International Journal of Poultry Science 7 (6): 579-585, 2008
ISSN 1682-8356
© Asian Network for Scientific Information, 2008
579
Productivity and Egg Quality Characteristics of Free Range
Naked Neck and Normal Feathered Nigerian Indigenous Chickens
A. Yakubu , D.M. Ogah and R.E. Barde
1 2 2
Department of Animal Science, Faculty of Agriculture, Nasarawa State University,
1
Keffi, Shabu-Lafia Campus, P.M.B. 135, Lafia, Nigeria
Department of Animal Science, College of Agriculture, Lafia, Nasarawa State, Nigeria
2
Abstract: A study was conducted in Nasarawa State, North Central Nigeria to determine the productivity and
egg quality traits of free range naked neck and full-feathered chickens. A total of one hundred and two
smallholder farmers were randomly selected. Information was obtained on average eggs per clutch,
hatchability and mortality, while hen’s body weight was measured directly on the day of egg collection. One
hundred and two freshly laid eggs (51 eggs from each genotype) were used to evaluate external and internal
egg qualities. Body weight and average eggs per clutch were significantly (p<0.05) higher in naked neck
genotype compared to the normal feathered birds (1.30 vs. 1.16kg; 11.63 vs. 9.71 respectively). Normal
feathered genotype recorded higher mortality (36.85%) than naked neck birds (28.60%). No significant
(p>0.05) difference was found between the two genotypes in hatchability. Mean values for egg weight, egg
length, egg width, egg shape index, shell thickness, albumen weight, albumen height, yolk weight, yolk
height, yolk width and haugh unit were significantly (p<0.05) higher in naked neck hens than their normal
feathered counterparts. There was no superiority in shell weight and yolk index. The association between
egg weight and other egg biometrical traits were found to be positive and significant (r = 0.22-0.79; p<0.05).
Other egg parameters were either positively or inversely correlated with each other. Egg weight was better
predicted (R = 34.44%) using a combination of egg length and egg width. The estimation of shell weight
2
from egg length, egg width and egg weight gave lower values (R = 2.86-3.91%). The incorporation of
2
allometry improved the prediction accuracy of shell thickness, albumen weight and yolk weight from egg
weight (R = 44.16,43.89 and 49.89%). It is concluded that the introgression of the naked neck gene into
2
poultry could play a pivotal role in the genetic improvement of traditionally managed flocks.
Key words: Productivity, egg parameters, relationships, indigenous chickens, Nigeria
Introduction
The Nigerian local chickens appear to be generally
heterogeneous with no specific colour pattern and non-
descriptive both in phenotype and genotype. The native
chickens constitute about 80 percent of the 120 million
poultry birds. They are known for their adaptation
superiority in terms of their resistance to endemic
diseases and other high environmental conditions
(Nwakpu et al., 1999). The local birds seen in villages
may have been crossed with exotic cocks in earlier years
through the cockerel exchange programme amongst
others, but such gene may have been dispersed and
lost in the population because of unplanned breeding
programme and absence of selection (Njue et al., 2002).
One way of overcoming challenges posed by past
strategies in improving sustainable productivity is
through genetic selection and development of
sustainable indigenous parent stock. Among the major
genes of interest that can be considered for this purpose
is the naked neck. The naked neck gene is incompletely
dominant with Na/na birds showing an isolated tuft of
feathers on the ventral side of the neck above the crop,
while Na/Na birds either lack this tuft or it is reduced to
just a few pin feathers or small feathers. The resulting
bare skin becomes reddish, particularly in males as they
approach sexual maturity (Somes, 1990). The reduction
in feather coverage in naked neck birds permits
convectional heat loss from the animal surface, thereby
leading to improved thermo-regulation under the
prevailing conditions. Mohammed et al. (2005) reported
the superiority of Bare-neck indigenous chickens over
two other Sudanese local fowls in terms of live weight.
Similarly, Merat (1990) reported that in high
temperatures near 30°C or higher, naked neck birds had
a better laying rate, mean egg weight, egg shell strength
and carcass yield than normal feathered birds.
In many developing countries, the local gene pool still
provides the basis for the poultry sector. The genetic
resource base of the indigenous chickens could form
the basis for genetic improvement and diversification to
produce breeds adapted to local conditions. However,
there is paucity of information about existing or potential
levels of productivity and production characteristics of
indigenous chickens managed under extensive systems
(Hoffman, 2005). In Nigeria, previous characterization
attempts on indigenous chickens with major genes have
been concentrated on on-station performance at the
expense of on-farm testing.