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Morphological features of indigenous chicken in Mekong delta

Nguyen Thi Kim Khang, Nguyen Thao Nguyen, Ngo Thi Minh Suong, Massashi Takahashi1 and Hanako Bai1

Department of Animal Sciences, College of Agriculture, Can Tho University, Viet Nam
ntkkhang@ctu.edu.vn
1 Research Faculty of Agriculture, Hokkaido University, Japan

Abstract

The objective of this study was to determine the quantitative and qualitative morphological characteristics of indigenous Noi and Noi-Asil chickens popularly raised in the Mekong delta of Vietnam in order to support the selection process of this local chicken breed respond to climate change. Data were collected from 1009 male chickens including 810 Noi and 199 Noi-Asil cocks, which were more than 6 months of age, were managed semi-intensively in some private farms of Mekong delta. Occurrence of different morphological features varied significantly (p<0.05) between breeds. Noi cocks were larger for some dimensions such as skull, neck, thigh and shank length and higher levels of diversity in the colors than that of Noi-Asil cocks. However, the smaller body weight and breast angle were found in Noi cocks in compared with Noi-Asil cocks. The almost positive and significant (P<0.05, P<0.001) phenotypic correlations among morphological features and body weight of rooster were found by Pearson's correlation. It is easy to distinguish Noi and Noi-Asil cocks using morphological characteristics based on body size and visual observations. The results of this study can be used to propose information on their performance using morpho-biometric characterizations.

Keywords: chicken, morphological characteristics, Noi, Noi-Asil, Vietnam


Introduction

The consumers preferred slow growing colored chickens because of their superior sensory quality of meat (Rizzi et al 2007) thus their meat markets developed rapidly compared with the commercial fast-growing type. However, a small percentage of this market demand can be supplied for several consequences such as low production volume, non-uniform size and irregular quality, causing high production costs. Therefore, the improvement of the indigenous population should entails with an establishment of a breeding protocol. Collecting information on their performance is one of main activities in this protocol.

Noi chicken is a native chicken, has larger market weight, dark feathers, yellow, white or black shank (Phan and Thieme 2008) and is highly resistant to disease (Khang et al 2010) as well as has a good quality of meat (Phan and Thieme 2008). Besides, this breed is also kept for the purpose of being a fighting chicken, which is widely distributed in every corner of the Mekong delta. Most fighting chickens are selected from Noi purebred and Noi-Asil chicken is crossbred with Asil or Aseel, a native Indian chicken breed (Singh 2001), for enduring fighting quality. Thus, to ensure the opportunity for production in commercial and industrial level, these chicken’s characteristic traits deserve an entire study for all fundamental data and information. Indeed, morphological indicators for identifying populations provide essential information on the suitability of breeds for selection. Methodology for morphological characterization was also applied in various livestock species with the purpose of comparing their different breeds (Francesh et al 2011). Body weight is one of the most important economical traits in meat market and also is a selected trait for ranking the best animals as parents for the next generation. However, this minor number showed in the databases indicates the shortage of data on Noi and Noi-Asil chicken resources existing in the locally adapted populations still remains undocumented. The aim of this study was to determine the quantitative and qualitative morphological characteristics of indigenous Noi and Noi-Asil chickens popularly raised in the Mekong delta of Vietnam in oder to support in the selection process of this native chicken breed respond to climate change.


Materials and methods

Sample collection

The study was carried out at a number of semi-intensive chicken farms in the provinces of Tien Giang, Ben Tre and Can Tho, in the Mekong Delta. All the birds above 6 months old were sampled and a total of 1009 healthy cocks including Noi (810 birds) and Noi-Asil (199 birds) chickens were sampled to determine for the qualitative and quantitative traits of the indigenous chickens. Visual observations of the most important qualitative parameters of the birds (comb type, colors of beak, eyes, shank and foot, feathers in neck, body and tail) were recorded according to FAO guidelines (FAO 2012). Quantitative traits were body weight (BW, gram) and skull length (SL, cm), skull width (SW, cm), neck length (NL, cm), neck circumference (NC, cm), back length (BL, cm), keel length (KL, cm), breast circumference (BC, cm), breast angle (BA, cm), breast depth (BD, cm), wing length (WL, cm), thigh length (TL, cm), shank length (ShL, cm) and shank circumference (SD, cm) according to the standard descriptors (FAO 2012).

