Brazilian Society of Angiology and Vascular Surgery 2023 guidelines on the diabetic foot.

The diabetic foot interacts with anatomical, vascular, and neurological factors that challenge clinical practice. This study aimed to compile the primary scientific evidence based on a review of the main guidelines, in addition to articles published on the Embase, Lilacs, and PubMed platforms. The European Society of Cardiology system was used to develop recommendation classes and levels of evidence. The themes were divided into six chapters (Chapter 1 - Prevention of foot ulcers in people with diabetes; Chapter 2 - Pressure relief from foot ulcers in people with diabetes; Chapter 3 -Classifications of diabetic foot ulcers; Chapter 4 - Foot and peripheral artery disease; Chapter 5 - Infection and the diabetic foot; Chapter 6 - Charcot's neuroarthropathy). This version of the Diabetic Foot Guidelines presents essential recommendations for the prevention, diagnosis, treatment, and follow-up of patients with diabetic foot, offering an objective guide for medical practice.

Full-fat corn germ improves the performance and milk fat yield of Girolando cows fed sugarcane bagasse and cactus cladodes as forage sources.

We investigated the effects of replacing ground corn with full-fat corn germ (FFCG) on milk production, milk composition, and nutrient use in cows fed sugarcane bagasse and cactus cladodes. Ten multiparous Girolando cows (average body weight 500 ± 66 kg, 90 ± 15 days in milk) were distributed in a replicated 5 × 5 Latin Square and assigned to five dietary treatments containing 0%, 25%, 50%, 75%, or 100% of full-fat corn germ in substitution to ground corn. Full-fat corn germ increased fat-corrected milk yield by 2.2 kg/day and the synthesis of fat, lactose, and total solids in milk by 94.4, 60.0, and 201.10 g/day, respectively (p < 0.05). Cows fed corn germ quadratically increased (p < 0.05) dry matter intake by 1.01 kg/day, with the intake of crude protein and total digestible nutrients following the same pattern. Conversely, the substitution of corn for full-fat corn germ linearly reduced (p < 0.05) the total non-fiber carbohydrate intake from 5.79 to 4.40 kg/d. Except for ether extract and non-fiber carbohydrates, full-fat corn germ did not alter (p > 0.05) nutrient digestibility. Cows fed corn germ excreted less (p < 0.05) urea-N in milk and urine N. These results demonstrate that full-fat corn germ can partially replace ground corn to enhance the milk production efficiency of crossbred cows fed cactus cladodes and sugarcane bagasse. Furthermore, including sugarcane bagasse in FFCG-supplemented diets prevents milk fat depression in cows fed cactus cladodes.

Brazilian guidelines on diagnosis and management of traumatic vascular injuries.

Trauma is a leading cause of death, permanent disability, and health care cost worldwide. The young and economically active are the most affected population. Exsanguination due to noncompressible torso hemorrhage is one of the most frequent causes of early death, posing a significant challenge to trauma and vascular surgeons. The possibility of limb loss due to vascular injuries must also be considered. In recent decades, the approach to vascular injuries has been significantly modified. Angiotomography has become the standard method for diagnosis, endovascular techniques are currently incorporated in treatment, and damage control, such as temporary shunts, is now the preferred approach for the patients sustaining physiological derangement. Despite the importance of this topic, few papers in the Brazilian literature have offered guidelines on vascular trauma. The Brazilian Society of Angiology and Vascular Surgery has developed Projetos Diretrizes (Guideline Projects), which includes this publication on vascular trauma. Since treating trauma patients is a multidisciplinary effort, the Brazilian Trauma Society (SBAIT) was invited to participate in this project. Members of both societies reviewed the literature on vascular trauma management and together wrote these guidelines on vascular injuries of neck, thorax, abdomen, and extremities.

Guidelines on vascular access for hemodialysis from the Brazilian Society of Angiology and Vascular Surgery.

Chronic kidney disease is a worldwide public health problem, and end-stage renal disease requires dialysis. Most patients requiring renal replacement therapy have to undergo hemodialysis. Therefore, vascular access is extremely important for the dialysis population, directly affecting the quality of life and the morbidity and mortality of this patient population. Since making, managing and salvaging of vascular accesses falls within the purview of the vascular surgeon, developing guideline to help specialists better manage vascular accesses for hemodialysis if of great importance. Thus, the objective of this guideline is to present a set of recommendations to guide decisions involved in the referral, evaluation, choice, surveillance and management of complications of vascular accesses for hemodialysis.

