Bangladesh is an agro-based country where its livestock contributes 2.79% of GDP and 17.15% of agricultural share (IUCN, 2011). Livestock rearing is a vital part of rural small or medium scale farming where the most popular poultry species is indigenous or native chicken followed by duck and pigeon under traditional or backyard (in situ) management system. About 130 million native chickens are distributed throughout the country (Sørensen, 2010) occupying 80% of the total chicken populations (DLS, 1998) and contribute a large part of meat (78%) and egg (75%) production locally (Bhuiyan et al., 2005).
Bangladeshi native chicken are mainly classified into common native birds of non-idiosyncratic type or Non-descript (Deshi or ND), Naked Neck (NN), Hilly (H), Aseel, Yasine, Frizzle plumage and Native dwarf genotypes where Deshi chickens constitute about 90% of the total native chicken population and others are endangered or critically endangered or extinct (Bhuiyan et al., 2005; Das et al., 2008). The indigenous chicken genotypes of Bangladesh are considered as one breed for small genetic distances among them (Okada et al., 1987), but their performance and morphological characters are distinct from each other. The village chicken is characterized by 35-45 eggs annually (Bulbul, 1983; Ahmed and Islam, 1985; Sazzad et al., 1990; Huque and Huque, 1990; Amin and Bhuiyan, 1995; Ershad, 2005). Among the available indigenous chicken genotypes in Bangladesh, Naked Neck is still considered superior for egg production and quality (Barua et al., 1992; Islam and Nishibori, 2009; Faruque et al., 2013). Native chickens are a huge treasure of variable genotypes (Yeasmin and Howlider, 1998) and the reservoirs of various adaptive traits controlling useful genes (Horst, 1989).
As huge studies are performed with village chicken so far, a summarized review including all the vital laying traits is required to screen and further decision making on the development of those native chicken genetic resources. Therefore, the laying performance traits of indigenous chicken located in various geographical locations or agro-ecological zones in both free range and intensive systems are described here. In addition, the effects of possessing various plumage colours, genotypes and age on laying traits of Bangladeshi indigenous chicken are also shown along with research based justifications of other countries.
Effect of geographical location on laying traits of indigenous chicken
The laying performance of indigenous chicken studied in different districts or agro ecological zones of Bangladesh has been depicted (Table 1). Age at first laying was observed earlier in the hen of Rajshahi district (Dutta et al., 2013). Clutch length of chicken was found lower in Sherpur district (Shahjahan et al., 2011) than south part of country at Noakhali after early weaning of chicks from hens (Sarkar and Bell, 2006). Sarkar and Golam (2009) identified an average 14.60 eggs per clutch and 3.10 clutches per year in local chicken of different districts of Chittagong division but annual clutch number was found higher in Mymensingh district (Shahjahan et al., 2011) followed by Saver region of Dhaka (Sazzad, 1993). The average annual egg production (68 eggs), egg weight (42.71 g) and hatchability (87.11%) were recorded highest in northern parts (Ahmed et al., 2012) while fertility (93.83%) was in western parts (Dutta et al., 2013) of Bangladesh. These variations in performance could be the results of individual genetic background, availability of feed or nutrients and care of birds.
In Ethiopia,
Tadelle et al., (2003) studied egg production of native chicken in five ecotypes where average egg production per clutch (17.70 eggs) was found higher than the findings of Bangladesh but annual clutch number (2.60) was lower. Another experiment in Ethiopia by
Mogesse (2007) depicted that age at first laying in the local chicken of Debre Elias (143.67 days) was lowest and Melo-Hamusite (168.33 days) ecotypes recorded highest out of seven ecotypes which was in concurrence to our country’s findings.
Effect of plumage colours (gene pooled) on performance of local chicken
Various plumage colours were observed in the indigenous chicken while few of those appeared predominantly. Thus, gene pooled predominant plumage colours remain as a subject of interest for a basic traditional tool of selection, although studies are very limited in this aspect. The laying traits (Table 2) of Bangladeshi native chicken identified by
Shahjahan et al., (2011) were based on six predominant plumage colours (Fig 1) while lower production was reported previously by
Islam et al., (2007).
