RESUMO
Beef production in Chilean Patagonia is based on steer finishing on pastures with low nutritive value. Grain supplementation for finishing calves on pasture arises as an attractive alternative to shorten the finishing phase and improve the production efficiency of the traditional system. The aim of this study was to compare meat quality and fatty acid (FA) composition of beef from steers and calves. Forty Angus cross steers were raised on pasture and slaughtered at 18 to 20 mo of age (448â ±â 31.7 kg body weight). An additional group of 10 calves from similar genetics was weaned at 9 mo of age (303â ±â 8.0 kg) and subsequently supplemented with 2.5 kg corn plus 1.0 kg commercial concentrate daily while on pasture during 47 d, until they reached slaughter weight (316â ±â 13.9 kg). All animals were slaughtered on the same day and the Longissimus thoracis muscle was removed from each carcass for meat quality and FA profile analysis. Hot carcass weight from calves was lighter than steers (174â ±â 7.9 vs. 224â ±â 17.5 kg, Pâ ≤â 0.001). Meat from calves was lighter (higher L*) and less red (lower a*). In addition, meat from calves showed lower level of yellow pigments in subcutaneous fat (lower b*) compared with meat from steers (Pâ ≤â 0.001). Meat from calves was more tender than meat from steers (Pâ ≤â 0.05), although both shear force values were low and within recommendations for high consumer acceptability. Meat from both production systems showed fat content and FA profiles within dietary recommendations for a healthy diet. However, meat from calves was leaner (1.10â ±â 0.29 vs. 2.00â ±â 0.72% fat, Pâ ≤â 0.001). Meat from calves showed lower percentages of saturated (Pâ ≤â 0.05) and monounsaturated (Pâ ≤â 0.001) FAs and higher percentages of polyunsaturated and n-3 (Pâ ≤â 0.001) FAs and conjugated linoleic acid (total and 9c,11t-18:2 isomer, Pâ ≤â 0.001) than meat from steers. Grain supplementation of calves on pasture can reduce the finishing period by 8 to 10 mo at the expense of lighter carcasses with similar or improved meat quality characteristics compared with the traditional finishing of steers on pasture. Implementation of the alternative production system will depend mainly on feed costs and target carcass weights for specific markets.
RESUMO
Twin-bearing pregnancies of sheep reared in harsh environmental conditions result in maternal undernutrition and feto-maternal oxidative stress, leading to intrauterine growth restriction (IUGR). We assessed the efficiency of supplementation with antioxidant herbal vitamins C and E alone or in combination with concentrate throughout gestation on pregnancy outcomes, pre-weaning growth, and survival of twin lambs from grazing ewes at the Magellan Steppe. Four groups (n = 30 each) of twin-bearing ewes received a base natural prairie (P) diet, supplemented with either herbal vitamins C 500 mg and E 350 IU per day (V) or concentrated food (S); groups were: P, P + V, P + S, and P + VS. Vitamins and concentrate were supplemented until parturition. At birth, lambs were weighed, and blood was drawn for total antioxidant capacity (TAC) evaluation. Lamb body weight (BW) and survival rate were evaluated at mid-lactation (60 days) and at weaning (120 days). Vitamin supplementation resulted in increased lamb birth weight and TAC, with a trend towards higher BW at weaning, while nutritional supplementation only had a positive effect on birth weight. Lamb survival was higher in both vitamin supplemented groups. In conclusion, supplementation with herbal vitamins C and E alone or in combination with concentrate food during pregnancy may constitute a good nutritional strategy for sheep reared in harsh environmental conditions.
RESUMO
Western Patagonia lamb production systems are based on extensive rangeland. The harsh climate limits the adoption of more intensive systems. Therefore, producers must focus on developing differentiated products. The aim of this study was to evaluate growth patterns, carcasses and nutritive value of meat from 45 lambs. Lambs were divided into three groups: 15 lambs were slaughtered at weaning (W), with the remaining 30 weaned lambs being allocated to grazing either alfalfa (AG) or permanent pasture (PPG). AG lambs were significantly heavier and had higher condition scores than PPG lambs. Further, AG lambs showed higher carcass weight and larger tissue depth and commercial cuts. Moreover, W lambs had lower shear force and more tender meat than either AG or PPG lambs. The three systems showed a low shear force and acceptable sensory traits. Low levels of cholesterol, with low levels of saturated fat, classified these cuts of meat as extra lean. W lambs had higher omega-3 fatty acid content than AG or PPG lambs. Overall, results showed that meat from the three lamb production systems showed health claimable levels of omega-3 fatty acids and were low in fat and thereby, can be classified as lean meat.
