also become potential threats to the swine industry (Dixon et al., 2019; Mazur-Panasiuk et al., 2019; Ouyang et al., 2019). Since the outbreak of ASF in Vietnam, more than 6 million pigs (in 2019) and 86,000 pigs (in 2020) have died or been culled (Ha, 2021). In addition, other threats are equally crucial in pig production, such as the increasing prevalence of antibiotic resistance (Nguyen et al., 2016), residues of chemicals used in livestock production, and increasing climate change (Le, 2017).
It's vital to find new solutions for that problems. Biosecurity is one of the critical solutions to prevent the transmission, establishment, and spread of diseases from outside to the farm, within the farm, and spread out to other farms (Dietze & Depner, 2019). Improving biosecurity in pig production has many positive effects on animal health and production performance and reduces antibiotic misuse (Postma et al., 2016; Rojo-Gimeno et al., 2016; Dewulf & Immerseel, 2019).
The Vietnamese Government has found that biosecurity is the key to the sustainable growth of pig production by promulgating regulations to force farmers to apply strict biosecurity strategies. The "National Plan for the Prevention and Control of African Swine Fever for the period of 2020 - 2025" was endorsed on July 7th, 2020 (972/QD-TTg) for ASF control and pig farm biosecurity application (FAO, 2021).
In fact, the implementation of thorough and effective biosecurity in pig production is not easy, depending on several factors such as the current situation of husbandry, human resources, and supporting tools. Biosecurity classification and rapid identification of risk factors in pig farms should be carried out by experts with a deep understanding of biosecurity. Many information technology application tools have effectively supported biosecurity assessment in pig production in recent years, such as BioCheck-Ugentยฎ and Combat ASF software (Ingelheim, 2018; Europeanpork, 2021). However, the above two software were developed in western countries. The evaluation criteria are not suitable for the characteristics of pig production in Asia and Vietnam. Other traditional biosecurity assessment methods are often paper-based, manual, time-consuming, and inconvenient. Moreover, the recent emergence of dangerous infectious diseases in animal husbandry, particularly in pig production, has led to the formation of a new thinking "new biosecurity concept" in pig production: safer and more sustainable.
Therefore, this study aimed to develop an application software Pighealth Security-X to assess biosecurity for disease prevention in pig production towards safety and sustainability.
2. MATERIALS AND METHODS
by applying the App in the field of pig farms. The App Pighealth Security-X was established with traditional and modern approaches (table 1). In the traditional approach, eight aspects of biosecurity assessment were concerned, including Location and structure; Husbandry practice;
Farm management; Transport; Husbandry equipment; Vermin and bird control; Feed, water, and equipment supply; Visitors and farm workers. In the modern approach, the eight aspects were put into space separated into regions of a farm (external and internal biosecurity). The internal biosecurity was divided into three distinct zones: Risk zone, Buffer zone, and Clean zone (Figure 1). The risk zone is related to the dirty area, where risk factors from outside the farm occur, so it is the first layer of protection; the Buffer zone is the second layer of protection where all risk factors have to be entirely eradicated before entering the Clean zone; Clean zone is the final layer of protection where the husbandry activities occur safely.
Figure 1. Swine production model with three distinct zones: Risk zone (1: area for vehicle washing facility, human disinfection room, car park; 2: area for warehouse and isolated room
of new equipments; 3: area for guest house and quarantine; 4: feed silos; 5: area for the treatment of feces, placenta, wastewater, and biogas; 6: area loading for pig selling), Buffer zone (7: area for admin office, dormitory and human disinfection room; 8: area quarantine for
introducing pigs), and Clean zone (9: boar and pregnant facility; 10: farrowing barn, 11: area for weaning and fattening pigs).