Statistical analysis

Data collected on qualitative and quantitative traits of indigenous chicken populations were coded and entered into a computer using Microsoft Office Excel 2007. All qualitative and quantitative data were analyzed using descriptive statistics and compared as percentages using Minitab 16 such as: (i) Chi-square analysis was performed to find out the differences of phenotypic groups with respect to each qualitative trait; (ii) Analysis of quantitative variations between 2 breeds of village chicken was carried out using ANOVA (one-way) test; (iii) The overall phenotypic correlation among these traits were also done to test the relationship between variables using Pearson correlation.


Results and discussions

Qualitative traits

Qualitative traits recorded on chickens in the study area in Table 1 showed a high diversity in qualitative phenotypic characters in Noi cocks in compared with Noi-Asil cocks. The dominant comb type in the study area was strawberry comb in both breeds, the second largest comb types were single comb (Noi breed) and cushion type (Noi-Asil breed) (Photo 1).

The occurrence of comb type across the study were comparable and significance differences (P<0.01) among types for 2 chicken breeds. Another study conducted in the North parts of Vietnam by Nguyen et al (2009) indicated that Ri, Mia and H’mong chickens were single. Studies from other countries also indicated that, single comb was the dominant type over any other comb types (Daikwo et al 2011, Melesse and Negesse 2011, Bekele et al 2015, Tadele et al 2018). However, similar observations for strawberry combs (24.05%) in Asil from Bangladesh reported by Sarker et al (2012), contrary to pea combs (98%) were reported in Asil from India (Rajkumar et al 2017). The dissimilarity in the occurrences of comb types may be attributed to differences in frequencies of alleles responsible for the comb types and interactions of different genes responsible for its expression.

The predominant beak colour was yellow + black (39.8% for Noi and 42.2% for Noi-Asil breed) followed by yellow beak colour (P<0.01) (Photo 2). Similar to the present study, yellow beak colour was predominantly found in both Asil from Bangladesh (Sarker et al 2012) and India (Rajkumar et al 2017). Various eye colours in Photo 3 were observed in the current study (P<0.05), accordingly, Noi cocks with yellow + orange and yellow eye colours at the proportion of 35.7 and 32.8%, while orange (32.2%) and yellow (25.1%) were found in Noi-Asil cocks. A similar trend was observed by Liyanage et al (2015) for Sri Lanka village chicken. Guni and Katule (2013) reported that orange was the most common eye color of indigenous chickens in Nigeria and Tanzania. Rajkumar et al (2017) revealed that most Asil birds in India were black (99%) and white (1%) eye colours, which was inconsistent with current results. Moreover, it was not in agreement with the observations of Nguyen et al (2012) from the North of Vietnam, the most frequent in bearded local chickens were brown eyes. Another study conducted in Quang Nam province of Vietnam indicated that most native chickens had orange eyes (97%) (Phan and Thieme 2008), while chickens’ eye colours in Ha Giang had black and brown (Berthouly 2008). The variation of beak and eye colours observed in different parts of districts in Vietnam indicates existence of genetic variability among the indigenous chicken populations.

Table 1. Qualitative variations between breeds of village chicken

Qualitative trait

Noi (n = 810)

Noi-Asil (n = 199)

N

Percentage
(%)

N

Percentage
(%)

Comb type
    Single
    Strawberry
    Cushion
    Buttercup
    Rose


205
373
121
79
32


25.3
46.1
14.9
9.8
3.9


27
85
72
9
6


13.6
42.7
36.2
4.5
3.0

p-value

0.000

0.000

Beak colour
    Black
    Black + white
    White
    White mix
    Yellow
    Yellow + black


171
76
48
13
180
322


21.1
9.4
5.9
1.6
22.2
39.8


27
30
10
-
48
84


13.6
15.1
5.0
-
21.1
42.2

p-value

0.000

0.000

Eye colour
    Black
    Brown
    Orange
    Orange + black
    Red
    White
    Yellow
    Yellow + black
    Yellow + orange
    Other


10
40
73
-
84
41
266
-
289
7


1.2
4.9
9.0
-
10.4
5.1
32.8
-
35.7
0.9


7
-
64
25
-
-
50
34
8
11


3.5
-
32.2
12.6
-
-
25.1
17.1
4.1
5.5

p-value

0.000

0.000

Shank and foot colour
    Black
    Gray
    Green
    White
    Yellow


71
76
219
80
364


8.8
9.4
27.0
9.0
44.9


-
58
39
21
81


-
29.1
19.6
10.6
40.7

p-value

0.000

0.000

Neck feather colour
    Black
    Green + red
    Orange
    Orange + black
    Orange + yellow
    Red
    Red + black
    Red + orange
    White
    White mix
    Yellow
    Yellow + brown
    Yellow + green
    Yellow + black
    Others


