The effects of a diet deficient in vitamin a on the development of the skull, optic nerves and brain of cattle

Hypovitaminosis A in extensively grazed beef cattle

“…The clinical signs (ataxia, agitation and seizures) and histological changes detected in the retinal nerves of the cattle in the present study were consistent with changes previously reported in cases of vitamin A deficiency in young growing cattle. [3][4][5][6] The very small concentrations of vitamin A in the liver samples from two of the cattle supported this diagnosis.…”

“…Young, growing cattle are more susceptible to vitamin A deficiency, having a greater requirement and smaller reserves for the vitamin . In one report, confined weaner calves developed neurological clinical signs, including blindness, and brain, eye and bone pathological abnormalities within 100 days of eating a diet of sugar beet pulp, straw and protein cake . Vitamin A requirements are also increased during pregnancy and lactation .…”

“…2 In one report, confined weaner calves developed neurological clinical signs, including blindness, and brain, eye and bone pathological abnormalities within 100 days of eating a diet of sugar beet pulp, straw and protein cake. 3 Vitamin A requirements are also increased during pregnancy and lactation. 2 Congenital blindness and other neurological abnormalities have also been reported; confined dairy heifers fed a grain-based diet without vitamin A supplementation gave birth to calves with severe eye, skull and brain abnormalities.…”

AKDENİz BÖLGESİNDE KÖR DOGAN BUZAGILARIN BULBUS OCULI, NERVUS OPTICUS VE SANTRAL sİNİR SİSTEMİNİN PATOLOJİK ANATOMİsİ

“…Konjenital körlük, beslenme (3,5,9,11,12,17,18) enfeksiyöz (I, 13-16) ve kalıtsal nedenlere bağlı olarak meydana gelebilmektedir (4,7). Tüm bu etkenler görme yollannda oluşturdukları lezyonlara paralelolarak değişen derecelerde körlüğe neden olmaktadır.…”

“…Sı-ğırlarda hipovitaminosis A'nın klinik bulguları hayvanın yaşına bağlıdır (17). Buzağılardaki bulgular total körlük veya gece körlüğüdür (3,8,17,18). Konjenital körlüğün etyolojik faktörleri arasında intrauterin enfeksiyöz ajanların oluş-turduğu enfeksiyonlarda vardır (I, 10, 13-16).…”