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1.0

INTRODUCTION Poultry production is one area of livestock production that contributes significantly

more to human animal protein supply than any other domestic or non-domestic animal. Consumers have high preference for poultry products (because of the taste and cheapness). Beside preference, poultry products provide protein of high biological value (Epstein, 1990). In a developing country like Nigeria, poultry production in both urban and rural areas is of great importance. It serves as a simple means of generating family income and employment opportunities (Akinokun, 1971). Compared to other domestic animals, poultry can be raised with relatively low capital investment and readily available household labour. Characterization, conservation and use of indigenous animal genetic resources are more appropriate in the tropics where production is usually characterized by low input. The locally adapted animals are also more readily available to resource-poor farmers and they can be productive without high disease control input, yet, lack of information about the genetic resources present in the indigenous farm animal in developing countries has led to their under-utilisation, replacement and dilution through crossbreeding

(http://www.nuffic.nl/ciran/ikdm/6-3/network.html). Therefore, characterisation, utilisation and conservation of these indigenous animal genetic resources are of paramount importance. Nigeria is endowed with many poultry species which are local to the country. These have lived, adapted and produced for several years in Nigerian environment (Momoh, 2005). FDLPCS (1992) estimated Nigeria's poultry population to be about 33 million. With the ever growing population and concomitant improvement in the living standard of Nigerians, the demand for egg and other poultry products will continue to grow, thus outstretching the supply from chicken. Therefore, there is need to explore other poultry species to supplement the provision of eggs meat and other poultry products from the chicken. This necessitates the

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quest for the development of the ducks which are also widely distributed and are prominent in the list of available poultry species in Nigeria (FDLPCS,1992). Ducks are an essential part of many human societies around the world. They are reported to be domesticated as early as 2500 BC (Farrell,1995). Today,the domestic duck has come to serve a variety of roles in modern society as a source of food supply (meat and eggs ), in other societies as a species that is selectively bred for show, feather as ornament and pillow stuffing, and as a pet. Ducks have several advantages over other poultry species;These include their disease tolerance and hardiness. They are excellent foragers and easy to herd, particularly in wet lands since they tend to flock together (Farrell,1995). Population of ducks The population of ducks in Nigeria was put at approximately eleven

million(11,000,000) and

reported to be distributed all over the agro ecological zones of the

country (FLDPCS, 1992). Domestic ducks were ranked third among various poultry species in Sokoto state of Nigeria (Hassan and Mohammed, 2003). In spite of this positive score, very little attention has been paid to the genetic improvement as well as improved husbandry practices to raise the performance of the domestic duck. There is little or no information

available on phenotypic and genetic parameters of the Nigeria indigenous Muscovy duck. Ecological Zones In Nigeria different agro-ecological zones exist and for all species of livestock

variations are reported to exist in both phenotypic and genetic characteristics as a result of adaptation to these different ecological zones. Numerous comparative studies have provided insight into the ecological mechanism underlying evolutionary diversification across habitat

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gradients. This is evident in the reports of Akinokun (1971), Oluyemi et al. (1982), Adedokun and Sonaiya (2001) for poultry, Adebambo et al. (1998) for cattle, Epstein (1990) and Wilson (1991) for sheep and goats. This diversity constitutes a valuable resource for use in animal breeding programme for improvement of the health and productivity of the animal species, particularly domestic poultry and also in designing proper conservation strategy. It also results in classification of the individual species into strains, breeds and ecotypes. Several varieties of Nigerian local poultry, particularly chickens have been described on the basis of location ( FLDPCS, 1992). Variations between populations from different locations arose from adaptation to different micro-environmental conditions and management

practices (Nwosu et al., 1985). Ecotypes are developed through selection and adaptation and vary from one agro ecological zone to another due to varied climatic characteristics such as humidity, temperature and rainfall, although in some cases some ecotypes may be similar in all traits (Adedokun and Sonaiya, 2001). Genetic and phenotypic variations, especially in quantitative traits occur in a population of different geographical locations and this may be as a result of genetic drift. The differences may also have arisen from limited geographical differentiation of the original population (Girand and Palabort, 1976; Ehiobu and Goddard, 1989; Ehiobu et al., 1990) which may reflect adaptation to different environmental conditions. Markers In genetic studies various types of genetic markers such as morphological, chromosomal, biochemical and molecular are used. Morphological (e.g., pigmentation and other features) and chromosomal (e.g., structural or numerical variations) makers usually show low level of polymorphism or differences. Biochemical markers have limitations as they are often sex-limited, age-dependent and are significantly influenced by the