RESUMO
Twinning and maternal nutritional restriction leads to fetal hypoxia, oxidative stress, and intrauterine growth restriction (IUGR) in near-term sheep pregnancies. Our aim was to determine the effect of oral supplementation of vitamins C and E in pregnant sheep on maternal and umbilical cord blood concentrations of vitamins C and E and the effects on fetal antioxidant status, growth, and placental efficiency. Sixteen single- and sixteen twin-bearing ewes, grazing natural Patagonian prairies, were selected after transrectal ultrasound at day 30 after mating. Half of ewes from each pregnancy rank were supplemented daily with vitamins C and E, administered orally, from 30 to 140 days of gestation, when maternal jugular and fetal venous cord blood samples were obtained during cesarean section. Fetuses were weighed and sexed. Placental weight in each fetus was also obtained. Blood plasma was harvested for measurements of maternal and fetal vitamins concentration and fetal antioxidant capacity. Maternal administration of vitamin C and E was associated with increased fetal cord levels of both vitamins, improved antioxidant status, and enhanced fetal growth in both singleton and twin pregnancies associated with increased placental efficiency. These results highlight the potential of vitamin C and E supplementation to reduce the impact of IUGR in both livestock and humans.
RESUMO
Actualmente, los padecimientos cardiovasculares tienen una gran prevalencia a nivel mundial, por lo cual es importante desarrollar tratamientos no farmacológicos para mejorar el pronóstico de las personas que los padecen. El objetivo fue evaluar el efecto de una intervención de manejo de estrés sobre el control de la hipertensión arterial en mujeres. Se utilizó un diseño cuasi-experimental, transversal, (pre-post intervención). Las participantes fueron 14 mujeres con edades entre 35 y 55 años, diagnosticadas con hipertensión arterial tipo 1, adscritas a un hospital de tercer nivel. Los instrumentos empleados fueron: la Lista de Eventos Recientes Potencialmente Estresantes, la Escala de distrés y una prueba computarizada (Stroop-cardiovascular). La intervención consistió en cuatro sesiones de diferentes tipos de relajación y terapia racional emotiva (reestructuración cognitiva). Los resultados, no arrojaron diferencias significativas al comparar la presión arterial del grupo, del pre al postest; no obstante, tres pacientes lograron reducirla al final del entrenamiento. Además, se registraron cambios favorables en eventos positivos, eventos negativos y distrés. El estudio concluyó que el manejo de estrés es una alternativa no farmacológica coadyuvante en el control de la hipertensión arterial, recomendable en poblaciones más grandes.
Currently, cardiovascular diseases have a high prevalence worldwise, so it is necessary to develop non pharmacological treatments to improve the prognosis of people who suffer from this disorder. The aim of this research was to identify the effect of an intervention program on stress management to control arterial hypertension in women. The design used was quasi-experimental cross-sectional (pre-post intervention). Participants were 14 women between 35 and 55 years old, diagnosed with hypertension type 1 and attached to a third level hospital. A special list of recent potentially stressful events, a distress scale, and a computerized discrimination test (Stroop-cardiovascular) were the instruments utilized. The intervention consisted of 4 sessions of different types of relaxation and rational emotive therapy (cognitive restructuring). Results did not indicate significant differences in the group between pre and post-test blood pressure measurements. Nevertheless, three patients reduced their blood pressure by the end of treatment. Additionally, favorable changes in positive events, negative events and distress were registered. The study concluded that stress management is a non- pharmacological alternative contributory to the control of arterial hypertension and recommended for larger populations.
