CHEMICAL AND NUTRITIONAL EVALUATION OF GENUS ACACIA OF THE FAMILY LEGUMINOSAE OF PAKISTAN

The genus Acacia of the family Leguminosae is a large genus of 850-900 species, approximate 700 of which are native to Australia. The remainder occur mainly in tropical and subtropical regions of Africa, Asia and America. In Pakistan 34 species of the genus are found to grow, among them, some are wild and abundantly available. The genus Acacia is rich in proteins. lipids and minerals. During these studies, seeds of seven Acacia species were investigated. The seeds of A. nilotica, A. modesta, A. albida and A catechu were collected from the suburb of Lahore district, while the seeds of A. cyanophylla, A tortilis and A victoriae were obtained from the Forest Research Institute, Peshawar. The seeds of these species were analyzed for dry matter, moisture, ash, ether extract. crude fibre, crude protein and nitrogen free extract. All the seeds showed good percentages of proteins. The ash was further analysed for sodium, potassium, zinc, copper, cadmium and lead by using atomic absorption spectrophotometer. The species are rich in potassium.\ud \ud Lipids from the finely ground seeds of A. nilotica, A modesta, A albida, A catechu, A. cyanophylla, A tortilis and A. victoriae were extracted and purified. Acacia cyanophylla was found to contain the highest percentage of lipids (9.8%). The purified lipids were individually fractionated into lipid classes like hydrocarholls. wax esters, triglycerides. free fatty acids, 1,3-diglycerides. 1.2-diglycerides. monoglycerides and polar lipids by thin layer chromatography. Total lipids and lipid fractions were analyzed for their fatty acid composition by gas chromatography. Triglyceride was found to be the major fraction among neutral lipids. The lipids of A. catechu, A. cyanophylla, A. tortilis, and A victoriae were rich in unsaturated fatty acids and their composition approached the fatty acid composition of cotton seed oil. Palmitic, oleic and linoleic acids were found to be the predominant fatty acids in most of the lipids.\ud \ud The feeding experiments were designed and carried out to assess the nutritive value of abundantly available local Acacia species, i.e. A nilotica and A modesta.\ud \ud A 15 weeks feeding trial on goats was carried out to determine the extent to which the pods of A nilotica can replace some conventional source of protein in goat rations. Four rations, containing 0.0%, 17.0%, 34.0%, and 70.0% of A nilotica pods respectively, were fed to four groups of animals having 6 goats in each group. The parameters such as weight gain, feed consumption, feed efficiency and digestibility coefficient of different nutrients were studied. The optimum amount of A nilotica pods for inclusion in the ration was found to be about 17%. The inclusion, of pods in goat rations. higher than this amount reduced the feed intake which resulted in a decrease in the weight gain.\ud \ud Another six weeks feeding experiment on broiler chicks was conducted to study the nutritional value and suitability of A. modesta seed oil for poultry feed. For this purpose four isonitrogenous and isocaloric rations having 0.0% vegetable oil; 1.0% soybean oil; 1.0% A. modesta seed oil and 2.0% A. modesta seed oil, respectively, were prepared and parameters such as weight gain, feed consumption, feed efficiency and dressing percentage were studied. The birds fed on diets having soybean and A. modesta seed oils had statistically similar (P> 0.05) weight gain, feed consumption and feed efficiency ratios, which showed lack of toxicity in A. modesta seed oil