Hevea brasiliensis

Para rubber, caoutchouc tree

Useful reference: 147

The rubber tree starts bearing fruit at four years of age. Each fruit contains three or four seeds, which fall to the ground when the fruit ripens and splits. Each tree yields about 800 seeds (1.3 kg) twice a year. The seed consists of a thin hard shell and a kernel. As the shell also contains some oil, the kernel and the shell sometimes are extracted together, yielding an undecorticated oilcake or meal with a very high fibre content. There is a great difference in feeding value between decorticated and undecorticated meal. The oil can either be expressed (hot or cold) or extracted. The press cake contains 8-15% residual oil, whereas the extracted meal has only 2-4%.

TOXICITY. Fresh rubber-seed oilcake contains up to 0.09% prussic acid, which is released, as in linseed, from a glucoside by an enzyme. The high temperature of normal processing destroys the enzyme that releases the prussic acid. Boiling - particularly in acid water - also renders the oil harmless. Oilcake that has been stored for at least six months can also be fed to animals without special precautions; however, undetoxified cakes must not be wetted before feeding.

USE. The oilcake has value as a cattle feed, but is not very palatable because it is powdery. It has been fed in amounts of 2-3 kg a day to adult cattle with good results. It is unpalatable to sheep.

Rubber-seed meal can be incorporated into poultry rations at levels between 10% and 15% for chicks and up to 25% for growers, but its use requires supplementation with sulphur amino acids.

					As % of dry matter
				DM	CP	CF	Ash	EE	NFE	Ca	P	Ref
Kernels, Malaysia				70.0	18.0	1.9	2.6	52.3	25.2			292
Oilcake with hulls,
mechanically extr-
acted, Thailand				91.9	14.4	46.6	2.7	4.8	31.5			56
Oilcake without
hulls, mechanically
extracted,
Sri Lanka				90.7	26.7	10.8	6.4	3.8	40.0	0.12	0.47	535
							Digestibility (%)
					Animal		CP	CF	EE	NFE	ME	Ref
Oilcake without hulls,
mechanically extracted					Sheep		91.0	99.0	97.0	95.0	4.34	30