Abstract

The study was undertaken to explore the nutritive potential of cassava leaves and Azolla as supplementary source of crude protein to cattle fed on either mixed range grass hay or Bracharia Mulato II. Two experiments were carried out, the first was the determination of the biomass yield of Azolla, its relative growth rate and doubling time while the second was a feeding trial to determine the performance of small East African Shorthorned Zebu heifers of similar age and weight. The heifers (four each) were randomly assigned to six treatments in the feeding trial that ran for 16 weeks. The doubling time for Azolla was 5 days while the relative growth rate was 0.15 g/g/day. The chemical analysis indicated that Azolla is rich in crude protein (18.8%) and minerals (3.29% calcium, 2.66% potassium and 0.15% phosphorus and other minerals in trace levels). All the supplemented groups showed more weekly weight gains ranging from 0.75 to 1.11 kg per day more than the control. Overall, the treatment with Azolla or cassava showed slightly higher but insignificant increases in weight gains. Azolla and cassava leaves can therefore be considered as potential feed for livestock.

Key words: Arid and range lands, cattle, doubling time, relative growth rate.