Journal of Kasetsart Veterinarians vol. 29 No. 1. 2019

Journal of Kasetsart Veterinarians vol. 29 No. 1. 2019 วารสารสตวแพทย ปท ๒๙ ฉบบท ๑ ๒๕๖๒

Practices and Factors Influencing the Use of Antibiotics

in Swine Farms in Central Region of Thailand

แนวปฏบตและปจจยทมอทธพลตอการใชยาปฏชวนะ

ในฟารมสกรในพนทภาคกลางของประเทศไทย

Narayan Pokhrel1, Suwicha Kasemsuwan2, Flavie Goutard3, Alongkot Boonsoongnern4,

Suksun Chumsing2, Phitsanu Tulayakul2,*

Narayan Pokhrel1 สวชา เกษมสวรรณ2 Flavie Goutard3 อลงกต บญสงเนน4

สขสนต ฉ�าสงห2 และ พษณ ตลยกล2,*

1Bio-Veterinary Science (InterRisk Program), Faculty of Veterinary Medicine, Kasetsart University,

Bangkok 10900, Thailand 1หลกสตรวทยาศาสตรชวภาพทางสตวแพทย (โครงการ InterRisk) คณะสตวแพทยศาสตร

มหาวทยาลยเกษตรศาสตร กรงเทพฯ 10900 2Department of Veterinary Public Health, Faculty of Veterinary Medicine, Kasetsart University,

Kamphaeng Saen Campus, Nakhon Pathom, 73140, Thailand 2ภาควชาสตวแพทยสาธารณสขศาสตร คณะสตวแพทยศาสตร มหาวทยาลยเกษตรศาสตร

วทยาเขตก�าแพงแสน นครปฐม 73140 3AGIRs unit, Centre de coopération internationale en recherche agronomique pour le développement

(CIRAD), Montpellier, France 4Department of Farm Resources and Production Medicine, Faculty of Veterinary Medicine,

Kasetsart University, Nakhon-Pathom 73140, Thailand 4ภาควชาเวชศาสตรและทรพยากรการผลตสตว คณะสตวแพทยศาสตร มหาวทยาลยเกษตรศาสตร

วทยาเขตก�าแพงแสน นครปฐม 73140

*Corresponding author: [email protected]

Received, October 7, 2018; accepted, April 30, 2019

บทคดยอ

ยาปฎชวนะมการใชอยางกวางขวางในอตสาหกรรมการผลตสกรเพอควบคมโรคชนดตางๆ

ในฟารม การใชยาปฏชวนะอยางกวางขวางในสตวทเปนอาหารนนยอมสงผลกระทบความเสยงตอการ

ดอยาปฏชวนะของแบคทเรยในสตวนน มความจ�าเปนอยางยงทตองมความเขาใจถงขอมลพนฐาน

ของฟารมสกร การใชยา การปฎบตตางๆ และปจจยทมอทธพลตอการใชยาปฏชวนะในฟารมสกร

34 วารสารสตวแพทย ปท ๒๙ ฉบบท ๑ ๒๕๖๒

การศกษานเปนการแสวงหาแนวปฏบตและปจจยทสงผลตอการใชยาปฏชวนะภายในฟารมสกรโดยใช

แบบสอบถามสงไปยงฟารมในพนทภาคกลาง จ�านวน 90 แหง ไดแก จงหวดราชบร นครปฐมและสพรรณบร

พบ 97.77% (88/90 ฟารม) มการใชยาทงสน 8 กลมใน 3 จงหวด เพอเปาหมายในการปองกนและการรกษา

ฟารมสวนใหญใชยาโคลสตน (76%) มรายงานวาเกดการทองเสยจากเชออโคไล คดเปน 71% ยาปฏชวนะ

ปรมาณมากถกใชไปเพอการรกษาโรคของระบบทางเดนหายใจมากกวาโรคชนดอนๆ ในชวงสองป

ทผานมา พบวาเกษตรกรผ เลยงสกรใชยาจากประสบการณคดเปนเปน 52% โดยทไมไดปรกษาสตวแพทย

ทเชยวชาญและพบวามการใหบคคลทไมใชสตวแพทยในการใหยากบสตวคดเปน 97% และเกษตรกร

ผ เลยงสกรสามารถเขาถงยาไดอยางสะดวกคดเปน 91% จากขอมลทไดจากการศกษาน เกษตรกรผ เลยง

สกรทมวฒการศกษาเทยบเทาระดบปรญญาตรหรอสงกวาจะมความตระหนกถงประเดนการดอยา (AMR)

