Abstract:
Indigenous Chickens (IC) population in Nigeria is threatened due to high Mortality
Rate (MR) from Viral Diseases (VD). Vaccination is currently the most effective
preventive measure against VD such as the Newcastle Disease (ND). Vaccination
during embryonation could help to mitigate susceptibility to ND post-hatch.
Information on in ovo and post-hatch vaccinations of IC in Nigeria is scanty.
Therefore, performance of three strains of IC vaccinated against ND in ovo and post hatch were investigated.
Parent stocks of IC comprising five cocks and 25 hens each of Normal Feathered (NF),
Frizzle Feathered (FF) and Naked Neck (NN) strains were obtained from a reputable
source to produce Hatchable Eggs (HE). Two hundred and forty HE of each of NF, FF
and NN chickens were incubated for 18 days. At day 18, HE were candled and 60
Fertilised Eggs (FE) from each strain were drilled and injected with 0.2 mL Injection
Water-IW (T11) or B1 Lentogenic Strain-B1LS (T12) ND vaccine using in ovo
procedures. At hatch, 10 chicks (r=6) each from the strains were injected
subcutaneously using 0.2 mL IW (T21) or B1-LS (T22) in a randomised complete
block design. On days 1, 21, 42, 63 and 84, blood (2 mL) was sampled (r=5) for
Geometric Mean Antibody Titre (GMAT), and at week 16, blood (5 mL) was sampled
(r=5) for haematological profile using standard procedures. Body Weight Gain
(BWG), mortality and hen-day production were recorded during early (22-42 weeks),
mid (43-59 weeks) and late (60-72 weeks) phases of egg production. Data were
analysed using ANOVA at 0.05
At days 21, 42 and 84, GMAT of birds vaccinated in ovo (T12) and post-hatch (T22)
and their controls (T11 and T21, respectively) were similar. At days 1 and 63, GMAT
differed significantly across all treatments and were 3.2±0.1 and 3.3±0.2 (T11), 4.0±0.1
and 6.0±0.2 (T12), 2.0±0.1 and 3.1±0.2 (T21), 2.5±0.1 and 4.5±0.2 (T22), respectively.
At day 63, GMAT was significantly higher in FF (4.8±0.2) than NF (4.4±0.2) and NN
(3.6±0.2), while at day 84, GMAT in FF (3.2±0.1) was similar to NF (3.0±0.1) but
significantly higher than NN (2.4±0.1). Monocytes and lymphocytes in T12
(3.41±0.03%, 64.1±0.1%) and T22 (3.36±0.03%, 64.2±0.1%) were significantly higher
than in T11 (3.31±0.03%, 63.2±0.1%) and T21 (3.28±0.03%, 63.1±0.1%, respectively).
Similarly, heterophil and white blood cell count (x103
/mm3
) in T12 (29.6±0.1%,
3.47±0.02) and T22 (29.5±0.1%, 3.47±0.02) were significantly higher than in T11
(29.2±0.1%, 3.41±0.02) and T21 (29.1±0.1%, 3.42±0.02, respectively). The B1-LS had
no effect on BWG, while it significantly reduced mortality from 2.8±0.0% (T11 and
T21) to 1.8±0.0% (T12 and T22). Hen-day production was significantly improved by
vaccination and ranged from 53.63±0.00% (T11) to 54.62±0.00% (T22), 68.56±0.00%
(T11) to 69.63±0.00% (T22), and 50.48±0.00% (T11) to 51.43±0.00% (T22) for early,
mid and late laying phases, respectively.
In ovo vaccination against Newcastle disease was superior to post-hatch vaccination.
Hen-day production was enhanced and mortality was reduced using the B1 Lentogenic
strain vaccine in the Nigerian Indigenous Chicken strains for both in ovo and post hatch vaccinations.
