determination of physical, chemical and digestibility of some agricultural by-products

in this experiment, physical and chemical characteristics and estimation of effective fiber and digestibility of some agricultural by-products such as lerd, pulp and date kernel, grape pomace, pistachio hulls, lime and rice straw were determined by using in vitro technique. experimental data were analyzed as a complete randomized design, with three replicates. physical and chemical characteristics and digestibility parameters among samples were significantly different. rice straw due to high water holding capacity and low-density mass were floating on the liquid phase of reticulo-rumen and stimulates rumination but palm seed with high bulk density tends to deposit in the rumen. chemical characteristics such as non-fibrous carbohydrates of lemon pulp and pistachio hull and crude protein of grape pomace, lerd and pulp of date were significantly different between samples. results of physical characteristics, particle size separation and physical effective cell wall showed that rice straw provides adequate fiber in diet. also, to some extent physical effective cell wall can be provided by grape pomace, kernel and lerd of date. the predictions of particle size separation and physical effective cell wall were found to compare reasonably well when new pennsylvania sieves, compare to old ones, were used. by considering physical and chemical characteristics of above mentioned agricultural by-products date pulp with non-fibrous carbohydrate and high protein content and digestibility can be used in higher amounts in ruminant diets.