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RESULTS ON STRENGTHENING DIAGNOSTIC CAPACITY ANDCONTROL OF DIARRHOEA IN SUCKLING PIGS Project title: Diagnosis and control of diarrhoea in suckling pigs Project code: CARD 001/04VIE Auth

RESULTS ON STRENGTHENING DIAGNOSTIC CAPACITY AND

CONTROL OF DIARRHOEA IN SUCKLING PIGS Project title: Diagnosis and control of diarrhoea in suckling pigs

Project code: CARD 001/04VIE

Authors: Do Ngoc Thuy1, Cu Huu Phu1, Au Xuan Tuan1, Nguyen Xuan Huyen1, Truong Van Dung1, Tony Fahy1, Steve Driesen2, Karen Moore2, Aileen Vanderfeen2, Darren Trott3

Collaborating organisations:

1

: National Institute of Veterinary Research

2

: Pig Research Unit, Victorian Department of Primary Industry, Melbourne, Australia;

3

: The University of Queensland, Australia

SUMMARY

During the implementation time (2005-2007), three objectives of the project, including: 1) Improved field and laboratory diagnosis of preweaning diarrhoea; 2) Production and testing of locally-produced E coli vaccines; 3) Development of a management plan for preweaning diarrhoea using a continuous improvement (CIP) model had been conducted and completed Some achievements are: 1)

A diagnostic procedure of six major causes of diarrhoea in suckling pigs has been applied successfully

at Department of Bacteriology, NIVR 2) A vaccine containing E coli strains bearing full pathogenic factors (fimbriae, toxins) has been produced and proven safe and effective in laboratory and in the field 3) An continuous improvement model, focused mainly on management of sows during farrowing and lactation has been developed and utilized in order to improve pig production and minimize the losses due to diarrhoea in suckling period.

Diarrhoea during the suckling period has been

recognised as the principle health problem

affecting both smallholder and commercial pig

production in Vietnam Previous research (4,

7) has confirmed the presence of a new

fimbrial type in E coli strains causing

colibacillosis in Vietnam that would not be

controlled by existing vaccines Existing

vaccines are currently imported into Vietnam

at considerable cost In addition, there are

many other causes of suckling diarrhoea, the

significance of which is currently unknown in

Vietnam, which are all affected by husbandry

and management during farrowing and

lactation Project 001/04VIE (Diagnosis and

control of diarrhoea in suckling pigs) began

with three objectives to solve this problem:

1 Improved field and laboratory diagnosis

of preweaning diarrhoea

2 Production and testing of

locally-produced E coli vaccines

3 Development of a management plan for preweaning diarrhoea using a continuous improvement (CIP) model

This project is designed to improve productivity of smallholder pig farmers in Vietnam through improved health management, particularly of piglets during the pre-weaning period Through consultation and dialogue with farmers and field veterinarians,

an appropriate disease management plan will

be developed This will concentrate on the pre-weaning period where greatest losses occur, but will include principles of herd health management in general Dissemination

of the plan will be through training programmes for field staff and selected farmers

2 Project contents and methods

2.1 Project Contents

The project focuses on:

1 Improved laboratory diagnosis of

preweaning diarrhoea

2 Production and testing of

locally-produced E coli vaccines

3 Development of a management plan for

preweaning diarrhoea using a

continuous improvement (CIP) model,

training for field veterinarians

2.2 Methodology

- Experimental design based on groups and

compare the significant difference (1 factor,

multiple factors)

- Isolation and identification of bacteria (E.

coli, C perfringens) according to SOPs

- Detection of virus (TGE virus, Rota virus)

by ELISA (commercial kit, Institute

Pourquier)

- Detection of Cocci oocysts by standard

faecal flotation, Cryptosporidium by

modified Ziehl-Neelsen staining of faecal smears

- Detection of virulence factors of E coli

(fimbriae, toxins) by PCR

- Production of vaccine according to SOP

3.1 Development of a procedure for quick diagnose some of the most common infectious causes of diarrhoea in suckling pigs