ซงแสดงใหเหนวามความรเกยวกบการใชยาและเชอดอตอยาปฏชวนะมากกวาเกษตรกรทมการศกษา

ในระดบอน จากขอมลขางตนน�าไปสการแสวงหามาตรการทเหมาะสมในการจดการการใชยาปฏชวนะท

มากเกน การใชยาผดประเภทและขอก�าหนดการใชยาและการเขาถงยาปฏชวนะของเกษตรกรผ เลยงสกร

ในประเทศไทย

ค�าส�าคญ: การดอตอยาปฏชวนะ สกร แนวปฏบตและปจจย ฟารมสกร

ABSTRACT

Antibiotics are extensively used in swine

production to control different kind of diseases

in the farms, extensive use of antibiotics in

food producing animals enhance the risk of

antibiotic resistance in the commensal

bacteria of these animals. It is essential to

understand the background of the swine

farms, drug usage, practice and factors

influencing use of antibiotics. This study was

conducted to investigate practices and factors

influencing use of antibiotics in swine farms

using questionnaire surveys among 90 pig

farmers in Central Thailand (Ratchaburi,

Nakhon Pathom and Suphanburi). Eighty-eight

of ninety farms (97.77%) in the three provinces

used eight classes of antibiotics for therapeutic

and prophylaxis purposes. Majority of the

farms used colistin (76%). Sixty-four of ninety

farms (71 %) of the farmers reported E. coli

diarrhoea on their farms, large quantity of

antibiotic was used to treat respiratory disease

as compared to other disease in the last two

years. Forty-six of eighty-eight farms (52%)

relied on experience to use antibiotics with no

supervision of veterinary personnel and in 97%

of the farms non-veterinary people administer

antibiotic in animals. Eighty of eighty-eight

farms (91%) had easy access to antibiotics.

Farmers with education equivalent to bachelor

degree and above and farmers who had

received awareness on AMR showed better

knowledge on antibiotic use and antibiotic

35วารสารสตวแพทย ปท ๒๙ ฉบบท ๑ ๒๕๖๒

resistant as compared to farmers with less

education and received no awareness on

AMR. These findings call for a want of prompt

actions on antibiotic overuse, antibiotic misuse

and strict regulation on the use and access to

antibiotics on piggery farms in Thailand.

Keywords: antimicrobial resistance, swine,

practices and factors, swine farming

INTRODUCTION

Pig production is one of the most important

food animals produced and consumed in

Thailand, There are approximately 9.7 million

pigs raised in Thailand (Love et al., 2015).

The main swine production area in Thailand

is the Central region with approximately 57%

of country’s swine population. Swine farms in

Central and Eastern regions are for commercial

production, and Northern has backyard as well

as commercial production. Swine raised in

backyard operation are basically used for

home consumption or sold locally in the

community, and swine from the commercial

farms are processed and exported to large

market (Phongpaichit et al., 2007).

Many diseases affect pig industry in

Asia, where antibiotics use is perceived

necessary. Some of the most common disease

is bacterial diseases including enzootic

pneumonia, pasteurellosis, post-weaning

diarrhea, porcine pleuropneumonia and viral

disease like swine fever, porcine coronaviruses,

foot and mouth disease and other parasitic

disease like coccidiosis (Cameron, 2000).

Many classes of antibiotics like tetracycline,

sulfonamides, fluoroquinolones, macrolides,

cephalosporin, lincosamide, polymyxin and

polypeptides are used in pig production in

Asia (Becker, 2010).

Antimicrobial usages in animal was

considered a major driven cause, especially

use of antimicrobials in food producing

animals were significant contributor to the

global burden of anti-microbial resistance in

humans as the antimicrobials use in animal

production and in human clinics were of

similar types (Nhung et al., 2016). Intensive

pig farming is identified as the sector which

uses large amount of antibiotics and has

major contribution in the development of

antimicrobial resistance (AMR) (Rushton et al.,

2014; Schwarz et al., 2001). Resistance

against colistin which is last resort of

antimicrobials have caused greater concern

and use of colistin in swine production is

a contributing factor (Nhung et al., 2016).

Farmers’ decision making and practice

of antibiotics are usually determined by

external and internal factors. External factors

such as farm factor like housing condition of

the animals. Internal factors like farmers

attitude towards antibiotics, awareness on

antibiotics resistance, need for antibiotics in

farming (Willock et al., 1999).


In many of the studies, it was reported

that most of the pig farmers have different

perceptions of antimicrobial resistance in the

farms. Marvin et al., 2010 reported that pig

farmers in Ontario (Canada) were much less

aware of risk of AMR than as compared to

veterinarian. A study done in Swiss pig farming

showed that farmers were more concerned

about financial affair than antimicrobial

resistance (Visschers et al., 2014). Some pig

farmers perceived that antibiotics are easy

to use and cost effective and very effective in

curing and preventing diseases in the farm,

and farmers are willing to use as prophylactic

treatment (Callens et al., 2012).

The antibiotic usage in farm is also

heavily influenced by non-infectious factors in

the farm such as the environment bestowed

to the pigs, biosecurity, management and

feeding practices in the farm which are directly

linked to animal health (Armstrong et al., 2014).

The aim of this study was to find out

the practices and factors influencing use of

antibiotics in swine farms in Central region of

Thailand. The findings of this study could be

used for educating farmers for smart animal

drug uses in their swine farming and informing

veterinarian and other stakeholders on the

detrimental effect of misuse of antibiotics in

the pig industry. In the global context outcome

of this study will be a recommendation to

institute programs to control development of

antibiotic resistance bacteria of swine origin

and to curb propagation of antimicrobial

resistance from swine to human and environment.

