Ruminal Behavior of Protein and Starch Free Organic Matter of Lupinus Albus and Vicia Faba in Dairy Cows

Abstract

Faba beans (vicia faba) (FB) and lupin seeds (Lupinus Albus) (LS) were dry roasted at three temperatures (110, 130, 150°C) for 15, 30 or 45 min to determine the effects of dry roasting on rumen degradation of crude protein and starch free organic matter ( P S F OM). Rumen degradation characteristics of P S F OM were determined by the nylon bag incubation technique in dairy cows fed 60% hay and 40% concentrate. Measured characteristics of P S F OM were undegradable fraction (U), degradable fraction (D), soluble fraction (S), lag time (TO), and the rate of degradation (Kd). Based on the measured characteristics, rumen availability (RA P S F OM) and bypass P S F OM (B P S F OM) were calculated. Dry roasting did not have a greater impact on rumen degradation characteristics of P S F OM (p>0.05). S varied from 32.1 (raw) to 30.0, 27.8, 30.8% (LS) and 15.4 (raw) to 14.4, 20.8, 20.9% (FB); D varied from 65.4 (raw) to 66.3, 66.9, 55.9% (LS) and 54.9 (raw) to 55.0, 51.0, 64.7% (FB); U varied from 2.6 (raw) to 7.3, 7.0, 7.7% (LS) and 29.7 (raw) to 30.6, 28.2, 14.4% (FB); Kd varied from 6.0 (raw) to 7.3, 7.0, 7.7% (LS) and 22.4 (raw) to 24.4, 21.1, 7.9% (FB); B P S F OM varied from 35.5 (raw) to 33.8, 36.6, 38.2% (LS) and 41.3 (raw) to 41.5, 39.7, 47.6% (FB) at 110, 130 and 150°C, respectively. Therefore dry roasting did not significantly affect RA P S F OM, which were 353.7, 367.9, 349.6, 336.9 (g/kg DM) (LS) and 12.82, 127.0, 133.7, 117.1 (g/kg DM) (FB) at 110, 130 and 150°C, respectively. These results alone with our previously published reports indicate dry roasting had the differently affected pattern of rumen degradation characteristics of various components in LS and FB. It strongly increased bypass crude protein (BCP) and moderately increased starch (BST) with increasing temperature and time but least affected P S F OM. Such desirable degradation patterns in dry roasted LS and FB might be beneficial to the high yielding cows which could use more dry roasted P S F OM as an energy source for microbial protein synthesized in the rumen and absorb more amino acids and glucose in the small intestine.