LONGITUDINALNO PRAĆENJE TITRA SPECIFIČNIH PROTUTIJELA NA VIRUS NEWCASTLESKE BOLESTI U SERUMU KOKOŠI NESILICA NAKON PROVEDENOG PROGRAMA IMUNOPROFILAKSE

master's thesis

• Title (english): Longitudinal monitoring of antibody titer against Newcastle disease virus in serum of laying hens after vaccination program
• Author: Nika Meštrović
• Mentor: Željko Gottstein (mentor)
• Committee member: Danijela Horvatek Tomić (predsjednik povjerenstva)
• Committee member: Maja Lukač (član povjerenstva)
• Committee member: Željko Gottstein (član povjerenstva)
• Granter: University of Zagreb; Faculty of Veterinary Medicine; Zagreb
• Defense date and country: 2021-10, Croatia
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Veterinary Medicine; Veterinary Public Health and Food Safety

Abstract

Newcastleska bolest je jedna od najznačajnijih bolesti u peradarskoj industriji.
Provođenjem specifične imunoprofilakse peradi pokušava se potaknuti dovoljna
količina protutijela za virus newcastleske bolesti i time adekvatna zaštita koja
sprječava izbijanje epizootija. Zbog različitih načina primjene cjepiva i različitog učinka
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cjepiva na imunosni odgovor važno je pratiti titar specifičnih protutijela u cijepljene
peradi kako bi se dobio što bolji uvid u zaštićenost cijepljenih jata.
Svrha ovog diplomskog rada je analiza rezultata ELISA titra specifičnih protutijela
na virus newcastleske bolesti u nekoliko jata longitudinalno na dvije farme kokoši
nesilica kako bi dobili prikaz dinamike titra.
Imunoprofilaksa newcastleske bolesti kokoši nesilica na praćenim farmama sastoji
se od višekratne primjene živog atenuiranog cjepiva, prvo primijenjenog postupkom
raspršivanja pilićima u valionici, a potom u dva navrata putem pitke vode, najčešće
koristeći soj La Sota. Nakon toga, a neposredno prije preseljenja u proizvodne
objekte, koristi se viševaljano inaktivirano cjepivo koje se primjenjuje i.m. ili s.c.
Za dokaz titra specifičnih protutijela na virus newcastleske bolesti korišten je
komercijalni ND ELISA kit (Biochek, Nizozemska) prema uputama proizvođača.
U našem istraživanju 36% (7) od ukupno pretraženih jata (19) ima zadovoljavajući
titar protutijela sukladno preporukama proizvođača dijagnostičkog kita odnosno 41 %
na farmi 1 i 27% na farmi 2. Od sveukupno 168 kokoši 65 ima adekvatan zaštitni titar
prema navedenim preporukama, odnosno 38% . Također 26% jata (5 od 19) ima
adekvatan %CV, a 31% (6 od 19) ima adekvatan VI indeks. Veću varijabilnost i niže
titreve treba očekivati kod jata dobi ispod 20 tjedana, no u starijoj dobi uočava se niža
razina titreva i veća varijabilnost, koja je moguće posljedica neadekvatno provedenog
programa imunoprofilakse kao i malog broja uzorka po jatu. Sukladno navedenom
potrebno je provesti kontrolu primjene cjepiva na farmama, kao i postupke uzimanja i
čuvanja uzoraka, te uzeti potreban broj uzoraka.

Abstract (english)

Newcastle disease is one of the most significant diseases in the poultry industry. By
induction of specific immunoprotection of poultry, an aim is to induce a sufficient
amount of antibodies to the Newcastle disease virus and thus adequate protection to
prevent the outbreak of epizootics. Due to the different routes of administration of the
vaccine and the different effect of the vaccine on the immune response, it is important
to monitor antibody titers of vaccinated poultry in order to obtain a better view of the
acquired protection.
The purpose of this thesis is to analyze the results of ELISA titers of specific antibodies
to Newcastle disease in several flocks of layer hens longitudinally on two farms to
acquire the dynamics of gained titers.
Immunoprophylaxis of Newcastle disease in layers on monitored farms consists of
repeated administration of a live attenuated vaccine, first administered by spraying
chickens in a hatchery and then twice by drinking water, most commonly using the La
Sota strain. After that, and immediately before the transfer to the production facilities,
a polyvalent inactivated vaccine is used which is applied i.m. or s.c.
A commercial ND ELISA kit (Biochek, The Netherlands) according to the
manufacturer's instructions was used to detect the titer of specific antibodies to
Newcastle disease virus. In our study, 36% (7) of the total tested flocks (19) have a
satisfactory antibody titer according to manufacturer's reference values, 41% and 27%
on farm 1 and farm 2, respectively. Out of a total of 168 hens, 65 have an adequate
protective titer according to reference values, or 38 %. Also 26% of flocks (5 of 19)
have adequate %CV and 31% (6 of 19) have adequate VI. Higher variability and lower
titers should be expected in younger flocks, below 20 weeks af age, while in older
flock we detected lower titers and higher variability, what could be result of improper
vaccination program as well as lower number of samples per flock. According to that
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it is important to control the vaccination protocol as well as blood sampling and sample
storing, and to take proper number of samples.

• Keywords: newcastleska bolest; kokoši nesilice; cijepljenje; titar protutijela; ELISA
• Keywords (english): Newcastle disease; layer hen; vaccination; antibody titre; ELISA
• Language: croatian
• URN:NBN: urn:nbn:hr:178:716267
• Study programme: Title: Veterinary Medicine; Study programme type: university; Study level: integrated undergraduate and graduate; Academic / professional title: doktor/doktorica veterinarske medicine (doktor/doktorica veterinarske medicine)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2021-10-18 07:42:06