Innovation in Formaldehyde-Free Feed Disinfectant: Strengthen Feed Biosecurity and Protect Animals from Pathogen Infection


Kin Ken Chew, Tobey Song and Grant Tan

 
 


Introduction


In modern livestock farming, a robust biosecurity program is crucial for ensuring healthy animals and safe food production. Feed safety is a vital component of biosecurity management. Feed and feed ingredients have been identified as key transmission vehicles for pathogens such as Salmonella spp. and African Swine Fever Virus (ASFV) (Sargeant et al., 2021; Niederwerder et al., 2022). Since feed is at the upstream end of the feed-to-farm chain, any pathogen contamination can significantly impact animal health, productivity, and food safety. Supplementing livestock feed with feed disinfectants can enhance biosecurity, preventing pathogen contamination and recontamination throughout the feed-to-farm chain, thereby safeguarding animal health and consumer safety (Dee et al. 2014; Stewart et al., 2020).


Innovation in Formaldehyde-Free Feed Disinfectant: Sal CURB™ K Plus Liquid


Sal CURB™ K Plus Liquid (SCK+L) is a formaldehyde-free feed disinfectant developed for rapid and effective inhibition of bacterial pathogens such as Salmonella spp. and emerging viral pathogens like ASFV present in feed. The formulation has an optimized ratio of ionic to non-ionic organic acids to enhance the pathogen-killing efficacy. Additionally, surfactant is incorporated to improve the dispersion of antimicrobial agents throughout the feed, maximizing the inhibition effect. SCK+L is also engineered with a dual anti-corrosion technology to reduce its corrosiveness and ensure end-user safety.


Optimized ratio of ionic to non-ionic organic acids for greater pathogen-killing effect


SCK+L is formulated with an optimized balance of ionic and non-ionic organic acids to improve the pathogen- killing efficacy. Figure 1 illustrates a study comparing the effectiveness of SCK+L in inhibiting the growth of Salmonella Enteritidis (ATCC® 13076™). and Escherichia coli (ATCC® 13076™) against a positive control formulation with the same composition of organic acids. At the same concentrations (i.e., 0.12% for S. Enteritidis and 0.14% for E. coli), SCK+L demonstrated greater effectiveness in inhibiting the growth of both pathogens.

 


Formulated with dual anti-corrosion technology


Despite its low pH, SCK+L is engineered with dual anti-corrosion technology to minimize its corrosiveness, making it user- and equipment-friendly (Figure 2).

 

An accelerated corrosion test was conducted by partially immersing galvanized metal plates in the products and incubating them at 65°C for 11 days (KID: TD-23-8917). Table 1 shows the pH and corrosivity of SCK+L compared to a product (Product X) with a higher pH. Although SCK+L has a lower pH, its dual anti-corrosion technology enabled it to be less corrosive than Product X, which has a higher pH.
 


Mitigating the ASFV transmission risk in feed


In addition to bacterial pathogens, SCK+L has demonstrated efficacy against viral pathogens such as ASFV in feed. A collaboration study with the National Institute of Veterinary Research (NIVR) in Vietnam was conducted to evaluate the effectiveness of SCK+L in inactivating ASFV activity in feed (KID: TD-22-8475). Sal CURB™ RM E Liquid, containing formaldehyde and proven effective against ASFV (Tran et al., 2020), was included as a reference in this study.
 
The experimental design comprised of four treatment groups: the Negative control (Corn-soy feed), Untreated control (Corn-soy feed contaminated with ASFV at 1 x 103 haemadsorption (HAD50); Treatment 1 (Contaminated feed treated with 1 kg/T Sal CURB™ RM E Liquid) and Treatment 2 (Contaminated feed treated with 3 kg/T SCK+L). Swine feed contamination was achieved by spiking highly virulent ASFV strain VN/Pig/HN/19 at a dose of 1 x 103 HAD50 on day 0. Samples were retained for 7 days, with samplings conducted on days 1, 3, and 7 post-contamination (dpc). Two assays were conducted: real-time polymerase chain reaction (qPCR) and hemadsorption assay (HAD).
 