A doença renal crônica é um problema de saúde pública global e em seu estágio terminal está associada à necessidade de terapia dialítica. A grande maioria dos pacientes que necessitam realizar a terapia renal substitutiva, a fazem através da hemodiálise. Portanto, o acesso vascular é de extrema importância para a população dialítica, implicando diretamente na qualidade de vida e na morbimortalidade deste grupo de pacientes. Sendo a confecção, gerenciamento e resgate dos acessos vasculares uma das áreas de atuação do cirurgião vascular, é de grande importância a elaboração de uma diretriz que oriente o especialista no manejo mais adequado do acesso vascular para hemodiálise. Assim, o objetivo desta diretriz é apresentar um conjunto de recomendações para guiar as decisões na referenciação, avaliação, escolha, vigilância e gestão das complicações do acesso vascular para hemodiálise.

Brazilian guidelines on chronic venous disease of the Brazilian Society of Angiology and Vascular Surgery.

The Brazilian Society of Angiology and Vascular Surgery has set up a committee to provide new evidence-based recommendations for patient care associated with chronic venous insufficiency. Topics were divided in five groups: 1. Classification, 2. Diagnosis, 3. Conservative or non-invasive treatment, 4. Invasive treatment and 5. Treatment of small vessels. This last series is closely related to the activities of Brazilian angiologists and vascular surgeons, who are heavily involved in the treatment of small superficial veins. These guidelines are intended to assist in clinical decision-making for attending physicians and health managers. The decision to follow a guideline recommendation should be made by the responsible physician on a case-by-case basis taking into account the patient's specific condition, as well as local resources, regulations, laws, and clinical practice recommendations.

A Sociedade Brasileira de Angiologia e de Cirurgia Vascular organizou uma comissão para fornecer novas recomendações baseadas em evidências sobre questões críticas de atendimento ao paciente com insuficiência venosa crônica. São abordados aqui os temas de classificação, diagnóstico, tratamento conservador, tratamento invasivo e tratamento de pequenos vasos. Esta última série está muito relacionada à atividade de angiologistas e cirurgiões vasculares, que possuem forte atuação no tratamento de pequenas veias superficiais. Estas diretrizes destinam-se a auxiliar na tomada de decisões clínicas de médicos assistentes e gestores de saúde. A decisão de seguir uma recomendação de diretriz deve ser feita pelo médico responsável caso a caso, levando em consideração a condição específica do paciente, bem como recursos locais, regulamentos, leis e recomendações de prática clínica.

Brazilian Society for Angiology and Vascular Surgery guidelines on abdominal aortic aneurysm.

The Brazilian Society of Angiology and Vascular Surgery, through the Guidelines Project, presents new Abdominal Aortic Aneurysm Guidelines, on the subject of care for abdominal aortic aneurysm patients. Its development prioritized descriptive guidelines, using the EMBASE, LILACS, and PubMed databases. References include randomized controlled trials, systematic reviews, meta-analyses, and cohort studies. Quality of evidence was evaluated by a pair of coordinators, aided by the RoB 2 Cochrane tool and the Newcastle Ottawa Scale forms. The subjects include juxtarenal aneurysms, infected aneurysms, and new therapeutic techniques, especially endovascular procedures. The current version of the guidelines include important recommendations for the primary topics involving diagnosis, treatment, and follow-up for abdominal aortic aneurysm patients, providing an objective guide for medical practice, based on scientific evidence and widely available throughout Brazil.

A Sociedade Brasileira de Angiologia e Cirurgia Vascular, por meio do projeto Diretrizes, apresenta as novas Diretrizes de Aorta Abdominal, referentes aos cuidados de pacientes com aneurisma de aorta abdominal. Para sua elaboração, foram priorizadas diretrizes descritivas, utilizando as bases EMBASE, LILACS e PubMed. As referências incluem ensaios clínicos randomizados, revisões sistemáticas, metanálises e estudos de coorte. A qualidade das evidências foi examinada por uma dupla de coordenadores, com auxílio da ferramenta RoB 2 da Colaboração Cochrane e dos formulários da Newcastle Ottawa Scale. Aneurismas justarrenais, infectados e novas técnicas terapêuticas, principalmente no âmbito endovascular, estão entre os temas estudados. A versão atual das Diretrizes apresenta importantes recomendações para os principais itens que envolvem o diagnóstico, tratamento e acompanhamento de pacientes com aneurisma de aorta abdominal, oferecendo um guia objetivo para prática médica, construído a partir de evidências científicas e amplamente acessível em todo o território nacional.