32
103
19
57
-
255
80
-
16
109
69
19
15
10
26


4.0
12.7
2.3
7.0
-
31.5
9.9
-
2.0
13.5
8.5
2.3
1.9
1.2
3.2


-
-
13
-
24
71
7
25
-
6
14
-
-
16
23


-
-
6.5
-
12.1
35.7
3.5
12.6
-
3.0
7.0
-
-
8.0
11.6

p-value

0.000

0.000

Body feather colour
    Black
    Brown
    Green
    Green + black
    Green + red
    Green + yellow
    Orange
    Red
    Red + black
    Red + brown
    Red + gray
    Red + orange
    White
    Whitemix
    Yellow
    Yellow + black
    Yellow + brown
    Yellow + gray
    Others


16
6
8
25
232
25
-
142
68
13
30
-
12
133
14
40
20
5
21


2.0
0.7
1.0
3.1
28.6
3.1
-
17.5
8.4
1.6
3.7
-
1.5
16.4
1.7
4.9
2.5
0.6
2.6


-
-
-
-
66
-
8
11
24
-
32
10
-
7
-
5
-
8
28


-
-
-
-
33.2
-
4.0
5.5
12.1
-
16.1
5.0
-
3.5
-
2.5
-
4.0
14.1

p-value

0.000

0.000

Tail feather colour
    Black
    Brown + black
    Gray + black
    Green
    Green+ black
    White
    White mix
    Others


131
18
15
72
410
13
141
10


16.2
2.2
1.9
8.9
50.6
1.6
17.4
1.2


-
-
-
-
163
-
30
6


-
-
-
-
81.9
-
15.1
3.0

p-value

0.000

0.000



(a) Single (b) Strawberry (c) Butter cup (d) Cushion
Photo 1. Types of combs of Noi and Noi-Asil chickens


(a) Black (b) Black and white (c) White (d) Yellow (e) Black and yellow
Photo 2. Types of beaks in Noi and Noi-Asil chickens


(a) Black (b) Orange (c) Yellow
Photo 3. Chicken eye colors

Yellow and green were the two most common shank and foot colours across both breeds (P<0.01) (Photo 4), which was in line with the report of Phan and Thieme (2008). Similar studies done elsewhere have also reported that there was a predominant occurrence of yellow colour shank among indigenous birds (Daikwo et al 2011, Cabarles et al 2012, Sarker et al 2012, Rajkumar et al 2017). In the present study, various plumage colours (neck, body and tail colours) were observed between the indigenous chicken populations in the study area (Photo 5, 6 and 7). Red neck, green mixed red body and tail were the most common colour in both chicken breeds (P<0.01). The occurrence of various plumage colors observed in the indigenous chicken populations of Mekong in general and particularly in this study area, might be due to the fact that, the preference of people for fighting towards red and green plumages which accounted for the largest occurrence of these plumage colors across this area. A number of authors have also highlighted high variation in phenotypic and plumage traits as a result of selection and geographical isolation (Abdelqader et al 2007, Daikwo et al 2012, Al-Qamashoui et al 2014). One study also reported that earliest in the ancestral chickens of these chickens mentioned that Asil has no fixed plumage color (Sarker et al 2012) and both plumage and shank colours are affected by genes (Round et al 1990).

(a) Yellow (b) Black (c) Green (d) White
Photo 4. Shank and foot colours in Noi and Noi-Asil chickens


(a) Red (b) Orange (c) Yellow (d) Black (e) White
Photo 5. Neck feather colours in Noi and Noi-Asil chickens


(a) Black and red (b) Orange (c) White (d) Red and green
Photo 6. Body feather colours in Noi and Noi-Asil chickens


(a) Green and black (b) Black (c) Brown (d) Grey
Photo 7. Tail feather colours in Noi and Noi-Asil chickens
Quantitative traits

The different body parameters measurements of both breeds were presented in Table 2.

