Amount of cassava powder fed as a supplement affects feed intake and live weight gain in laisind cattle in Vietnam

An experiment was conducted in Vietnam to test the hypothesis that supplementation with cassava powder up to 2% of live weight (LW)/d (DM basis) would linearly increase digestible organic matter intake and LW gain of Laisind cattle. There were five treatments: a basal diet of elephant grass fed at 1.25% of LW and rice straw fed ad libitum or this diet supplemented with cassava powder, containing 2% urea, at about 0.3, 0.7, 1.3 or 2.0% LW. The cattle fed cassava powder at about 2.0% LW did not consume all of the supplement, with actual intake similar to the 1.3% LW treatment. Organic matter, digestible organic matter and digestible energy intakes increased (p < 0.001) curvilinearly with increased consumption of cassava powder. Rice straw intake declined curvilinearly with increasing intake of cassava powder (p < 0.001), and there was a small linear decline (p = 0.01) in grass intake. The substitution rate of cassava powder for forage was between 0.5 and 0.7 kg DM reduction in forage intake per kg DM supplement consumed, with no difference between treatments. Apparent digestibility of organic matter increased (p < 0.001) in a curvilinear manner, while digestibility of neutral detergent fibre declined (p < 0.001) in a curvilinear manner with increased consumption of cassava powder. Live weight gain increased (p < 0.01) linearly with increased consumption of supplement. It was concluded that the amount of cassava powder fed should be limited to between 0.7 and 1.0% LW.