Plasma concentrations of vitamin E in six species of bustard (Gruiformes: Otididae)

Abstract

Vitamin E (measured as α-tocopherol) and cholesterol concentrations were determined in plasma samples collected from 86 clinically healthy captive adult bustards of six species and 23 captive juveniles (6-12 mo old) of two of these species. Adult houbara bustards (Chlamydotis undulata macqueenii) had higher plasma α-tocopherol concentrations than juveniles (adult: mean ± SE, 11.07 ± 0.41 μg/ml, n = 32; juvenile: 6.33 ± 0.48, n = 12) and higher α-tocopherol: cholesterol ratios (adult: 6.09 ± 0.44. n = 12; juvenile: 2.94 ± 0.22, n = 11). No age difference was evident for kori bustard (Ardeotis kori) plasma α-tocopherol concentrations (adult: 4.43 ± 0.42, n = 21; juvenile: 4.46 ± 0.26, n = 11) or α-tocopherol: cholesterol ratios (adult: 3.67 ± 0.44, n = 20; juvenile: 3.71 ± 0.36, n = 11). Adult houbara bustards had significantly higher (P < 0.01) α-tocopherol concentrations compared with adult rufous-crested (Eupodotis ruficrista; 6.64 ± 0.33, n = 19) and white-bellied (Eupodotis senegalensis; 7.75 ± 0.81, n = 8) bustards, but similar α-tocopherol: cholesterol ratios (rufous-crested: 5.56 ± 0.32, n = 18; white-bellied: 5.83 ± 0.43, n = 8). Juvenile houbara bustards had higher plasma α-tocopherol concentrations than juvenile kori bustards but similar α-tocopherol: cholesterol ratios. Adult houbara bustard plasma α-tocopherol levels and α-tocopherol: cholesterol ratios did not differ significantly between sexes. The vitamin E status of adult bustards appeared to be influenced by environmental conditions that varied due to species-specific husbandry regimes, but no clear relationship was seen with dietary vitamin E levels. Juvenile bustards did not have higher vitamin E levels than adults, despite being maintained on four-fold dietary vitamin E concentrations and in similar environmental conditions. This paper presents the first published data for plasma vitamin E concentrations in bustards. The plasma α-tocopherol and cholesterol concentrations and α-tocopherol: cholesterol ratios of captive bustards were similar to those previously reported for omnivorous avian species. Further research is required to determine which components of the identified environmental conditions affect bustard vitamin E status and to confirm whether differences exist between species independent of the variation in their management regimes.