Proximate principles analysis for dry matter, crude protein, ether extract, crude fiber, nitrogen free extract and total ash
Protein (CP) Nitrogen present in the samples of feed ingredient, diet or excreta is estimated by Micro-Kjeldahl’s method of AOAC (1984). The nitrogen content was multiplied by factor 6.25 to arrive at crude protein content.
Ether extract (EE) Take About 5-10 g dried powered samples of feed ingredient, diet or excreta in a readymade thimble. The samples were extracted continuously for 60 minutes with petroleum ether (40°C) at 250°C in a modified Soxhlet extraction apparatus.
Crude fiber (CF) Take About 5-8 g fat free dried sample in a one litre capacity of spout less tall beaker. boil it with 200 ml 1.25% sulphuric acid for 30 minutes and filtered through a muslin cloth and washed with hot water till it became acid free. Thereafter transferred it in the same beaker and boiled with 200 ml 1.25% NaOH solution for 30 minutes. Then make it alkali free through continuous washing with hot water. The residue left was transferred to the previously weighed silica crucible. dried it at 100± 0.5°C in hot air oven for over night. The dried material ignited in the muffle furnace at 600°C for 30 minutes. The loss in the weight is consider as crude fiber content of sample.
Total ash (TA) Take about 5-10 g dried sample in previously weighed silica crucible and charred on a low flame of the gas burner. Thereafter ignite it in furnace at 600°C for 30 minutes. After cooling it in desiccators weighed it for constant weight. The ignited material left in the crucible was considered as total ash.
Nitrogen free extract (NFE) NFE was calculated by subtracting the sum percentage of crude protein, crude fiber, ether extract and total ash from 100. NFE (%) =100 – (CP % + CF % + EE % + Total ash %)
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