The pathology of vitamin E deficiency in the chick

Histopathology of monensin-tiamulin myopathy in broiler chicks

Thirty-six 7-day-old broiler chicks were simultaneously given food containing monensin, and water containing tiamulin, both drugs being at normal levels of usage. Equal numbers of chicks on a basal diet and plain water served as the controls. Anorexia, depression, drowsiness, leg weakness and a decrease in body weight appeared on days 2 to 3 of administration in several treated chicks. These clinical signs and growth retardation were prevalent and severe on days 4 to 7, at which time some chicks became recumbent. From day 9, chicks showed gradual recovery from the clinical signs and growth retardation. Histopathologically, the neck and leg skeletal muscles examined were severely affected in treated chicks, but cardiac and pectoral muscles were intact. Besides hyalinisation and floccular change which appeared infrequently in early stage of the experiment, muscle fibres showing an enlargement of the nuclei and a distention of a pale to basophilic sarcoplasm, suggestive of partial myofibrillar lysis and subsequent reparative change, dominated all affected muscles. These degenerative and reparative changes were considered to be distinctive for monensin-tiamulin myopathy in chicks.

Etiologic factors and pathologic alterations in selenium-vitamin E deficiency and excess in animals and humans

The etiology of selenium-vitamin E (Se-E) deficiency diseases may be complex. Many of the syndromes involve combined deficiency of selenium and vitamin E. Selenium moves into the animal and human food chain from soil and plants, which may contain inadequate amounts of the nutrient in many areas of the world. Vitamin E may be in low concentration in many animal feeds unless supplements are added. Some syndromes, such as steatitis in cats, result from an increased requirement of vitamin E in diets that contain large amounts of polyunsaturated fatty acids, and these diseases will only respond to vitamin E administration. Deficiency syndromes in animals owing to pure Se deficiency are infrequent and have been produced mainly by laboratory studies utilizing extreme deficiency conditions. Other factors that may affect the occurrence of these deficiency diseases are concurrent dietary deficiency of S-containing amino acids, bioavailability of different forms of dietary Se, intake of compounds that antagonize Se (e.g., silver salts), and exposure to various prooxidant substances (e.g., iron compounds, oxygen, ozone, and various drugs).

Avian encephalomalacia in Barbados, West Indies: a description of spontaneous field cases with feed analyses

The clinical, necropsy and histopathological findings in four natural outbreaks of encephalomalacia are reported. Feed analyses implicated low levels of vitamin E as the probable cause of the condition. Treatment with vitamin E has proved to be very effective. The instability of vitamin E in animal feed ingredients during long periods of shipment into the Caribbean may be important in the pathogenesis of the disease.

Selenium-responsive myopathy in broiler breeder hens in Queensland

A syndrome characterised by bilateral paralysis and associated with degenerative changes in skeletal musculature, has been noted in adult breeder hens, and their progeny broilers, in a commercial poultry organisation in Queensland. Paralysis occurred between the ages of 24 to 63 weeks in broiler breeder hens and at approximately 6 weeks in the broiler chickens. Onset is slow, taking up to 2-3 days from the time leg weakness if first noticed until paralysis was complete. Other than the paralysis the birds appeared normal. Histopathological and experimental observations indicate that the muscular dystrophy is caused by a selenium deficiency. Supplementation of the diet with selenium at a level of 0.1 ppm completely alleviated the symptoms such that the birds may be returned to the mating pens.

Phospholipids in artificially induced muscular dystrophy of calves

1. Phospholipds were studied in the heart muscles, skeletal muscles and livers of seven Ayrshire calves which received vitamin E-free maize oil (in filled milk) with and without supplementary α-tocopherol from 1 week old for 17 d. The calves that were not given vitamin E developed muscular dystrophy.

2. Decreased amounts of cardiolipin and increased amounts of sphingomyelin were found in the skeletal muscles of vitamin E-deficient calves. There was a significant decrease of phosphatidyl choline in the livers of vitamin E-deficient calves.

3. The decrease in cardiolipin concentration confirmed the electron-microscopical picture (reported elsewhere) of preferential destruction of mitochondria in muscular dystrophy of calves.