In this study, rumen fluid of animal ruminant was used as inoculums to increase biogas production rate from cattle manure at mesophilic condition. A series of laboratory experiments using 400 ml biodigester were performed in batch operation mode. Given 100 grams of fresh cattle manure (M) was fed to each biodigester and mixed with rumen fluid (R) and tap water (W) in

-In this study, rumen fluid of animal ruminant was used as inoculums to increase biogas production rate from cattle manure at mesophilic condition. A series of laboratory experiments using 400 ml biodigester were performed in batch operation mode. Given 100 grams of fresh cattle manure was fed to each biodigester and mixed with rumen fluid and tap water resulting five different feed to inoculum (F/I) ratios (i.e. 17.64, 23.51, 35.27, and 70.54). The operating temperatures were varied at room temperature. The results showed that the rumen fluid inoculated to biodigester significantly effected the biogas production. Rumen fluid inoculums caused biogas production rate and efficiency increase more than two times in compare to manure substrate without rumen fluid inoculums. At four F/Is tested, after 80 days digestion, the biogas yield were 191, 162, 144 and 112 mL/g VS, respectively. About 80% of the biogas production was obtained during the first 40 days of digestion. The best performance of biogas production will be obtained if F/I ratio is in the range of 17.64 to 35.27 (correspond to 25 -50 % of rumen fluid). The future work will be carried out to study the dynamics of biogas production if both the rumen fluid inoculums and manure are fed in the continuous system.

-The objective of study was to indentify of the sources and characteristic of slaughterhouse waste for biogas production. The identification waste was done by observing the slaughtering activities on slaughterhouse owned by Regional Government of Semarang City. The wastes studied include the rumen, wastewater, and manure and the characteristics include physical and chemical. Based on the slaughterhouse waste characteristic, either liquid or solid, slaughterhouse waste was very suitable and has high potential to be treated anaerobically for biogas production. The wastewater has the potency for producing total biogas as 2.472 m 3 /m 3 of wastewater.

Problem statement: Anaerobic digestion was a biological method used to convert organic wastes into biogas and a stable product for land application without adverse environmental effects. The biogas produced could be used as an alternative renewable energy source. The aim of this study was to analyze the influence of total solid contents on biogas yield from cattle manure using fluid rumen inoculums. Approach: A series of laboratory experiments using 400 mL biodigester were performed in batch operation mode. Given 100 g of fresh cattle manure was fed to each biodigester and mixed with fixed 50 mL of rumen fluid and different volumes of tap water resulting six different Total Solid (TS) contents i.e., 2.6, 4.6, 6.2, 7.4, 9.2, 12.3 and 18.4%. Results: The results showed that the best performance for biogas production was the digester with 7.4 and 9.2% of total solid i.e., gave biogas yield 184.09 and 186.28 mL gVS −1 , respectively after 90 days observation. While the other TSs content of 2.6, 4.6, 6.2, 12.3 and 18.4% gave the biogas yield 115.78, 122.33, 172.34, 137.99 and 54.87 mL gVS −1 , respectively. Conclusion: These results suggested that, based on TS content effects to biogas yield, rumen fluid inoculum exhibit the similar effect with other inoculums. In all cases, there was no variation of pH, fat, protein and ash content in sludge after digestion at several variation of pH. During digesting, pH tends to increase to neutral pH i.e., optimum pH for methanogenic bacteria. The effect of rumen fluid concentration to biogas production will need to be studied in the next step research.

The objective of this research was to study the relationship between body measurement and body weight and closeness among swamp buffalo at three populations in Central Java. The 110 heads of swamp buffalo measured were from 29 heads of Pati district, 56 heads of Kudus district, and 25 heads of Semarang city. Age of buffaloes used was 1-5 years old. The quantitative traits measured were body weight ( BW), body length (BL), shoulder height (SH), pelvic height (PH), chest depth (CD), chest circumference (CC), chest width (CW), Pelvic width (PW), and waist width (WW). The data was analyzed by using multivariate procedure of SAS ver 6. The results showed that best equation to estimate BW for male buffalo was Y= -601,8 + 2,3 BL + 3,4 CD + 2,4 CC, while that for female was Y = -644,5 + 2,8 BL + 1,6 CD + 2,9 CC. Swamp buffalo in Semarang-Pati showed the closer relationships compared to the Pati-Kudus Districts and to Kudus District-Semarang City.