N-alkane as an internal marker for predicting digestibility of forages.

摘要: Independent digestion trials with 5 forages were conducted to compare n-alkane indigestible acid-detergent fiber (IADF) as internal markers predict in vivo dry matter digestibility (digestibility). Forages mixed grasses from subirrigated meadow (meadow), regrowth (regrowth), native range (range), mature grass hay meadow, and alfalfa (Medicago sativa L.) hay. Meadow, regrowth, diets immature harvested 0.5 hours before feeding. Feces the divided freeze drying oven (60 degrees C). All subjected vitro fermentation for 0, 48, or 96 hours. N-alkane was separated samples by 4.5-hour saponification alcoholic KOH followed extraction n-hexane. Indigestible ADF measured 96-hour extraction. Digestibility estimated compared digestibilities. based digestibilities lower (P < 0.01) than all diets. N-alkanes provided higher estimates of IADF 0.01), = 0.06), 0.02). Digestibilities calculated using n-alkanes tended be 0.14) values. Freeze increased amount extracted hay, but did not affect 0.1) disappeared 0.001) residue collected after 48 fermentation, no additional disappearance 0.78) evident at Neither marker completely recoverable, although recovery 4 tested. DOI:10.2458/azu_jrm_v53i2_sandberg