MATERIALS AND METHODS

The study design, study area and study population

It was a cross-sectional study performed

using questionnaire surveys on practices and

factors influencing use of antibiotics in swine

farms in the Central Region of Thailand, mainly

in the three provinces of Ratchaburi, Nakhon

Pathom and Suphan Buri from February 2017

to May 2017. The samples were collected

in the Diagnostic Centre Unit at Faculty of

Veterinary Medicine, Kaemphaeng Saen,

Nakhon Pathom; Piggery farms in these region

referred fecal samples to Diagnostic Center

Unit for laboratory diagnosis of infections in

the farms. The sampling unit for the survey was

large-scale pig farm in the three provinces of

the central region which holds more than 50

pigs in the farm. The classification of farm size

was adapted from the study by Thanapongtharm

et al., 2016. There were 931 large scale farms

in the three provinces (DLD, 2015). The

population was assumed to be homogenous

based on the identical pig husbandry practices

and management in the area.

Sample Size

Initially the sample size calculation was

based on simple random sampling method;

non-probability convenience sampling was


adapted to meet the minimum required sample

size of 88. Hypothesis was that the expected

50% (worst-case scenario) of the respondents

had better knowledge and follow good

practices of antibiotic use and AMR. ProMESA

(Version 2.3.0.2. EpiCentre, Massey University,

NZ) was used with population size of 931,

with confidence interval of 95% (CI) and 10 %

acceptable relative error. The following

formula was used to calculate the sample size.

n = p x (1 – p) x z2 e2

Where:

n The sample size calculated for an

infinite population

p The assumed prevalence of the event

in the population under study

z The critical value obtained from

a standard normal distribution. (For 95% CI,

z value is 1.96)

e Maximum absolute acceptable error

Questionnaire design and administration

The questions in the questionnaire were

developed taking into consideration all the

factors and practices associated to misuse of

antibiotics in the pig husbandry and formation

of AMR microorganism in farms. Questionnaire

for evaluating factors and practices influencing

use of antibiotics include relevant information

including rearing model, farm size, disease in

the farm, antibiotic usage, accessibility of

antibiotics for farm use, reason for antibiotic

use. Questions were also related to farm

management, public health concern and

assessment of farmers’ awareness, knowledge

and attitude on antibiotic resistance and

farmers’ profiles. Eight questions were asked

to assess farmers’ knowledge and attitude on

antibiotic use and AMR, Sixteen questions

were asked to evaluate antibiotic use practices

and accessibility to antibiotic, fifteen questions

asked to assess farm and respondents’

demographic status, two questions each were

asked to see public health concern of the

farmer and common pig disease encountered

in the farm.

Questionnaires were originally developed

in English language and objectives of the

survey was mentioned, participation was

mainly on the willingness of the participants,

confidentiality of the participants was maintained.

Questionnaires were translated into Thai and

it was done a pretested using expert opinion

and retested with ten swine farmers which

these data were not included in the real study.

Questions were edited and modified based

on the feedbacks received from the mock

survey.

Questionnaire surveys were conducted

in the field with the help of local veterinarians

of the study area, before the survey interviewers

involved in the survey were oriented on the

objectives of the study, and were explained

all the questions thoroughly. Owing to lack of


proper sampling frame, farm to farm survey

was conducted. Interview was done face to

face with the farmers and the answers were

recorded. After failing to get access to many

farms and farmers refusal to participate in the

study, postal mail survey was administered,

farmers received a questionnaire with a

stamped and addressed return envelope.

In record, 250 mail surveys were administered

in three provinces. The final samples received

were 54 samples from the face to face interview

and 37 samples from the postal mail survey

(one of the postal mail surveys received was

blank, with no response), so in all 90 samples

were collected by the combined procedure

and the database received did not show any

difference in term of response between face

to face and postal survey.

Data analysis

The Microsoft excel was used to store

and clean the data generated from the

questionnaire survey. The statistical analyses

were performed using Epi Info TM statistical

software (Version 7.2.1.0, Centers for Disease

Control and Prevention, Atlanta, GA, USA).

Descriptive statistics: Used chart /Percentage

with a 95% CI to describe the data. Inferential

statistics: Chi square test was used to assess

the significantly statistical association (when

the expected frequency in any cell is less than

5. Fisher’s exact test was used). p-values of

<0.05 was considered statistically significant.

RESULTS

Respondents and surveyed farms demographic

and characteristics

A total of 90 respondents were surveyed

(one per farm). Table 1 shows the demographic

and characteristics of the respondents and

surveyed farms. The median age of the

respondents was 43 years (mean 44 years;

range 26-76 years). Farms surveyed fell into

equal distribution of small, medium and large

category, had pigs per farm ranging from

100 to 100,000 pigs. Around 80% of the farms

depend on underground water like well and

bore well.

Common disease encountered on the farms

Various kind of disease affected pigs in

the farms, disease affecting piggery were

categorized as respiratory, enteric and

vesicular diseases from the questionnaire

survey as shown in (Figure 1).