A diagnostic procedure of six major causes of diarrhoea in suckling pigs, including the infectious gastroenteritis virus (TGEV), Rota virus, E coli, C perfringens, Coccidiosis and Cryptosporidium have been established, in accordance with the laboratory conditions at Department of Bacteriology, National Institute

of Veterinary Research This procedure has been used for diagnosis of faecal samples collected from commercial piggeries (participated in the project) and small holder farmers in the nearby areas Results are presented in table 1

Table 1: Prevalence of enteric pathogens in pre-weaning piglets with diarrhoea

Agent(s) detected

No of positive samples (%) Commercial

piggeries (n=117)

Small holder farmers (n=45)

Agent(s) detected

No of positive samples (%) Commercial

piggeries (n=117)

Small holder farmers (n=45)

3.2 Production and testing of local

produced E coli vaccine

A vaccine containing E coli strains bearing

full pathogenic factors (fimbriae, toxins) has

been produced according to SOP Specialised

culture media were prepared in order to

provide favourable growth conditions for the production of fimbriae Each dose of vaccine (2 ml) contains of ~ 1.5 x 109bacteria Vaccine has been tested on sterility, safety and efficacy

in laboratory and in the field (for small scale trial)

Results of ELISA for efficacy testing of

vaccine show that there was a significant

difference between the OD levels for the

treatment groups (p<0.003) There was no

significant difference between the antibody

response elicited (as demonstrated by OD

values) by Litterguard, EcoVac or NIVR

vaccines (p>0.1) All three vaccines were

significantly different from the control group

(p< 0.005) (Table 2)

Table 2: Mean OD values of sera between

treatment and control group

* Means with different subscripts differ

significantly p<0.005

Vaccine was tested in some piggeries in the

North Pregnant sows twice at 9 and 12 weeks

of gestation each received 2 ml of vaccine

(approximately 1.5 x 109 bacteria) Results

show that under experimental conditions, the

vaccine is both safe (100%) and efficacious

(>85%) No local or systemic reaction to the

vaccine was observed and all sows gave birth

at the correct stage of gestation to an average

of 9.3 healthy piglets per sow The prevalence

of pre-weaning diarrhoea in piglets born from

vaccinated sows at 1, 2 or 3 weeks of age

were: 16.1; 22.7 and 26.5%, compared with

those of 48.1; 33.8 and 37.5%, respectively

from control group (P<0.005)

3.3 Recommendations on herd health

monitoring

II.3.1 Sow management

o Pigs must have access to feed at least

daily and the diet must be nutritionally

adequate to maintain health and meet the

o When the body condition score of a pig falls below 2.5 (on the scale of 1-5, appendix 1), remedial action must be taken

o All pigs (excluding piglets) must be maintained at a body condition score of 2

or more

o Feed must be provided in such a way as to prevent undue competition or injury

o Pregnant sows should be given enough bulky or high fibre feed to satisfy hunger The feed intake for dry sows needs to be nutritionally balanced, appropriate to the sow’s physiological needs (which vary during pregnancy) and to provide satiety without the sow becoming overweight

o Body score of breeding sows at farrowing should be 3.5 – 4

o Body score of breeding sows at weaning should be 3 or above

o Condition scoring is recommended as a way of assessing the adequacy of nutrition, along with monitoring of health and productivity A guide to condition scoring of pigs is given in the next part

o Drinkable water and/or other wholesome liquid must be easily available to pigs in sufficient quantities to meet the physiological needs of the pigs at all times

o Water provided should be fresh, palatable, and at a temperature that does not inhibit drinking

o Drinker allocation per pen group and drinker design and flow rates should be such that water requirements of different classes of pig are easily met

o Pigs should have constant access to water

or other suitable wholesome liquid The daily consumption of water (or other wholesome liquid) by a pig will vary according to environmental temperature, diet ingredients and live-weight

* Feed requirements for lactating sows

Table 3: Feed requirements for lactating sows

Day of lactation Daily feed

requirement (kg)

