Leaves from palm oil plants are a waste product of palm oil plantations that could potentially become a source of forage for ruminant livestock. The maintenance of palm plants typically involves pruning of leaves or leaf midribs.
In addition to the pruning program, palm fronds are also cut regularly every harvest. Palm oil production will continue to increase as the palm oil plantation acreage grows. This indicates that palm has considerable potential as feed forage for ruminants.
Although palm leaf midribs have substantial potential as a feed forage, their utilization as an animal feed is still very limited. This limit is partly due to the low biological quality of palm leaf midribs. The lignin content of oil palm leaves is quite high and this high content leads to a low digestibility of palm leaf stems1.
The in vitro digestibility of small palm oil leaves is approximately 50% and it is recommended that only 15-20% of palm leaves are used in rations. To use more than 40% of palm leaves in rations, it is necessary to process them using physical, chemical or biological treatment or a combination of these methods. A new study was carried out to determine the best palm leaf processing method to increase the nutrient content and digestibility of palm leaf midribs2.
The treatments used for study purpose were; Treatment A, Control (without treatment), B, Physical processing (steam), C, Chemical treatment (ammonia), D, Biological treatment (ensilage) and E, Chemical-physical combination (steam-ammonia). The parameters that were measured included the nutrient content, dry matter digestibility, organic matter, crude protein, and in vitro fiber fraction and rumen fluid characteristics.
It was observed that treatment with steam and steam-ammonization significantly increased the dry matter content compared to the control, whereas ammonization and ensilaging significantly decreased the dry matter content compared to the control.
However, the difference in dry matter content between ammonization and ensilaging treatments was not significant and there was a similar result for steam-ammonization. Moreover, there was an increase in the nutrient content which was followed by an increase in dietary digestibility.
The fiber fraction content in the steam-ammonization (E) treatment was similar to that of the control (A) and there was no decrease in the fiber fraction. This outcome suggested that steam treatment followed by ammonization was ineffective for reducing the fiber fraction since the steam processing removes some soluble substances through evaporation, which leaves only soluble and ammonia substances, which are unable to reduce the fiber fraction content3.
It was thus established the ammonization method of processing palm oil leaf bark produces the best levels of nutrients and in vitro digestibility, as well as results in beneficial rumen fluid characteristics, compared to the effects of steam, ensilage and steam-ammonization treatments.
Palm leaf stem, steam, ammonization, ensilage, steam-ammonization, nutrient digestibility, soluble substances, fiber fraction, evaporation, dry matter content, Chemical-physical combination, biological quality.
- Suyitman, L. Warly and Evitayani, 2013. S and P mineral supplementation of ammoniated palm leaves as ruminant feed. J. Nutr., 12: 903-906.
- Suyitman, LiliWarly and Evitayani , 2018. In-vitro Digestibility of Palm Leaf Waste Treated with Different Processing Methods. J. Nutr., 17: 368-373.
- Suyitman, L. Warly, A. Rachmat and D.R. Ramadhan, 2015. Effect of minerals S, P and cassava flour leaf supplemented with ammoniation palm leaves on the performance of beef cattle. J. Nutr., 14: 849-853.