2.2. Establishing the set of questions for biosecurity assessment
Pighealth Security-X application software (App) was built based on answering a set of questions, including biosecurity implementation measures. The questionnaire was created by reviewing scientific reports, research articles from universities, conferences, and experts's presentations and opinions on biosecurity measures from representatives of veterinary companies and farms. The "filtering funnel method" was used to select the information and documents most relevant to biosecurity. This method was described by Andraud and Rose (2020). Research documents were collected on the databases Pubmed, Google scholar, and Veterinary research, including articles with search terms: "Biosecurityโ, "Pig", "Farm", and
"ASF". The documents were then selected if related to biosecurity, duplicate reports, articles related to bacteriological, virological, or immunological aspects, etc., were removed. Then, reviewing the content of selected scientific reports and related sources of knowledge to select critical biosecurity criteria in the farm to establish a set of evaluation questions.
The questionnaire focused on biosecurity in general and common aspects of the transmission of infectious diseases mentioned by OIE (Madec et al., 2010) (table 1). The questionnaire was designed to suit the farm models. Questions that do not match with the farm model were
removed. Each question had multiple choice answers. The answer options were either qualitative (yes or no) or quantitative. Every answer resulted in a score between 0 (when this measure was not implemented at all or the least optimal answer was given) and 0.5 (when the measure was fully implemented). Depending on the importance of the measure, the score was multiplied by a weight. The weight was high when the question was important, the frequency of violations was high, and the ability to overcome was difficult. The final score can vary from 0, indicating the total absence of biosecurity measures, to 100, indicating a complete application of measurements. The result included The final score was calculated by the score that users get divided by the score of the aspect category and multiplied by 100%. The App did not give the total score for the entire assessment process, instead, the App gave the assessment results for each biosecurity aspect separately. In summary, the App has 165 evaluation questions; the maximum total scores achieved for the entire questionnaire were 100 points.
2.3. Building the software Pighealth Security-X
The App was technically developed by IT team. The App was run in both IOS and Android systems. To build the software, a programming language was used for smartphones, the writing application software was Dart, and using Frameworks (which are pre-written pieces of code that make up a framework and packaged programming libraries) were Flutter. The three steps to write App included: Step 1, building a database for the application software based on a set of questions; Step 2, developing application software including the contents of Login, Evaluation of biosecurity criteria; and Step 3, check the operation and appearance of the application software.
2.4. Evaluating the reliability of scores by applying the App in the file of pig farms To evaluate the reliability of scores given by Pighealth SecurityX software in the field, a survey was conducted on pig farms. Thirty pig farms were randomly selected in Binh Phuoc province for biosecurity assessment using App (table 2). The models of these farms include breeding sow farm models raised from piglets to weaning, and fattening pig farms that raise from weaning to finishing. In addition, the above thirty farms were also divided by size, including ten large-scale farms and twenty medium-sized farms; regulations on the division of farm size are mentioned in the Circulars 13/2020/ND-CP 20/01/2020. Biosecurity was assessed by both traditional and modern approaches. The results were recorded in the system and converted into an excel file for further data analysis. The farm owners, farm veterinarians, and epidemiologists were interviewed about disease incidence on the farms. The number of cases in each symptom category (respiratory disease, gastrointestinal problem, lameness, nervous system problem, skin problem, mastitis, and reproductive problem) within each pig group (sows, sucklers, weaners, fatteners, and boars) of the herd was converted into percentages then encode into disease incidence. The percentage of each disease symptom in each pig group was calculated by the below formula. The data were analyzed to examine the correlation between the farm's biosecurity score and the farm's disease incidence over the last six months.
