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Cyanide is a strong toxin in many tropical forage plants that can negatively affect ruminants. The aim of this study is to determine the cyanide removal efficiency, silage quality, and in vitro rumen fermentation of fresh cassava roots ensiled without an additive (control) and with Acremonium cellulase (AC), two cyanide-utilizing bacterial inoculants (Enterococcus feacium KKU-BF7 (BF7) and E. gallinarum KKU-BC10 (BC10)), and their combinations (BF7 + BC10, AC + BF7, AC + BC10 and AC + BF7 + BC10). A completely randomized design was used with eight treatments × four small-scale silo replicates. Additionally, extra silage samples (seven silos/treatment for individually opening after 0, 1, 3, 5, 7, 15, and 30 days of ensiling) were added to observe the changes in the total cyanide concentration and pH value. The fresh cassava root contained an optimal number of lactic acid bacteria (105 colony forming units/g fresh matter), and the contents of dry matter (DM) and total cyanides were 30.1% and 1304 mg/kg DM, respectively. After 30 days of ensiling, all silages demonstrated a low pH (<3.95; p < 0.01). Cyanide content ranged from 638 to 790 mg/kg DM and was highest in the control (p < 0.01). The addition of BF7 + BC10 increased the crude protein (CP) content (p < 0.01). The addition of AC decreased the fibrous contents (p < 0.01). The control had less acetic acid and propionic acid contents (p < 0.01) and a greater butyric acid content (p < 0.01). However, the degrees of in vitro DM digestibility (IVDMD) and gas production were similar among treatments. Methane production ranged between 29.2 and 33.3 L/kg IVDMD (p < 0.05), which were observed in the AC + BC10 and BF7 + BC10 treatments, respectively. Overall, our results suggested that the cyanide removal efficiency after 30 days of ensiling with good-quality cassava-root silage was approximately 39% of the initial value. The enterococci inoculants and/or AC could improve the ensiling process and cyanide removal efficiency (increasing it to between 47 and 51% of the initial value). The novel enterococci inoculants (BF7 + BC10) were associated with a decreased cyanide content and an increased CP content. They appeared to promote the methanogenesis potential of the cassava root silage. More research is required to validate the use of cyanide-utilizing bacterial inoculants in cyanogenetic plants, bioenergy fermentation, and livestock. [ABSTRACT FROM AUTHOR]

The objective of this research was to supplement the cyanide-utilizing bacteria and sulfur in the HCN-rich diet, affecting the gas production and fermentation of rumen in vitro, and lowering the HCN content and the digestion of nutrients. A 2 × 2 × 3 factorial experiment in a completely randomized design was applied during the test. In the experiments, three factors were used. Factor A was the level of CUB at 0 and 108 CFU/mL. Factor B was the level of sulfur in the diet at 0% and 3% of dry matter (DM). Factor C was the three levels of potassium cyanide (KCN) at 0, 300, and 600 ppm. The interaction of CUB × sulfur × KCN affected gas production from the immediately soluble fraction (a) (p < 0.05). However, the greatest ruminal cyanide concentration was found when CUB (with and without), sulfur (3%), and KCN (600 ppm) were introduced at 0 h (p < 0.05). It revealed that the addition of CUB and sulfur had a significant impact on gas accumulation at 96 h (p < 0.05). The addition of CUB with sulfur had an effect on pH at 2 h and ruminal cyanide levels at 6 h (p < 0.05). At 2 h, sulfur supplementation with KCN had an effect on NH3-N (p < 0.01). The addition of sulfur (3%) and KCN (300 ppm) produced the highest ammonia nitrogen. However, the combination of sulfur (3%) and KCN (600 ppm) produced the lowest level of ammonia nitrogen (p < 0.01). CUB supplementation increased the in vitro dry matter digestibility (IVDMD) by 11.16% compared to the without-CUB supplemented group (p < 0.05). Supplementation with 3% sulfur increased the in vitro neutral detergent fiber (IVNDFD) by 16.87% but had no effect on IVDMD or in vitro acid detergent fiber (IVADFD) (p < 0.05). The volatile fatty acid (VFA) such as acetate, propionate, and butyrate were not different when CUB, sulfur, and KCN were added. Doses above 600 ppm had the lowest concentrations of TVFA and propionate (p < 0.01). Based on the results of this investigation, supplementing with CUB and sulfur (3%) may improve cumulative gas, digestibility, and TVAF. Supplementing with CUB, on the other hand, reduced HCN the most, by 54.6%. [ABSTRACT FROM AUTHOR]

