Vitamin A reserves of sheep maintained on mulga (Acacia aneura)

Abstract

The hepatic reserves of vitamin A were determined in different classes of Merino sheep maintained on the leaves of mulga (Acacia aneura F. Muell) for periods varying from 33 to 16 months. Concurrent data were obtained on the p-carotene content of mulga leaves growing in different habitats and at different periods after cutting. The mean liver vitamin A concentration in 27 sheep was 610 ± 376 µg per g with a range of 63 to 1,710 µg per g. The mean â-carotene content of 13 samples of fresh mulga leaves was 21.5 ± 8.7 mg per lb D.M. with a range of 37.7 to 4.6 mg per lb. Drying caused a variable loss in â-carotene unrelated to the time of exposure. A maintenance drought ration of mulga leaves is adequate to meet the requirements of vitamin A in sheep.