Increasing the level of cassava chips or cassava pulp in leucaena based diets increases feed intake and live weight gain of Bali bulls

Abstract

The live weight gain response of Bali bulls (<i>Bos javanicus</i>) fed increasing levels of cassava chip or cassava pulp mixed with a leucaena based diet was measured. Forty Bali bulls with initial live weight (LW) of 112±7.1 kg and around 18 months of age were assigned into 10 treatment groups. Each treatment group was offered ad <i>libitum</i> leucaena mixed with either cassava chips or cassava pulp included at levels of 0, 15, 30, 45, 60% on an approximate dry matter basis. All diets included rice straw provided at 0.5% live weight/day and urea at 2% of cassava chip or cassava pulp on a dry matter basis. Including cassava chip up to 30% of the ration increased total daily dry matter intake from 24.1 g/kg LW to 29.3 g/kg LW. The dry matter intake with cassava pulp was lower than with cassava chip at all levels of inclusion. Consequently, the live weight gain was generally higher with cassava chip. The equations for the response of the live weight gain (kg/d) in relation to level of cassava chip or cassava pulp inclusion were quadratic with values higher for cassava chip inclusion. The inclusion of cassava chip resulted in a higher live weight gain response most likely due to the higher starch content. The maximum live weight gain was achieved at a level of inclusion of 47.5% for the cassava chip and 28% for cassava pulp. Feeding higher amounts than these optimal levels significantly decreased feed intake and live weight gain. Dry matter digestibility was higher with cassava chip inclusion compared with cassava pulp inclusion. Generally, the digestibility increased with increasing levels of both cassava chip and cassava pulp inclusion. Rumen ammonia concentrations declined with the increasing levels of cassava chip and cassava pulp inclusions as the crude protein levels declined. The VFA concentrations were within the normal range (82-137 mM) but there were no particular patterns of molar % related to the levels of cassava chip and cassava pulp inclusions.