* WATER REQUIREMENTS

For planning purposes the following consumption estimates are provided for normal ambient temperatures:

Table 4: Average water consumption (litres

per day)*

Boar or dry sow 12–15 Sow and litter 25–45 Grower pig:

25 kg

45 kg

65 kg

3–5 5–7 7–9

Flow rates will vary depending on the number

of drinking points and care should be taken to ensure adequate pump capacity and supply to maintain flow

Recommended water flow rates and maximum water pressures

(litres/minute)

Maximum pressure (kPa)

* Care should be made not to have excessive pressure as water wastage can occur

* TEMPERATURE REQUIREMENTS

Pigs, except the very young, are able to

tolerate a wide range of temperatures without

detriment to their well being, provided

temperature changes do not occur abruptly

During very hot weather (35°C or more) adult pigs are very susceptible to heat stress, and steps should be taken to alleviate distress and avoid deaths Pigs may die if transported in very hot weather The heat index in most sheds

we visited was 37-38°C

The ranges of temperature that afford optimum comfort for different classes of pigs are:

Piglets — newborn 30–35°C

Piglets — 3 weeks of age 24–30°C (reducing to 26°C at 5 weeks of age)

Weaners 28–30°C first week (start at 30C, reduce by 2°C per week to

22°C) Growers Aim for 20-24°C, aim to keep daily fluctuations below 6°C

Finishers Aim for 20-24°C, aim to keep daily fluctuations below 6°C

Sows and boars 18 – 24°C, aim to keep daily fluctuations below 6°C

Table 5: Thermal comfort zone (assuming concrete floors, no drafts and 15% skin wetness)

Stock Weight (kg) Lower critical temp Evaporative critical temp

Weaners

Growers

 At the lower critical temperature pigs

will feel cold, huddle and change

position to conserve heat They will

also need more feed to generate heat

 At the upper limit (evaporative critical

temperature) the pigs will begin to

pant in an effort to cool down

3.3.1 Condition scoring of sows

The following criteria can be used as reference for

scoring sows:

Condition scoring of sows

Numerical Score

Pelvic Bones,

1

Pelvic bones very prominent

Deep cavity around the tail head

Loin very narrow Sharp edges on transverse spinal process Flank very hollow

Prominent and sharp

throughout the length of the backbone

Individual ribs very

prominent

2

Pelvic bones obvious but some slight cover Cavity around tail head

Loin narrow

Only very slight cover to edge of transverse spinal process Flank rather hollow

Prominent Rib cage less

apparent Difficult to see individual ribs

3

Pelvic bones covered

Edge of transverse spinal processes covered and rounded

Visible over the shoulder Some cover further back

Covered but can be felt

4

Pelvic bones only felt with firm pressure

No cavity around tail

Edge of transverse spinal processes felt only with firm pressure

Felt only with firm pressure

Rib cage not visible Very difficult to feel any ribs

5

Pelvic bones impossible to feel Root of tail set deep in surrounding fat

Impossible to feel bones

Flank full and rounded

Impossible to feel vertebrae

Not possible to feel ribs

4.1 Conclusions

 A diagnostic procedure of six major

causes of diarrhea in suckling pigs,

including the infectious gastroenteritis

virus (TGEV), Rota virus, E coli, C.

perfringens, Coccidiosis and

Cryptosporidium have been established This procedue can be easily applied for diagnosis in laboratory conditions in Vietnam

 A vaccine containing E coli strains

bearing full pathogenic factors (fimbriae, toxins) has been produced and proven safe and effective in

laboratory and in the field Vaccine

can be used to vaccinate pregnant sows

twice at 9 and 12 weeks of gestation,

each received 2 ml of vaccine to

control diarrhoea in suckling pigs

 An continuous improvement model,

focused mainly on management of

sows during farrowing and lactation

has been developed and utilized in

order to improve pig production and

minimize the losses due to diarrhoea in

suckling period

4.2 Recommendations

The E coli vaccine should be commercialised

as soon as possible so that it can be used for

control of diarrhoea in suckling pigs in

Vietnam

References

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