Effect of genotype and age on the performance of laying traits in native chicken
Reproductive efficiency and egg production
The reproductive efficiency and egg production performance of indigenous chicken genotypes (Fig 2) of Bangladesh are presented in Table 3. Early sexual maturity is an important trait for egg production in hen which was revealed by laying of first egg. The findings of
Faruque et al., (2007), (2010),
(2013) and
(2015) were investigated lower days for laying first egg in ND (155-157 days), NN (152.70-156.10 days) and H (152.10-159.10 days) chicken genotypes in
ex situ which could be the reasons of better management and systemic selection overtimes in case rearing which was supported the findings of
Dutta et al., (2013) at
in-situ condition with better management too. But delayed sexual maturity was observed by
Shahjahan et al., (2011) for laying first egg in ND/FF (203 days) and NN (202 days) genotypes were in agreement with the results of
Barua (1992) for ND hen and
Jahan et al., (2017) for NN chicken. Moderate sexual maturity in common
deshi hen (ND) was identified within 175 days (
Huque, 2001;
Jahan, 2013) which was supported by the findings of
Yeasmin et al., (2003). Similar observation was also reported in NN (234 days) and Aseel (240-300 days) genotypes by
Huque (2001).
Ahmed et al., (2012) found 14.93 and 15.18 days of clutch length in ND and NN hens, respectively. Another type of ND chicken named Cap Headed (CH) showed the average age at first laying in 182 days, 16.43 days length per clutch, 15.43 eggs per clutch, 3.50 clutch per year and 46 eggs annually
(Shahjahan et al., 2011) which was also supported by
Jahan (2013).
The study of
Shahjahan et al., (2010) revealed height egg production per clutch in village chicken at 37-66 month of age (17.33 egg) while
Islam et al., (2007) showed comparatively lower at 25 months or above age (14 eggs per clutch) in village chicken of Bangladesh. The annual egg production of native ND hen was studied 35-40
(Sazzad et al., 1990), 35-45 (
Bulbul, 1983;
Amin and Bhuiyan, 1995) and 40-45 (
Ahmed and Islam, 1985;
Huque and Huque, 1990;
Ershad, 2005) which was supported by the findings of
Sarkar and Bell (2006) and
Sarkar and Golam (2009).
Huque (2001) reported annual egg production in ND (45-50 eggs) and Aseel (33 eggs) genotypes of Bangladesh. The observation of
Yoshimura et al., (1997) pertaining to annual egg production (50-55 eggs) of NN hen did not match with the results of
Ahmed et al., (2012) who was found higher annual egg production in NN (71 eggs) and ND (67 eggs) genotypes.
Paul and Huque (1996) also confirmed better annually egg production in NN (99 eggs) and H (91 eggs) genotypes but similar productive trait was not found in Yasine (58 eggs) and Assel (34 eggs) in
ex situ. More than double laying performance (up to 99 eggs and 5.53 clutches per year) could be possible in free range by little changes in management practices like early weaning and creep feeding (
Sarkar and Bell, 2006) which was agreed with
Khan (1983) in intensive system.
In India,
Sunder et al., (2005) and
Sharma (2004) observed delayed age at first laying on 186 and 203 days in native hen, respectively, which were in agreement with the data of Bangladeshi native chicken. But early maturity age was comparatively lower to the Indian improved backyard Vanaraja (152 days), Gramapriya (145 days) breeds except in Aseel (184 days) chicken
(Sree et al., 2017). Benabdeljelil et al., (2001) supported the previous reports for age at first laying in the native Beldi chicken genotype with an average of 3 clutches per year, 13.5 eggs per clutch and 78 eggs annually in Morocco. The experiment of
Farooq et al., (2003) confirmed maximum 14 days for clutch length in different seasonal variation of Pakistani
deshi hen.
Mwalusanya et al., (2001) studied the average performance of Tanzanian native chicken on eggs per clutch (11.80), clutches per year (2.68) and annual egg production (31.60) which were lower than our country’s findings mentioned before but similar results were observed in the traits of clutch length per year, egg per clutch and annual egg production in Ethiopian Shayi (4, 13 and 52 ), Selamber (4, 15 and 60) and Bechi (4 clutch per year, 14 eggs per clutch and 56 eggs annually) chicken, respectively (
Abegaz and Gemechu, 2016).
Petrus (2011) pointed out genotype and age pool annual egg production of indigenous chicken in Senegal and Kashmir (50-60 eggs) and Morocco (60-80 eggs) which were agreed with most of our country’s findings but was not similar with Jordan (18-30 eggs), Somalia (100-144 eggs) and Namibia (100-150 eggs) and other Indian improved backyard chicken breeds
viz. Vanaraja (160 eggs), Gramapriya (178 eggs) and Aseel chicken (62 eggs). However, due to the variation of two managements in the indigenous chicken rearing at Egyptian rural areas, it was found that there was an average of 183 and 87 eggs annually in full adoption package group and non-adoption package groups, respectively
(Hamouda et al., 2018) which were partially agreed with our findings.
