Influence of mastitis and repeat breeding incidence on participation in the animal insurance program for dairy farmers in Ba Vi, Hanoi, Vietnam
ISSN 2588-1299
VJAS 2019; 2(4): 461-468
Vietnam Journal
of Agricultural
Sciences
Influence of Mastitis and Repeat Breeding
Incidence on Participation in the Animal
Insurance Program for Dairy Farmers in
Ba Vi, Hanoi, Vietnam
Kentaro Koide1, Ryo Murata1, Au Xuan Khoa2, Nguyen Khanh
Ly2, Phan Thi Tam2, Vu Thi Thu Tra3, Duong Van Nhiem3,
Satoko Kubota4, Hiroichi Kono4 & Kohei Makita1
1 School of Veterinary Medicine, Rakuno Gakuen University, Bunkyodai Midorimachi,
Ebetsu, Hokkaido, 069-8501, Japan
2 National Center for Veterinary Diagnosis, Hanoi, Vietnam
3 Faculty of Veterinary Medicine, Vietnam National University of Agriculture, Hanoi
131000, Vietnam
4 Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokaido,
080-8555, Japan
Abstract
The livestock insurance program for dairy farmers in Vietnam
targeting various acute diseases began in 2011 as a pilot project;
however, due to vaccination campaigns, outbreaks of such diseases
are rare. The objective of this study was to investigate the effects of
mastitis and reproductive failure-which chronically affect the
farming economy-on the decision to participate in the insurance
program. A survey involving a questionnaire and milk sampling from
apparently healthy animals was conducted on the 38 participating and
59 non-participating dairy farms in the livestock insurance program
in Ba Vi, Hanoi, Vietnam, in August 2014. Microbiological tests
were performed to detect sub-clinical mastitis, whereas the
questionnaire was administered to collect information regarding farm
management and the occurrence of clinical mastitis and reproductive
failure over the previous three months. There were no significant
differences in the proportion of farms having cows with clinical
mastitis (insured: 8/38 farms, 21.1% vs. non-insured: 13/58 farms,
NA = 1, 22.8%, p = 1) and repeat breeders (insured: 16/36 farms, NA
= 2, 44.4% vs. non-insured: 20/57 farms, NA = 2, 35.1%, p = 0.49)
over the previous three months. The proportion of farms having cows
with sub-clinical mastitis at the time of the survey was also not
significantly different between insured (5/38 farms, 13.2%) and non-
insured (7/59 farms, 11.91%) farms (p = 1). Based on the obtained
results, neither endemic disease nor farm management is respectably
involved in the decision of farms to participate in the animal
insurance program targeting acute animal infectious diseases.
Received: June 17, 2019
Accepted: December 15, 2019
Correspondence to
Keywords
ORCID
Kohei Makita
0246
Animal insurance, decision, bovine mastitis, repeat breeding,
Vietnam
461
Influence of Mastitis and Repeat Breeding Incidence on Participation in the Animal Insurance Program
the insurance program for participating farmers
Introduction
Milk production has drastically increased
(Kadowaki et al., 2016). Crop and livestock
insurance was first introduced in Vietnam
between 1985 and 1987 (phase 1), without
government support. However, except for crude
rubber insurance, phase 1 was withdrawn in 1987
due to problems associated with moral hazards
and conflicts regarding pay-out value (Kono et al.,
2017). By order of the Vietnamese prime minister,
dairy insurance premiums were implemented in
2011 within the phase 2 pilot program for three
years, covering rice plants, livestock (buffaloes,
cows, pigs, and chickens), and aquatic products
(catfish, tiger prawns, and white-leg shrimp)
(Kono et al., 2017). Under the pilot program
involving commercial insurance companies, the
state-subsidized 100% of the insurance premiums
for poor farming households and individuals,
initially 80% and later 90% for near-poor, 60% for
the remaining, and 20% for relevant farming
organizations (Duc, 2017). Three causes of death
were covered by the dairy insurance: FMD,
anthrax, and Pasteurella infection, but no
treatment costs were covered for endemic and
non-infectious production diseases. Vaccination
campaigns against FMD, anthrax, and Pasteurella
infection are being implemented in dairy
production areas of Vietnam (personal
communication with local veterinary officers),
and animal deaths due to these diseases appear to
be rare. The Ba Vi district of Hanoi is an important
dairy production area in Vietnam and
characterized by advanced dairy technology. As
of October 2013, 260 farms in Ba Vi were
participating in the insurance program (Kono et
al., 2017). The phase 2 pilot insurance program
was successful, with a high proportion (76.8%) of
poor households in the target area participating.
