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Production and application technology of probiotics to improve growth performance of farm animals and decrease ammonia concentration of manure

Physiology Division, Livestock Research Institute, Council of Agriculture, Executive Yuan
Ren-Bao Liaw (Researcher)
Tel:886- 6-591-1211 ext. 2502


June 30, 2022

        In response to the important issues of climate change and net zero emissions, reducing carbon emissions from livestock farming is one of the important goals of agricultural production. Adding probiotics to the feed to improve feed efficiency is indeed a feasible measure for carbon reduction. This technology is to screen and identify potential probiotic isolates from the livestock production environment. After molecular analysis, the isolates are confirmed to be positive listed microorganisms in feed additives, and the analyses on their important characteristics are completed including the comparison of important decomposing enzyme activities (protease, lipase, α-amylase, β-glucanase and xylanase), animal validation tests and sporulation production condition tests. Therefore, this R&D technology can provide high-quality probiotic products for industrial selection and application.

        The isolate screened by this technique has been identified and named Bacillus subtilis TLRI 211-1. In the analysis of the activity of important decomposing enzymes, it was shown by the comparison of the size of the transparent area of the enzyme decomposition substrate around the colony of the culture plate that the TLRI 211-1 strain had better activity performance than the commercial product A strain.

       Animal experiments on white broilers, laying hens and goats showed that: (1) In the treatment group added with probiotic isolate TLRI 211-1, the body weight of white broilers increased. The feed efficiency and production efficiency were significantly better than those of the control group (including the group without probiotics and the group with commercial strains). The chickens had significantly lower abdominal fat, significantly higher intestinal weight. The ammonia concentration in the litter in the middle and late feeding period was significantly lower than that of the control group, with a reduction rate of more than 40%. (2) The addition of probiotic isolate TLRI 211-1 and electrolytes to the feed of laying hens could significantly improve the laying performance, egg weight, protein height and color of laying hens in the hot season. This could also significantly improve the feed efficiency of laying hens to eggs, and reduce the odor of excrement (including NH3, H2S and CH3NH2). (3) After the probiotic isolate TLRI 211-1 was added to the feed of the goat and lamb, there were positive benefits for protein digestibility, food intake and daily weight gain, and it also reduced the concentration of ammonia in the feces of lambs. The above research and development results have been published in academic journals or seminars for reference.

        In the development of the probiotic isolate TLRI 211-1 powder product, the sporulation conditions were initially evaluated by shaking flask culture. The results showed that after 48 h of induction with the ionic formula, a better spore concentration of 2.62 × 109 CFU/mL could be obtained. Then the sporulation conditions were evaluated in a small automatic fermentation tank. After vegetative cells were induced with ionic formula for 24 h, the bacterial concentration was 1.47 × 109 CFU/mL, the spore concentration was 1.38 × 109 CFU/mL, and the transfer rate was 93.88%. Then  the carrier was added to the bacterial solution and the mixture was centrifuged and concentrated. Finally, the sporulated bacterial powder obtained can reach 3.94 × 1010 CFU/g after simple drying conditions. In addition, the effects of drying at moderate temperature (40°C) or freeze-drying (-40°C) on the yield and activity of the final product were investigated, and the results showed that the effective total spore number of the freeze-dried product was approximately equal to that of the moderate-temperature drying.

      Based on the above analysis of probiotic characteristics, animal validation test and end-use product development, the isolate Bacillus subtilis TLRI 211-1 is indeed competitive in the industry.