Ensiling of fresh cassava root pulp and fresh soybean pulp with or without rice bran

Abstract

The aim of this study was to investigate the effect of rice bran inclusion on silage properties and nutrient content of fresh cassava root pulp (CRP) and fresh soybean pulp (SBP). The experiments were arranged according to a completely randomized design with 3 replications per treatment and incubation time. CRP and SBP were anaerobically fermented (ensiled) for 7 and 14 days with different inclusion levels of rice bran (0, 5, 10 and 20% on fresh weight basis). Sugar cane molasses (5% on fresh weight basis) was included in all treatments. For both CRP and SBP there was a gradual decrease in pH with time of ensiling. Inclusion of rice bran resulted in an elevation of pH in both CRP and SBP. Within level of rice bran inclusion dry matter (DM) content gradually increased with time of ensiling. DM content was gradually elevated with increasing inclusion of rice bran. In CRP the crude protein (CP) content gradually increased with time of ensiling, while there was a gradual decrease in CP content in SBP. Increasing inclusion of rice bran resulted in a gradual elevation of the crude protein (CP) content in CRP, while there was a reduction of CP content in SBP. Increasing inclusion of rice bran resulted in a gradual elevation of the NH3-N content in both CRP and SBP, and the NH3-N content within pulp source remained elevated during ensiling. The initial relative proportion of ammonia nitrogen (NH3-Nprop, % of total N) was different between CRP and SBP. Increasing inclusion of rice bran resulted in a gradual decline of the NH3-Nprop in CRP while there was a gradual elevation of the NH3-Nprop in SBP. The effect rice bran inclusion on NH3-Nprop within pulp remained during ensiling. The HCN content in CRP decreased with time of ensiling. In conclusion, ensiling cassava root pulp and soy bean pulp without inclusion of rice bran resulted in a pH (3.9-4.0) that should allow long-term storage with maintained silage quality. However, ensiling cassava root pulp and soy bean pulp with inclusion of more than 5% rice bran inclusion (fresh weight basis) resulted in a pH (>4.7) that was too high to inhibit the growth of spoilage bacteria and cannot be recommended.

Keywords

Anaerobic fermentation; By-products; Crude protein; PH; Storage

Published in

Livestock Research For Rural Development
2018, volume: 30, number: 6, article number: 107
Publisher: Fundacion CIPAV

SLU Authors

• Taysayavong, Lotchana

  • Department of Applied Animal Science and Welfare, Swedish University of Agricultural Sciences
    
  • Champasack University

• Ivarsson, Emma

  • Department of Applied Animal Science and Welfare, Swedish University of Agricultural Sciences
    

• Lindberg, Jan Erik

  • Department of Applied Animal Science and Welfare, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Food Science

Permanent link to this page (URI)

https://res.slu.se/id/publ/130265