However, the program also had several
weaknesses, including a lack of testing and
certification facilities for diseases, resulting in
limited compensation or farmers receiving
inconsistent damage assessments (Duc, 2017).
The government, therefore, considered instituting
a public-private partnership (Duc, 2017) covering
90% of insurance premiums for poor and near-
poor farming households and 20% for remaining
households (Viet Nam News, 2018).
over the last four decades, particularly in
Southeast Asia, including Vietnam (Food &
Agricultural Organization, 2013). This growth
has been attributed to an increase in the domestic
demand for dairy products and the government-
led importation of highly productive dairy
animals for breeding purposes (Garcia et al.,
2006). A comparison with the average milk yield
in 1997 indicated that due to genetic
improvements in the lactating ability of
Vietnamese dairy cows, one Vietnamese cow
produces as much milk as four dairy cows in
India, the second-largest milk-producing country
in the world. Proper nutritional management is
necessary for high milk-producing cows because
of their sensitive energy balance (Grant &
Albright, 1995). The risk factors for diseases in
dairy cows are interconnected (LeBlanc et al.,
2006), and rapid changes in dairy productivity
are assumed to have increased the incidence of
various diseases, including sub-clinical forms of
mastitis, ketosis, rumen acidosis, and
endometritis.
In addition to the increased production and
consumption of livestock products in Southeast
Asia, rapid economic growth has been
accompanied by increased risks of infectious
disease epidemics such as foot-and-mouth
disease (FMD) (Vu et al., 2017) and avian
influenza (Poolkhet et al., 2018), primarily due
to increases in the frequency and quantity of
trade and travel. As the majority of livestock
producers in Southeast Asia are small scale, the
economic impact of such outbreaks is immense.
One method of dealing with the risk of
disease outbreaks is insurance. In Japan,
agricultural insurance for dairy farms is
subsidized 50% by the government and covers not
only the death of animals but also treatment costs
(Japanese Ministry of Agriculture Forestry &
Fisheries, 2010). Moreover, under the Act on
Domestic Animal Infectious Diseases Control, the
Japanese government compensates farmers for
80% of the value of animals culled due to several
important infectious diseases, such as FMD, and
the remaining 20% of the value is compensated by
Vietnam Journal of Agricultural Sciences
462
Kentaro Koide et al. (2019)
Mastitis has been described as the most
expensive disease affecting dairy farms
worldwide; however, the chronic nature of this
disease can lead farmers to ignore and/or
underestimate the financial effects of decreased
milk production and increased culling (Hogeveen
et al., 2011). Mastitis is caused by a wide variety
of pathogenic bacteria. Microorganisms causing
mastitis are classified as either contagious or
environmental pathogens, depending on the
vector of transmission. The major contagious
pathogens are Staphylococcus aureus and
Streptococcus agalactiae, S. aureus is reportedly
the most problematic udder pathogen in bovine
mastitis in many parts of the world (Roberson et
al., 1994). In southern Vietnam, mastitis is
commonly caused by S. agalactiae, a contagious
organism associated with sub-clinical mastitis
(Keefe, 1997; Östensson et al., 2013). In Ba Vi, a
25% prevalence of sub-clinical mastitis was
reported (Suzuki et al., 2006), but much higher
prevalences (63.2% at quarter, and 88.6% at cow
levels) were reported in southern Vietnam
(Lam, 2011).
decision-making process regarding participation in
the phase 2 dairy insurance scheme among dairy
farmers in a dairy-production area of Vietnam.