Common antibiotics used on the farms

Only 2 surveyed farms (2.2%) did not

use antibiotics whilst other 88 (97.8 %) farms

reported that they use antibiotics. Over 11

antibiotic agents consisting of 8 antibiotic

classes were utilized on the surveyed piggery

farms. Colistin was employed in majority of the

farms (76.1%) as shown in figure 2. There was

no significant difference in the use of antibiotics

in the surveyed farms (p >0.05).


Table 1 Characteristics of respondents in a study of practices and factors influencing use of

antibiotics in swine farms in Central region of Thailand

Respondents demographic characteristics n (%)

Gender

Male

Female

62/90 (68.9)

28/90 (31.1)

Age (years)

26 - 40

41 - 55

≥ 56

37/90 (41.1)

41/90 (45.6)

12/90 (13.3)

Education Level

< Bachelor

≥ Bachelor

29/90 (32.2)

61/90 (67.8)

Province (Location)

Ratchaburi

Suphan Buri

Nakhon Pathom

34/90 (37.8)

29/90 (32.2)

27/90 (30.0)

Have training in pig rearing

Yes

No

74/90 (82.2)

16/90 (17.8)

Received awareness to reduce use of antibiotic in the farm

Yes

No

40/90 (44.4)

50/90 (55.6)

Farms demographic characteristics

Size

Small (51500- pigs)

Medium (501- 5000 pigs)

Large (>5000 pigs)

23/90 (25.6)

34/90 (37.8)

33/90 (36.6)

Age of farm (years)

< 20

≥ 20

48/90 (53.3)

42/90 (46.7)


Table 1 Characteristics of respondents in a study of practices and factors influencing use of

antibiotics in swine farms in Central region of Thailand (Coutinue)

Respondents demographic characteristics n (%)

Pig rearing model

Farrow to finish

Farrow to nursery system

Finishing system

61/90 (67.8)

8/90 (8.9)

21/90 (23.3)

Pig operation type

One site

More than one site

49/90 (54.4)

41/90 (45.6)

Type of feed use

Commercial feedstuff

Feed formulated in the farm

22/90 (24.4)

68/90 (75.6)

Source of water

Well

Bore well

Pipe borne

Rainfall collection

Irrigation canal

26/90 (28.9)

54/90 (60.0)

1/90 (1.1)

2/90 (2.2)

7/90 (7.8)

Waste management

Open lagoon

Bio gas

Open release

45/90 (50.0)

34/90 (37.8)

11/90 (12.2)

Other livestock integrated

Yes

No

24/90 (26.7)

66/90 (73.3)

Percentage of Nursery Pig lost in last one year (%)

< 5

≥ 5

57/90 (63.3)

33/90 (36.7)


31.1 33.3 28.9

71.1

37.8

10.0

47.8

27.8 32.2

14.1

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76.1

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Figure 1 Common disease encountered in the pig farms (n= 90) in Central Thailand

Figure 2 Common antibiotics used in pig farms in central Thailand


Purpose of antibiotics use and accessibility

to antibiotics on the surveyed farms

In all the surveyed farms in the three

provinces, different antibiotic agents were

utilized for treatment of diseases and for

prophylactic purposes ; no farm reported use

of antibiotic as growth promoters. 18.2 % of

the farms used antibiotics only for treatment

purposes whilst 81.8% of farms used antibiotics

for both treatment and for prophylaxis. Over

90.9 % of the farmers did not have difficulty in

accessing antibiotics, private drug company

is a major source of antibiotics for the piggery

farms. 72.7 % of the farmers mostly rely on

their experience to use antibiotics as shown

in Table 2.

Table 2 Accessibility to antibiotics and antibiotics related information, comparing large pig farms

with small and medium pig farms in Central Thailand [n = 88 (only farms using antibiotics)]

Variables /category n (%)

Small and Medium

Farm (≤5000 pig)

[n= 57(%)]

Large Farm

(>5000 pig)

[n=31(%)]

p-value

Access to antibiotics

Easy

Difficult

80/88 (90.9)

8/88 (9.1)

52/57 (91.2)

5/57 (8.8)

28/31 (90.3)

3/31 (9.7)1*

Source of antibiotics

Animal pharmacy

Private drug company

18/88 (20.4)

70/88 (79.6)

14/57 (24.6)

43/57 (75.4)

4/31 (12.9)

27/31 (87.1)0.271*

Antibiotic use information

Veterinarians

Experience

24/88 (27.3)

64/88 (72.7)

20/57 (35.1)

37/57 (64.9)

4/31 (12.9)

27/31 (87.1)0.043*

Purpose of antibiotics

Treatment only

Treatment and prevention

16/88 (18.2)

72/88 (81.8)

10/57 (17.5)

47/57 (82.5)

6/31 (19.4)

25/31 (80.6)1

Frequency of antibiotic use

Use every day

Not every day

49/88 (55.7)

39/88 (44.3)

34/57 (59.7)

23/57 (40.3)

15/31 (48.4)

16/31 (51.6)0.428

* Fisher’s exact test; significant difference at p < 0.05


Practices related to the use of antibiotics

among piggery farmers

Of the 88 surveyed farms which used

antibiotics, 96.6% reported that non-veterinarians

administer antibiotics in the farms, veterinarian

administer antibiotics only in 3.4% of the farms.

