Evaluation of Acacia nilotica seeds for protein and carbohydrate fractions, gas production, energy value and mineral contents from diverse locations in India

In many parts of India, more animals feed on shrubs and trees than on surface fodders like grasses and grass-legume pastures. The objective of the study was to evaluate the Acacia nilotica seeds collected from different locations in India for chemical composition, carbohydrate and protein fractions, energy value, mineral contents, in vitro dry matter digestibility (IVDMD) and gas production. Seeds were sampled from 20 locations in 2003 and from 9 locations in 2005 from different states of country. Crude protein content ranged from 114 to 218 g/kg DM. Seeds from Rewari also had the least neutral detergent fibre (NDF), hemicellulose, and lignin contents (data not shown). A. nilotica seeds harvested in Damoh had the greatest NDF, acid detergent fibre, and cellulose contents. The proportion of degradable CP fractions ranged from 0.97 to 0.99 of total CP. Wide variations were also noted in total carbohydrates and the fractions. There were differences in the cumulative gas volume of the seeds. Rate of gas production ranged from 1.19 to 2.48 ml/h. Seeds from Mandla had the highest IVDMD of 679 versus 507 g/kg DM for seeds harvested in Jhajjar. Wide variations were noted in total phenolics content, with seeds from Rewari having the least value compared with seeds from Sagar, which were more than 16-fold greater. Variation in the gross energy of A. nilotica seeds was less than 3 MJ/kg. As observed in the chemical composition of the seeds, the mineral composition of A. nilotica varied among the different locations, with Ca ranging from 2.19 to 6.30 g/kg DM in Wardha and Coimbatore, respectively. Results revealed that A. nilotica seeds have a high potential as protein and energy supplements for ruminants and that their feeding value is similar to that of the widely used soybean meal and rapeseed meal. Variations in nutritional attributes among A. nilotica seeds from the different locations could be used in tree breeding to develop nutritional superior Acacia cultivars.