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 American Journal of  
Food Science and Technology (AJFST)

Comparative Antibody Responses of  Four Turkey Strains to Attenuated Salmonella
Vaccine: A Path to Enhanced Poultry Production

Jude Ngozichukwuka Efienokwu1, Ekerette Emmanuel Ekerette2*

Volume 3 Issue 2, Year 2024
ISSN: 2834-0086 (Online)

DOI: https://doi.org/10.54536/ajfst.v3i2.3754
https://journals.e-palli.com/home/index.php/ajfst

Article Information ABSTRACT

Received: September 10, 2024

Accepted: October 12, 2024

Published: November 14, 2024

The increasing demand for turkey as a protein source necessitates effective management 
practices, particularly in combating Salmonella infections. This study evaluated the 
immune response of  four turkey strains (black, white, exotic, and lavender) to a Salmonella 
gallinarum-9R strain vaccine. A total of  180 samples of  day-old poults (45 from each strain) 
were used for the experiment. Following initial blood sampling at four weeks, all birds 
were vaccinated orally with the Salmonella vaccine. Monthly blood samples were collected 
over four months to assess antibody titres using a serial dilution method. Results revealed 
significant differences in the mean antibody responses among the strains. The black strain 
exhibited the highest mean antibody titre (1.38), followed closely by the exotic (1.32) and 
white (1.30) strains, while the lavender strain showed the lowest titre (1.17). The antibody 
titres significantly increased post-vaccination compared to pre-vaccination values (p < 0.05). 
These findings highlight the effectiveness of  vaccination in enhancing immunity in turkeys, 
suggesting that selective breeding of  more responsive strains could improve flock health and 
reduce the risk of  Salmonella infection.

Keywords

Antibody, Serial Dilution, 
Strains, Turkey, Vaccination

1 Department of  Science Laboratory, Delta State Polytechnic, PMB 1030, Ogwashi-uku, Delta State, Nigeria
2 Animal Genetics and Genomic Unit, Department of  Genetics and Biotechnology, University of  Calabar PMB 1115, Calabar, Nigeria
* Corresponding author’s e-mail: ekerette.ekerette@unical.edu.ng

INTRODUCTION 
Over recent decades, egg and poultry meat production 
and consumption have witnessed significant increases 
worldwide. Notably, in recent years, the consumption 
of  eggs and meats from poultry, such as chicken and 
turkey, has upsurged (Can & Can, 2022; Connolly et al., 
2022). This surge connotes the growing importance of  
poultry products, particularly in Africa, where they serve 
as a critical source of  income and play a vital role in the 
protein supply chain (FAO, 2010; Mottet & Tempio, 
2017; Grace et al., 2024). Nigeria has one of  the lowest 
levels of  animal protein consumption, averaging 45.4g 
which falls below the minimum benchmark of  53.8 g per 
capita daily protein intake recommended by the Food and 
Agriculture Organization (FAO) (Challenge et al., 2020). 
The majority of  animal protein from the poultry industry 
in Nigeria stems from chicken (Akhigbe & Akaeze, 2023), 
but there has been a recent decline in production owing to 
factors such as environmental changes (Wasti et al., 2020; 
Osuji et al., 2024) and production costs (Sesay, 2022).  In 
this context, turkeys provide a complementary option 
to chickens, as they adapt well to various environmental 
conditions and offer superior meat quality characterized 
by lower fat content (Pinto e Silva et al., 2008).
Despite their nutritional and economic potential, turkey 
breeding remains relatively underdeveloped. Turkeys, 
which belong to the genus Meleagris, include two primary 
species: Meleagris gallopavo (the domesticated strain) 
and Meleagris ocellata (the wild strain) (David, 2018). 
Unfortunately, these birds are particularly vulnerable to 
infections from Salmonella, a pathogen that can not only 
affect their health and productivity but also serve as a 
vector for transmission to humans. In Nigeria, outbreaks 