SCK+L exhibited an inhibitory effect on the ASFV activity in the feed matrix (Figure 3). In qPCR, SCK+L at 3 kg/T demonstrated comparable efficacy against ASFV as Sal CURB™ RM E Liquid at 1 kg/T. In the HAD assay, SCK+L showed a significant reduction in HAD values at 3- and 7-dpc.
 

Figure 3. qPCR detection (left) and HAD assay (right) of ASFV in untreated control, feed treated with 1 kg/T Sal CURB™ RM E Liquid (SCRME) and feed treated with 3 kg/T SCK+L on 1-, 3- and 7-dpc. No cycle quantification (Cq) values and viral activities were detected in negative controls. One-way ANOVA and Tukey's honest significant difference were conducted to examine differences between groups. Mean and standard deviation are presented (n = 3). Different letters indicate significant differences between groups (p < 0.05).
 
Alternative to medium-chain fatty acids for mitigating the ASFV transmission risk in feed
 
Medium-chain fatty acids (MCFA) have been reported for their antiviral properties as feed additives. In collaboration with NIVR in Vietnam, a study was conducted to examine the antiviral activity of SCK+L against ASFV, comparing its efficacy to MCFA (KID: TD-22-8475). The experiment consists of six groups: Negative control (Corn-soy feed), Untreated control (Corn-soy feed contaminated with ASFV); Treatment 1 (Contaminated feed treated with MCFA at 1, 2, and 3 kg/T), and Treatment 2 (Contaminated feed treated with 3 kg/T SCK+L). The antiviral efficacy of the feed additives was tested against a higher viral contamination level of ASFV at 1 x 105 HAD50 on day 0. Samples were maintained for 7 days, with samplings conducted on days 1, 3, and 7 post-contamination (dpc). Two assays were conducted: real-time polymerase chain reaction (qPCR) and hemadsorption assay (HAD).
 
A minimum dosage of 3 kg/T of MCFA was required to exhibit significant antiviral activity against ASFV spiked at a high contamination level, i.e., 105 HAD50 (p < 0.05). SCK+L demonstrated a comparable antiviral effect against ASFV at the same dosage of 3 kg/T (vs. 3 kg/T MCFA; p > 0.05). This suggests that SCK+L is a viable alternative to MCFA for controlling ASFV in feed.
 


Figure 4. qPCR detection (left) and HAD assay (right) of ASFV in untreated control, feed treated with medium-chain fatty acids (MCFA) at 1 kg/T, 2 kg/T, and 3 kg/T, and feed treated with 3 kg/T Sal CURB™ K Plus Liquid on 1-, 3- and 7-dpc. No Cq values and viral activities were detected in negative controls. One-way ANOVA and Tukey's honest significant difference were conducted to examine differences between groups. Mean and standard deviation are presented (n = 3). Different letters indicate significant differences between groups (p < 0.05).

 

Summary


Feed safety is paramount in modern livestock farming, as it serves as a potential vector for pathogens like Salmonella spp., E. coli, and ASFV, posing risks to both animal health and consumer safety. SCK+L provides livestock producers with a formaldehyde-free solution for effectively inhibiting a wide range of pathogens in feed, including Salmonella spp., E. coli, and emerging viral pathogens such as ASFV. Its optimized balance of ionic to non-ionic formulation of organic acids enhances its pathogen inhibition effect. Additionally, the inclusion of a surfactant in the formulation improves the dispersion of antimicrobial actives throughout the feed, maximizing the inhibition effect. The incorporation of dual anti-corrosion technology in SCK+L further ensures its efficacy and user-friendliness, making it an essential choice for modern livestock producers dedicated to protecting animal health and consumer safety.
 
 
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