Table 2. Quantitative variations between 2 breeds of village chicken

Quantitative
traits
(cm)

Total
(n=1009)

Breed

p-value

Noi
(n=810)

Noi-Asil
(n=199)

BW

2525±423

2472±436

2743±271

0.000

SL

4.07±1.46

4.12±1.55

3.87±1.02

0.033

SW

3.16±0.29

3.24±0.23

2.84±0.26

0.000

NL

16.00±2.42

16.56±1.92

13.56±2.72

0.000

NC

10.94±1.83

10.47±1.24

12.87±2.47

0.000

BL

20.70±1.6

20.97±1.36

19.66±2.02

0.000

KL

12.70±0.94

12.84±0.82

12.36±1.25

0.000

BC

32.31±2.35

32.53±2.00

31.38±3.27

0.000

BA

78.72±5.61

77.00±5.29

81.67±5.89

0.000

BD

10.40±2.44

10.10±2.30

11.36±2.74

0.000

WL

27.31±2.44

27.05±2.54

28.34±1.64

0.000

TL

17.93±4.24

18.76±4.09

14.58±2.99

0.000

ShL

9.13±1.07

9.24±0.85

8.67±1.60

0.000

SD

5.09±1.61

5.15±1.78

4.86±0.38

0.022

BW= body weight (gram); SL= skull length; SW= skull width; NL= neck length; NC= neck circumference; BL= back length; KL= keel length; BC= breast circumference; BA= breast angle; BD= breast depth; WL= wing length; TL= thigh length; ShL= shank length; SD= shank circumference. Means in the same row are significantly different (P<0.05)

Quantitative traits are important for breed or species identification and economic valuation in its utilization. The traits that show less variability within breeds or types indicate homogeneity and identity of those categories (Liyanage et al 2015). Traits showing wider variation could be used for prediction purposes such as live weight prediction (Assan 2013). Occurrence of different morphological features varied significantly (p<0.05) between study breeds. Noi cocks were significantly higher than Noi-Asil cocks in skull length (SL), skull weight (SW), neck length (NL), back length (BL), keel length (KL), breast circumference (BC), shank length (ShL) and shank circumference (ShD). While Noi-Asil cocks were significantly higher than Noi cocks in terms of body weight (BW), neck circumference (NC), breast angle (BA), breast depth (BD) and wing length (WL) (P<0.05). The overall average body weight of Noi and Noi-Asil was higher than those of reported by Liyanage et al (2015) at the same age and recorded by Phan and Thieme (2008) for Choi or Noi native cocks from Quang Nam province. This result was also different from the finding of Daikwo et al (2011) and Rajkumar et al (2017) in Asil cocks. In addition, other measurements of body parameters for Noi and Noi_ Asil cocks reported in this study disagreed with the study results of several authors (Daikwo et al 2011, Rajkumar et al 2017). Daikwo et al (2011) reported Asil cocks from Denkina had longer BL and lower ShL than those of the current study, while the ShL in this present study is consistent with the trend for indigenous cocks recorded in Quang Nam province (Phan and Thieme 2008). In the present study, NC, BA, BD and WL of Noi-Asil were higher than that of Noi. Breast circumference and WL, generally having less variability in poultry are used to characterize different phenotypic groups (Momoh and Kershima 2008). Generally, Noi breed was significantly taller than Noi-Asil because their TL and ShL.

The results on linear body measurement traits in the current study were also comparable with most of the observations in different parts of the country. The morphometric characteristics of the current study in cocks over 6 months old were higher than those of reported by Nguyen et al (2009) and Nguyen et al (2012) showed the report for 4 months of age cocks. The observed significant effects of age on BW and body measurement traits of chickens in the present study were consistent with that reported by Semakula et al (2011) cited that BW and linear body measurements increase with the advancing age of chickens.

Prediction of live body weight

In the current study, phenotypic correlations between BW and linear measurements of Noi and Noi-Asil chickens are shown in Table 3. Body weight had significant positive correlations with all the traits except for negative correlation with SL, SW and NL (P<0.01). The highest positive correlation was observed between BW and WL (0.694), BD (0.671) and BA (0.607). In line with this, SW had highest significantly positive correlation with NL (0.725), TL (0.703) and ShL (0.529), between NL and TL (0.826). Based on the positive correlation of BW and linear body measurements, many authors have suggested that measuring one of these quantitative traits could predict the body weight of local chickens in the rural area (Negassa et al 2014, Tabassum et al 2014, Tadele et al 2018, Abdulraheem et al 2020) and therefore the selection of any linear body measurement traits can be used to directly improve the body weight of indigenous chickens. Because of its strong correlation with meat yield, body weight is used as a proxy indicator of production (FAO 2012).

