Phenotypic Characterization of Indigenous Chicken Ecotypes in Awi Zone, Ethiopia

: The study was conducted in three districts of Awi zone in Amhara region, with the aim to characterize and identify the phenotypic variation of indigenous chicken ecotypes. A total of 720 indigenous chicken ecotypes were (504) females and (216) males from the whole districts) to describe qualitative and quantitative traits. Local chicken were mostly normally feathered and large phenotypic variability among ecotypes was observed for plumage color. A many plumage colors were identified in all districts in which Red in high-land and mid-land and Gebsima (grayish) colours in low-land were the predominant color of the study area beside a large diversity. The average body weight of local chickens in high-land, mid-land and low-land agro-ecologies were 1.476, 1.75 and 1.71kg respectively, while the respective values for mature cocks and hens were 1.78 and 1.51kg. Variations were also observed in shank length, chest circumference, body length, neck length, wingspan, wing length, comb width, comb length and shank circumference. In conclusion, there is diversity of indigenous chicken population and farmers’ preference of different traits that may invite to design community based genetic improvement. These were recommended in poultry breeding policy which focused on managemental system, selection, and trait preference should be designed.


Introduction
Poultry is the largest livestock group in the world estimated to be about 23.39 billion, consisting mainly; chickens, ducks and turkeys [1]. Ethiopia is believed to have the largest livestock population. According to [2], there are about 56.53 million chickens in Ethiopia, comprising of 94.31, 3.21 and 2.49% of indigenous, hybrid and exotic types, respectively. Phenotypic characterization of Animal Genetic Resources (AnGR) generally refers to the process of identifying distinct breed populations and describing their external and production characteristics within a given production environment [3]. The term "breed" is used in phenotypic characterization to identify district Animal Genetic Resources (AnGR) populations as units of phenotypic reference and measurement.
Characterization is the initial step for long-term genetic improvement as it provides the basis for any other livestock development interventions and provides information for designing appropriate breeding programs [4]. Phenotypic characterization of breed includes all activities related with the description of the source, development, structure, and populations of quantitative and qualitative characteristics in the defined climatic condition [3]. Furthermore, characterization can identify breeds and/or populations which are at risk of extinction or which are highly desired by farmers, and hence is an important input into nation's chicken development planning [5].
No such characterization studies have been carried out to characterize and classify the existing local chicken Ecotypes in these area, in general the study districts in particular (Faggeta lekoma, Dangila and Zigom) districts. Given the highest potential for poultry production and presence of diverse ecotypes, it is imperative to conduct comprehensive studies to characterize morphological, functional, and adaptive traits of local chickens. Therefore, the objective of this study was to identify and characterize the new local chicken ecotypes in Awi zone, Ethiopia.

Material and Methodology
The study was conducted in Faggeta lekoma, Dangila and Zigom districts of Awi Zone based on their altitude classification into three agro-ecologies of Awi zone, Amhara regional state, Ethiopia. The administrative centre of Awi zone is Injibara; other towns include Chagni, Adis kidame, jawi, gimjabet, ----Dangila. Topographically, Awi zone is relatively flat: the altitude of the zone ranges from as low as 550 to 3100 m.a.s.l and the Minimum and maximum annual temperature ranges between 5°C and 27°C. Daily temperature becomes very high during the months of March to May. Average mean annual rainfall for the area is about 1700 mm. The study site is presented in figure 1.   [2]. The Samples were conducted from three districts, Faggeta lekoma, Dangila and Zigom.

Sample Size Determination and Sampling Technique
The study was conducted in Faggeta lekoma, Dangila and Zigom districts of Awi zone.
Purposive sampling was employed to select districts based on distribution of chicken population and Agro-ecological variations. Thus, three sample districts and six rural Kebeles (2 from each district) were selected for the study. The numbers of sampled households and total populations in the study area were determined by the formula described by [6] No = Z² * (p)(q) e² Where no= required sample size Z 2 = is the abscissa of the normal curve e 2 = is the margin of error (eg. ±0.05%, margin of error for confidence level of 95%) p = is the degree of variability in the attributes being measured refers to the distribution of attributes in the population q = 1-p. This is for one district, for the three districts 3×240= 720. Therefore totally 720 indigenous chickens used for collecting data of quantitative and qualitative traits.

