GP Department Fakieh Poultry Company KSA
TO,
Operation managers
Introduction
This is the first year
that the poultry health course was co-organized by pirbright health institute (a
world-leading center for research into viral diseases of livestock) for the first
whole week, and 2nd week at university of Nottingham (school of veterinary
medicine and science) and minster veterinary practice, under the umbrella of
the Agri-food advanced training partnership funded by the united kingdom,
Biotechnological and biological science research Council (BBSRC).
The poultry health
course covers, Avian immune system, Major and emerging viral pathogens,
Bacterial, protozoan, and fungal pathogens, feed-related problems, Management
and Biosecurity in poultry production, Vaccination strategies, and vaccination techniques,
Autogenous vaccines, Field
investigation, PM examination, and approaches to molecular diagnosis. The
precise and comprehensive points of the course are the following.
Poultry:
Poultry is all birds that are reared or kept in Captivity for
breeding, the production of other meat or eggs for consumption, the production
of other commercial products, or for restocking supplies of game. Chicken is
still the largest specie of live Stock being used as food. 55 billion
Avian immune system:
Birds have natural
immunity against many pathogen infections. There should be a balance b/w pathogen
and immune response, more parasites more damage. There are 2 elements in the immune
system
i Recognition ii killing
Ø Immunity based upon
1) Coordination activation of cells and molecules
2) Cell-cell interaction
3) Movement of cell to the site of infection.
Ø
Types
of immunity:
1. Innate (no exposure to pathogen
2. Adaptive (exposure to pathogen and specific action)
3. Passive (maternal immunity)
Viral pathogens:
The important viral diseases of Economical importance are
ND, MD, IBD, IB, ILT,
POX, ASTROVIRUS,
CIRCOVIRUS, AI, REV, ALV,
AE, MPV,(TRT), IBH, and HPS.
The important points in some diseases of our area are as follow.
1- ND is
caused by APMV-1 has 15500 nucleotides and long codes for 7 proteins. NDV had been
demonstrated to infect more than 241 species representing 27 of the 50 orders
of class Aves.
2- Probably all birds are susceptible to infection but the
disease caused by any given virus varies from one species to other.
3- Leucosis
has no pathogenic gene while
MD has many pathogenic genes. 1st organ of the tumor is
bursa, then the liver and other organs. Viruses account for more than 90% of cancers
in birds, and noninfectious forms of cancer such as ovarian carcinoma also affect
avian health.
4- MDV is
cell-associated remains inside the cell, when the cell dies, the virus dies.
5- ALV-J induced
myelocytomatosis of the skull and myeloid tumors.
6- Over 20 billion doses of MD vaccine are administered
each year; MD vaccines are probably one of the most widely used.
7- Clots of blood, mucus, coughed-up beak feathers, walls
floor, and blood stains are the distinguishing feature of ILT in laying birds. Landmark work at the University of
Melbourne Australia, different live ILT vaccines are recombined in chicken to generate
a virulent virus.
8- IBDVs
have the ability to resist environment and disinfectants, it has 3 strains 1) mild
2) classical 3) virulent strain.
9- There is another new strain of IB called IB Q1 (nephritis) Some IB
variants show an increase in virulence. IB
Ox false layer. IB
Q1 is different from Ox. But both are found in China. It is neither realistic nor desirable to develop a new
live attenuated vaccine for every variant of IB, broad protection can be provided against most variants
using a suitable combination of existing IB
vaccines,
10- The REO
virus can be vertically transmitted at a low rate from
asymptomatic hens, Nucleus of infected chicks infect hatch mates.
11- H7N9 is
an emerging threat, severe respiratory disease in Humans, onset 19 Feb --- 14
Apr 2013. Age range= 4-87 (median 65), no human–human transmission proved,
independent exposure to poultry.
12- AE
virus might be the smallest virus only 24 nm, stable in the environment.
Vertically transmitted causes opacity of the lens.
13- Chicken Astro
virus vertically transmitted was isolated as the second Astro virus in 2004,
when chickens were infected during lay. The antibody of the Chicken Astro
virus is widespread in UK & European poultry
organizations. Antibodies were also detected in GP & GGP flocks, even when
biosecurity was high.
14- The diagnosis of Chicken
Astro virus is done by multiplex PCR. While white chicken dead in
shells is also a distinguishing feature. Also, cross infection b/w species.
15- Adenovirus classification has recently changed, previously 3 avian adenovirus groups i, ii, and iii now five genera.
Bacterial pathogens:
There are many bacterial pathogens affecting poultry, but important ones are
Salmonella, clostridium, E.coli,
campylobacter, listeria, and mycoplasma.
The keynotes are about
some important pathogens:
Mycoplasma:
Belong to a class mollicutes, mollis= soft
cutis = skin, mycoplasma is bacteria, but it differs from other bacteria
due to these reasons.
