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Animal ; 15(9): 100336, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34371468


Many of the studies in Campos grasslands focus on management aspects such as the control of herbage allowance, and application of nutrients and/or overseeding with legumes. However, there is little literature on how the Campos grassland resource is utilised, especially regarding the grazing pattern and the relationship between pasture quantity and quality on daily grazing activities. The study of the ingestive behaviour in species-rich and heterogeneous native grasslands during daylight hours, and understanding how animals prioritise quality or quantity of intake in relation to pasture attributes, are important to comprehend the ingestive-digestive processes modulating the energy intake of animals and to achieve a better grazing management. Therefore, the objective was to describe and quantify the daily grazing behaviour of growing cattle grazing native pasture with different structures as a result of different management practices, and study the relationship of pasture attributes and intake through multivariate analysis. The study was carried out at the Faculty of Agronomy, Paysandú, Uruguay. Treatments were native grassland, overseeding with Trifolium pratense and Lotus tenuis + phosphorus, and native pasture + nitrogen-phosphorus. Grazing activities were discriminated into grazing, searching (defined when animals take 1-2 bites in one feeding station and then change to another feeding station and so on), ruminating and idling. The probability of time allocated to each activity was continuously measured during daylight hours (0700-1930) and was related to pasture structure and forage quality using regression tree models, while the bite rate was determined every 2 h. The diurnal pattern of growing cattle showed grazing and searching sessions, followed by ruminating and idling sessions. The length of sessions (as the probability of time allocated to each activity) varied throughout the day. The grazing probability was greater during afternoon than morning and midday (0.74 vs 0.45 vs 0.46, respectively), and it was associated with higher bite rate (34.2 bites/min). Regression tree models showed different grazing, searching and ruminating strategies according to pasture attributes. During the morning, animals modified grazing, searching, ruminating and idling strategies according to bite rate, crude protein in diet and herbage allowance. At midday, they only adjusted ruminating and idling, while during afternoon sessions, grazing activities were modified by pasture quantity attributes such as herbage mass and herbage allowance. By controlling the herbage allowance, herbage mass and pasture height, animals prioritise quality in the morning and quantity in the afternoon, integrating and modifying the grazing-searching and ruminating-idling pattern.

Comportamento Alimentar , Pradaria , Ração Animal/análise , Animais , Bovinos , Dieta/veterinária , Ingestão de Alimentos , Feminino , Lactação
G Ital Cardiol ; 26(2): 177-86, 1996 Feb.
Artigo em Italiano | MEDLINE | ID: mdl-8666175


AIM: To study post-ischemic dysfunction and persistent ischemia in early post-infarction, by means of Echo-dobutamine-Atropine stress test (ECHO-DOB). Methods. We studied 138 patients (pts) aged < or = 75 yrs (mean 59.2 +/- 9.8) at their first uncomplicated myocardial infarction (AMI), treated with systemic thrombolysis. All pts underwent the test within 2 weeks since the onset of the attack and they were reevaluated in follow-up 3 months later. Under Echo and ECG monitoring, ECHO-DOB was performed according to EDICS protocol. Low doses was infused (5-10 mcg/Kg/min every 3') to assess the viability and high doses (20 > or = 40 mg/Kg/min + Atropine) to assess a possible persistent ischemia. The Wall Motion Score Index (WMSI) was used for the semiquantitative analysis of kinesis in a model of left ventricle divided into 16 segments. coronary angiography was performed within 30 days from the AMI, in 82.3% of pts. Results. Low dose of Dobutamine (DOB) induced in 92/136 (67.6%) pts an improvement in the contractile dysfunction in the region of necrosis; in 31.5% (29/92) it remained until the end of the test, suggesting the presence of viable myocardium, In absence of myocardium "at risk". High doses DOB induced worsening of contractile dysfunction in 64 pts (47%); in 40 (62.5%) viability had been previously detected (viable but ischemic myocardium); In 30 (75%) it was homozone or adjacent (viable but ischemic myocardium in the region of the coronary artery or in the tributary vessels correlated to the necrosis). In 24/64 (37.5%) pts the absence of modification of WMSI (no improvement and no worsening), suggested the presence of necrotic tissue in the tributary region of the vessel of necrosis. The significant improvement in kinesis revealed in 92 pts, by the follow-up control was confirmed in 64 (p < 0.001) (69.5%). Forty-four pts without hyperkinesia showed no significant improvement compared with the base line (stunned or hibernating myocardium). The sensitivity of low doses for viable myocardium (gold standard follow-up) was 69%; specificity was 77%. The sensitivity of high doses for ischemia (gold standard coronary arteriography) was 78%; specificity was 100%. No major side effects during the Dobutamine Atropine test were observed. CONCLUSIONS: The ECHO-DOB test in the post-infarction period allow the assessment of the functional significance of what is the objectified by coronary angiography and identifies pts at risk of more serious events. An integration of the test with the angiographic data can direct towards more suitable therapeutical or surgical choices.

