Showing papers on "White Muscle Disease published in 1972"

Selenium Deficiency in Soils and Its Effect on Animal Health

Abstract: Selenium in minute quantities has been shown to be a dietary essential for animal life, and soil-plant-animal relations have been identified in the distribution of the element. In some cases, soils are frankly deficient in selenium—most particularly those derived from igneous rocks, and the deficiency in surface layers may be aggravated by intensive irrigation. Alternatively, soil selenium may exist in a form that is either unavailable to plants or absorbed by them with difficulty. Representative of such a form is the highly insoluble ferric oxide-selenite complex which frequently occurs in high-moisture, acid soils. Uptake of selenium by plants may also be inhibited by presence of interfering substances in the soil, such as sulphur, or it may be enhanced by liming. Analytical surveys have revealed also that considerable variation exists among plant species in their abilities to take up and retain selenium from the soil. Legumes have been consistently implicated as forages conducive to white muscle disease, a selenium-responsive myopathy, and New Zealand observations have shown white clover (Trifolium repens L.) to contain significantly lower levels of selenium than grasses, and particularly a native grass, browntop (Agrostis tenuis Sibth.). In addition to the differences in absolute selenium uptake, it has been suggested that some plants, and again legumes are suspect, may contain organic inhibitors of selenium utilization by livestock. Some experiments have investigated the effectiveness of additions of selenium to the soil in overcoming selenium deficiency among farm animals. Protection for 2 yrs has been achieved by this technique; however, the various factors influencing the soil-plant-animal relations of selenium direct caution in its application.

The moderating effect of regular exercise on the development of nutritional muscular dystrophy in lambs

Abstract: Merino lambs have been weaned on to two types of dystrophogenic diet, one a synthetic-type dirt with selenium-low Torula yeast supplying most of the protein, and the other a natural diet consisting solely of selenium-low hay. Lambs not supplemented with selenium developed white muscle disease within two to three months on either regimen, some of the lambs dying within that period. Selenium, given at the rate of 2 X 3 mg per week as Na2 SeO3 as an oral drench prevented the onset of muscular dystrophy. When unsupplemented animals were subjected to daily exercise consisting of one-sixth to one-third of a mile canter in a treadmill each day from weaning, muscular dystrophy was either modified or delayed. In some cases it was entirely prevented over the experimental period. As judged by creatine phosphokinase levels in blood plasma, ECG records taken throughout the experiments, and histological examination of muscle post mortem, eight out of ten lambs in the non-exercised group developed white muscle lesions, compared with two out of ten in the exercised group.

Selenium Deficiency in Soils and Its Effect on Animal Health

Abstract: Selenium in minute quantities has been shown to be a dietary essential for animal life, and soil-plant-animal relations have been identified in the distribution of the element. In some cases, soils are frankly deficient in selenium—most particularly those derived from igneous rocks, and the deficiency in surface layers may be aggravated by intensive irrigation. Alternatively, soil selenium may exist in a form that is either unavailable to plants or absorbed by them with difficulty. Representative of such a form is the highly insoluble ferric oxide-selenite complex which frequently occurs in high-moisture, acid soils. Uptake of selenium by plants may also be inhibited by presence of interfering substances in the soil, such as sulphur, or it may be enhanced by liming. Analytical surveys have revealed also that considerable variation exists among plant species in their abilities to take up and retain selenium from the soil. Legumes have been consistently implicated as forages conducive to white muscle disease, a selenium-responsive myopathy, and New Zealand observations have shown white clover (Trifolium repens L.) to contain significantly lower levels of selenium than grasses, and particularly a native grass, browntop (Agrostis tenuis Sibth.). In addition to the differences in absolute selenium uptake, it has been suggested that some plants, and again legumes are suspect, may contain organic inhibitors of selenium utilization by livestock. Some experiments have investigated the effectiveness of additions of selenium to the soil in overcoming selenium deficiency among farm animals. Protection for 2 yrs has been achieved by this technique; however, the various factors influencing the soil-plant-animal relations of selenium direct caution in its application.