Data Collection Procedure
For this study, primary data sources were used. In order to collect primary data, the Participatory Rural Appraisal (PRA) involves local communities as active analysts of their own situations where they estimate, quantify, compare and list priorities of resources and constraints of poultry based on their circumstances.
Data generated by the actual recording of linear body measurements (such as; body weight, shank length, earlobe length, body length, wing span, chest circumference, comb length, comb width, beak length, wing length, neck length, wattle length, shank Circumference, wattle width) and Qualitative data such as plumage color, comb type, feather distribution, shank colour, earlobe color, eye colour, beak colour, comb colour, shank feather and head shape was gathered based on standard format breed descriptor list [3].

Data Management and Analysis
Both the qualitative and quantitative data were entered into Microsoft EXCEL. Simple descriptive statistics such as average and standard error of the mean were applied for quantitative data, or frequencies and tabulations for qualitative attributes. And chi-square was used to compare variables for significantly or not across the three agro-ecologies. Multivariate analyses variance technique was applied to determine the most interesting traits from a set of traits, in order to differentiate chicken population based on their nature of similarity. The results of the analysis of the data were presented as tables.

Quantitative Data
A general linear model procedure (PROC GLM) of the SAS was employed for quantitative variables to detect statistical differences among sampled indigenous chicken populations. For mature animals, agro-ecology and sex of the experimental indigenous chickens are fitted as fixed variables. The effects of class variables and their interaction is expressed as Least Square Means (LSM) ± SE. Mean comparisons of significant differences were carried out using Tukey test (studentized range test) method at p<0.05. The following Model was used for the least -squares analysis of local chicken.

Phenotypic Characteristics of Local Chicken
The results on phenotypic (morphological) characterization of local chicken in the study areas were presented in Table 2 and figure 2 The phenotypic characterization was studied in terms of feather distribution, plumage colour, beak colour, eye colour, comb shape, comb colour, head shape, earlobe colour, shank colour and shank feather. The results are discussed as under: (

a) Feather Distribution and Plumage Colour
The results showed that local chicken were either normal feathered or necked neck. Out of these two-feather distributions, normal feathering was more numerous as indicated by proportion of birds (70, 59.2, 53.8% for female birds and 30, 28.3, 25% for male birds in Highland, Midland and Lowland agro-ecologies, respectively). The naked-neck genotype is characterized by featherless skin on the neck and on the breast part of the body [7]. Similarly, the naked-neck traits found in indigenous chicken population of the tropics considered to have desirable effect on heat tolerances [8].
The results showed that the plumage colours were red, white, black, gebsima, Tetrima and multi-colour. Out of these colours, red plumage colour was more numerous in both male and female birds in Highland (28.8, 20.2) female and male, in Midland (29.6, 19.2) female and male and in Lowland (19.2, 17.9%) in female and male birds, respectively). In Lowland red plumage colour was more numerous in only male (17.9%) birds where as in female birds gebsima was more numerous (24.6%).

b) Eye Colour and Beak Colour
The various eye colours exhibited by the local chicks were red, orange, brown and blue. The overall percentages of orange, red, brown and blue eye color of chicken in all agroecologies were 39.3, 36.00, 22.50 and 1.90% in the present study. The results showed that orange eye colour was more numerous in females in the three agro-ecologies (28.3, 32.5, 29.2% in Highland, Midland and Lowland agro-ecologies, respectively); whereas in males red eye colour was more numerous in Highland (13.8%) and Lowland (16.3%) agroecologies. However, orange eye colour was more numerous in Midland (13.3%).
The study showed that local chicks showed white, yellow and brown beak colour. The white beak colour was more numerous in Highland (33.3, 17.1% in female and male birds, respectively); in Midland yellow was more numerous in females (27.5%) whereas white was more numerous in males (13.8%); in Lowland females had white beak colour in more birds (26.7%) and male had more yellow beak colour (11.7%). The results also showed that white, yellow and brown proportions were generally number one, two and three in descending order of proportions.
(c) Comb Shape and Comb Colour Regarding comb types rose, pea and single comb types was observed in all agro-ecologies. The rose comb type was predominant in all agro-ecologies followed by pea and single. The overall average proportion of rose, pea and single combs were 52.78%, 30.97% and 16.25% in present study. The comb colours observed in the studied population were red, brown and black. The dominant comb color was red 95.69% (Overall proportions) whereas the remaining 2.77% and 1.54% proportion (Overall) of studied birds had brown and black comb colors, respectively. The red comb colour was more numerous in all agro-ecologies. This result was similar with [10] who reports that commonest comb color observed was red (hens 95%, cocks 97%), whereas the remaining 5% of hens and 3% of cocks showed brown and black colors in Centeral Tigray. (

