Effects of feeding mother liquor, by-product of monosodium glutamate, on digestibility, energy and nitrogen balances, and rumen condition in Thai native bulls.

Four Thai native bulls were used to evaluate the availability of mother liquor (ML), by-product of monosodium glutamate, as a replacement of soybean meal (SBM) consisting of 10% in concentrate. The SBM was replaced by the ML at 0% (C), 20% (T1), 40% (T2), and 60% (T3), and the experiment was a randomized block design experiment. The animals were fed concentrate and roughage (60:40, on a dry matter [DM] basis). There were no significant differences in the digestibility of DM, crude protein, ether extract, acid detergent fiber expressed exclusive of residual ash and non-fibrous carbohydrate, and energy and nitrogen balances among the treatments. However, the digestibility of the neutral detergent fiber in T2 was lower than the other treatments (p < .05). The valeric acid of T2 was lower than those of C and T1 and the iso-valeric acid of T3 was the lowest (p < .05), followed by those of T2, T1, and C at 4 hr post-feeding. No significant differences were observed in the ruminal total VFA concentrations, pH, and NH3 -N among the treatments. These results suggested that SBM could be replaced by the ML up to 60% without adverse effects on nitrogen and energy balance, rumen conditions, and blood metabolites in Thai native bulls.