A biotechnological process for the recycling of poultry waste manure and its use in the animal feeding industry

摘要

The poultry waste manure (litter and excreta) are generally applied to the soil as a fertilizer. This final step in the poultry farming management strategy entails a big risk for the environment due to the nutrients and microorganisms contained in high concentrations in these waste materials. The biopreservation and biotransformation processes are currently the only safe and economical means of recycling these highly contaminated wastes. These processes will allow the recovery of a good constituentwith an added value by the least expensive means and at the same time, the protection of the environment by avoiding the accumulation of very polluting solid wastes. Many studies have been achieved on the poultry manure silage technology. Numerous researchers have reported the use of biomethanization and composting to transform these materials. However, none of these methods used a microbial controlled fermentation by acid-producing microorganisms (pure culture of lactic acid bacteria) to ferment thesewastes. In the present study, we explored the possibility of using fermented poultry manure as an ingredient lor animal feeding, For this purpose, fresh poultry waste manure (FVF) were humidified by adding the same amount of water 50-50 (w/w). They werethen mixed with 10 percent cane molasses and well homogenised. The pH was adjusted to 6.5 by adding a 10 percent sulfuric acid solution. The crude prepared mixture (MTF) was inoculated with a starter culture of Lactobacillus plantarum and Pediococcus acidolactici and incubated at 30 deg C for 7-10 days. Microbiological analyses were performed before and after the fermentation period. Concurrently, changes in nutritional quality and biochemical properties were determined for the crude and the fermentedpoultry manure (MFF) product. Results indicated that the wastes were highly contaminated with hazardous microorganisms. Enterobacteria counts attained 3.10 cfu/g. Enterococci counts were also high and reached 410~7 cfu/g. whereas the standard plate countvaried between 8.10~7 and 4.10~9 cfu/g and Clostridium levels were around 200 cfu/g. All these microbial populations were totally reduced by the fermentation process (< 10 cfu/g). Results showed a steady decrease of the pH (4.0 vs 6.5), and the growth curve of the starter culture (lactic acid bacteria) showed that the fermentation process was successful. The total nitrogen was conserved (crude proteins: 22.9 vs 24.6 percent) and the total volatile nitrogen (ammoniac) entirely disappeared (0 percent) inthe transformed poultry wastes. The non protein nitrogen level increased from 0.16 to 0.36 of the total nitrogen. The fermented product (poultry manure silage) was used for substituting some protein sources in a conventional commercial formula used in laying feeding. Two formulae (F20 and F40) containing respectively 20 and 4O percent of the product obtained were compared to the control feed (FT: 0 percent) in laying feeding of three lots of 16 hens each. The food consumption and laying perlormances were observed tor 30 days. The nutritional caracterization of the final feed formulae was reported in a table. The high contents in proteins and minerals would make the fermented poultry wastes suitable for supplying other animal feeds with these components and the use of the ingredient as a source of proteins anct minerals would be more interesting than the use of other materials. Results of the nutritional test indicated that the incorporation of the poultry manure silage at a rate of up to 40 percent along with the climination of Premix and the relative replacement of corn by bran, resulted in laying performances similar to those obtained with the conventional formula. These results altogether show that it is possible to transform poultry waste manurein the lactic controlled fermentation and that the product obtained constitutes a precious component with an added value fit for animal feeding.