Proximate and phytochemical compositions of some browse plant species of southeastern Nigeria

Abstract

The proximate and phytochemical composition of some browse plant species were studied at the rainforests at Oban National Park and Umudike, Nigeria to determine their suitability as feeding material for wild and domestic animals. Questionnaire was served to 50 individuals who are either hunters or rear upto six goats or sheep within Umudike and Oban National Park enclave to know the plant species fed upon by wild animals and domestic animals. Two 10 - hectare blocks were laid at Oban National Park and the rain forest at Umudike. Leaves of all the plant species eaten by vertebrate animals within the 10 hectare blocks were collected and identified to species level at the Forest Herbarium, Forestry Research Institute at Jericho, Ibadan, Nigeria. Out of 27 plant species eaten by animals, 17 plant species were selected at random for study of their leaves proximate, phytochemical and mineral composition. It was observed that moisture content ranged between 8.08 and 11.10 per cent. The dry matter ranged between 88.90 and 91.92 per cent. The percent crude protein was highest in Uvaria chamae (21.88%) and least in Andropogeon tectorum (10.50%). The crude fat ranged from 1.38 percent in Gmelina arborea to 10.26 in U. chamae. The crude fibre was highest in Ficus exasperata (38.04%) and least in U.chamae with 8.96 per cent. The percent ash ranged from 5.98 to 9.44. The carbohydrates ranged from 37.76 to 54.56 per cent while the energy ranged from 226.08 to 387.30. In all of the studied plant species, the percent alkaloid, saponine, flavanoid, tannin and steroid were often less than 10 per cent. However, the Hydrogen cynide ranged from 0.05 in Uvaria chamae to 0.93 in Aspilia africana. The percent Sodium, Potassium, Calcium, Magnesium, Phosphorus, Iron, Zinc, Copper, Lead, Cadmium and Manganese were often less than 5.0 percent. Mercury was in trace amount. Based on the contents of the leaves, these plants: Allophylus africanus, Costus afer, Uvaria chamae, Myrianthus arboreus, Carpolobia lutea, Ficus exasperata and Hannoa klaineana having upto 10% per cent crude protein, 5.00 percent crude fat and high palatability should be used in the establishment of fodder bank. The use of leaves of Treculia africana as fodder should be discouraged as it
contains little quantity of Cadmium and Chromium which could have cumulative adverse effects.