Materials and Methods
Study site
This study was conducted in two communes,
Yen Bai and Van Hoa, located in Ba Vi, Hanoi
(Figure 1). This area, located in northern
Vietnam, has a humid tropical climate,
characterized by monsoons. Summers (May to
July) are very hot, with an average temperature
over 27°C, whereas winters (November to
January) are cold and relatively dry (Garcia et al.,
2006). This survey was carried out in August
2014. The average precipitation in August is the
highest of the entire year, at over 300 mm.
Precipitation in winter is low, but these
communes are at or near a lake, and extensive
irrigation and pumping systems have been
established (Garcia et al., 2006).
Sampling and questionnaire survey
Sample size was calculated for a comparison
of two proportions, with the confidence level set at
95% and the power set at 80% (Equation 1), in
order to primarily compare the prevalence of sub-
clinical mastitis at the animal level between insured
and non-insured farms (Dohoo et al., 2014). In
equation 1, 푍훼 is a multiplier for type I errors, alpha
= 0.05, 1.96; 푍훽 is a multiplier for type II errors =
0.2; p is the expected prevalence, 0.25 (Suzuki et
al., 2006); q is the expected prevalence
complement, 0.75; p1 is the expected prevalence at
insured farms, 0.35; and p2 is the expected
prevalence at non-insured farms, 0.15, assuming a
20% difference in the prevalence of sub-clinical
mastitis. The sample size was adjusted for a
clustering effect assuming an intra-class correlation
Repeat breeders are cows that have failed to
conceive after three or more services. Repeat
breeders are characterized by a normal estrus
cycle length, no abnormalities in vaginal
discharge, and no palpable abnormalities in the
reproductive tract (Bartlett et al., 1986;
Gustafsson & Emanuelson, 2002). A repeat
breeder cow appears to be normal, and it is,
therefore, difficult to diagnose the cause of the
failure to conceive. Repeat breeding results in a
delay in starting lactation and fewer calves per
cow; therefore, total farm milk yield is also
reduced, causing substantial economic losses to
farmers. A study involving Holstein and Lai Sind
crossbred cattle in Ho Chi Minh city found that
reproductive performance was satisfactory in
heifers but poor for cows due to declining body
condition scores during the first months of
lactation and at insemination (Nguyen-Kien et
al., 2017), suggesting the potential for
improvement in feed management.
coefficient of 0.1 (Dohoo et al., 2014).
2
(푍 2푝푞−푍 푝 푞 +푝 푞 )
√
√
훼
훽
1
1
2 2
(Equation 1)
2
(
)
푝 −푝
1 2
The sample size was calculated at 73;
however, 95 farms were involved in the study.
The sample size was proportionally allocated
between Yen Bai and Van Hoa communes to
reflect the total number of insured dairy farmers
This study aimed to determine whether the
occurrence of chronic and expensive diseases such
as mastitis and repeat breeding affected the
463
Influence of Mastitis and Repeat Breeding Incidence on Participation in the Animal Insurance Program
Figure 1. Study areas: (A) a map of Vietnam indicating the location of Hanoi,
and (B) the locations of Van Hoa and Yen Bai communes in Hanoi
in each commune reported to the commune
offices. These numbers were accessed based on
availability from the field.
(Reinemann, 2007). The average score of the
three parts for all cattle was recorded as the
farm’s hygiene score. Farmers were also asked to
rate their level of awareness regarding diseases
common in cows, including mastitis and repeat
breeding, using a Likert scale, with 0 indicating
no problem and 5 indicating a significant
problem.
Milk samples were collected from lactating
dairy cows exhibiting no obvious clinical
symptoms of mastitis and no visible changes in
milk composition. Samples were taken from 60%
of the delivered cows at all of the studied farms.
The first few streams were discarded. Samples
from each of the four quarters were collected into
the same bottle and defined as a single milk
sample for this study.
Informed consent was obtained from all the
farmers participating in this study at the time the
interview was performed. This study did not
involve invasive treatments in animals or
collection of personal information through
interviews. All interviewing and sampling
procedures adopted in this study were approved
by the ethics committee of Rakuno Gakuen
University, Japan (approval number: 16-8).