Superficial Femoral Artery in-Stent Restenosis Treated with Paclitaxel-Coated Balloon Angioplasty - Results of Three-Year Follow-Up.

BACKGROUND: In-stent restenosis remains a common and important complication after endovascular treatment of superficial femoral artery peripheral artery disease. It occurs in 14 to 35% of cases in 1 year and there is still no efficient treatment for this condition. Paclitaxel-coated balloons have shown promising results. OBJECTIVE: Investigate the 3 year results of superficial femoral artery in-stent restenosis treated with paclitaxel-coated balloon angioplasty, using the Lutonix™ 035 device. METHODS: We conducted a retrospective observational study with patients with symptomatic (Rutherford 2 to 5) superficial femoral artery in-stent restenosis, that were treated with paclitaxel-coated balloon angioplasty using the Lutonix™ 035 device, in a single center from January 2016 to December 2020. Duplex scan was used to follow the patients. Primary patency was obtained through Kaplan-Meier analysis. Mortality, and amputation rates were also evaluated. RESULTS: 105 patients were included. Two patients had technical failure and required an additional stent, and were thus excluded. 103 patients were analyzed. Primary patency was 91.26, 80.47, and 67.71%, respectively, in the first, second, and third year after the procedure. There were no deaths 30 days after the procedure. There were no major amputations during the 3 year follow-up. CONCLUSION: Paclitaxel-coated balloon angioplasty with the Lutonix™ 035 device was a safe and effective treatment to superficial femoral artery in-stent restenoses. The results were maintained along the 3 year follow-up.

Assisted total thermal ablation: presentation of the ATTA technique.

Treatment of lower limb chronic venous disease has progressed exponentially over recent decades. The advances achieved have made it possible to develop a proposal for a systematized intravenous laser ablation technique - assisted total thermal ablation (ATTA). The technique constitutes a standardized method for management of axial or tributary veins that are varicosed or esthetically unappealing, whether in the lower limbs or other areas, that can be performed on an outpatient or day-hospital basis. This article describes the processes for preoperative preparation and detailed marking, the materials needed, venous access, anesthesia, calculation of power and energy, the ablation technique itself, follow-up, and adverse events. The ATTA technique is proposed as a tool for treatment of chronic venous disease and of esthetically unappealing veins, suggesting possible extension of the applications for lasers beyond trunk veins to any vein that can be punctured.

ROS: Basic Concepts, Sources, Cellular Signaling, and its Implications in Aging Pathways.

Reactive oxygen species (ROS) are bioproducts of cellular metabolism. There is a range of molecules with oxidizing properties known as ROS. Despite those molecules being implied negatively in aging and numerous diseases, their key role in cellular signaling is evident. ROS control several biological processes such as inflammation, proliferation, and cell death. The redox signaling underlying these cellular events is one characteristic of the new generation of scientists aimed at defining the role of ROS in the cellular environment. The control of redox potential, which includes the balance of the sources of ROS and the antioxidant system, implies an important target for understanding the cells' fate derived from redox signaling. In this review, we summarized the chemical, the redox balance, the signaling, and the implications of ROS in biological aging.

Effects of Baru Almond Oil (Dipteryx alata Vog.) Treatment on Thrombotic Processes, Platelet Aggregation, and Vascular Function in Aorta Arteries.

Background: This study assessed the effects of Baru (Dipteryx alata Vog.) almond oil supplementation on vascular function, platelet aggregation, and thrombus formation in aorta arteries of Wistar rats. Methods: Male Wistar rats were allocated into three groups. The control group (n = 6), a Baru group receiving Baru almond oil at 7.2 mL/kg/day (BG 7.2 mL/kg, n = 6), and (iii) a Baru group receiving Baru almond oil at 14.4 mL/kg/day (BG 14.4 mL/kg, n = 6). Baru oil was administered for ten days. Platelet aggregation, thrombus formation, vascular function, and reactive oxygen species production were evaluated at the end of treatment. Results: Baru oil supplementation reduced platelet aggregation (p < 0.05) and the production of the superoxide anion radical in platelets (p < 0.05). Additionally, Baru oil supplementation exerted an antithrombotic effect (p < 0.05) and improved the vascular function of aorta arteries (p < 0.05). Conclusion: The findings showed that Baru oil reduced platelet aggregation, reactive oxygen species production, and improved vascular function, suggesting it to be a functional oil with great potential to act as a novel product for preventing and treating cardiovascular disease.

