchorage might not be feasible in cases with bulky implants and/or poor bone stock. METHODS Rotational stability of new plate inserts with extracortical anchorage for cerclage fixation was measured and compared to the stability found using a standard technique in a biomechanical setup using a torsion testing machine. In a synthetic PUR bone model, transverse fractures were fixed distally using screws and proximally by wire cerclages attached to the plates using "new" (extracortical anchorage) or "standard" (intracortical anchorage) plate inserts. Time to fracture consolidation and complications were assessed in a consecutive series of 18 patients (18 female; mean age 81 years, range 55-92) with periprosthetic hip fractures (ten type B1, eight type C-Vancouver) treated with the new device between July 2003 and July 2010. RESULTS The "new" device showed a higher rotational stability than the "standard" technique (p < 0.001). Fractures showed radiographic consolidation after 14 ± 5 weeks (mean ± SD) postoperatively in patients. Revision surgery was necessary in four patients, unrelated to the new technique. CONCLUSION In periprosthetic hip fractures in which fixation with intracortical anchorage using conventional means might be difficult due to bulky revision stems and/or poor bone stock, the new device may be an addition to the range of existing implants.

Evaluation of a new six degrees of freedom couch for radiation therapy

Purpose: The aim of this work is to evaluate the geometric accuracy of a prerelease version of a new six degrees of freedom (6DoF) couch. Additionally, a quality assurance method for 6DoF couches is proposed. Methods: The main principle of the performance tests was to request a known shift for the 6DoF couch and to compare this requested shift with the actually applied shift by independently measuring the applied shift using different methods (graph paper, laser, inclinometer, and imaging system). The performance of each of the six axes was tested separately as well as in combination with the other axes. Functional cases as well as realistic clinical cases were analyzed. The tests were performed without a couch load and with a couch load of up to 200 kg and shifts in the range between −4 and +4 cm for the translational axes and between −3° and +3° for the rotational axes were applied. The quality assurance method of the new 6DoF couch was performed using a simple cube phantom and the imaging system. Results: The deviations (mean ± one standard deviation) accumulated over all performance tests between the requested shifts and the measurements of the applied shifts were −0.01 ± 0.02, 0.01 ± 0.02, and 0.01 ± 0.02 cm for the longitudinal, lateral, and vertical axes, respectively. The corresponding values for the three rotational axes couch rotation, pitch, and roll were 0.03° ± 0.06°, −0.04° ± 0.12°, and −0.01° ± 0.08°, respectively. There was no difference found between the tests with and without a couch load of up to 200 kg. Conclusions: The new 6DoF couch is able to apply requested shifts with high accuracy. It has the potential to be used for treatment techniques with the highest demands in patient setup accuracy such as those needed in stereotactic treatments. Shifts can be applied efficiently and automatically. Daily quality assurance of the 6DoF couch can be performed in an easy and efficient way. Long-term stability has to be evaluated in further tests.

Frameless linac-based (Novalis TX) stereotactic treatment for vestibular schwannoma that extend distally into the iac (Internal Acoustic Canal): an analysis of the dose to the cochlea