At each visit, an interview with the
questionnaire was administered to obtain
information regarding dairy management and
hygiene awareness as well as cattle health
outcomes. Occurrences of mastitis and repeat
breeding within the previous three months were
queried for each individual cow. The degree of
each farm’s sanitation was graded on a scale of
1-4 (1: cleanest to 4: dirtiest) for three parts of
each cow: legs, udder, and flank and upper leg
Laboratory examinations
Causal organisms of sub-clinical mastitis
were isolated from the collected milk samples.
Microbial species isolated included coagulase-
Vietnam Journal of Agricultural Sciences
464
Kentaro Koide et al. (2019)
positive staphylococci (CPS) other than
S. aureus, S. agalactiae, Escherichia coli, and
Klebsiella spp. Cows were categorized as having
sub-clinical mastitis if they presented no
apparent symptoms but their milk samples were
positive for bacterial growth. Milk samples were
streaked on sheep blood agar plates, which
support the growth of various types of bacteria.
The plates were incubated at 37°C overnight.
Three major bacterial colonies on each agar plate
were selected and sub-cultured on blood agar
plates. Biochemical tests were used for species
identification, including the hemolysis, CAMP,
catalase, and tube coagulase tests. Bacterial
isolates that produced no hemolysis were
subjected to biochemical testing for confirmation
as E. coli or Klebsiella spp. Staphylococcus hyicus
produces no hemolysis on blood agar, but
S. aureus, S. intermedius, and S. agalactiae
exhibit β-hemolysis. Therefore, these bacteria
were classified based on the catalase test, which
is primarily used to distinguish gram-positive
bacteria. The results obtained with the catalase
and coagulase tests were confirmed by PCR for
S. aureus species-specific genes using the
forward primer 5'-GCG ATT GAT GGT GAT
ACG GTT-3' and the reverse primer 5’-AGC
CAA GCC TTG ACG AAC TAA AGC-3’
(Sasaki et al., 2010).
Results
Farm characteristics
All of the farms in the study were small scale
(1 to 22 cows per farm), and 88.7% (86/97) of the
farms had less than 10 cows. Table 1 shows the
number of farms, milk samples, and mean herd
sizes of the insured and non-insured farms. All
cattle were housed on concrete surfaces. Cattle
were fed raw grass and purchased concentrate at
both insured and non-insured farms. There were
no significant differences between insured and
non-insured farms in any of the characteristics
examined (Figure 2).
Cumulative incidence of clinical mastitis and
prevalence of sub-clinical mastitis
In the questionnaire survey, factors related to
mastitis were investigated using data from 95
farms, as two farms did not provide information
regarding the incidence of mastitis in the
interviews. The three-month cumulative
incidence of clinical mastitis, calculated from the
questionnaire survey results, was 22.1% (21/95)
at the farm level. In addition, at the individual
level, the incidence was 8.4% (29/344, health
information regarding clinical mastitis was not
obtained for 85 cows).
In the laboratory analyses, the prevalence of
sub-clinical mastitis was 11.1% (17/153) at the
individual level, and the prevalence at the farm
level was 12.4% (12/97). Two samples had
mixed infections involving S. agalactiae and
S. aureus, and of the 19 isolates, these bacteria
accounted for 57.9% (11 isolates) and 21.1% (4
isolates), respectively. There were three CPS
isolates other than S. aureus, and these
Statistical analysis
Data were digitized in a Microsoft
Access® Database and analyzed using R
statistical software (R×64, version 3.0.3) for
Windows®.
The
association
between
insurance subscription and the aforementioned
disease occurrence/ management practices was
analyzed at the farm level. A farm was denoted
as positive for mastitis/repeat breeding if at
least one animal with the problem was reported
or diagnosed by microbiological testing. These
occurrences (0 = negative and 1 = positive)
were used as response variables, and the other
data collected in the questionnaire were used as
explanatory variables. Each variable was
analyzed using the Wilcoxon rank-sum, chi-
square, or Fisher’s exact test, depending on the
data structure.
contagious
mastitis-causing
bacteria
(S. agalactiae and CPS) accounted for 94.7%
(18/19). One Klebsiella isolate causing
environmental mastitis was detected; however,
E. coli was not detected. Sub-clinical mastitis
was found at 12 farms; thereby, both clinical
mastitis and sub-clinical mastitis were identified
in cattle at one farm.