Yeast carboxymethyl-glucan improves endothelial function and inhibits platelet aggregation in spontaneously hypertensive rats.

Carboxymethyl-glucan is a semi-synthetic derivative of ß-D-glucan, a polysaccharide widely found in several natural sources, such as yeast, fungi, and cereals. This compound has beneficial effects on health and is considered an important immunomodulator. However, studies exploring carboxymethyl-glucan bioactivity in cardiovascular health remain lacking, mainly in hypertension. Thus, this study sought to expand understanding of the effects of carboxymethyl-glucan on vascular and platelet functions in a hypertensive animal model. Spontaneously hypertensive rats and their normotensive Wistar-Kyoto controls were assigned to five groups: control, carboxymethyl-glucan (60 mg kg-1), control spontaneously hypertensive rats, spontaneously hypertensive rats carboxymethyl-glucan (20 mg kg-1), and spontaneously hypertensive rats carboxymethyl-glucan (60 mg kg-1). Animals were treated for four weeks with carboxymethyl-glucan at doses of 20 and 60 mg kg-1 orally, and control rats received saline as a placebo. Vascular reactivity, platelet aggregation, and reactive oxygen species production were evaluated at the end of treatment. The results showed that carboxymethyl-glucan improved vascular function and reduced platelet aggregation, mainly at a 60 mg kg-1 dose. However, despite these effects, there was no reduction in levels of reactive oxygen species. These findings suggested that carboxymethyl-glucan modulates endothelial function. It also acts as a platelet antiaggregant, which is an interesting resource for managing hypertension and its thrombotic complications.

Application of Tissue Engineering in Manufacturing Absorbable Membranes to Improve the Osteopromoting Potential of Collagen.

The membranes are an important biomaterial that contribute to osteopromotion. This study aimed to evaluate the osteopromotive potential of collagen membranes associated with Hydroxyapatite (HA) in critical size calvaria rat's defects. Ninety-six Albinus Wistar rats were divided into four groups: (CG) negative control: clot only (CG); positive control: porcine collagen membrane (BG); fish collagen membrane associated with HA (CP); bovine collagen membrane associated with HA (CB), analyzed at 7, 15, 30, and 60 postoperative days. At 30 days, membrane integrity was observed in the CB and fragments in the CP and BG groups were dispersed in the center of the defect. At 60 days, BG demonstrated better results with no statistical difference for the CP group (p = 0.199) and a statistically significant difference for the CB group (p = 0.013). The inflammatory profiles of the BG and CP groups were similar. Immunohistochemistry demonstrated at 60 days moderate osteopontin staining for the BG and CP groups, light staining for the CB, and intense osteocalcin staining for the BG, while the CB and CP groups demonstrated moderate staining. Microtomography revealed the highest mean bone volume (14.247 mm3) in the BG, followed by the CB (11.850 mm3), and CP (9.560 mm3) group. The collagen membranes associated with HA demonstrated an osteopromotive potential.

Case report: Biliobronchial fistula after biliary tract stenosis.

Biliobronchial fistula (BBF) is a rare abnormality resulting from congenital or acquired communication between the bile ducts and the bronchial tree. Patients often suffer from chronic cough, dyspnea, and bilioptysis, a pathognomonic symptom of this condition. Conservative methods such as less-invasive procedures are gradually consolidating. Nonetheless, surgery remains the primary treatment, especially in more complex cases. We present the case of a 44-year-old woman with a chronic cough, no verified periods of fever, cyclic jaundice, and episodes of yellowish sputum. She had undergone cholecystectomy in 2018 and had been hospitalized several times since for pneumonia treatment. All consequent investigations for mycobacteriosis were negative. When referred to our hospital, she had cyclic jaundice and parenchymal consolidation in the right lower lobe. Suspected bilioptysis motivated the search for a biliobronchial fistula. Magnetic resonance cholangiography (MRC) confirmed stenosis of the biliary tract and fistulous path, and sputum analysis indicated high bilirubin levels. External biliary bypass was performed as an initial conservative and definitive therapy due to the presence of liver cirrhosis. Although BBF is a rare condition when bilioptysis is suspected, a diagnostic investigation should be initiated. Our case study proposes two criteria for diagnosis: an imaging exam demonstrating the fistulous path and confirmation of bilirubin in the sputum or bronchoalveolar lavage (BAL). When diagnosed, surgical correction should be performed.