Objectives: We compare the dose parameters between 3 different radiosurgery delivery techniques which may have an impact on cochlea function. Methods: Five patients with unilateral vestibular schwannoma (VS) were selected for this study. Planning procedure was carried out using the BrainLAB® iPlan planning system v. 4.5. For each patient three different planning techniques were used: dynamic arc (DA) with 5 arcs per plan, hybrid arc (HA) with 5 arcs per plan and IMRT with 8 fields per plan. For each technique, two plans were generated with different methods: with the first method (PTV coverage) it was the goal to fully cover the PTV with at least 12 Gy (normalization: 12 Gy covered 99% of the PTV) and with the second method (cochlea sparing) it was the goal to spare the cochlea (normalization: 12 Gy covers 50% of the PTV/V4Gy of cochlea lower than 1%). Plan evaluation was done considering target volume and coverage (conformity and homogeneity) and OAR constraints (mean (Dmean) and maximum dose (Dmax) to cochlea, Dmax to brainstem and cochlea). The total number of monitor units (MU) was analyzed. Results: The median tumor volume was 0.95 cm³ (range, 0.86-3 cm³). The median PTV was 1.44 cm³ (range, 1-3.5 cm³). The median distance between the tumor and the cochlea's modiulus was 2.7 mm (range, 1.8-6.3 mm). For the PTV coverage method, when we compared the cochlear dose in VS patients planned with DA, HA and IMRT, there were no significant differences in Dmax (p = 0.872) and in Dmean (p= 0.860). We found a significant correlation (p< 0.05) between the target volume and the cochlear Dmean for all plans with Pearson's coefficient correlation of 0.90, 0.92 and 0.94 for the DA, HA and IMRT techniques, respectively. For the cochlea sparing method, when we compared the cochlear dose in VS patients planned with DA, HA and IMRT, there were no significant differences in Dmax (p = 0.310) and in Dmean (p= 0.275). However, in this group the V4Gy of the ipsilateral cochlea represents less than 1%. When using the HA or IMRT technique, the homogeneity and conformity in the PTV, but also the number of MUs were increased in comparison to the DA technique. Conclusion: VS tumors that extend distally into the IAC had an equivalent sparing of cochlea with DA approach compared with the HA and IMRT techniques. Disclosure: No significant relationships.

Low-lying excited states and nonradiative processes of 9-methyl-2-aminopurine

he UV spectrum of the adenine analogue 9-methyl-2-aminopurine (9M-2AP) is investigated with one- and two-color resonant two-photon ionization spectroscopy at 0.3 and 0.05 cm−1 resolution in a supersonic jet. The electronic origin at 32 252 cm−1 exhibits methyl torsional subbands that originate from the 0A′′1 (l = 0) and 1E ″ (l = ±1) torsional levels. These and further torsional bands that appear up to 000+230 cm−1 allow to fit the threefold (V 3) barriers of the torsional potentials as ∣∣V′′3∣∣=50 cm−1 in the S 0 and ∣∣V′3∣∣=126 cm−1 in the S 1 state. Using the B3LYP density functional and correlated approximate second-order coupled cluster CC2 methods, the methyl orientation is calculated to be symmetric relative to the 2AP plane in both states, with barriers of V′′3=20 cm−1 and V′3=115 cm−1. The 000 rotational band contour is 75% in-plane (a/b) polarized, characteristic for a dominantly long-axis 1ππ* excitation. The residual 25% c-axis polarization may indicate coupling of the 1ππ* to the close-lying 1 nπ* state, calculated at 4.00 and 4.01 eV with the CC2 method. However, the CC2 calculated 1 nπ oscillator strength is only 6% of that of the 1ππ* transition. The 1ππ* vibronic spectrum is very complex, showing about 40 bands within the lowest 500 cm−1. The methyl torsion and the low-frequency out-of-plane ν′1 and ν′2 vibrations are strongly coupled in the 1ππ* state. This gives rise to many torsion-vibration combination bands built on out-of-plane fundamentals, which are without precedence in the 1ππ* spectrum of 9H-2-aminopurine [S. Lobsiger, R. K. Sinha, M. Trachsel, and S. Leutwyler, J. Chem. Phys.134, 114307 (2011)]. From the Lorentzian broadening needed to fit the 000 contour of 9M-2AP, the 1ππ* lifetime is τ ⩾ 120 ps, reflecting a rapid nonradiative transition.

A critical evaluation of secondary cancer risk models applied to Monte Carlo dose distributions of 2-dimensional, 3-dimensional conformal and hybrid intensity-modulated radiation therapy for breast cancer