Cyanide is a strong toxin in many tropical forage plants that can negatively affect ruminants. The aim of this study is to determine the cyanide removal efficiency, silage quality, and in vitro rumen fermentation of fresh cassava roots ensiled without an additive (control) and with Acremonium cellulase (AC), two cyanide-utilizing bacterial inoculants (Enterococcus feacium KKU-BF7 (BF7) and E. gallinarum KKU-BC10 (BC10)), and their combinations (BF7 + BC10, AC + BF7, AC + BC10 and AC + BF7 + BC10). A completely randomized design was used with eight treatments × four small-scale silo replicates. Additionally, extra silage samples (seven silos/treatment for individually opening after 0, 1, 3, 5, 7, 15, and 30 days of ensiling) were added to observe the changes in the total cyanide concentration and pH value. The fresh cassava root contained an optimal number of lactic acid bacteria (105 colony forming units/g fresh matter), and the contents of dry matter (DM) and total cyanides were 30.1% and 1304 mg/kg DM, respectively. After 30 days of ensiling, all silages demonstrated a low pH (p < 0.01). Cyanide content ranged from 638 to 790 mg/kg DM and was highest in the control (p < 0.01). The addition of BF7 + BC10 increased the crude protein (CP) content (p < 0.01). The addition of AC decreased the fibrous contents (p < 0.01). The control had less acetic acid and propionic acid contents (p < 0.01) and a greater butyric acid content (p < 0.01). However, the degrees of in vitro DM digestibility (IVDMD) and gas production were similar among treatments. Methane production ranged between 29.2 and 33.3 L/kg IVDMD (p < 0.05), which were observed in the AC + BC10 and BF7 + BC10 treatments, respectively. Overall, our results suggested that the cyanide removal efficiency after 30 days of ensiling with good-quality cassava-root silage was approximately 39% of the initial value. The enterococci inoculants and/or AC could improve the ensiling process and cyanide removal efficiency (increasing it to between 47 and 51% of the initial value). The novel enterococci inoculants (BF7 + BC10) were associated with a decreased cyanide content and an increased CP content. They appeared to promote the methanogenesis potential of the cassava root silage. More research is required to validate the use of cyanide-utilizing bacterial inoculants in cyanogenetic plants, bioenergy fermentation, and livestock.

The objective of this research was to supplement the cyanide-utilizing bacteria and sulfur in the HCN-rich diet, affecting the gas production and fermentation of rumen in vitro, and lowering the HCN content and the digestion of nutrients. A 2 × 2 × 3 factorial experiment in a completely randomized design was applied during the test. In the experiments, three factors were used. Factor A was the level of CUB at 0 and 108 CFU/mL. Factor B was the level of sulfur in the diet at 0% and 3% of dry matter (DM). Factor C was the three levels of potassium cyanide (KCN) at 0, 300, and 600 ppm. The interaction of CUB × sulfur × KCN affected gas production from the immediately soluble fraction (a) (p < 0.05). However, the greatest ruminal cyanide concentration was found when CUB (with and without), sulfur (3%), and KCN (600 ppm) were introduced at 0 h (p < 0.05). It revealed that the addition of CUB and sulfur had a significant impact on gas accumulation at 96 h (p < 0.05). The addition of CUB with sulfur had an effect on pH at 2 h and ruminal cyanide levels at 6 h (p < 0.05). At 2 h, sulfur supplementation with KCN had an effect on NH3-N (p < 0.01). The addition of sulfur (3%) and KCN (300 ppm) produced the highest ammonia nitrogen. However, the combination of sulfur (3%) and KCN (600 ppm) produced the lowest level of ammonia nitrogen (p < 0.01). CUB supplementation increased the in vitro dry matter digestibility (IVDMD) by 11.16% compared to the without-CUB supplemented group (p < 0.05). Supplementation with 3% sulfur increased the in vitro neutral detergent fiber (IVNDFD) by 16.87% but had no effect on IVDMD or in vitro acid detergent fiber (IVADFD) (p < 0.05). The volatile fatty acid (VFA) such as acetate, propionate, and butyrate were not different when CUB, sulfur, and KCN were added. Doses above 600 ppm had the lowest concentrations of TVFA and propionate (p < 0.01). Based on the results of this investigation, supplementing with CUB and sulfur (3%) may improve cumulative gas, digestibility, and TVAF. Supplementing with CUB, on the other hand, reduced HCN the most, by 54.6%.