79.5% followed withdrawal periods, 89.8%

completed antibiotic course duration in the

farms and 64.8% maintained drug use record

book. 72.8% of the farms sought veterinarians’

advice to decide dose of antibiotics while only

38.6 % consulted veterinarians before buying

antibiotics. Choice of kind of antibiotics used

in the farms mainly based on experience,

only 37.5% followed veterinarians’ prescription.

The differences in practices factors among

three provinces as well as among different

category of farms were not statistically

significant (p >0.05). Figure 3 summarizes the

percentage of respondents good practices

related to antibiotic uses.

Swine farmers’ knowledge and attitude of

antimicrobial resistance and antibiotic use

Table 3 includes bivariate analyses of

the swine farmers’ knowledge and attitude on

antimicrobial resistance and antibiotic use in

the three provinces. In total, 50% (45/90) of

the farmers knew that use of antibiotics is the

main cause of emergence of antibiotic

resistant bacteria in the farm. When asked if

they have any plan to stop using antibiotics in

the farm, 58.9% had no plan to stop using

antibiotics as there is high prevalence of disease

in the pig farming, 7.8% were concerned about

AMR and food safety. Figure 4 and 5 summarizes

the percentage of response to knowledge and

attitude on AMR and antibiotic use in pig farms.

3.438.6

37.510.2

52.327.2

89.879.5

92.090.992.0

77.8

0 10 20 30 40 50 60 70 80 90 100Veterinarians administer antibiotics in the farmConsult veterinarian before buying antibiotics

Choice of kinds of antibiotics use in a farm mainly based on veterinarianChoice of kinds of antibiotics use in a farm mainly based on lab. diagnosis

Choice of kinds of antibiotics use in a farm mainly based on experienceConsult veterinarian to decide the dose of antibiotics

Complete the course of antibiotics in the farmMaintain the withdrawal of antibiotics in the farm

Maintain drug use records in the farmEasy accessibility to antibiotics

Antibiotics added in the feedVeterinarians visit farm

Percentage

Figure 3 Antibiotics use practices in the pig farms in Central region of Thailand.


Table 3 Descriptive and bivariate chi square analyses of responses to questions related

to knowledge and attitude of antimicrobial resistance and antibiotic.

Variable/Category n (%)

Pig farmers have

training in pig

rearing (%)p-value

Pig farmers who have

received awareness

on AMR and to reduce

antibiotic use (%)p-value

Yes No Yes No

Antibiotics can cure and

prevent all the disease of

my farm

Yes

No

37/88 (42.0)

51/88 (58.0)

27 (37.5)

45 (62.5)

10 (62.5)

6 (37.5)

0.101

23 (57.5)

17 (42.5)

14 (28.0)

36 (72.0)

0.009

Antibiotics work less

effectively than in the past

on my farm

Yes

No

69/88 (78.4)

19/88 (21.6)

56 (77.8)

16 (22.2)

13 (81.2)

3 (18.8)

1*

33 (84.6)

6 (15.4)

36 (73.5)

13 (26.5)

0.316

Use of antibiotics

increases production and

hence profit in my farm

Yes

No

68/88 (77.3)

20/88 (22.7)

53 (73.6)

19 (26.4)

15 (93.8)

1 (6.2)

0.105*

31 (79.5)

8 (20.5)

37 (75.5)

12 (24.5)

0.852

Use of antibiotic is the

cause of emergence of

antibiotic resistant bacteria

in the farm

Yes

No

45/90 (50.0)

45/90 (50.0)

35 (47.3)

39 (52.7)

10 (62.5)

6 (37.5)

0.220

26 (65.0)

14 (35.0)

19 (38.0)

31 (62.0)

0.019

Inappropriate use of

antibiotics in food animals

can lead to resistance in

pathogens

Yes

No

62/90 (68.9)

28/90 (31.1)

48 (64.9)

26 (35.1)

14 (87.5)

2 (12.5)

0.133*

36 (90.0)

4 (10.0)

26 (52.0)

24 (48.0)

0*


Table 3 Descriptive and bivariate chi square analyses of responses to questions related

to knowledge and attitude of antimicrobial resistance and antibiotic. (Coutinue)

Variable/Category n (%)

Pig farmers have

training in pig

rearing (%)p-value

Pig farmers who have

received awareness

on AMR and to reduce

antibiotic use (%)p-value

Yes No Yes No

Believe overuse of

antibiotics in animals

could lead to antibiotic

resistance among farm

workers

Yes

No

44/90 (48.9)

46/90 (51.1)

38 (51.4)

36 (48.6)

6 (37.5)

10 (62.5)

0.465

27 (67.5)

13 (32.5)

17 (34.0)

33 (66.0)

0.003

* Fisher’s exact test

48.9

88.9

68.9

50.0

77.3

78.4

42.0

0 10 20 30 40 50 60 70 80 90 100

Believe overuse of antibiotic in animals could lead to antibiotic resistance among farm workers

