Formulating rations with cassava meal to promote high live weight gain in crossbred Limousin bulls

Formulating rations with high energy and protein feeds such as cassava and locally sourced protein meals is an important strategy to increase live weight gain (LWG) of crossbred bulls in Indonesia. Current systems of production for Indonesian smallholders fatten bulls using cut and carry. Formulating a diet for an optimal combination of available feeds will increase production and potential profitability for smallholders. An experiment was conducted to evaluate the effect of using cassava meal in the diet at levels of 70C, 60C, 50C, 40C and 30%C (with most of the remainder being the protein meals) on the LWG of Limousin x Ongole bulls so as to determine the optimum combination of cassava meal and protein meals for LWG. Thirty bulls were allocated in a completely randomized block design with 6 blocks based on initial live weight (LW) and 5 treatments based on level of cassava meaL The combination of cassava meal (with 2% urea) and protein meals significantly affected LWG with the highest (135 kg/day) recorded at 40C (40% cassava meal, 40% protein meals and 20% maize stover). The LWG and nutrient intake increased curvilinearly with decreasing cassava meal and increasing protein meals (P < 0.05). Measured cassava meal inclusion in the final ration as a consequence of the changes in intake was 60, 56, 47, 37 and 28% for the designated 70C, 60C, 50C, 40C and 30C treatments, respectively. Dry matter intake reached 96 g/kg(0.75) per day or equal to 2.24% LW at this 40% level of inclusion. At the 70C treatment with 60% cassava meal and 9% protein meals, DM digestibility (69.1%) was lowest and that value increased as the proportion of cassava meal decreased and was highest at the 40C treatment (75.8%). Feed treatments significantly affected rumen pH, ammonia N (NH3N) and volatile fatty acid concentrations (P < 0.05). There was no significant effect on protozoal population (P> 0.05). Rumen pH ranged from 6.3 to 6.9. IL was concluded that a combination of 40% dried cassava meal and 40% protein meals with roughage (20%) maximized intake and LWG and beyond that level of cassava meal inclusion, LWG and intake decreased markedly. (C) 2020 The Authors. Published by Elsevier Inc. on behalf of The Animal Consortium.

Automated summary

Formulating rations with high energy and protein feeds like cassava and locally sourced protein meals is crucial for increasing live weight gain of crossbred bulls in Indonesia. An experiment showed that a combination of 40% dried cassava meal and 40% protein meals maximized intake and live weight gain, with a marked decrease in intake and weight gain beyond that level of cassava meal inclusion.