Authors : G.I. Crawford , M.D. Stern , R.L.K. Hulbert , K.A. Caperoon and P.G. Summer
Abstract: A liquid byproduct of monosodium glutamate (MSG) production containing 13.7% N and 8.3% NH3N (DM basis) was evaluated as a N source for ruminal microbes using eight dual-flow continuous culture fermenters. Two dietary treatments were utilized, with the primary N source being provided by soybean meal (SBM) in the first treatment and by the MSG byproduct (MSGN) in the second treatment. Each treatment was formulated to contain approximately 17% CP, 30% NDF, 17.5% ADF and 5% fat (DM basis). The experiment consisted of one 10-d experimental period, including a 7-d stabilization period followed by 3 d of sampling. Fermenter pH was allowed to fluctuate between 5.8 and 6.5 throughout the experiment. Measured pH was greater (P < 0.05) for SBM (5.83) than for MSGN (5.82). Digestion of ADF was 63.4 and 69.3% for SBM and MSGN, respectively, and tended to be greater (P = 0.06) with MSGN. Organic matter, CP, and NDF digestion were not influenced (P > 0.05) by treatment. Efficiency of bacterial synthesis averaged 20.5 g of N/kg of OM truly digested and was not different (P > 0.05) between treatments. Effluent concentration of NH3N was greater (P < 0.05) for MSGN (13.5 mg/100 mL) compared with SBM (2.4 mg/100 mL). Molar proportions of acetate (P = 0.07) tended to be greater with MSGN, while molar proportions of propionate (P = 0.07) and valerate (P = 0.08) tended to be greater with SBM. Total amino acid input and flow were greater (P < 0.05) with SBM and total amino acid flow relative to input was greater (P < 0.05) with MSGN. Results from this experiment indicate that the liquid byproduct of MSG production supported similar in vitro microbial growth as SBM, and also supported greater ADF digestion. However, the MSG byproduct was unable to support AA flows to match those produced when SBM was the primary N source.
G.I. Crawford , M.D. Stern , R.L.K. Hulbert , K.A. Caperoon and P.G. Summer , 2004. Effects of a Liquid Byproduct Nitrogen Source on Nitrogen Utilization by Ruminal Microbes in Continuous Culture Fermenters . Journal of Animal and Veterinary Advances, 3: 872-880.