Table 3. Phenotypic correlations of the body weight and morphometric traits of chickens

Traits

BW

SL

SW

NL

NC

BL

KL

BC

BA

BD

WL

TL

ShL

SD

BW

1

SL

-0.551***

1

SW

-0.127***

0.360***

1

NL

-0.224***

0.421***

0.725***

1

NC

0.444***

-0.163***

-0.035

0.074

1

BL

0.381***

-0.367***

0.315***

0.243***

0.204***

1

KL

0.341***

-0.221***

0.300***

0.332***

0.354***

0.496***

1

BC

0.254***

0.000

0.463***

0.476***

0.406***

0.498***

0.479***

1

BA

0.607***

-0.378***

-0.288***

-0.486***

0.088***

0.066**

0.027

-0.079**

1

BD

0.671***

-0.849***

-0.221***

-0.280

0.463***

0.467***

0.358***

0.229***

0.375***

1

WL

0.694***

-0.339***

-0.038

-0.098***

0.310***

0.297***

0.293***

0.156***

0.438***

0.446***

1

TL

-0.342***

0.679***

0.703***

0.826***

0.040

0.061

0.200***

0.398***

-0.509***

-0.516***

-0.119***

1

ShL

0.185***

0.021

0.529***

0.499***

0.315***

0.346***

0.404***

0.436***

0.001

0.206***

0.116***

0.369***

1

SD

0.003

0.078**

0.140***

0.111***

-0.001

0.063**

0.041

0.142***

-0.003

-0.050

0.010

0.100***

0.045

1

***Significant at P<0.001 for all correlation coefficients except where otherwise stated; **Significant at P<0.01, *Significant at P<0.05; body weight (BW), skull length (SL), skull width (SW), neck length (NL), neck circumference (NC), back length (BL), keel length (KL), breast circumference (BC), breast angle (BA), breast depth (BD), wing length (WL), thigh length (TL), shank length (ShL) and shank circumference (SD)


Conclusion

This study has highlighted a great phenotypic and various diversity of local poultry genetic resources found in Mekong delta. The dominant comb type was strawberry comb in both breeds. Yellow and black beak, yellow eyes, red neck, reddish-green plumage and yellow and green shank were identified distinguishing characteristics of indigenous chicken in Mekong delta. Wing length, breast angle and breast depth were the best predictors of live weight of Noi cocks contributing in breeding programs for the future under climate change and production efficiency.


Acknowledgments

This study is funded in part by the Can Tho University Improvement Project VN14-P6 supported by a Japanese ODA loan, code A4-ODA.


References

Abdelqader A, Wollny C B and Gauly M 2007 Characterization of local chicken production systems and their potential under different levels of management practices in Jordan. Tropical Animal Health and Production 39(3): 155-164.

Abdulraheem A O, Raji A O, Alade NK, Mohammed I D, Aliyu J, Mohammed G, Saleh B, Adamu J and Mohammad A 2020 Phenotypic relationships between body measurements of indigenous chickens in Borno State. Nigerian Journal of Animal Science and Technology 3(4): 99-106.

Al-Qamashoui B, Simianer H, Kadim I and Weigend S 2014 Assessment of genetic diversity and conservation priority of Omani local chickens using microsatellite markers. Tropical Animal Health and Production 46(5): 747-752.

Assan N 2013 Bioprediction of body weight and carcass parameters from morphometric measurements in livestock and poultry. Scientific Journal of Review 2(6): 140-150.

Bekele G, Kebede K and Ameha N 2015 On-farm phenotypic characterization of indigenous chicken and their production system in Bench Maji Zone, South Western Ethiopia. Science, Technology and Arts Research Journal 4(1): 68-73.

Berthouly C 2008 Characterisation of the cattle, buffalo and chicken populations in the northern Vietnamese province of Ha Giang. PhD thesis. Life Sciences [q-bio]. AgroParisTech, 2008. English. ffNNT:2008AGPT0031ff. ffpastel-00003992.

Cabarles J C, Lambio A L, Vega R S, Capitan S S and Mendioro M S 2012 Distinct morphological features of traditional chickens ( Gallus gallus domesticus L.) in Western Visayas, Philippines. Animal Genetic Resources Information 51: 73-87.

Daikwo I S, Okpe A A and Ocheja J O 2011 Phenotypic characterization of local chickens in Dekina. International Journal of Poultry Science 10(6): 444-447.