Limb ischemia in patients with COVID-19.

This narrative review covers the life-threatening thromboembolic events associated with SARS-CoV-2 infection/COVID-19. It addresses the physical changes that cause vascular and arterial damage to limbs, laboratory management of coagulation, and management of anticoagulation. COVID-19's relationship with deep venous thrombosis and arterial thrombosis is also emphasized. The main thromboembolic events described in the literature are illustrated with examples from our experience with COVID-19 patients.

Esta revisão narrativa abrange os eventos tromboembólicos com risco de vida associados a infecção por SARS-CoV-2/COVID-19. Aborda as mudanças físicas que causam danos vasculares e arteriais aos membros, o manejo laboratorial da coagulação e o manejo da anticoagulação. A relação de COVID-19 com trombose venosa profunda e trombose arterial também é enfatizada. Os principais eventos tromboembólicos descritos na literatura são ilustrados a partir de nossa experiência com pacientes COVID-19.

Comparative assessment of mortality risk factors between admission and follow-up models among patients hospitalized with COVID-19.

OBJECTIVES: This study aimed to compare differences in mortality risk factors between admission and follow-up incorporated models. METHODS: A retrospective cohort study of 524 patients with confirmed COVID-19 infection admitted to a tertiary medical center in São Paulo, Brazil from 13 March to 30 April 2020. Data were collected on admission, and the third, eighth and fourteenth days of hospitalization. The hazard ratio (HR) was calculated and 28-day in-hospital mortality risk factors were compared between admission and follow-up models using a time-dependent Cox regression model. RESULTS: Of 524 patients, 50.4% needed mechanical ventilation. The 28-day mortality rate was 32.8%. Compared with follow-up, admission models under-estimated the mortality HR for peripheral oxygen saturation <92% (1.21 versus 2.09), heart rate >100 bpm (1.19 versus 2.04), respiratory rate >24/min (1.01 versus 1.82) and mechanical ventilation (1.92 versus 12.93). Low oxygen saturation, higher oxygen support and more biomarkers-including lactate dehydrogenase, C-reactive protein, neutrophil-lymphocyte ratio, and urea remained associated with mortality after adjustment for clinical factors at follow-up compared with only urea and oxygen support at admission. CONCLUSIONS: The inclusion of follow-up measurements changed mortality hazards of clinical signs and biomarkers. Low oxygen saturation, higher oxygen support, lactate dehydrogenase, C-reactive protein, neutrophil-lymphocyte ratio, and urea could help with prognosis of patients during follow-up.

External validity of type 2 diabetes clinical trials on cardiovascular outcomes for a multimorbid population.

AIM: To investigate the external validity of recent antihyperglycaemic trials evaluating cardiovascular outcomes in a multimorbid population. MATERIALS AND METHODS: Selection criteria of 15 randomized controlled trials from the 2020 American Diabetes Association Standard of Care statement were applied in a stepwise manner to tertiary care patients with type 2 diabetes. Primary outcomes were the number of patients eligible per individual trial and for the aggregate of trials. Secondary outcomes included patient predictors of trial eligibility. RESULTS: Of 1059 patients, the mean (SD) age was 66 (10.74) years, the median (IQR) Charlson index was 2 (2, 3) and 458 (43%) had documented cardiovascular disease. The median (IQR) number of patients included in individual trials was 263 (174.25-308.75) and 795 (75.1%) of them were eligible for at least one trial. Among those 264 ineligible, 127 (48.1%) had an HbA1c level of 7% or less and no cardiovascular disease; 53.5% and 34.4% of the patients were eligible for two and three different classes of drugs, respectively. The strongest predictor of trial eligibility was cardiovascular disease (risk ratio 2.17, 95% CI 2.01-2.35). CONCLUSIONS: A considerable proportion of multimorbid patients would be eligible for recent antihyperglycaemic trials. This positive finding can be attributed to development guidance in diabetes trials and the different approach we took, in which we evaluated inclusion by trials as an aggregate.

