Assessment of biogas production and bacterial load from manure of layer chicken fed with two different types of feed

Abstract

Background: The focus of this research was to assess the biogas production of Chicken Manure (CM) collected from hybrid layer chickens fed non-commercial (CMNC) and commercial (CMC) feed, as well as to evaluate the bacterial load of feeding stock and digested slurry samples before and after Anaerobic Digestion (AD). The effects of the feedstock and digestion composition of CM on biogas production were measured. The experiment was carried out utilizing lab-based proto-type digesters for CM with or without inoculum. For each commercial and non-commercial feed, four experimental groups (CMNC1, CMNC2, CMC1, and CMC2) were designed using mixing ratios of CM: H 2 O: inoculum (25:25:50) and CM: H 2 O (50:50). For Hydraulic Retention Time (HRT), the digesters were set up at ambient temperature (28-34 C) for 30 days. The spread plate technique was used to determine the Total Viable Count (TVC), E. coli, and Salmonella spp. counts. Results:The highest average cumulative biogas yield was achieved from CMC2 > CMNC2 > CMC1 > CMNC1. The biogas production of inoculum added groups were statistically significant (p < 0.01) than the without inoculum groups. The average concentration of CH 4 and CO 2 in biogas was 49% and 51% for CMNC1, 58% and 42% for CMNC2, 46% and 54% for CMC1, 52% and 42% for CMC2. However, the H 2 S content was within the acceptable range except for the CMNC2 group. The bacterial load was decreased by 2-3 logs before and after AD, and this reduction was statistically significant (p < 0.05). Conclusion:The study concluded that the CM diluted with water and inoculum (25:25:50) ratio was recommended for sustainable biogas production.

Evaluation of biogas production and bacterial load from co‐digestion of chicken manure with different types of household waste

“…This could be attributable to the low VS content (% of TS) of the substrate in the T1 group, where the average concentration of CH 4 was marginally lower. In mono‐digestion of CM, the average concentrations of CH 4 and CO 2 in biogas were 46%–58% and 42%–54%, respectively, as reported by Haque et al 14 Elasri and El amin Afilal 35 reported that the AD of CM produced biogas containing at least 60% methane and 39% carbon dioxide.…”

“…For group T3, which produced the highest methane yield, the C:N ratio of 17:1 was within the optimal range 31 . Compared with CM mono‐digestion, the fertilizer values (N, P, K, and S) of digestion were found to be slightly higher 14 . All groups' VFA concentrations fell within the permissible range of 384–674 mg/L (Table 4).…”

“…In the case of SO, the sample was abundant in carbon; thus, the C:N ratio of 52:1 was relatively high compared with the range of 7:1 to 34:1 reported for feedstock 28 . The C:N ratio of CM typically ranged between 10:1 and 15:1 14 . The C:N ratio of SO and FW may vary based on cooking and dietary practices, seasons, etc.…”

“…Then, 1 g of feedstock and digested slurry samples were diluted with 9 mL of peptone broth (1:10) using a 10‐fold serial dilution technique. According to the method of Haque et al, 14 the total viable count (TVC), total Escherichia coli count (TEC), and total Salmonella spp. count (TSC) of feedstock and digested slurry samples were determined.…”

“…Some of the bacteria that were identified in manure and bio‐slurry were Salmonella spp., Listeria monocytogenes , Mycobacterium avium subsp. paratuberculosis , Clostridium spp., Bacillus spp., Campylobacter spp., Yersinia enterocolitica , Staphylococcus , and Streptococci 14 …”