d) Head Shape and Earlobe Colour
The study of head shapes showed that local chicken had either plain or crest head shape. Out of these two shapes, the plain head shapes was more common in both sexes in all agro-ecologies (40.00, 20.40% in female and male in Highland; 36.30, 20.80% in females and males in Midland; 50.00, 23.8% in female and males in Lowland agroecologies). The overall mean values of head shapes were 63.75% plain head and 36.25% crest. This result agreed with [11] who reported 72.8% and 27.2% were plain and crest headed shape in Southwest Oromia and Gurage zone.
The earlobe colours found in the studied populations were either white or red or mixture of red + white olours. The overall proportion of earlobe colour showed that 36.30, 32.20 and 31.50% of birds had mixture of red+white, red and white colours. This result was more or less comparable to those of [12] who reported that red and white earlobes showed 41.4% and 49.5% in Horro and Jarso ecotypes, respectively and also close to the reports of [13] for Fogera chicken.
(e) Shank Colour and Shank Feather Most of the indigenous chickens evaluated in scavenging management systems in the study area showed white (45.97%), yellow (33.6%), brown (17.08%), red (2.36%) and black (0.97%) shank colour (Overall proportions) were exhibited by these birds. This result was comparable with the findings of [10] who reported that yellow shank colour (41.17%) was dominant over white (19.83%) and black (15.5%) shank colours in Centeral Tigray. Similarly, a study conducted in districts of North West Ethiopia also revealed that most indigenous chickens had yellow, white, red, black and grey shank colours by [5]. The results on presence / absence of shank feathers showed that all studied chickens in mid-land and low-land agro-ecology were not having shank feather whereas only 2.5% hen and 1.67% cock had shank feather in Highland agro-ecologies in the present study.

Quantitative Traits
The quantitative traits studied were Bwt (Body weight), Bl (Body length), Cl (Comb length), Cw (Comb width), Ww (Wattle width), Ws (Wingspan), Bel (beak length), Wl (Wattle length), Cc (Chest circumference), El (Ear lope length), Sl (Shank length), Sc (Shank circumference), Nl (Neck length), and Wil (wing length) in the present study. The least square ANOVA for agro-ecologies, sex and interaction between sex X agro-ecologies was presented in the least square means of these traits was presented in Tables  3, 4 and 5. (a) Agro-ecology Effect The least square mean showed that AEGs significantly (P<0.05) influenced all quantitative traits studied except Bl, Cl, Ww, Bel, Wl and El. The least square mean values of body weight, wing length, shank length, shank circumference, and chest circumference, were significantly (p<0.05) maximum in mid-land chicken but wing span and neck length were higher in low-land.
(b) Sex Effect The least square mean showed that sex significantly (P<0.05) influenced all quantitative traits studied except Ww, Sc and Bel. The results showed that there was wide variation in these quantitative traits between two sexes. The average measurement parameters of female and male indigenous The sex differences in live weight and most of the LBMs, observed in this study, showed that these parameters are sex dependent. The cocks had consistently higher measurement value than hens across all the significantly affected variables except some variables, that was not significant (p<0.05).
The possible reason for higher values of studied quantitative traits in males (Cocks) might be ascribed to the effect of sex hormones, stress on hens during egg formation/ laying and brooding time (which reduce period spent on feeding/ scavenging). The present results were in good agreement with the report of [5,4,14] who stated that male chickens had better performance than females. These differences was also agreement with [12] in Jarso and Horro; [13] in Fogera; [5] in Northwest Ethiopia; and [14]; from North Gonder who reported that differences between sexes may be due to the differential effects of androgens and estrogens hormones on growth.
(c) Interaction Effect There was no significant (P<0.05) interaction observed between agro-ecologies and sexes with respect to quantitative traits studied except for comb length and wattle length. In these traits higher measurements were mostly observed in mid-land and low-land as compare to high-land. The significant interaction between agro-ecology and sexes with respect to these morphmetric traits might be due to the differences between the three agro-ecologies with respect to the degree of expression of sex dimorphism for the traits.