The comparison of radiotherapy techniques regarding secondary cancer risk has yielded contradictory results possibly stemming from the many different approaches used to estimate risk. The purpose of this study was to make a comprehensive evaluation of different available risk models applied to detailed whole-body dose distributions computed by Monte Carlo for various breast radiotherapy techniques including conventional open tangents, 3D conformal wedged tangents and hybrid intensity modulated radiation therapy (IMRT). First, organ-specific linear risk models developed by the International Commission on Radiological Protection (ICRP) and the Biological Effects of Ionizing Radiation (BEIR) VII committee were applied to mean doses for remote organs only and all solid organs. Then, different general non-linear risk models were applied to the whole body dose distribution. Finally, organ-specific non-linear risk models for the lung and breast were used to assess the secondary cancer risk for these two specific organs. A total of 32 different calculated absolute risks resulted in a broad range of values (between 0.1% and 48.5%) underlying the large uncertainties in absolute risk calculation. The ratio of risk between two techniques has often been proposed as a more robust assessment of risk than the absolute risk. We found that the ratio of risk between two techniques could also vary substantially considering the different approaches to risk estimation. Sometimes the ratio of risk between two techniques would range between values smaller and larger than one, which then translates into inconsistent results on the potential higher risk of one technique compared to another. We found however that the hybrid IMRT technique resulted in a systematic reduction of risk compared to the other techniques investigated even though the magnitude of this reduction varied substantially with the different approaches investigated. Based on the epidemiological data available, a reasonable approach to risk estimation would be to use organ-specific non-linear risk models applied to the dose distributions of organs within or near the treatment fields (lungs and contralateral breast in the case of breast radiotherapy) as the majority of radiation-induced secondary cancers are found in the beam-bordering regions.

The influence of tibial morphology on the design of an anatomical tibial baseplate for TKA.

BACKGROUND Finding the right balance between tibial coverage and minimal implant overhang is an important factor in TKA. Another significant cause of failure is component malrotation. METHODS An average master shape of the proximal tibia at TKA resection level was calculated using fine slice computed tomographies of 117 cadaveric knees. To find out whether alternate implant contours would be necessary depending on the patient's body size, we established five subgroups to compare. CAD-Analysis was performed to simulate the overhang produced after ±4°/±7°/±10° rotation. RESULTS A master shape for the tibial resection cut (with a 5° posterior slope, 7 mm under lateral joint line) could be determined. Neither left vs. right knee joint, nor male vs. female nor the size subdivision appears to alter the calculated master shape significantly. The optimized shape allowing for ±4° of rotational freedom was found to be the best variant. CONCLUSIONS Valid methods have been obtained to design a two-dimensional average shape of the tibial plateau. The modifications described in this study might come in useful, when designing future implant designs. CLINICAL RELEVANCE An optimized fit at the tibial plateau and lower rates of component malrotation may result in better outcomes after TKA.

Definitive intensity modulated radiotherapy in locally advanced hypopharygeal and laryngeal squamous cell carcinoma: mature treatment results and patterns of locoregional failure.

PurposeTo assess clinical outcomes and patterns of loco-regional failure (LRF) in relation to clinical target volumes (CTV) in patients with locally advanced hypopharyngeal and laryngeal squamous cell carcinoma (HL-SCC) treated with definitive intensity modulated radiotherapy (IMRT) and concurrent systemic therapy.MethodsData from HL-SCC patients treated from 2007 to 2010 were retrospectively evaluated. Primary endpoint was loco-regional control (LRC). Secondary endpoints included local (LC) and regional (RC) controls, distant metastasis free survival (DMFS), laryngectomy free survival (LFS), overall survival (OS), and acute and late toxicities. Time-to-event endpoints were estimated using Kaplan-Meier method, and univariate and multivariate analyses were performed using Cox proportional hazards models. Recurrent gross tumor volume (RTV) on post-treatment diagnostic imaging was analyzed in relation to corresponding CTV (in-volume, > 95% of RTV inside CTV; marginal, 20¿95% inside CTV; out-volume, < 20% inside CTV).ResultsFifty patients (stage III: 14, IVa: 33, IVb: 3) completed treatment and were included in the analysis (median follow-up of 4.2 years). Three-year LRC, DMFS and overall survival (OS) were 77%, 96% and 63%, respectively. Grade 2 and 3 acute toxicity were 38% and 62%, respectively; grade 2 and 3 late toxicity were 23% and 15%, respectively. We identified 10 patients with LRF (8 local, 1 regional, 1 local¿+¿regional). Six out of 10 RTVs were fully included in both elective and high-dose CTVs, and 4 RTVs were marginal to the high-dose CTVs.ConclusionThe treatment of locally advanced HL-SCC with definitive IMRT and concurrent systemic therapy provides good LRC rates with acceptable toxicity profile. Nevertheless, the analysis of LRFs in relation to CTVs showed in-volume relapses to be the major mode of recurrence indicating that novel strategies to overcome radioresistance are required.