Ø No cell wall,
Ø Smallest free-living bacteria
Ø Minimum set of genes
Ø Highly evolved
Ø High nutrition demand.
Survival
MG & MS
survives at least 9 days on unwashed synthetic hair, but 4 hrs.,
On unwashed
natural hair, no apparent survivals on either if washed.
Eradication:
Earlier procedures to eradicate mycoplasma are:-
Ø Hatching eggs treated to break the cycle of infection
Ø Birds hatched and reared in small groups.
Ø Monitored for infection and any infected group was eliminated.
Ø Monitoring of flocks and maintaining strict biosecurity
and management.
Treatment of mycoplasma:
1). Antimicrobials can control the disease but will not
usually eliminate the organism
2) Many mycoplasmas have high mutation rates so overuse of antimicrobials can encourage resistance.
Vaccines of mycoplasma
1) Once considered as an admission of defeat.
2). Now used in layers and breeders in some areas.
3). should be used in areas where field exposure is
inevitable e.g. multi-age sites
4). Can cause difficulty in diagnosis
5). Protective mechanism of mycoplasma vaccines is to
induce mucosal surface immunity.
6). Live vaccines are more effective than killed ones.
“Some TS-11 vaccines have been recommended to reduce egg
transmission in breeders. Antibiotic use should be avoided before and after the
use of live vaccines’’
Foodborne infections:
Ø 2.5 million Death occurs due to food-borne disease per
annum.
Ø Over 1.4 million salmonellosis cases in USA per anum.
Ø Foodborne diseases are estimated to cost $35 billion
annually in the USA
Ø Salmonellosis is the major cause of death in HIV+ patients in
Sub-Saharan Africa.
E.coli:
Avian colibacillosis is hard
to control completely. Related to poor hygiene & biosecurity.
Further leads to air
sacullitis, Egg peritonitis, septicemia, omphalitis, yolk sac infection, and
salpingitis. It is an opportunistic
bacterium.
Parasitic and protozoan diseases:
Although there are many protozoans involved in poultry
diseases but Emeria (coccidiosis & Histomoniasis) is
of economical importance.
There are 7 species of Eimeria means 7 different diseases but 2 or
three are more important. E.Tenella in caecum & E. Maxima in the small
intestine.
Black head:
Turkeys
are most affected, unfortunately, up to now there is no drug & vaccine
available for this disease, and a lot of research is going on to find some solution. There
are some other parasites, Roundworms, and Tapeworms affecting poultry.
According to the Minster vet poultry specialist,
It’s advisable to treat during production; if worms are present
the dewormer will not affect production.
Feed-related problem:
The feed of birds should have sufficient minerals, and trace
elements.
There are several problems relating to feed.
Ø Rickets.
Ø Leg problems like femur head necrosis, tibial
dyschondroplasia, osteomyelitis, perosis, paralysis,
Ø Stifle joints swellings, rupture of gastrocnemius
tendon, and plantar abscess.
Ø The most of problems are related to the improper amount of
calcium, phosphorous, chloride, and manganese.
Ø Disease of coccidiosis will predispose to tendinitis in
production.
Ø Staphs are often opportunist infections in already
inflamed tissue.
Lab diagnosis techniques:
With the development in technology, there are several new techniques implemented in the poultry industry to diagnose real problems. For this purpose, several methods had been used in recent
years.
1) Conventional tests (isolation of the virus in culture &
embrocated eggs
electron microscopy, HA.
2) Molecular tests (PCR, sequencing, DNA fingerprinting)
3) Serological tests (HI, Virus neutralization, and ELISA
‘‘In the current age, many people rely on real time PCR.’’
Advantages of RT- PCR:
1) Very reproducible
2) Highly sensitive
3) Use fluorescent to detect PCR products.
Summary:
In short, it’s an informative course, which is
specially designed for poultry veterinarians and Managers for practical knowledge
of diseases and predisposing factors to diseases. Actually, it's a combination of
some eminent speakers from different universities, who devoted their most of
life span in research and thesis work relating to the practical aspect of
diseases. Like Adrian smith from Oxford University on immunology, Kannan Ganapathy,
Janet Bradbury from Liver pool university. And some practical expert
Vets who are doing their practice in poultry throughout U.K. like
Grant Hayes very reputed vet in U.K. and Micheal Clark from Minster vet. Also, a
chance to interact, and communicate with famous vets mostly from the U.K for refreshing
your knowledge. In addition from this year if choose an accredited module, then
can get a post-graduate degree of 20 credit hours from Nottingham University by
qualifying exam later on.
I felt that our vets are performing much better, but
they should give more exposure to the Lab work, for basic tests to diagnose
disease, some exposure to hatchery work, and regular postmortem. We should send
further vets & Managers in future for this course. I am especially Thankful
to you & higher Management for providing me this opportunity.
Yours Faithfully,
DR.Abbas
Ur Rehman
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