Believe vaccines will help reduce use of antibiotics in a farm

Inappropriate use of antibiotics in food animals can lead to resistance in pathogens

Believe use of antibiotics is the cause of emergence of antibiotic resistant bacteria in a farm

Use of antibiotics increases production hence profit in my farm

Antibiotics work less effectively than in the past on my farm

Antibiotics can cure and prevent all disease in my farm

Percentage

Figure 4 Response to knowledge and attitude of AMR and antibiotics use in pig farms

from Central region of Thailand (Responses to the first three questions are from

88 respondents who use antibiotics, whilst rest responses are from 90 respondents)


Figure 5 Respondents’ attitude towards plan to stop using antibiotics in pig farms in Central

region of Thailand

11.1

7.8

22.2

58.9

No response

Have plan to stop, concerned about AMR and food safety

Have plan to stop using antibiotics to decrease expenditure in the farm

No plan to stop using antibiotics as there is high prevalence of disease in the pig farming

Percentage0 10 20 30 40 50 60 70 80 90 100

Table 4 shows chi square analysis

of farmers’ knowledge of antibiotic and

antibiotic resistance linked with education

and awareness on AMR. A significant relation

was found between the belief that antibiotic

can cure and prevent all the disease and

the level of education (p=0.03), A similar

relationship was noted in the knowledge

that use of antibiotic is the cause of emergence

of antibiotic resistant bacteria in the farm

(p=0.024), farmers who had bachelor and

more education showed better knowledge

as compared to those with less education.

DISCUSSION

This cross-sect ional study was

conducted to understand the practices,

knowledge and attitude of antibiotic use and

antimicrobial resistance and to investigate

factors influencing use of antibiotics in the

pig farms. It provides valuable information

on which to build antimicrobial resistance

awareness education programme and to

institute proper antibiotic use guidelines in

the pig farming.

A total number of 90 pig farms were

calculated and surveyed from three provinces.

All of the surveyed farms were large scale

farms representing large scale-farming

system (pig holding more than 50 per farm).

The high concentration of large scale farms

in the selected region could be due its proximity

to Bangkok metropolitan city, large scale pig

farming are located surrounding Bangkok

metropolitan region for easy transportation of

produce to consumption market and to gain

easy access to supply chain of pig feed

ingredients (Kunavongkrit and Heard, 2000).


Table 4 Chi square analysis of farmers’ knowledge of antibiotic and antibiotic resistance linked

with education and awareness on AMR

Variable/Categoryn (%)

Level of Education of farmers

p-valueOdd

ratios< Bachelor

n = 29 (%)

≥ Bachelor

n = 61 (%)

Antibiotics can cure and prevent

all the disease in the farm?

Yes

No

37/88 (42.0)

51/88 (58.0)

19 (65.5)

10 (34.5)

18 (30.5)

41 (69.5)

0.003 4.3

Use of antibiotic is the cause

of emergence of antibiotic

resistant bacteria in the farm?

Yes

No

45/90 (50.0)

45/90 (50.0)

9 (31.0)

20 (69.0)

36 (59.0)

25 (41.0)

0.024 0.31

Common disease encountered on the

surveyed piggery farms included respiratory,

enteric and vesicular disease, which are known

to be common disease of swine (Cameron,

2000). Such disease could be a cause of

great financial loss to farmers (VE Boamah

et al., 2016). Farmers try to prevent and also

treat them, and use of antibiotics is a major

option for treatment of infections in pig farms.

Antibiotics used in pig farming were

employed for therapeutic and non-therapeutic

purposes (Marshall and Levy, 2011). Farmers

in this study used antibiotics mainly for

therapeutic and prophylaxis purposes, no one

reported of using antibiotic as growth promoter,

it may be due the strict regulation by the

concerned authorities. Use of antibiotic as

growth promoters in animals was banned in

Thailand since 2015 (Thamlikitkul et al., 2015).

Prophylaxis purpose of antibiotics

but not for metaphylactic is associated

with sub-therapeutic doses of antibiotics in

food animals (Om and McLaws, 2016),

sub-therapeutic dose results to antibiotic

resistance in bacteria in these animals, animal

products and environment (Boeckel et al.,

2015). Eight classes of antibiotics were

employed by the farmers and most of these

antibiotics used on the surveyed farms were

categorized into antibiotic class described by

the World Health Organization as essential

antibiotics (WHO, 2010). The inappropriate

and over use of these antibiotics could extent

the emergence of resistance bacteria to the

different class of antibiotic (Cogliani et al.,

2011). Majority of the farmers in the surveyed

farms used colistin as compared to other

antibiotics, the reasons could be due to


ineffectiveness of other antibiotics as compared

to colistin, as bacterial resistant against colistin

is still low as compared with other antibiotics

(Nhung et al., 2016).

Swine farmers in the study region did

not have difficulty in accessing to antibiotics.

They could easily get antibiotics from private

drug companies, and most of the farms use

antibiotics daily. It is good to have easy access

to antibiotics in the farm but the demerits of

the easy accessibility to antibiotics is that

unauthorized person could easily get access

and misuse antibiotics, which could results in

antibiotic resistance. In Thailand, antibiotics

could be purchased over the counter without

veterinarians’ prescription (Love et al., 2015).