Manual Therapies for Posterior Thigh Muscles Enhanced Ten-Repetitions Maximum Test Performance and Hip Flexibility in Young Soccer Players.

This study investigated how different manual therapies applied to the posterior thigh muscles affect the ten-repetitions maximum performance test (10 RM) and hip flexion range-of-motion among young soccer players. Seventeen non-professional male soccer players performed the 10RM and range of motion pre-testing, and, in separate laboratory visits, they underwent three different experimental activities presented to each participant in a randomized order: (a) rest control activity with no intervention, (b) manual massage, and (c) muscle energy. Comparing pre-testing performances to repeated tests after each intervention condition, participants increased their maximum load lift on the 10-repeitions maximum test following manual massage and muscle energy interventions (p < 0.05), but not following the control condition. They also increased their hip range-of-motion on flexibility testing following manual massage and muscle energy (p < 0.05), but not following the control condition. Thus, both manual massage and muscle energy therapies applied to the posterior thigh were beneficial to performance. This finding has clear implications when preparing athletes for competition.

Unveiling the Role of Inflammation and Oxidative Stress on Age-Related Cardiovascular Diseases.

The global population above 60 years has been growing exponentially in the last decades, which is accompanied by an increase in the prevalence of age-related chronic diseases, highlighting cardiovascular diseases (CVDs), such as hypertension, atherosclerosis, and heart failure. Aging is the main risk factor for these diseases. Such susceptibility to disease is explained, at least in part, by the increase of oxidative stress, in which it damages cellular components such as proteins, DNA, and lipids. In addition, the chronic inflammatory process in aging "inflammaging" also contributes to cell damage, creating a stressful environment which drives to the development of CVDs. Taken together, it is possible to identify the molecular connection between oxidative stress and the inflammatory process, especially by the crosstalk between the transcription factors Nrf-2 and NF-κB which are mediated by redox signalling and are involved in aging. Therapies that control this process are key targets in the prevention/combat of age-related CVDs. In this review, we show the basics of inflammation and oxidative stress, including the crosstalk between them, and the implications on age-related CVDs.

Leg ulcers in sickle cell disease patients.

Leg ulcers are the most common cutaneous complication of sickle cell disease. These lesions occur mainly in homozygous forms, are slow to heal and often relapse, causing negative physical, emotional, and economic impacts. In this paper, we discuss the clinical presentation, diagnosis, and pathophysiology of sickle cell leg ulcers and their implications for treatment.

Nutritional and performance viability of cactus Opuntia-based diets added to concentrate levels for Girolando lactating dairy cows.

OBJECTIVE: The aim of this research was to evaluate the effect of different concentrate levels in diets based on cactus Opuntia Stricta (Haw.) Haw cladodes over the performance of lactating Girolando cows. METHODS: The experiment involved 10 Girolando multiparous dairy cows (512.6 kg of body weight and producing 13.2kg milk/day), allocated into two 5 x 5 Latin squares. The experimental treatments consisted of control diet composed by cactus Nopalea cochenillifera. Salm-Dyck. cladodes (Nopalea), forage sorghum silage and concentrate (20% at DM basis), and four concentrate levels diets (20, 24, 28 and 32%) plus cactus Opuntia stricta (Haw.) Haw. cladodes (Opuntia) and forage sorghum silage. RESULTS: Regarding cows fed control diet, the nutrients intake were greater than for cows fed with cactus Opuntia and concentrate. Regarding concentrate levels, intakes of dry matter (DM), organic matter (OM), crude protein (CP), non-fiber carbohydrates (NFC) and total digestible nutrients (TDN) of cows increased linearly. The OM, CP and NDF digestibilities were similar in between to control diet and cactus Opuntia-based diets. The digestibility of NFC increased linearly when the concentrate was inserted. The N balance was the same for control diet and cactus Opuntia-based diets, irrespective the concentrate levels. CONCLUSION: For cows producing 14 kg/day with 3.5% of fat, it is recommended 32% of concentrate inclusion in cactus Opuntia-based diets, and the increase in concentrate level promotes a linear increase in milk yield.