feed analysis Flashcards
moisture
hay=5-15% moisture
grains=5-15% moisture
pasture=65-75% moisture
dry matter
100-moisture=dry matter
hays=85-95% DM
grains=85-95% DM
pasture=25-35% DM
Crude protein
total protein in feed
calculated from the amount of nitrogen (N)
does not assess amino acids
crude fat
“ether extract”, accounts for all lipids in feed
ash
total mineral in the sample
major and trace minerals
most are easily measured except selenium, iodine and chlorine
acid detergent fiber (ADF)
contains cellulose (moderately digestible) and lignin (indigestible), overall 30-40% digestible by the horse (microbes)
neutral detergent fiber (NDF)
contains cellulose and lignin (ADF is part pd NDF), hemicellulose is slightly more digestible than cellulose, NDF digestibility is 40-50%, as NDF and ADF increase, digestibility and palatability usually decrease
crude fiber
an old method for measuring fiber, still use for commercial feeds, but not as useful as NDF or ADF for evaluating digestibility
relative feed value (RFV)
developed for cattle feeding to compare different forages, RFV 100=mature alfalfa hay
RFV>100=higher value/quality
RFV<100=lower value
total digestible nutrients (TDN)
old term, calculations based on cattle, higher value=more digestible
Digestible energy (DE)
DE=gross energy-fecal energy
calculated value based on other chemical components, fairly accurate for hays and traditional concentrates, less accurate for concentrates with non-traditional ingredients ex. added fat, beet pulp, soybean hulls
usually expressed as megacalories (Mcal) per lb of kg or megajoules (MJ) per lb or kg (1Mcal=4.184 MJ)
non-fiber carbohydrates (NFC)
not cellulose, hemicellulose or lignin, calculated by difference, 100%-(CP%-ash%-fat%+NDF%+moisture)
NFC is starch, sugar and fibers that are not captured in NDF (like pectin and fructan)
pectin
highly digestible in the LI (beet pulp)
fructan
highly digestible in LI (cool season grass pasture), can be rapidly fermented and too much can disrupt the large intestine