Atropina , Dobutamina , Ecocardiografia , Isquemia Miocárdica/diagnóstico , Adulto , Idoso , Angiografia Coronária , Interpretação Estatística de Dados , Eletrocardiografia , Seguimentos , Humanos , Pessoa de Meia-Idade , Infarto do Miocárdio/complicações , Isquemia Miocárdica/diagnóstico por imagem , Fatores de Risco , Fatores de Tempo
Eur Heart J ; 16(4): 465-70, 1995 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-7671890


INTRODUCTION: We investigated whether apolipoprotein A1 (ApoA1) could better identify patients with severe vessel damage than HDL-cholesterol in a population with recent acute myocardial infarction (AMI). METHODS: One hundred and forty-one male patients (mean age: 54.3 +/- 7.3 years) who had undergone coronary angiography within 3 weeks of an AMI were studied. Coronary angiography data were evaluated both anatomically (as single, double or multivessel disease) and by means of the Gensini score. The main lipid parameters were evaluated on admission to the Coronary Care Unit. RESULTS: ApoA1 and the ApoA1/ApoB ratio (A1/B) mean values were significantly (P < 0.05) different when patients were divided on the basis of HDL-cholesterol cut-off value (35.0 mg.dl-1); when divided on the basis of Gensini score (< or = 18 or > 18), there was a statistically significant difference for ApoA1 (P < 0.01), HDL-cholesterol and A1/B (P < 0.05): only this latter was able to discriminate between the two groups. The mean ApoA1 and A1/B (P < 0.01), Gensini score (P < 0.001) and total cholesterol/HDL-cholesterol (P < 0.05) values of patients in the single-vessel disease group differ from those both of double- and multivessel disease groups. A1/B is also able to discriminate between single- and double-vessel disease. DISCUSSION: Our results confirm that ApoA1 and ApoA1/ApoB ratio are better than HDL-cholesterol in assessing the severity of coronary damage.

Apolipoproteína A-I/sangue , HDL-Colesterol/sangue , Doença das Coronárias/sangue , Adulto , Idoso , Apolipoproteínas B/sangue , Doença da Artéria Coronariana/sangue , Doença da Artéria Coronariana/complicações , Doença das Coronárias/complicações , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/etiologia , Estudos Retrospectivos
G Ital Cardiol ; 24(4): 417-28, 1994 Apr.
Artigo em Italiano | MEDLINE | ID: mdl-8056217


AIM OF THE STUDY: To compare two stress tests: Dipyridamole-echocardiography (ECHO-DIP) and Dobutamine-echocardiography (ECHO-DOB) with angiographic data (still "gold standard") in early postinfarction period in order to identify ischemic and/or viable myocardium (considering the echocardiographic follow-up as "gold standard"). METHODS: 40 consecutive patients (pts), mean age 56, at their first uncomplicated acute myocardial infarction (AMI) treated with thrombolytic agents were studied. All underwent coronary angiography. RESULTS: The ECHO-DIP test resulted positive in 17 pts for transient regional asynergy (homozone 13/17; heterozonal positivity 4/17). The mean basal Wall Motion Score Index (WMSI) was 0.46 +/- 0.30 and at asynergy was 0.58 +/- 0.33 (p < 0.001). The ECHO-DOB test resulted positive in 20 pts; mean basal WMSI was 0.42 +/- 0.31 and at asynergy 0.55 +/- 0.35 (p < 0.001). Both tests were positive in 14 pts; the site of regional asynergy was the same in each test. During ECHO-DOB hypercinesia appeared in 27/39 pts (WMSI form basal 0.42 +/- 0.31 to 0.22 +/- 0.21 p < 0.001). Recovery of contractile function seems to identify viable myocardium: viable tissue shows early functional recovery during ECHO-DOB infusion. In 14 pts it remained until the end of the test, and in 12 it was transient, denoting the presence of myocardium "at risk". Remote (3- or 6-month) clinical and echocardiographic follow-up were carried out in all pts (25 undergoing medical therapy and 15 after PTCA or coronary bypass). In 26 pts with hyperkinesia at ECHO-DOB, basal echocardiogram revealed improvement of WMSI from 0.42 +/- 0.31 to 0.32 +/- 0.29 (p < 0.001). CONCLUSIONS: "Passive" ECHO-stress tests in the early postinfarction period are easy to perform and free of major risks, they allow pts at risk due to residual ischemia to be revealed with a high degree of specificity and sensitivity. The improvement of kinesis during inotropic stimulus of Dobutamine suggests stunned or hibernating myocardium.

Dipiridamol , Dobutamina , Infarto do Miocárdio/diagnóstico por imagem , Adulto , Idoso , Angiografia Coronária , Ecocardiografia , Teste de Esforço , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Contração Miocárdica , Infarto do Miocárdio/tratamento farmacológico , Terapia Trombolítica