ANSI 3543 Lecture Notes - Lecture 9: Kjeldahl Method, Dry Matter, Carbohydrate
Document Summary
Not all feeds are equal: nutrient composition. Set of chemical/analytical procedures developed in weende, germany over 100 years ago. Estimates: h20, cp, ether extract (fat, ash measure mineral content, crude fiber (cf, nitrogen free extract. Most utilized chemical scheme to describe feedstuffs. Determination by proximate analysis: dry matter (dm) = estimates water. More concerned with dm for ruminants than nr. Forages, grasses, hay contain significant water: crude protein (cp) 100 g pure protein / 16 g nitrogen = 6. 25: thus, % nitrogen x 6. 25 = % cp. Sbm = 7. 6% nitrogen x 6. 25 = 48% cp. Hay = 1. 6% nitrogen x 6. 25 = 10% cp. Corn = 1. 38% nitrogen x 6. 25 = 8% cp: ether extract (ee) Weigh sample, extract with either, weigh sample. 2. 25x more energy than cho: ash (minerals) What is left is ash or minerals: carbohydrate. Nfe = 100 (%cp +%h2o + %ee+%cf+%ash)
