Cassava (Manihot esculenta, Crantz) is an important root crop in tropical climates for both human consumption and animal feed as a source of energy (ME, R 12.2 MJ/kg). Cassava produces high yields of dry matter and therefore, this study was conducted to evaluate the effects of including cassava as a source of energy replacing to corn on intake, rumen fermentation and animal performance in lactating dairy cows fed a diet based on rice straw.

Thirty-six crossbred cows (˃75% Holstein Friesian) in mid-lactation were randomised to 4 dietary treatments. They were individually tethered and offered ad libitum rice straw together with concentrate twice a day after milking. The diets were iso-nitrogenous (155 g/kg CP). The dietary treatments were concentrate containing 13.5, 27, 40.5 and 54% of cassava replacing corn meal. Milk yield and feed intake were measured daily. Composited milk samples were collected and the components analysed.