Читать книгу Selenium Contamination in Water - Группа авторов - Страница 58

Toxicity in any animal depends on the different parameters or factors, such as forage organisms, animal feeding, and dietary components etc. Alkali disease or chronic cow toxicity occurs when 5–40 mg Se/kg BW diets are fed for several months. There is acute toxicity when eating feed, which contains 10–20 mg Se/kg BW (National Research Council [NRC] 1983). One research found that the feed conversion efficiency in young calves was affected by 10 mg Se/kg DM. The winter season is the most vulnerable to Se toxicity in dairy cattle, though handling Se‐enriched stall feed (Jenkins and Hidiroglou 1986; Ropstad et al. 1988). Se toxicity in animals has caused many symptoms, such as hair loss, coat roughness, dullness and lack of strength, emaciation, joint bone deterioration, higher respiration levels, weakness and lameness, hooves detachments, etc. (Ghosh et al. 1993; Rosenfeld and Beath 2013).