FAO 2012 Phenotypic characterization of animal genetic resources. Food and Agriculture Organization, Animal Production and Health Guidelines, No. 11. Rome, Italy.

Francesh A, Villalba I and Cartana M 2011 Methodology for morphological characterization of chicken and its application to compare Penedesenca and Empordanesa breeds. Animal Genetic Resources 48(48): 79-84.

Guni F S and Katule A M 2013 Characterization of local chickens in selected districts of the Southern Highlands of Tanzania: I. Qualitative characters.  Livestock Research for Rural Development. Volume 25, Article #153, from https://www.lrrd.cipav.org.co/lrrd25/9/guni25153.htm

Khang N T K, Lam P H, Vo CT and Vo V S 2010 Detection disease resistance of Vietnamese local chicken breeds by using SDS-PAGE. Journal of Genetic Applications 6: 46-48 (In Vietnamese).

Liyanage R P, Dematawewal C M B and Silva G L L P 2015 Comparative study on morphological and morphometric features of village chicken in Sri Lanka. Tropical Agricultural Research 26(2): 261-273.

Melesse A and Negesse T 2011 Phenotypic and morphological characterization of indigenous chicken populations in Southern region of Ethiopia. Animal Genetic Resources Information 49: 19-31.

Momoh O M and Kershima D E 2008 Linear body measurement as predictors of body weight in Nigerian local chickens. International Journal of Environmental Science and Technology A 8(2): 206-212.

Negassa D, Melesse A and Banerjee S 2014 Phenotypic characterization of indigenous chicken populations in Southeastern Oromia Regional State of Ethiopia. Animal Genetic Resources Information 55: 101-113.

Nguyen C T, Le T T, Dang V B, Tran T K A 2009 Biological characteristics and productivity of 3 local chicken breeds: Ho, Dong Tao and Mia chickens. Journal of Animal Science and Technics 122: 2-10 (In Vietnamese).

Nguyen B M, Nguyen C T, Le A D and Nguyen B H 2012 Externality characteristic and meat production of bearded local chicken in Luc Ngan, Bac Giang. Journal of Science and Development 10 (7): 978-985 (In Vietnamese).

Phan T G T and Thieme O 2008 Management of poultry flocks in Quang Nam and Da Nang provinces of central Viet Nam. FAO. GCP/RAS/228/GER Working Paper No. 9. Rome.

Rajkumar U, Haunshi S, Paswan C, Raju M V L N, Rao S V R and Chatterjee R N 2017 Characterization of indigenous Aseel chicken breed for morphological, growth, production, and meat composition traits from India. Poultry Science 96(7): 2120-2126.

Rizzi C, Marangon A and Chiericato G M 2007 Effect of genotype on slaughtering performance and meat physical and sensory characteristics of organic laying hens. Poultry Science 86(1): 128-135.

Round F E, Crawford R M and Mann D G 1990 Diatoms: Biology and morphology of the Genera. Cambridge University Press, Cambridge, UK.

Sarker M J A, Bhuiyan M S A, Faruque M O, Ali M A and Lee J H 2012 Phenotypic characterization of Aseel chicken of Bangladesh. Korean Journal of Poultry Science 39(1): 9-15.

Semakula J, Lusembo P, Kugonza D R, Mutetikka D, Ssennyonjo J and Mwesigwa M 2011 Estimation of live body weight using zoometrical measurements for improved marketing of indigenous chicken in the Lake Victoria basin of Uganda. Livestock Research for Rural Development. Volume 23, Article #170, from https://www.lrrd.cipav.org.co/lrrd23/8/sema23170.htm

Singh D P 2001 Aseel of India. In: Souvenir, National Seminar on Appropriate Poultry for Adverse Environment, Organized by Acharya, N.G. Ranga Agricultural University and Project Directorate on Poultry, Hyderabad (2001), 11th January 2001.

Tabassum F M A, Hoque F, Ritchil C H, Faruque M O and Bhuiyan A K F H 2014 Phenotypic and morphometric characterization of indigenous chickens at Jhenaigati Upazila of Sherpur district in Bangladesh. SAARC Journal of Agriculture 12(2): 154-169.

Tadele A, Melesse A and Taye M 2018 Phenotypic and morphological characterizations of indigenous chicken populations in Kaffa Zone, SouthWestern Ethiopia. Animal Husbandry, Dairy and Veterinary Science 2(1): 1-9.