Excited-State Structure, Vibrations, and Nonradiative Relaxation of Jet-Cooled 5-Fluorocytosine

The S0 → S1 vibronic spectrum and S1 state nonradiative relaxation of jet-cooled keto-amino 5-fluorocytosine (5FCyt) are investigated by two-color resonant two-photon ionization spectroscopy at 0.3 and 0.05 cm–1 resolution. The 000 rotational band contour is polarized in-plane, implying that the electronic transition is 1ππ*. The electronic transition dipole moment orientation and the changes of rotational constants agree closely with the SCS-CC2 calculated values for the 1ππ* (S1) transition of 5FCyt. The spectral region from 0 to 300 cm–1 is dominated by overtone and combination bands of the out-of-plane ν1′ (boat), ν2′ (butterfly), and ν3′ (HN–C6H twist) vibrations, implying that the pyrimidinone frame is distorted out-of-plane by the 1ππ* excitation, in agreement with SCS-CC2 calculations. The number of vibronic bands rises strongly around +350 cm–1; this is attributed to the 1ππ* state barrier to planarity that corresponds to the central maximum of the double-minimum out-of-plane vibrational potentials along the ν1′, ν2′, and ν3′ coordinates, which gives rise to a high density of vibronic excitations. At +1200 cm–1, rapid nonradiative relaxation (knr ≥ 1012 s–1) sets in, which we interpret as the height of the 1ππ* state barrier in front of the lowest S1/S0 conical intersection. This barrier in 5FCyt is 3 times higher than that in cytosine. The lifetimes of the ν′ = 0, 2ν1′, 2ν2′, 2ν1′ + 2ν2′, 4ν2′, and 2ν1′ + 4ν2′ levels are determined from Lorentzian widths fitted to the rotational band contours and are τ ≥ 75 ps for ν′ = 0, decreasing to τ ≥ 55 ps at the 2ν1′ + 4ν2′ level at +234 cm–1. These gas-phase lifetimes are twice those of S1 state cytosine and 10–100 times those of the other canonical nucleobases in the gas phase. On the other hand, the 5FCyt gas-phase lifetime is close to the 73 ps lifetime in room-temperature solvents. This lack of dependence on temperature and on the surrounding medium implies that the 5FCyt nonradiative relaxation from its S1 (1ππ*) state is essentially controlled by the same ∼1200 cm–1 barrier and conical intersection both in the gas phase and in solution.

Grazing behaviour, physical activity and metabolic profile of two Holstein strains in an organic grazing system

The challenge for sustainable organic dairy farming is identification of cows that are well adapted to forage-based production systems. Therefore, the aim of this study was to compare the grazing behaviour, physical activity and metabolic profile of two different Holstein strains kept in an organic grazing system without concentrate supplementation. Twelve Swiss (HCH ; 566 kg body weight (BW) and 12 New Zealand Holstein-Friesian (HNZ ; 530 kg BW) cows in mid-lactation were kept in a rotational grazing system. After an adaptation period, the milk yield, nutrient intake, physical activity and grazing behaviour were recorded for each cow for 7 days. On three consecutive days, blood was sampled at 07:00, 12:00 and 17:00 h from each cow by jugular vein puncture. Data were analysed using linear mixed models. No differences were found in milk yield, but milk fat (3.69 vs. 4.05%, P = 0.05) and milk protein percentage (2.92 vs. 3.20%, P < 0.01) were lower in HCH than in HNZ cows. Herbage intake did not differ between strains, but organic matter digestibility was greater (P = 0.01) in HCH compared to HNZ cows. The HCH cows spent less (P = 0.04) time ruminating (439 vs. 469 min/day) and had a lower (P = 0.02) number of ruminating boli when compared to the HNZ cows. The time spent eating and physical activity did not differ between strains. Concentrations of IGF-1 and T3 were lower (P ≤ 0.05) in HCH than HNZ cows. In conclusion, HCH cows were not able to increase dry matter intake in order to express their full genetic potential for milk production when kept in an organic grazing system without concentrate supplementation. On the other hand, HNZ cows seem to compensate for the reduced nutrient availability better than HCH cows but could not use that advantage for increased production efficiency