Na atualidade as doenças cardiovasculares têm muita prevalencia no mondo. Portanto é importante desenvolver tratamentos não farmacológicos para melhorar o prognóstico dos pacientes. O objetivo foi avaliar o efeito de uma intervenção de manejo do estresse no controle da hipertensão arterial em mulheres. Foi aplicado um desenho transversal quase experimental (pré-pós intervenção). Participaram 14 mulheres com idades entre 35 e 55 anos, diagnosticadas com hipertensão arterial tipo 1, inscritas a um hospital do terceiro nível. Empregaram-se os seguintes instrumentos: Lista de Eventos Recentes Potencialmente Estressantes, Escala de distrés e uma prova computadorizada (Stroop-cardiovascular). A intervenção consistiu em quatro sessões de diversas classes de relaxação e terapia racional emotiva (re-estruturação cognitiva). Os resultados não mostraram diferencias significativas ao comparar a pressão arterial do grupo, do pré ao pós-test. No entanto, três pacientes a reduziram ao final do treinamento. Além disso, foram registradas mudanças favoráveis em eventos positivos, eventos negativos e distrés. O estudo conclui que o manejo do estresse é uma alternativa não farmacológica coadjuvante no controle da hipertensão arterial, recomendável em populações maiores.
Assuntos
Humanos , Feminino , Esgotamento Profissional , Teste de Stroop , HipertensãoRESUMO
El precondicionamiento isquémico del miocardio es un mecanismo protector endógeno en la célula cardiaca que disminuye las manifestaciones de isquemia secundarias a una oclusión coronaria cuando previamente a la oclusión se realiza uno o varios períodos cortos del isquemia (isquemia precondicionante). El proceso es gatillado por la liberación de diversas substancias durante los períodos cortos de isquemia, pero especialmente adenosina, y es traducido por la activación de diversas proteínas kinasas que parecen actuar sobre un efector final común que probablemente es el cK+ATP de la mitocondria. El proceso puede ser remedado farmacológicamente con diversas substancias que se producen durante el gatillamiento como por ejemplo la administración de adenosina o por fármacos que abren los cK+ATP mitocondriales como nicorandil. El precondicionamiento isquémico ofrece una fase protectora precoz (pocos minutos después de la isquemia precondicionante) y otra tardía (varias horas después). Esta última requiere de la transcripción de varias moléculas que ejercen la acción protectora lo cual explica la demora en su aparición. Existen varias evidencias de la existencia del precondicionamiento precoz y tardío en el hombre y dado que el precondicionamiento tardío produce una protección más prolongada, 3-4 días, es probable que la inducción farmacológica de este tipo de precondicionamiento pueda mejorar el pronóstico de pacientes con alto riesgo de obstrucción coronaria como ocurre en el síndrome coronario agudo sin elevación de ST. El precondicionamiento puede también ser inducido por un aumento del metabolismo cardíaco en lugar de una isquemia precondicionante, como por ejemplo taquicardia, y por el ejercicio físico lo cual implicaría la existencia de una protección miocárdica a la isquemia de carácter más o menos permanente según la magnitud de la actividad física del individuo
Assuntos
Humanos , Doença das Coronárias , Isquemia Miocárdica/etiologia , Precondicionamento Isquêmico Miocárdico , Adenosina , Isquemia Miocárdica/prevenção & controle , Mitocôndrias Cardíacas , Canais de PotássioRESUMO
Metalloproteinases (MTP) are enzymes that degrade the extracellular matrix, mainly collagen tissue. Normally these enzymes are expressed in vascular walls as proenzyme together with inhibitors of the active enzymes. By effect of different citokines, produced by an inflammatory process in the vascular wall, these proenzymes are activated to an extent that surprasses the action of the inhibitors and degrade collagen. This action may partly explain the rupture of atherosclerosis plaques (vulnerability) and also the remodelling of the vessel wall with compensatory enlargement of the vessel (increase in the outer size of the vessel) that allows the plaques to develop inside the arterial wall without protruding into the vessel lumen for many years. The occlusion of safenous vein in aortocoronary bypass grafts is due to fibromuscular proliferation and atheroma development and therefore the participation of MTP in the occlusion of these vessels is a reasonable hypothesis. However, the structural features of safenous vein bypass grafts are different from those of atheroma in native coronary arteries. Mainly the compensatory enlargement of the vessels does not occur because of intense fibrous tissue development including the adventitia and therefore the new tissue in the wall is forced to protrude into the vessel lumen. The reason for this difference in the vessel wall remodeling is not clear and the article by Grez et al in this issue of this journal is an starting and promising study in the regard