Anaerobic mesophilic batch tests of dairy cow manure, dairy cow manure/saw dust mixture and dairy cow manure/ rice hull mixtures collected from bedded pack barn were carried out to evaluate their ultimate biodegradability and two distinctive decay rates (k1 and k2) with their corresponding degradable substrate fractions (S1 and S2). Each 3 liter batch reactor was operated for more than 100 days at substrate to inoculum ratio (S/I) of 1.0 as an initial total volatile solids (TVS) mass basis. Ultimate biodegradabilities of 37 ~ 46% for dairy cow manure, 32 ~ 40% for dairy manure/saw dust mixture and 31 ~ 38% for dairy cow manure/rice hull mixture were obtained respectively. The readily biodegradable fraction of 90% (S1) of dairy manure BVS (So) degraded with in the initial 29 days with arange of k1 of 0.074 day−1, where as the rest slowly biodegradable fraction (S2) of BVS degraded for more than 100 days with the long term batch reaction rate of 0.004 day−1. For the dairy manure/saw dust mixture and dairy manure/rice hull mixture, their readily biodegradable portions (S1) appeared 71% and 76%, which degrades with k1 of 0.053 day−1 and 0.047 day−1 for an initial 30 days and 38 days, respectively. Their corresponding long term batch reaction rates were 0.03 day−1.

This study was carried out to investigate the effect of DDGS hydrolysate (H-DDGS) and rumen-protected lysine-choline complex (RPLC) on milk production and blood metabolites in dairy cows. Feeding trials was performed to latin-square design using the 4 mid-lactational cows for 8 weeks, and treated with T1 (H-DDGS 1.1 kg), T2 (H-DDGS 0.73 kg + RPLC 0.15 kg), T3 (H-DDGS 0.37 kg + RPLC 0.30 kg) and T4 (H-DDGS 0.37 kg + RPLC 0.15 kg) according to the content of protein source. Dry matter intake (DMI) of TMR and average weight showed no significant difference between treatments. The milk production of T1, T2 and T4 were significantly higher than T3 treatment (p < 0.05), and milk/DMI efficiency tend to increase in the T1. Milk components showed no significant difference between treatments, however, the milk protein of T2 increased to 0.15% than T1. Also blood metabolites showed no significant difference between treatments. But T-CHO level numerically represented a lower trend in the treatments of adding to RPLC compared with T1. This result suggests that the high level (1.1 kg) of H-DDGS is expected to improve the feed utilization without the negative impact on weight gain, feed intake and milk production as the lactation stage of dairy cows proceeds, and 0.15 kg of RPLC under the same feeding conditions of H-DDGS may be useful on fat metabolism.