These was in agreement with a report

from Cambodia, where farmers had easy

access to antibiotics and no prescription

from veterinarian is required, and it was

considered as one of the most important

driver to facilitate misuse of antibiotics and

emergence of antibiotic resistant bacteria

in Cambodian animal farming (Om and

McLaws, 2016). A study in poultry farms in

Ghana also revealed that easy access to

antibiotics was the main driver of misuse of

antibiotics in poultry farming (VE Boamah

et al., 2016). This findings supports various

studies claiming that antibiotic is the most sold

drugs in developing countries without

prescription (Om and McLaws, 2016; Shehadeh

et al., 2012; Sirijoti et al., 2014).

In approximately 97% of the surveyed

farms, non-veterinary person administer

antibiotics to pigs. The administration of

antibiotics by such person could easily lead

to mis-dosing of animals (Maron et al., 2013).

In other countries like Denmark, Sweden

and Norway, the administration of antibiotics

to the animals in the farm are under strict

supervision of a veterinarian (Cogliani et al.,

2011), so the misuse of antibiotics is greatly

reduced. This study has also revealed

that the antibiotics were mainly chosen on

the basis of the experience of the farmer,

and only few farmers sought veterinarians’

advice or laboratory confirmation. This showed

that using of antibiotics by farmers without

veterinary prescription and supervision is

common in pig farming in the study region.

Such practice of antibiotic use in animal

production may lead antibiotic resistance

and residues in animal products, a survey in

Vietnam revealed similar trend of antibiotic use

practices in the pig faming (Kim et al., 2013).

Around 89 % of the farms completed

antibiotic treatment course, rest of the farms

did not complete the treatment course, and it

could be due to the absence of veterinarians’

supervision on farms or ignorance of farmers

on the outcome of such practices. Correct

dose of antibiotics along with completion of

the duration of antibiotic course is important

(Maron et al., 2013). Incomplete course of

antibiotic treatment will expose bacteria to


sub-inhibitory concentrations of antibiotics

which lead to the development of antibiotic

resistance (Kohanski et al., 2010). A study

from northern Thailand reported few swine

farmers stop administration of antibiotics

once the clinical signs are no longer shown

by the animals, without completing the

recommended course (Love et al., 2015).

To reduce antibiotic residues in animal

products, farmers are required to maintain

recommended withdrawal period after antibiotic

administration, at this period products from

the farms are not to be sold (Darwish et al.,

2013). Interestingly, in this study it was found

that around 21 % of the farms did not maintain

antibiotic withdrawal period. Failure of farms

in maintaining withdrawal period is associated

with financial loss that comes up with maintaining

withdrawal periods(Annan-Prah et al., 2012),

since products acquired in the withdrawal

period have to be disposed. Failure to maintain

withdrawal period had led to detection of high

level of antibiotics such as aminoglycosides,

chloramphenicol, macrolides, β-lactams,

fluoroquinolones and tetracycline residues

in animal products both in many parts of the

world (Er et al., 2013; Mbodi et al., 2014).

Farmers’ denial of maintaining withdrawal

period not only results into detection of

antibiotics residues in animal products but it

has also been linked with severe public health

concerns including hypersensitivity reactions,

antibiotic resistance, toxicity, teratogenicity

and carcinogenicity in humans (Darwish et al.,

2013).

Pig farmers use antibiotics extensively,

according to the regulation of veterinary drugs,

antibiotic should only be used to treat bacterial

infections (Kim et al., 2013). 42 % of the farmers

reported that antibiotic can cure and prevent

all the disease in the farm. These data explains

that some of the pig farmers do not have clear

knowledge about the curative and preventive

use of antibiotics; this could lead to misuse of

antibiotics as farmers tend to use antibiotics to

prevent and treat for all the disease encountered

in the pig farms. A similar Spanish study

revealed that pig producer had no clear

knowledge of preventive and curative use of

antibiotics(Moreno, 2014).

Use of antibiotic is considered as

the main cause of emergence of antibiotic

resistant bacteria (Mladenovic-Antic et al.,

2016). On the question related to the cause

of antibiotic resistant bacteria, 50% of the

farmers believed that antibiotic use is the

cause of antibiotic resistant bacteria in the

farm, whilst 50% do not believe so. Interestingly

more farmers with bachelor degree and more

education and those farmers who had

received awareness on AMR showed better

knowledge regarding the cause of antibiotic

resistant bacteria as compared to farmers

with lower education and farmers who had no

awareness. It shows that level of education

and awareness education could be useful to


understand the antibiotic resistance among

farmers. This finding is in same direction as

the study in southern Thailand by (Sirijoti

et al., 2014), where respondents with more

education had better knowledge of antibiotic

and its use. A study in Sudan, regarding KAP

of antibiotic use and resistance reported

identical findings with this study, farmers with

low education were associated with lack of

knowledge on antibiotic use and antibiotic

resistance and author had recommended

awareness education on antibiotic resistance

(Eltayb et al., 2012).

