ABSTRACT
Twenty pregnant ewes were selected and classified into two groups. The first group received subcutaneous selenium supplementation (0.1 mg of sodium selenite/kg BW) at the 8th and 5th weeks before birth and 1st week after birth while the other was control group without selenium injection. Maternal plasma and serum samples were collected weekly from the 8th week before birth until the 8th week after birth and milk samples were taken from ewes weekly, while plasma and serum samples were collected at 48 hours, 1st, 2nd, 3rd, 5th, and 8th weeks after birth from the newborn lambs. Results demonstrated significant positive relationship between maternal plasma selenium and serum T3 in supplemented and control ewes (r = 0.69 to 0.72, P < 0.05). There was significant (P < 0.001) increase in T3 in supplemented ewes and their lambs until the 8th week after birth. There was positive relationship between milk, selenium concentration, and serum T3 in the newborn lambs of the supplemented group (r = 0.84, P < 0.01), while the relationship was negative in the control one (r = -0.89, P < 0.01). Muscular and thyroid pathological changes were independent of selenium supplementation. Selenium supplementation was important for maintaining T3 in ewes and newborn lambs until the 8th week after birth.
ABSTRACT
Pregnancy toxemia was induced in nine pregnant goat does with twins by the stress of fasting with access to water in late pregnancy to investigate the effect of pregnancy toxemia on immunoglobulins (IgA, IgM, and IgG), cortisol, insulin, thyroid, and growth hormones and their correlations with the plasma levels of glucose and beta-Hydroxybutyrate. Plasma samples were collected at 0, 12, 24, 36, 48, and 72 hours after induction of pregnancy toxemia. The result revealed that experimental animals developed neurological findings with convulsions and acetone odor from the mouth with recumbency after 72 hours. Laboratory findings showed a significant increase in beta-Hydroxybutyrate, cortisol, and insulin while there were significant decreases in glucose, thyroid, and immunoglobulins (IgA, IgM, and IgG). Plasma glucose concentrations had significant negative correlations with beta-hydroxybutyrate, cortisol, and insulin while the correlations were significantly positive with immunoglobulins and thyroid hormone. Plasma beta-hydroxybutyrate concentration was significantly positively correlated with cortisol and negatively correlated with immunoglobulins, insulin, and thyroid hormone. From this study we can conclude that pregnancy toxemia might affect humoral immune responses as well as insulin, cortisol, and thyroid hormones. Moreover, insulin might have a compensatory role to increase suppressive effect on ketogenesis in experimentally pregnant toxemic goats.
ABSTRACT
El selenio (Se) es un mineral esencial en la nutrición animal y se considera su participación en diversos procesos asociados a la producción animal, tan diversos como la fertilidad de la especie y la prevención de enfermedades. Laglutatión-peroxidasa (GSH-Px), fue la primera enzima en que se demostró la presencia activa del selenio y su importancia al evitar el daño oxidativo de las membranas celulares. Con anterioridad se había demostrado que la conocida como Enfermedad del músculo blanco era consecuencia de la deficiencia de Se, determinando muerte en animales recién nacidos y ocasionalmente en animales en desarrollo y aún en adultos, en particular en rumiantes. Actualmente ha quedado claro que el Se también es crítico en la estructuración de las enzimas necesarias para la síntesis de la hormona tiroidea y para su activaciónen los tejidos periféricos, pasando de T4 a T3. La deficiencia de Se afecta seriamente la capacidad de respuesta inmune de los animales. El diagnóstico de la deficiencia debe fundamentarse en los niveles del elemento en los suelos, las plantas forrajeras y la condición del animal en sangre y tejidos. Se han instrumentado diversas formas de suplementación del elemento que pueden emplearse dependiendo de las condiciones productivas de los animales y sus niveles previos de Se. La intoxicación por Se (Selenosis) debe tenerse en cuenta en los programas de suplementación, y puede ocurrir en formas crónicas o agudas. Las formas crónicas ocurren en regiones con suelos ricos en el elemento y condiciones que favorecen su absorción por las plantas forrajeras. Las formas agudas generalmente ocurren por excesos del elemento en las dietas o las sales que se administran a los animales o por errores de dosificación en las formulaciones parenterales. La relación metabólica del Se entre la hembra gestante, el feto y el recién nacido, es un área que requiere mayor investigación.
O selênio (Se) é um mineral essencial na nutrição animal e se considera sua participação em diversos processos associados à produção animal, tão diversos como na fertilidade das espécies e prevenção de enfermidades. A glutation peroxidase (GSH-Px), foi a primeira enzima em que se demonstrou a presença ativa do selênio e sua importância para evitar o dano oxidativo nas membranas celulares. Anteriormente sabia-se que a enfermidade do músculo branco era conseqüência da deficiência de Se, determinando a morte em animais recém-nascidos e ocasionalmente em animais em desenvolvimento, animais adultos e em particular em ruminantes. Atualmente, está claro que o Se é crítico na estruturação das enzimas necessáriaspara a síntese de hormônios da tireóide e para sua ativação nos tecidos periféricos, passando de T3 a T4. A deficiência de Se afeta seriamente a capacidade da resposta imune dos animais. O diagnóstico da deficiência deve fundamentar-se nos níveis deste elemento no solo, nas plantas forrageiras e nas condições do animal. Indicam-se diversas formas de suplementação deste elemento, que podem ser empregadas dependendo das condições produtivas dos animais e seus níveis prévios de Se. As intoxicações por Se (selenose), devem ser consideradas nos programas de suplementação, que pode ocorrer de forma crônica ou aguda. As formas crônicas ocorrem em regiões com solos ricos no elemento e nas condições que favorecem a absorção pelas plantas forrageiras. As formas agudas geralmente ocorrem por excesso do elemento nas dietas, ou sais administrados aos animais ou por erros na dosagem das formulações parenterais. A relação metabólica do Se na fêmea gestante, o feto e orecém-nascido, é uma área que requer uma maior investigação.
Selenium (Se) is an essential trace element for animal nutrition and plays multiple actions related to animal production, fertility and prevention of diseases. Glutathione peroxidase enzyme (GSH-Px) was the first seleno enzyme to demonstrate the active presence of selenium and its importance to prevent cellular membrane oxidative damage. Formerly, White muscle disease (WMD) was recognized as resulting from Se deficiency, determining new born mortality and adult animals, especially in ruminants. Nowadays, it is clear that Se is critical for thyroid hormone synthesis and its activation in peripheral tissues from T3 to T4. Lack of Se seriously affects the capacity of immune response by the animals. Se status in the soil, plants, animal blood and tissues can be used as a tool to diagnose Se deficiency. Several forms of Se supplementation are described which can be applied depending of the productive capacity of the animals and their previous levels of Se. Acute and chronic Se intoxication (Selenosis) should be considered in supplementation programs as it may occur in a chronic or acute way. Chronic forms are associated to regional seleniferous soils, with permanent or repeated consumption of seleniferous plants. Acute forms are associated with high ingestion of Se as a result of wrongly designed diets, salt provided to the animals or parenteral injection dosage mistakes. The metabolic relation among Se, the fetus, the newborn and the pregnant dam requires further investigations.