Clinical and/or sub-clinical mastitic cattle were
present on 33.0% (95% CI: 24.0-43.4, 32/97) of the
farms, based on the questionnaire survey and
465
Influence of Mastitis and Repeat Breeding Incidence on Participation in the Animal Insurance Program
laboratory examination results. The proportion of
farms with mastitic cattle was not significantly
different between insured (34.2%, 13/38) and non-
insured farms (32.2%, 19/59, p = 1). There was
also no significant difference in terms of the
incidence rates of clinical and/or sub-clinical
mastitis between insured (29.3%, 17/58) and non-
insured farms (22.1%, 21/95, x2 = 0.6527, p = 0.42).
Table 1. Farm size and number of milk samples
Farms in
Yen Bai
Farms in
Van Hoa
Mean herd size
Milk samples
(sampling fraction)
Insurance
Adult cows
(range)
l
16
33
49
22
26
48
5.4 (2-22)
5.9 (1-13)
5.7 (1-22)
153
239
392
58 (37.9%)
95 (39.7%)
153 (39.0%)
Non-insured
Total
Figure 2. Statistical analysis results
Vietnam Journal of Agricultural Sciences
466
Kentaro Koide et al. (2019)
The average scores regarding farmers’
awareness of mastitis were not significantly
different between insured (3.22, 95% CI: 3.0-4.5)
and non-insured farms (2.88, 95% CI: 2.75-4.00, p
= 0.36). For the treatment of mastitis, 77% (64/83)
of farmers called a veterinarian, whereas 23%
(19/83) of farmers called other staff or treated the
disease themselves. There was no significant
difference between insured and non-insured farms
in terms of factors relating to mastitis.
greater than 0.30, but the p-value associated with
the milking method was relatively lower (p =
0.16), and farms with milking machines tended
not to participate in the insurance program.
Milking by machine is a sign of intensive dairy
farming, and economically developed farmers
may evaluate the significance of the program
carefully. Another study carried out during the
same period but with different farmers (Kono et
al., 2017) showed that a farmer’s decision to
purchase animal insurance was affected by the
absence of a trustworthy person nearby and a low
rate of time discounting. Such sociological
factors seemed to be more significant
determinants of insurance participation by dairy
farmers than disease burden.
Incidence and farmers’ awareness of repeat
breeding
Ninety-three farmers answered the questions
relating to reproductive difficulties, and the
results indicated that repeat breeding occurred at
38.7% (36/93) of the studied farms. The
proportion of farms with these reproduction-
related problems did not differ between insured
(44.4%, 16/36) and non-insured farms (35.1%,
20/57, x2 = 0.47, df = 1, p = 0.49). In addition,
the average score of awareness of repeat breeding
was not significantly different between insured
(3.2, 95% CI: 2.5-4.5) and non-insured farms
(2.8, 95% CI: 2.50-3.75, p = 0.35). Artificial
insemination was used at all the farms.
Conclusions
This study found that the incidence of two
important production diseases, mastitis and
repeat breeding, was not the primary determining
factor for the decision to participate in the animal
insurance program in Ba Vi, Vietnam. The risk
factors for mastitis and repeat breeding in
Vietnam will be published elsewhere.
Acknowledgements
Discussion
This study was supported by KAKENHI
Grant Number 25304035, from the Ministry of
Education, Culture, Sports, Science, and
Technology of Japan.
The main purpose of this study was to test
the hypothesis that Vietnamese dairy farmers
were motivated to participate in an animal
insurance program due to experience with
chronic production diseases, even though the
program targeted acute infectious diseases. For
that reason, two economically important
diseases, mastitis and repeat breeding, were
examined.
Conflicts of Interest
The authors declare no conflicts of interest.
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