๐๐๐๐๐๐๐๐๐ก๐ก๐ก๐ก๐๐๐๐๐ก๐ก๐ก๐ก๐ก๐ก๐ก๐ก ๐๐๐๐๐๐๐๐ ๐๐๐๐๐ก๐ก๐ก๐ก๐๐๐๐๐ก๐ก๐ก๐ก๐๐๐๐ ๐๐๐๐๐๐๐๐ ๐๐๐๐๐ ๐ ๐ ๐ ๐ก๐ก๐ก๐ก๐๐๐๐๐ก๐ก๐ก๐ก๐๐๐๐๐ก๐ก๐ก๐ก๐๐๐๐ ๐๐๐๐๐ ๐ ๐ ๐ ๐ก๐ก๐ก๐ก๐ ๐ ๐ ๐ ๐ก๐ก๐ก๐ก๐๐๐๐๐ก๐ก๐ก๐ก๐๐๐๐
๐๐๐๐๐๐๐๐๐ก๐ก๐ก๐ก๐๐๐๐๐ก๐ก๐ก๐ก๐ก๐ก๐ก๐ก ๐๐๐๐๐๐๐๐ ๐ก๐ก๐ก๐กโ๐ก๐ก๐ก๐ก ๐ก๐ก๐ก๐ก๐๐๐๐๐ก๐ก๐ก๐ก๐ก๐ก๐ก๐ก๐ก๐ก๐ก๐ก ๐ ๐ ๐ ๐ ๐ก๐ก๐ก๐ก๐๐๐๐๐๐๐๐ ๐ก๐ก๐ก๐ก๐ก๐ก๐ก๐ก ๐ก๐ก๐ก๐ก๐ก๐ก๐ก๐ก๐๐๐๐โ ๐๐๐๐๐ก๐ก๐ก๐ก๐๐๐๐๐๐๐๐๐ ๐ ๐ ๐ ๐ฅ๐ฅ๐ฅ๐ฅ 100%
Table 2. The model and size of 30 studied pig farms
Farm models Numbers of farms Farm size
Large Medium
Breeding sow farms 6 6 0
Fattening pig farms 24 4 20
Total 30 10 20
The interviews were conducted face-to-face between the researchers and the interviewees. The users were guided through installing and using the App Pighealth SecurityX. The results of the assessment were recorded and saved in the system. Information on estimates of the disease incidence was also collected. There were five predefined disease symptom categories for the sucklers, weaners, fatteners, and boars: respiratory, gastrointestinal, lameness, nervous, and skin problem. The symptoms of mastitis and reproductive disorders were added to this list for sows. The levels of disease score range from 0 to 5 (0: no disease, 1: โค 5% morbidity; 2: โค 10%
morbidity; 3: โค15% morbidity; 4: โค 20% morbidity; 5: > 20% morbidity). For suckling piglets, weaning pigs, growing pigs, and boars, the maximum disease score for each group of pigs was 25 points. For the sow group, the maximum disease score was 35 points. So with breeding sow farms with suckling piglets, sows, and boars, the maximum disease score was 85; in the case of fattening pig farms, the maximum disease score was 50. The disease incidence results on the farm were converted to a percentage (%) by dividing the total disease score on the farm by the maximum disease score and multiplied by 100%.
The formula calculated disease incidence of breeding sow farms:
๐๐๐๐๐๐๐๐๐๐๐๐๐ก๐ก๐ก๐ก๐ก๐ก๐ก๐ก ๐๐๐๐๐๐๐๐ ๐๐๐๐๐๐๐๐๐๐๐๐๐๐๐๐๐ก๐ก๐ก๐ก๐๐๐๐๐๐๐๐ ๐๐๐๐๐๐๐๐๐๐๐๐๐๐๐๐๐๐๐๐
85 100%
The formula calculated disease incidence of fattening pig farms:
๐๐๐๐๐๐๐๐๐๐๐๐๐ก๐ก๐ก๐ก๐ก๐ก๐ก๐ก ๐๐๐๐๐๐๐๐ ๐๐๐๐๐๐๐๐๐๐๐๐๐๐๐๐๐ก๐ก๐ก๐ก๐๐๐๐๐๐๐๐ ๐๐๐๐๐๐๐๐๐๐๐๐๐๐๐๐๐๐๐๐
50 100%
The scores from the App was reliable if there was inverse correlation with disease incidence of studied farms. Beside that, to see how users think about the App, some questions for users about their opinion of Pighealth Security-X were also surveyed. Any comments or contribution for the App were also recorded for further updated.
2.5. Data analysis
The data was recorded and calculated by Microsoft Excel 2016. The correlation between the biosecurity score and disease incidence of the farms was assessed by the Pearson Correlation method. The differences in the mean score were evaluated by T-test in R software.