Overuse of antibiotic in farms could lead

to antibiotic resistance and transfer of AMR

bacteria between animals and farm workers

(Visschers et al., 2016), but in the present study,

majority of the farmers do not believe so

(51.1%). This explains that farmers appeared

to have less awareness of the risk of overuse

of antibiotics in animals for their own health.

A similar finding was seen in a study by (Moreno,

2014) in Spanish pig farms. This is in line with

the various studies which explains that people

in the community level throughout the world

predominantly have inaccurate knowledge,

unsound attitude and improper practices

regarding antibiotic use (Kim et al., 2011;

Shah and Rahim, 2017; Shehadeh et al., 2012;

Sirijoti et al., 2014).

Prevalence of disease in the pig farming

could be the determining factors in using

antibiotic by farmers, as farmers do not want

to suffer financial loss from losing their pigs to

infections. Farmers worry more about financial

reasons than antibiotic resistance (Visschers

et al., 2015). In this study, when farmers were

asked if they have any plan to stop using

antibiotics in their farms, 58.9% of the farmers

voiced out that they are not in position to stop

using antibiotics as there is high prevalence

of disease in the pig farming. This statement

explains that farmers are highly tormented by

large number of disease in the farms, and use

of antibiotics remains the sole alternatives to

treat their pigs to avoid financial loss. Similarly,

farmers in Cambodia were of the opinion that

antibiotic is indispensable for animal raising

(Om and McLaws, 2016). A study conducted

in Swiss pig farmers also revealed that farmers

were more worried about financial reasons,

so they use antibiotics for taking preventive

measures (Visschers et al., 2014).

Like many other questionnaire survey

studies, this study is not without limitations.

It is important to record; the study design used

in this study had some limitations. Firstly, the

required sample size could not be attained

owing to logistical reasons and time constraints,

bias and error is increased. Antibiotic resistance

in pig farming as a result of excessive use of

antibiotics, and use of essential antibiotics in

the pig farming is under scrutiny of media,

consumer group, public health and DLD, so it

is sensitive issue and most of the pig farmers

were hesitant to participate in the questionnaire


survey. Reason being so study was redesigned;

sample size was estimated assuming 50%

(worst-case scenario) of the respondents had

better knowledge and follow good practices

with 10% acceptable relative error. Initially

stratified random sampling was designed but

convenience sampling was accepted later to

meet the sample size of simple random sample

(88 respondents).This could have resulted in

self-selection of motivated farmers only.

Secondly, farms were not randomly selected

owing to the reasons aforementioned, however

looking at the address of the respondents, it was

assured that a representative sample of pig

farms were selected and interviewed from

23 districts from three provinces (there are

27 districts in 3 provinces), and sample

represented fair share of large scale farms

(small, medium and large), but sample did not

represent the size of farms in proportionate

to the population.

Thirdly, questionnaires were also

administered through postal mail when some

farms were not accessible to interviewer, so

there was non-response bias. We could not

send the reminder to the farmers owing to the

time constraint. Other possible bias could be

recall and interviewer bias, as farmers were

asked to recall disease and antibiotics used

in last two years, to minimize the interviewer

bias few hours long training was given to the

interviewer. Farmers might have thought that

there will be no absolute anonymity of the data,

so there could be social desirability bias, as

farmers may have given socially desirable

answers and this may have caused no actual

relationship or correlations between factors/

variables.

Lastly, only farmers that were cooperative

and were willing to participate and respond to

the postal mails were involved in this study,

we acknowledge that those farmers who were

not involved in this study may have different

knowledge, attitude and practices of antibiotic

resistance and antibiotic use. In consideration

of the aforementioned issues, the study results

should be interpreted cautiously. The findings

from the three provinces may not be

generalized outside of those study population

due to convenience sampling technique used.

In conclusion, pig farmers in the three

provinces used several essential antibiotics

on their farms for therapeutic and prophylaxis

purposes. High disease prevalence in pig

farming is considered as determining factors

in using antibiotics by the farmers, as it is the

sole alternative to rescue financial loss in the

farm from infected pigs. Their unscientific way

of antibiotics use, mainly relying on their

experience with limited supervision of veterinary

personnel and easy access to antibiotics is

another factor contributing to the use of excessive

antibiotics which ultimately results to misuse

of antibiotics. Majority of the farmers had

limited knowledge about antibiotic use,

antibiotic resistant and risk to public health


from antibiotic use; this can easily lead

to increase of antibiotic use leading to

antibiotic resistance in bacteria in farms.

Strict regulation must be implemented on

the choice of antibiotics use in the pig

farming, choice and dose of antibiotics in

the farm should be based on veterinarians’

prescription and used under veterinarians’

supervision and it also calls for stricter monitoring

of antibiotic usage in the pig farming industry.

ACKNOWLEDGMENTS

The authors would like to thank Faculty

of Veterinary Medicine, Kasetsart University

for providing grant support as well as the

valuable response towards distributed

questionnaire from the swine farmers in these

3 provinces.

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Documents

Journal of Kasetsart Veterinarians vol. 29 No. 1. 2019