IPB Researchers Analyzed Silage Juice to Evaluate its Capability of Inhabiting the Growth of Pathogenic Bacteria

Lactobacillales or lactic acid bacteria (LAB) are an order of Gram-positive, low-GC, acid-tolerant, generally nonsporulating, nonrespiring, either rod- or coccus-shaped bacteria that share common metabolic and physiological characteristics. These bacteria, usually found in decomposing plants and milk products, produce lactic acid as the major metabolic end product of carbohydrate fermentation. Lactobacillales have been reported to play an important role in inhibiting pathogenic bacteria. Beneficial bacteria or the fermentation products produced by these bacteria are used in biopreservation to control spoilage and render pathogens inactive in food. The fermented feed of BAL can prevent contamination of Salmonella bacteria. Lactic acid bacteria inhibit growth of other microorganisms or activity of clostridia in feed ingredients and are able to break the cycle of the spread of Escherichia coli in the feed. LAB can be used as additives in silage making.

Silage is fermented, high-moisture stored fodder which can be fed to cattle, sheep and other such ruminants (cud-chewing animals) or used as a biofuel feedstock for anaerobic digesters. Silage as fermented product does not only produce durable feed but also produces organic acid and BAL which can be used as a potential and economical source of feed additive. Previous studies have shown that fermented poultry feeds is also beneficial as dry form feeds.

Researchers from the Department of Nutrition Science and Feed Technology of the  Faculty of Animal Husbandry of Bogor Agricultural University (FAPET IPB), Prof. Nahrowi, Dr. M. Ridla, and other researcher from the Faculty of Veterinary Medicine of IPB, Prof.Dr. Agus Setiyono implemented research on corn silage. This study aims to analyse  and compare the characteristics of 45 and 365 days silage juice of maize and  its ability to inhibit Escherichia coli and Salmonella sp. isolated from a dairy calves due to calf diarrhea.

Two tons of 2-month-old corn consisting of stems, leaves and seeds were chopped into 1-2 centimeters by chopper and then stirred and put into a 0.35 millimeter plastic bag. The plastic bag is then vacuumed and tied with rubber is then put into twenty container vats and tightly sealed. Tong were then kept each for 45 days and 365 days for ensilage process.  

A total of ten silage samples aged 45 and 365 days were taken randomly from a container vessel. The silage plastic bag is opened and discarded the top one inch thick (the damaged part). Half of the good parts are removed from the package  before both the side and bottom parts of the packaging are perforated to be pressed. The silage juice is obtained by pressing the silage using a hydraulic press. Juice and samples were removed from the packaging, and were brought to the laboratory and chemical composition analysis,  organic acid concentration, total amount of BAL, acidity (pH), and its resistance against E.coli and Salmonella sp.

The corn silage from the study has a moisture content of 45 percent. Hydraulic pressing of silage can produce juice as much as 270 kilograms per kilogram silage. The 45-day silage juice contains lactic acid four times higher than lactic acid from old-age silage juice. The lactic acid content of 45 days silage juice is 0.4 grams per liter, whereas a year juice silage is 0.07 grams per liter. In addition containing high lactic acid, 45 day silage juice contains acetic acid, but this juice does not contain propionic acid, iso butyrate and iso valerate. In contrast, the 365 day silage juice is dominated by acetic acid and butyrate, and small amounts of propionic acid, valerate and isobutyrate. The emergence of butyric acid indicates the presence of Clostridia activity that degrades both amino acids and lactic acid.

Prof. Nahrowi concluded that the silage juice was able to inhibit the growth of gram-negative pathogenic bacterium tested (E. coli and Salmonella spp) both isolated from the feces of pedetal calf, as well as from other pathogenic bacteria. Silage juice is better in inhibiting Salmonella bacteria than into the  E. coli. These results have reinforced previous results comparing the ability of silage juice with Chlor-tetracyclin combined antibiotics with Erythtromycin against E. coli and Salmonella spp isolated from dairy calves. Further the  research has indicated the best characteristics of good corn silage juice is at pH 2.98, the number of BAL is more than 2.2 x 10 8, and is dominated by lactic acid with a concentration above 0.4 grams per liter. The quality of juice decreases with increasing age of silage. (Wied) 

Published Date : 14-Sep-2017

Subject : Prof. Nahrowi, Dr. M. Ridla, Prof.Dr. Agus Setiyono

Keyword : IPB Researchers Analyzed Silage Juice to Evaluate its Capability of Inhabiting the Growth of Pathogenic Bacteria