Two experiments were undertaken to screen for ruminal cyanide-utilizing bacteria (Experiment 1), and to evaluate the influence of fresh cassava root (FCR) and pellets containing high sulfur (PELFUR) on cyanide content, gas production parameters, in vitro degradability, and ruminal fermentation (Experiment 2). Experiment 1 was conducted in a completely randomized design (CRD) for the screening of cyanide-utilizing bacteria and the dietary treatments consisted of cyanide at 0, 150, 300, and 450 ppm. In Experiment 2, a 5 × 3 factorial arrangement in a completely randomized design was used for the in vitro study. Factor A was the level of FCR at 0, 260, 350, 440, and 530 g/kg of dry matter (DM) substrate, and factor B was the level of PELFUR at 0, 15, and 30 g/kg DM substrate. In Experiment 1, adding different doses of cyanide significantly affected cyanide-utilizing rumen bacterial growth (p < 0.05). Increasing the concentration of cyanide from 0 to 150 and 150 to 300 ppm resulted in increases in cyanide-utilizing rumen bacteria of 38.2% and 15.0%, respectively. In Experiment 2, no interaction effects were found between FCR and PELFUR doses on gas production parameters (p > 0.05). Increasing the FCR level to more than 260 g/kg of DM substrate could increase cumulative gas production (p < 0.05). Increasing doses of PELFUR from 15 to 30 g/kg increased the cumulative gas production when compared with that of 0 g PELFUR/kg of DM substrate (p < 0.05). The cyanide concentration in rumen fluid decreased with PELFUR (p < 0.05) supplementation. Degradability of in vitro DM and organic matter following incubation increased at 12 and 24 h due to PELFUR supplementation with FCR and increased additionally with 15 g PELFUR/kg of DM substrate (p < 0.05) in 440 g FCR/kg of DM substrate. Proportions of the total volatile fatty acids, acetic acid (C2), propionic acid (C3), and butyric acid among supplementations with FCR (p < 0.05) were significantly different. In conclusion, the present results represent the first finding of bacteria in the rumen that are capable of utilizing cyanide, and suggests that cyanide might function as a nitrogen source for bacterial cell synthesis. The inclusion of FCR of 530 g/kg with 30 g PELFUR/kg of DM substrate could increase the cumulative gas production, the bacterial population, the in vitro degradability, the proportion of C3, and the rate of the disappearance of cyanide. [ABSTRACT FROM AUTHOR]

Two experiments were undertaken to screen for ruminal cyanide-utilizing bacteria (Experiment 1), and to evaluate the influence of fresh cassava root (FCR) and pellets containing high sulfur (PELFUR) on cyanide content, gas production parameters, in vitro degradability, and ruminal fermentation (Experiment 2). Experiment 1 was conducted in a completely randomized design (CRD) for the screening of cyanide-utilizing bacteria and the dietary treatments consisted of cyanide at 0, 150, 300, and 450 ppm. In Experiment 2, a 5 × 3 factorial arrangement in a completely randomized design was used for the in vitro study. Factor A was the level of FCR at 0, 260, 350, 440, and 530 g/kg of dry matter (DM) substrate, and factor B was the level of PELFUR at 0, 15, and 30 g/kg DM substrate. In Experiment 1, adding different doses of cyanide significantly affected cyanide-utilizing rumen bacterial growth (p < 0.05). Increasing the concentration of cyanide from 0 to 150 and 150 to 300 ppm resulted in increases in cyanide-utilizing rumen bacteria of 38.2% and 15.0%, respectively. In Experiment 2, no interaction effects were found between FCR and PELFUR doses on gas production parameters (p > 0.05). Increasing the FCR level to more than 260 g/kg of DM substrate could increase cumulative gas production (p < 0.05). Increasing doses of PELFUR from 15 to 30 g/kg increased the cumulative gas production when compared with that of 0 g PELFUR/kg of DM substrate (p < 0.05). The cyanide concentration in rumen fluid decreased with PELFUR (p < 0.05) supplementation. Degradability of in vitro DM and organic matter following incubation increased at 12 and 24 h due to PELFUR supplementation with FCR and increased additionally with 15 g PELFUR/kg of DM substrate (p < 0.05) in 440 g FCR/kg of DM substrate. Proportions of the total volatile fatty acids, acetic acid (C2), propionic acid (C3), and butyric acid among supplementations with FCR (p < 0.05) were significantly different. In conclusion, the present results represent the first finding of bacteria in the rumen that are capable of utilizing cyanide, and suggests that cyanide might function as a nitrogen source for bacterial cell synthesis. The inclusion of FCR of 530 g/kg with 30 g PELFUR/kg of DM substrate could increase the cumulative gas production, the bacterial population, the in vitro degradability, the proportion of C3, and the rate of the disappearance of cyanide.