Cassava is increasingly available in the United Kingdom for use in compound feeds. The trial reported here was a 2 × 4 factorial and compared dairy cow compound feeds containing nil or 400 g of cassava per kg, and crude protein levels of 100, 120, 140 and 160 g/kg, given in conjunction with grass silage.
Forty-eight Friesian cows were used in a change-over design with four periods each of 4 weeks. The trial, therefore, compared six blocks of four cows on each of the non-cassava and cassava treatments, with each cow in a block receiving a different protein level. Compound feeds without cassava had a mean barley content of 600g/kg whereas feeds with cassava had a mean barley content of 103g/kg.
There were no significant differences in milk yield (21 14 and 22·27 kg/day) or milk fat level (41·4 and 40·4g/kg milk) on the non-cassava and cassava treatments respectively (P ≤ 0·05). Differences in solids-not-fat concentration were also not significant.
Average intakes of silage were similar on each type of diet. Daily intakes of the compound feed per cow varied from 6·95kg on the non-cassava treatment to 7·08kg on the cassava treatment. This difference in compound intake was not significant. The results indicated that compound feed containing 400 g of cassava per kg perform as well as cereal-based feeds and, therefore, cassava can be considered as a satisfactory replacement for cereals up to a level of 400 g/kg in compound feeds for dairy cows.