Feed profile analysis of oil palm-integrated beef cattle farming systems by metabolic energy budgeting and implications for beef production and pastoral system design

Abstract

Background

Oil palm is a tropical crop with worldwide plantings approaching 20 million ha and large areas in Indonesia, Malaysia and Thailand. The plantations are readily managed as silvopastoral systems incorporating cattle grazing (Oil Palm Silvopastoral System for Cattle, OPSC) but there is a need for analytical tools and data to understand system herbage supply and feed conversion efficiency (FCE).

Methods

Metabolic energy budgeting was used to estimate herbage harvested by cattle in three OPSC subsystems, 9 and 12 years after oil palm establishment, and FCE of the subsystems was determined. Understorey herbage was also analysed for nutritive value, botanical composition and herbage accumulation within one grazing-regrowth cycle.

Results

The herbage-harvested estimate was 2.0−2.4 t dry matter (DM) ha⁻¹ year⁻¹ for 9 year old subsystems and 1.4−1.7 t DM ha⁻¹ year⁻¹ for a 12 year old subsystem. Herbage metabolisable energy (ME) was 8.3−8.5 MJ kg⁻¹ DM and crude protein (CP) was 15%−16% DM. FCE values for subsystems ranged from 32 to 94 kg DM kg⁻¹ liveweight-gain.

Conclusions

Herbage DM yield is declining, while herbage ME is marginal but CP is adequate. FCE is suboptimal but can be optimised by defining the trajectory of declining herbage production with canopy closure as plantations age and matching stocking rate to herbage supply using a comparative-stocking-rate-type statistic.