Fertility and hatchability
In free range, it was observed that egg fertility and hatchability (Table 4) waslower
(Hoque et al., 1975; Barua, 1992;
Sarkar and Golam, 2009) in common
deshi (ND) chicken than intensive system
(Islam et al., 2001; Khatun et al., 2005) except
Dutta et al., (2013) who stated maximum 96% fertility and 88% hatchability and also
Shahjahan et al., (2011) reported in ND (88.74%), NN (93.50%) and CH (89.20%) types of chicken while highest records were identified at 16-20 months of age group (90.64%) in the rural area of Bangladesh.
Faruque et al., (2010) and
(2013) studied egg fertility and hatchability on ND, NN and H genotypes in intensive system which was not in agreement with
Huque and Salahuddin (2001) who pointed out much lower egg fertility and hatchability in NN, H, Assel and Yasine chicken genotypes of Bangladesh in same rearing system. In extensive system, average egg hatchability performance (85-87%) of native chicken could be influenced by incubation system
(Bhuiyan et al., 2005), availability of feed and routine physical exercise
(Das et al., 2008), egg fertility and hygiene, seasonal temperature and humidity, size and number of incubated eggs and body surface of hen. In addition, eggs fertility of hen mainly depends on the availability of breeding cock, maturity of chicken with functional gonads, nutritional and hormonal balance, mating preference, timing and sperm quality. However, the best HDEP (51.40%) and HHEP (49.70%) production were observed in ND chicken genotypes compared to others
(Faruque et al., 2015).
Hossary and Galal (1994) studied on fertility (87-96%) and hatchability (77-89%) for Egyptian Fayoumi native hen at one year of age in intensive care which was similar to the results of Bangladeshi village chicken and these results were supported by the findings of
Abegaz and Gemechu (2016) for hatchability percentage in Ethiopian Shayi (80%), Selamber (82%) and Bechi (78%) chicken in confined areas. In addition, such hatchability percentage was supported by
Khank (2004) of Vietnam and
Mwalusanya et al., (2001) of Tanzania and showed slightly lower in Beldi chicken (71%) of Morocco
(Benabdeljelil et al., 2001). Mogesse (2007) reported 85-100% fertility in Ethiopian native chicken. In Pakistan,
Parveen et al., (2013) stated season-based hatchability of native chicken in winter (65.43%), summer (49.70%) and rainy (44.45%) seasons which were much lower than previous studies.
Egg weight, feed conversion ratio and egg quality
The egg weight, feed conversion ratio to egg mass and various egg quality traits of Bangladeshi indigenous chicken genotypes in different ages are presented in Table 5. In scavenging system, several findings by
Barua and Howlider (1990),
Amin and Bhuiyan (1995),
Ershad (2005) and
Islam and Dutta (2010) reported average egg weight was around 35-40 g in native ND hen, although
Ahmed et al., (2012) identified 42.07 g in ND and 44.17 g in NN chicken genotypes. In intensive system,
Faruque et al., (2010) and
(2013) recorded egg weight in ND, NN and H genotypes but they found lower egg weight in the age of sexual maturity for those chickens. These findings are also supported by
Yeasmin et al., (2003) for the weight of first laying egg (29.76 g) and 46 week’s egg (37.76 g) in ND genotype.
Khan (1983) and
Yeasmin and Howlider (1998) observed feed conversion ratio 8.8 in local
deshi (ND) chicken for egg mass production.
Yeasmin and Howlider (1998) and
Islam and Nishibori (2009) reported different egg quality traits of NN genotypes where dry matter of albumen (12.70-14.90%) was the common trait among the studied different traits on egg quality. Yeasmin and Howlider (1998) found comparatively lower values than NN in average egg weight (33.50 g), yolk index (0.390), yolk dry matter (51.03%), albumen index (0.080), dry matter of albumen (13.43%) and Haugh Unit (81.26) per egg in autosomal indigenous dwarf (adw) chicken genotype of Bangladesh.
In Kenyan native chicken, average egg weight of dwarf (38.1), normal (42.5) and NN (45.8 g) genotypes (
Njenga, 2005) showed similar data to our country’s findings which were partially agreed with the studies of
Sunder et al., (2005) on Nicobari native hen (46.70-48.20 g) and improved native chicken breeds Vanaraja (51 g), Gramapriya (49 g) and Aseel chicken (41 g) of India
(Sree et al., 2017). In case of improved backyard chicken in West Bengal of India, the average weights of first laid egg were 49.80 g, 51.20 g and 41.40 g in Gramapriya, Vanaraja and Haringhata breeds, respectively
(Roy et al., 2018) while in another study of Egyptian native chicken at 46 and 94 weeks revealed that the egg weights were 44.26 and 28.60 g respectively
(Hamouda et al., 2018). The FCR for egg mass was recorded 10.50-16.20 in Ethiopian local chicken at 22-44 weeks of age (
Mogesse, 2007). This study also pointed out egg weight (34.11-41.75 g), yolk colour (3-4), yolk weight (10.81-13.34 g) and Haugh Unit (55-65) which were lower than Bangladeshi research findings (
Islam and Nishibori, 2009;
Ahmed et al., 2012; Faruque et al., 2010 and
2013) and similar to the parameters of egg weight (40.73 g) and yolk weight (13.03 g) in indigenous Fulani chicken of Nigeria
(Fayeye et al., 2005).
