Effect of cassava bioethanol by-product and crude palm oil in Brahman x Thai native yearling heifer cattle diets: I. Nutrient digestibility and growth performance.

The effects of cassava bioethanol by-product (CEP) and crude palm oil (CPO) on feed intake, nutrient digestibility, and growth performance of yearling heifers were investigated in a 150-day feeding trial. Eighteen, crossbred heifers (Brahman x Thai native) were randomly allotted according to 2 × 3 factorial arrangement. Low or high levels of CEP (15 or 30% of concentrate, LCEP, or HCEP) were basal treatments and 0, 2, and 4% CPO were daily top-dressed. Concentrate was supplemented at 1.75% of body weight (BW) and rice straw offered ad libitum. CEP level had no significance on feed intake. CPO increased roughage intake, concentrate intake, and total feed intake when expressed as %BW/d (P < 0.01) and as metabolic BW (kg(0.75)/d, P < 0.05). Intakes of dry matter (DM), organic matter (OM), and crude protein (CP) were similar (P > 0.05). Intake of fat increased with higher levels of CPO (P < 0.001). The DM, OM, CP, and EE digestibility of cattle-fed HCEP was lower than LCEP, but adding 4% CPO increased digestibility. Growth performance was similar for all diets (P > 0.05). We concluded that CEP can be used up to 30% in the diet, with or without additional fat inclusion.