of  food poisoning have been linked to Salmonella 
infections (Ojeniyi & Montefiore, 2009). Worldwide, 
approximately 1.3 billion cases of  gastroenteritis each 
year are associated with Salmonella (CDC, 2019). While 
the increasing demand for protein drives the production 
of  turkeys, the prevalence of  Salmonella infections 
significantly undermines these efforts, resulting in 
reduced productivity and diminished commercial viability 
compared to more commonly produced poultry species 
(Lamichhane et al., 2024). Nonetheless, turkey meat 
remains a popular dietary choice in Nigeria, as it is not 
subject to the same cultural or religious restrictions as 
other poultry sources. Thus, there is a pressing need to 
focus on producing healthy turkeys that are free from 
these harmful bacteria to improve economic stability and 
ensure the safety of  consumers (Lamichhane et al., 2024).
However, diseases continue to pose substantial threats 
to Nigeria’s burgeoning poultry economy. Among 
the various ailments that affect poultry, Newcastle 
disease, Salmonella infections, and blackhead disease 
are particularly prevalent. The presence of  Salmonella 
is a significant concern, as it is responsible for causing 
salmonellosis, a disease that has far-reaching impacts on 
both commercial and local turkey populations due to their 
heightened susceptibility to this pathogen (Lamichhane 
et al., 2024). Estimates suggest that salmonella infections 
may represent a greater economic burden than any other 
bacterial infection affecting livestock (Baptista et al., 
2023). Despite the widespread use of  antibiotics and 
antiseptic treatments intended to prevent outbreaks, 
Salmonella infections persist, affecting even those birds 
that receive such interventions (Lamichhane et al., 2024). 
In many developed nations, effective control measures 



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Am. J. Food. Sci. Technol. 3(2) 83-87, 2024

have led to significant reduction but the most prevalent 
is in Sub-Saharan Africa (Stanaway et al., 2019). The 
majority of  Salmonella transmission to humans has 
been through food, including meat (Kirk et al., 2015). 
However, in Nigeria, a multitude of  factors complicates 
effective management, as numerous potential sources of  
Salmonella infection and product contamination exist 
within integrated poultry enterprises.
In light of  these challenges, there is an increasing 
interest in developing effective prevention strategies, 
particularly through vaccination, to combat the impact 
of  salmonellosis and improve turkey breeding, which 
has suffered due to the disease (Oyeagu et al., 2022). This 
situation calls for a comprehensive investigation into 
the resistance of  various turkey strains to Salmonella 
infection, especially following vaccination with the 
Salmonella gallinarum-9R strain. The findings from this 
research could contribute significantly to improving 
strategies for managing Salmonella infections, thereby 
enhancing turkey production and ensuring public health 
safety for consumers.

MATERIALS AND METHODS
Experimental Birds and Management Procedures
This study utilized day-old poults from four different 
strains: 45 black, 45 white, 45 exotic, and 45 Lavender. 
The poults were sourced from Francisco Turkelings, 
Calabar, Nigeria, and transported to the experimental 
site set up at the Department of  Science Laboratory, 
Delta State Polytechnic, Delta State. The birds were kept 
in standard cages with natural ventilation. Before their arrival, 
the cages were thoroughly fumigated and disinfected using an 
organophosphate insecticide and Dettol to minimize the risk 
of  infection. The poults were acclimatized for two weeks and 
provided with Turkey Starter feed and water ad libitum. After 
eight weeks, the feed was switched to grower feed.

Experimental Design
Following the acclimatization period, the poults were 
randomized into four groups using a Randomized 
Complete Design, with each group corresponding to a 
strain. There were 45 replicates per strain.

Vaccination and Blood Sampling
At four weeks of  age, 1 ml of  blood was collected 
from each strain through the wing veins using a sterile 
needle and syringe. This initial blood sample, collected 
into EDTA bottles, was used for antibody assessment 
(control). Subsequently, the birds were vaccinated with 
the Salmonella gallinarum-9R strain. The Salmonella 
gallinarum-9R strain vaccine was dissolved in 100 ml of  
water and 1 ml was given to each bird orally. Monthly 
blood sampling and antibody assessments were conducted 
for four months.

Preparation of  Buffer Solution and Measurement of  
Antibody Titre
The buffer solution used for measuring antibody titre was 

phosphate-buffered saline (PBS), prepared as follows: 
sodium chloride (8 g/L), potassium chloride (0.2 g/L), 
disodium hydrogen phosphate (1.15 g/L), and potassium 
dihydrogen phosphate (0.2 g/L) were dissolved in 10 
litres of  distilled water. The buffer was maintained at a 
pH of  7.3. Antibodies present in the serum were detected 
using a serial dilution method. A constant dilution factor 
of  2 was applied, with serial dilutions ranging from 10² 
to 10²⁵⁶. The butter solution was poured into a test tube 
in different volumes: 2 ml, 4 ml, 8 ml, 16 ml, 32 ml, 64 
ml, 128 ml and 256 ml. Afterwards, 1 ml of  antigen was 
added across all the buffer volumes followed by 1 ml of  
serum. The mixture was incubated for 1 hour, at room 
temperature before recording the result. Antibody titre 
was recorded as the highest dilution showing a positive 
reaction for each strain. 

