Characterization of the Fulani-ecotype chicken for thermoregulatory feather gene

T R Fayeye and A B Oketoyin

Department of Animal Production, Faculty of Agriculture, University of Ilorin, Nigeria
fayetiro@yahoo.com

Abstract

One thousand and twenty -eight (563: 465, male: female) adult Fulani-ecotype chicken from twelve communities in two states of Nigeria were assessed for thermoregulatory (feather morphology and feather structure) genes. The gene frequency for the dominant gene carriers for feather morphology (F) was 0.005 (0.5%) while the gene frequency for the dominant gene carriers for feather structure (Na) was 0.003 (0.3%).

The observed gene frequencies failed to conform to the expected Mendelian ratios. There is a need for researchers and extension workers to take adequate measures to preserve Fulani-ecotype chicken with dominant alleles to enhance their utilization in future livestock improvement programs.

Key words: Feather morphology, feather structure, Fulani ecotype

Introduction

Native chicken constitutes 80% of the poultry birds in Nigeria. According to Akinwumi (1979) and Sonaiya (1992) more than 80% of the total poultry population are found in the rural households. Annually the native chicken has remained largely genetically uncharacterized and unimproved (Oluyemi and Roberts 2000)

NRC (1993) recommended a study of the level of genetic diversity in different populations as the first step to bring about improvement in the performance of chicken in the developing countries. The work of Ojo (2002) and Adesina (2002) on the characterization of native chickens for adaptive genes failed to recognized the diversities that may exist in different populations.

Fulani-ecotype chicken is one of the best-preserved local chickens in Nigeria because of the cultural lifestyle of the Fulani- keepers. A comparism of the Fulani -ecotype with the Yoruba eco-type (Olori,1992) showed that Fulani-ecotype chicken has superior bodyweight and fleshing. The present work is aimed at assessing the Fulani-ecotype chicken for adaptive feather morphology (F/f) and feather structure (Na/na) genes.

Material and methods

A total of 1028 (one thousand and twenty-eight) Fulani- ecotype chicken were used for this study. The birds were obtained from six communities in Kwara State (namely: Bolorunduro, Gaa-Saka, Fufu, Oloru, Budo Egba and Madi) and six communities in Oyo state (namely Gaa-Olohunmike, Gaa-Oloko, Budo-Ayiki, Aroje, Ade-Oyo and Aladaba). Enumeration of the birds was done in batches very early in the morning at their usual time of congregation for whole grain diet.

The frequencies of the alleles for feather morphology (F/f) and feather structure (Na/na) were calculated using the Hardy-Weinberg equilibrium approach (Falconer 1989) as follows:

q = root m/t

Where: q = frequency of the recessive allele
            m= observed number of adult Fulani-ecotype with the recessive phenotype.
            t= total number of adult Fulani- ecotype.

The frequencies of the respective dominant allele (p) were calculated as p= 1- q

The observed frequencies were tested against the expected Mendelian ratios using the chi-square test (Thompson 1941) with the assumption of zero value for artificial selection.

Results and discussion

The proportion of birds with dominant gene for feather morphology (Ff) and feather position (NaNa, Nana) were 0.97% and 0.58%, respectively, while that of the recessive gene carriers were 99.03% and 99.42%, respectively. The gene frequencies for frizzled (F) and Naked neck (Na) were 0.05 and 0.03, respectively. (Table 1).  The chi-square analysis showed that the phenotype ratios for both feather morphology (frizzled versus normal) and feather structure (naked neck versus normal) failed to conform to expectation for a Mendelian population.

The present result indicated that Fulani-ecotype chickens with the dominant alleles for thermoregulatory feather morphology and feather structure genes are at the brink of extinction. Similar observations were made in earlier studies (Adesina 2002, Ojo 2002) on unspecified native chickens . According to Ojo (2002) a lot of social and traditional values are placed on the dominant gene carriers (i.e. Frizzled and naked neck chickens) due to their roles in rituals and sacrifices. The low frequency of occurrence of frizzling in adult birds may also be due to the lethality of the frizzle gene (F) when it is in homozygous condition (Adeniyi 2001).

Conclusions

• The investigated adaptive feather genes are at the brink of extinction in the Fulani-ecotype chicken.

• There is the need for both researchers and field extension workers to take adequate measures to preserve these rare varieties of dominant gene carriers for future livestock development programs.

References

Adesina O M 2002 Gene Frequency and influence of polydactyl and ptylopody on body size of Nigerian local chickens. M.Sc thesis, University of Ilorin. Nigeria

Akinwumi J A 1979 Economic Analysis of Nigerian poultry industry. Federal Livestock Department. Lagos.

Falconer D S 1989 Introduction to quantitative genetics 3^rd edition, Longman Scientific and Technical/ London 438pp.

Ojo V 2002 Incidence and influence of Naked neck and frizzle genes on body size of local chickens M.Sc thesis, University of Ilorin, Nigeria.

Olori V E 1992 Evaluation of two-ecotype of the Nigerian indigenes chicken . M.Sc thesis, Obafemi Awolowo University, Ile -Ife, Nigeria.

Oluyemi J A and Roberts F A 2000 Poultry production in warm-wet climate. Spectrum Books Ltd, Ibadan, Nigeria.

NRC 1993 National Academy of Sciences, Washington D.C.

Sonaiya E B 1992 (editor) Rural Poultry in Africa: Proceedings of an International conference on rural poultry production. Thelia House, OAU , Ile-Ife.

Thompson C M 1941 Table of percentage points of the X (chi-square) distribution, Biometrica. Volume 32 (1941).

Received 13 January 2006; Accepted 15 January 2006; Published 24 March 2006

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