Osteopathology and selenium deficiency co-occurring in a population of endangered Patagonian huemul (Hippocamelus bisulcus)

Background: About 1,000 endangered Patagonian huemul deer (Hippocamelus bisulcus) remain in Chile and 350-500 in Argentina. Most groups (>100) are not recovering, and prevalence of osteopathology in Argentina was at least 57%. Here I describe relevant cases of osteopathology from a Chilean population which, however, recently also provided data on trace mineral status, supporting the initial hypothesis that nutrition may be a primary etiologic factor. Additionally, recent data on bone chemical composition of Argentine cases and soil analyses are discussed. Results: Fluoride levels in Argentine cases with osteopathology were low and fluorosis was discarded as an etiological factor. Selenium deficiency occurred in 73% of huemul from the Chilean population which exhibited several cases with osteopathology. The pathophysiognomy included extensive erosion; tooth loss;  porosification; perforations of palate, maxillar and mandibular bone with frequent exposure of tooth roots; and fractured mandibula. Areas currently used by remaining huemul have mainly acidic volcanic soils, which reduces selenium bioavailability: mean soil selenium levels from areas typically used by extant huemul were very deficient (0.19 ppm), corroborating documented overt selenium deficiency in local livestock and plants. The area of extant huemul is known to result in primary iodine deficiency in livestock which is aggravated by selenium deficiency. Conclusions: Currently the most parsimonious explanation for frequent osteopathology and lack of numerical recovery are the combined effects of selenium and iodine deficiencies based on: osteopathology in a population of selenium deficient huemul; selenium deficient livestock, plants and soils; acidic soils; and regional primary iodine deficiency. The nexus between mineral nutrition and population dynamics of huemul may be due to constraints on their movements to fertile lowlands, including the elimination of historic migratory traditions, and concomitant elimination of source populations

Plasma retinol concentration in grazing heifers: First data obtained from a dairy herd in the south of Chile

COMMUNICATION Plasma retinol concentration in grazing heifers RESUMEN En Chile no existen antecedentes sobre la concentración de retinol en plasma sanguíneo de bovinos a pastoreo, por ello el objetivo de este estudio fue medir las concentraciones plasmáticas de retinol en vaquillas a pastoreo en invierno y primavera y comparar ambos períodos. Para el estudio se utilizaron 15 vaquillas Frisón negro, clínicamente sanas, entre 16 y 18 meses de edad, mantenidas a pastoreo sobre praderas naturales mejoradas. Mensualmente de cada animal se obtuvo muestras de sangre, desde julio hasta diciembre. Las concentraciones plasmáticas de retinol se midieron utilizando cromatografía líquida de alto rendimiento en fase reversa. Los valores promedios de las concentraciones plasmáticas de retinol fueron de 0,46 ± 0,09 μg/ml (rango de 0,18 a 0,69 μg/ml). En invierno se observan los valores más bajos 0,42 ± 0,09 μg/ml (rango 0,18 a 0,57 μg/ml) y en primavera los más altos 0,50 ± 0,09 μg/ml (rango 0,29 a 0,69 μg/ml). Los valores promedio de concentraciones plasmáticas de retinol, obtenidos en este estudio, son los primeros datos presentes en Chile en bovinos mantenidos a pastoreo. Palabras clave: vaquillas, retinol, invierno, primavera