Statistical Analysis
All data obtained from the experiment were subjected 
to analysis of  variance (ANOVA) and the means were 
separated using the least significant difference (LSD) test 
at a 5% level of  probability.

RESULTS AND DISCUSSION
Response of  Turkey Strains to Salmonella Vaccine
The antibody responses of  the four turkey strains to 
the Salmonella vaccine are presented in Figure 1. The 
results reveal significant differences among the strains, 
indicating that the black, white, and exotic strains 
produced higher antibody titres compared to the lavender 
strain. Specifically, the black strain exhibited the highest 
antibody titre, measuring 1.38. This was closely followed 
by the exotic strain, which recorded an antibody titre of  
1.32, and the white strain, with a titre of  1.30. In stark 
contrast, the lavender strain showed the lowest antibody 
titre value at 1.17. 

Figure 1: Mean titre response of  four turkey strains to 
Salmonella vaccine



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Am. J. Food. Sci. Technol. 3(2) 83-87, 2024

Antibody Titre Response before and after Vaccination 
Table 1 presents the antibody titre values for the four 
turkey strains before and after vaccination with the 
Salmonella vaccine. A statistical analysis of  the data 
indicated significant differences (p < 0.05) in the antibody 
titre values across the various turkey strains both before 
vaccination and at different time points following 
vaccination. In the case of  the black strain, the initial 
antibody titre was the lowest recorded before vaccination. 
However, after vaccination, antibody titres increased, and 
by months 2, 3, and 4, the black strain showed consistent 
titres. For the white strain, the results were particularly 

noteworthy, revealing a marked increase in antibody 
titres, peaking at month 4 with a value of  1.78. This 
was accompanied by titres of  1.44 at month 3, 0.59 at 
month 2, and a control titre of  0.33 before vaccination. 
The lavender strain’s response was characterized by some 
variability, with antibody titre values at months 2, 3, and 4 
being statistically similar yet significantly higher (p < 0.05) 
than the initial response before vaccination. The exotic 
strain demonstrated the most pronounced response, 
achieving the highest mean titre value at month 4, which 
was measured at 1.84. This was followed by a strong 
response at month 3, with a titre of  1.44.

Table 1: Mean titre (loge HI) response of  turkey strains before and after Salmonella vaccination
Duration Black White Lavender Exotic
Month 1(Initial) 0.45 ± 0.06b 0.33 ± 0.06d 0.63 ± 0.08b 0.48 ± 0.07c

Month 2 1.38 ± 0.09a 0.59 ± 0.07c 1.08 ± 0.13a 0.59 ± 0.07c

Month 3 1.38 ± 0.09a 1.44 ± 0.06b 1.33 ± 0.12a 1.44 ± 0.06b

Month 4 1.38 ± 0.09a 1.78 ± 0.08a 1.13 ± 0.10a 1.84 ± 0.68a

Mean values with different superscripts along the same vertical lines are significantly different (p<0.05). Haemoglobin inhibition (HI)

Discussion 
Salmonella infection remains one of  the most significant 
bacterial diseases affecting poultry, leading to considerable 
economic losses and public health concerns due to its 
zoonotic potential (Baptista et al., 2023). In response 
to this challenge, various control strategies have been 
employed, including the administration of  antibiotics 
and probiotics, as well as the implementation of  
selective breeding programmes aimed at enhancing the 
resistance of  turkey stocks to these infections. Despite 
these efforts, the production of  turkey meat continues 
to be constrained by the limited attention given to turkey 
research, particularly regarding their health management 
and immune responses (Oyeagu et al., 2022). This neglect 
is troubling, especially considering the significant protein 
supply potential that turkeys offer, which is important for 
food security.
The findings from this study revealed significant 
differences in the antibody responses among the turkey 
strains, particularly highlighting that the black, white, and 
exotic strains produced notably higher antibody titres 
compared to the lavender strain, both before and after 
vaccination. This differential response indicates that the 
immunological capacity of  these strains was significantly 
influenced by the vaccine, demonstrating varying levels 
of  effectiveness in stimulating an immune response. 
The marked increase in antibody levels post-vaccination 
suggests a robust immunological response, critical for 
establishing protection against Salmonella. A similar trend 
was observed by Ikpeme (2021) following the vaccination 
of  turkey strains with Newcastle vaccine. The observed 
increase in antibody levels post-vaccination signifies that 
the immune systems of  these strains were effectively 
stimulated by the vaccine. The findings suggest that the 
administration of  the Salmonella vaccine elicited a strong 
immune response, characterized by the production of  