Conceptual breeding strategies for improving laying traits in village chicken
Genetic improvement of indigenous chicken is difficult in the rural (
in-situ) areas because of uncontrolled mating, poor management and irregular vaccination or deworming. However, several attempts for upgrading or crossbreeding was conducted in the early of 1970s for the development of indigenous chicken in Bangladesh using White Leghorn, New Hampshire and White Cornish birds with indigenous chicken
(Hoque et al., 1975). In another backward poultry development programme during 1970s carried out by Bangladesh Agricultural University (BAU) and UNICEF, farmers were suggested to dispose their native cocks from flock and exotic breeding cocks of Rhode Island Red (RIR) or White Leghorn (WLH) × RIR or Australorp cocks of 18-20 weeks were distributed in 100 rural villages with the aim to produce 50% Local-50% Exotic crossbred chicken (
Ahmed and Islam, 1985). After that the government’s initiative for the improvement of native chicken was undertaken through improved exotic cockerel (WLH, RIR, Fayoumi) exchange programme in the country which was continued up to 1990s
(Bhuiyan et al., 2005). The collaboration of Bangladesh Livestock Research Institute (BLRI) with several national and international organizations was introduced toimprove the
deshi cocks in different districts of Bangladesh for the genetic improvement of native chicken. Unfortunately, all the aforementioned activities were not succeeded in respective goals perfectly or facing various difficulties so far. Considering all, strict breeding strategies (Fig 3) are required to control the desired breeding programme including upgraded management system towards the development of laying traits among the indigenous village chicken of Bangladesh (Fig 4). However, it would be quite impossible unless and until follow the following steps carefully:
Selection of community and chicken
Community selection is important to control natural mating using a confined area which might be separated from other areas by any water body or crop field or desert or forest or fencing or any other barrier. All of the households in a selected community should be under the same umbrella either by direct chicken farming or supporting the farmers for executing farming by following rules and regulation of that community. In brief, if any farmer doesn’t agree for such chicken farming, he/she will also not be able to purchase or exchange any chicken from anywhere to rear during this project period. In each communal territory, only one genotype with similar plumage coloured (
e.g. non descriptive chicken predominant red plumage) chicken will be allowed to rear.
Establishment of cooperative society with farmers
A group of selected farmers from a community should form a cooperative society in which money will be deposited from each farmer for 10 laying hens and 2 breeding cocks (G
0 population) with specific plumage color (
e.g. red predominant), one year’s vaccination and deworming cost and miscellaneous cost. This society will establish a quarantine shed centrally by which all the purchased chicken will be handed over to the farmers of this cooperative society after observing a quarantine period with required vaccination, medication and deworming. One of the farmers will have to take this responsibility and also for routine vaccination and deworming to the whole territory at a time according to prescribe schedule. The society will pay for this work to that volunteer.
Strict culling and selection procedure
The society will select another volunteer who will visit each farmer’s farm regularly to collect mismatch plumage coloured (
e.g. other than red plumage) cockerel and pullet as culling chicken (G
1 population) from community. All such chicken will be slaughtered and sold in market or in any suitable place from where 80% cash will be transferred back to farmer and 20% will be deposited to the cooperative society for serving various development works for this project. From each hatching batch, 10% cockerel and 50% pullet will be raised to attain sexual maturity and production based on selection of plumage colour (
e.g. red predominant) in G
1 population. Inside the community, breedable chicken and their egg exchange are possible but not allowed to outside. Such selection and culling will continue to G
2, G
3, G
4 and G
5 population while laying traits will be considered beside a selected plumage colour. In addition, 50% of the breeding cocks of each farmhouse will be exchanged to other farmers of this community rotationally through cooperative quarantine procedure to minimize inbreeding.
Declaration of certified community
After five generations, the desire plumage colour and laying traits would be fixed in chicken flock of a community by about 3.5 to 4 years and such a community would be considered as a certificate community for a specific plumage based developed village chicken variety.
Exchanging or selling genetic materials from certified community
A certified community having a specific plumage coloured chicken flock could only be exchanged genetic materials to a similar community in a division or a country through respective cooperative society. Without certified community, the selling genetic materials would be non-living either by slaughtering (meat) or boiling egg. A certified community will produce and use specific wing or leg band for exchanging or selling live chicken to another similar certified territory to control genetic admixture among the plumage coloured based developed flocks.