antibodies that could help combat infection. This aligns 
with the principle that a greater quantity and diversity 
of  antibodies correlate with the strength of  the immune 
response (Zimmermann and Curtis, 2019, Cosgon et 
al., 2023). The consistent titres recorded across the 
black, white, and exotic strains in the months following 
vaccination further support the notion that a higher 
antibody response is indicative of  enhanced resistance to 
disease.
Interestingly, the white strain demonstrated the highest 
antibody response at four months post-vaccination, with 
a mean titre of  1.78, indicating an effective and sustained 
immune response. The exotic strain also exhibited strong 
titres, with 1.84 at month four, suggesting that these 
strains could be prioritized in breeding programmes 
aimed at improving overall flock health and productivity. 
In contrast, the lavender strain’s response was less 
pronounced, though it did show a statistically significant 
increase in antibody levels at months 2, 3, and 4 
compared to pre-vaccination titres. This accentuates the 
importance of  evaluating breed-specific responses when 
developing vaccination strategies which has been noted 
in many reports (Ravikumar et al., 2022; Miyumo et al., 
2024; Abdelaziz et al., 2024; Geletu et al., 2024). Moreover, 
the temporal dynamics of  antibody levels observed in 
this study indicate a natural progression in the immune 
response. The decline in antibody levels following the 
peak response period is consistent with findings from 
earlier research (LeBaron et al., 2009; Klein et al., 2023; 
Vashishtha & Kumar, 2024), which indicated that while 
vaccines are effective in priming the immune system, 
antibody levels naturally decrease over time. This suggests 
the necessity for ongoing monitoring of  antibody levels 
in the turkey population, as well as the potential need 
for booster vaccinations to sustain an adequate level of  
immunity over time. According to Chen et al. (2022), 



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antibody levels peak around one month after vaccination 
and gradually decline, stabilizing at a plateau significantly 
higher than pre-vaccination levels due to continuous 
production from long-lived plasma cells (LLPCs) in the 
bone marrow. This was the observation made across 
the different strains where the antibody titres were 
generally higher than levels before vaccination despite 
the variations between months. Maintaining optimal 
immunity is particularly important in environments 
where the risk of  Salmonella exposure is heightened, as it 
directly impacts flock health and productivity. In addition, 
the implications of  this research extend beyond individual 
strain performance. Understanding the differences in 
immune responses among various turkey breeds can 
inform breeding programmes and management practices 
aimed at enhancing disease resistance. Selecting strains 
with superior antibody responses could lead to a more 
resilient poultry population, ultimately contributing to 
better animal health, reduced transmission to humans, 
and reduced economic losses due to Salmonella.

CONCLUSION 
This study demonstrates that vaccination with the 
Salmonella gallinarum-9R strain significantly enhanced 
the immune response of  various turkey strains, with the 
black, white, and exotic strains showing notably higher 
antibody titres compared to the lavender strain. The 
results indicate that effective vaccination is essential 
for improving the health and productivity of  turkeys, 
particularly in the context of  Salmonella prevention. 
Given the significant differences observed in immune 
responses among the strains, it is evident that selective 
breeding for higher vaccine responsiveness could further 
enhance flock resilience against Salmonella infections. 
The present findings demonstrate the importance of  
implementing robust vaccination strategies in turkey 
management to ensure both animal health and food 
safety.

Acknowledgement
We extend our heartfelt appreciation to the Department 
of  Microbiology, University of  Calabar where the 
Antibody response test was performed.

Funding
This research was funded by the Tertiary Education 
Trust Fund (TETFund) under the grant number: TETF/
DR&D/CE//POLY/OGWASHI-UKU/IBRVOL.1

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