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environment. Phenotypic features are also influenced by dominance effect and provide a crude estimate of the average of the functional variants of genes carried by a given individual population. These makers are reported to reflect variability in their coding sequence that constitutes less than 10% of the total genome (Williams et al., 1990). Molecular makers have been shown to be an efficient tool in the quantification of genetic diversity of various populations (Saitbekova et al., 1999; Barker et al., 2001). Quite a number of techniques are used in molecular maker analysis. The most common and cost effective is the Random amplified polymorphic DNA technique. This technique has been used extensively in

molecular characterisation of livestock population in detecting polymorphism between populations and establishing genetic relationship among them (Ali et al., 2003). Some research findings on ducks by Ksiazkiewic (1995) and Farrell (1995) showed that they are very susceptible to effective inbreeding and genetic drift if kept in a small population for few generations. This genetic flexibility will suggest that variation can easily be found in different populations at different locations .These variations could either be morphological or genetic or both. Nigerian indigenous Muscovy ducks suffer neglect in the area of research and improvement leading to remarkable absence of publication relating to productivity, genetic diversity and phenotypic characterisation .This may not be unconnected with the fact that ducks are considered as dirty birds. The genetic improvement of the Muscovy ducks in Nigeria will first require investigation into their productivity, genomic structure and geographical diversity.

1.1 Research Objectives The overall objective of this study was to evaluate the phenotypic and genetic characteristics of the Nigerian Muscovy ducks from rainforest and guinea savannah zones with a view to

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highlighting their

potential to contribute to egg and meat production in Nigeria. This

information will provide a framework for the development of breeding programmes for conservation and sustainable use of the Muscovy duck genetic resources in Nigeria. The specific objectives are to: 1. Evaluate the morphological/phenotypic characteristics of local Muscovy ducks from tropical Rainforest and Guinea Savannah zones; 2. Estimate morphological distance between the two populations;

3. Evaluate performance of the ducks from these zones in basic production traits; of growth (0-to 20 weeks of age) and egg production; 4. Estimate genetic parameters of growth and egg production traits of the ducks from the two ecotypes; and 5 Estimate genetic relatedness among the two ecotypes using random molecular techniques.

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2.0 2.1

LITERATURE REVIEW Domestic Ducks: Origin and Domestication

Ducks belong to the order Anseriformes diverged from the chicken Galliformes in about 11 million years ago (Tuinen and Hadley, 2004) According to paleontological data, the main radiation of the modern duck took place during the Miocene, 5 -23 million years ago domestic ducks have served as a source of food and

(Olson, 1985). From ancient times

income for people in many parts of the world. Ducks are source of meat, eggs and down feathers. Their meat and eggs are good dietary sources of high quality protein and energy in addition to several vitamins and minerals. Tuinen and Hadley (2004) classified domestic ducks into Common,Muscovy and Sterile. Common Ducks: Most ducks are classified as common ducks and are believed to have originated from the Mallard (Anas platy rhynchos). Some of the better known breeds of common domestic ducks include the Pekin, Asylesbury, Rouen, Call, and Indian Runner, Khaki Campbell, Cayugi, Albio, Maya and Tsaiya. They further added that these ducks can interbreed and produce fertile offspring. Muscovy duck The Muscovy (Cairina moschata) is distinctly different genetically from common ducks. The breed is reported to have originated differently. Several reports on its origin

have been presented by (Clayton, 1984; Hahn et al ., 1995; Farrell, 1995; Hugue and Sultana, 2002). Sterile Hybrid Ducks These are products of crosses between Muscovy and common ducks. When allowed to mate naturally their fertility is usually very low. The offspring are often sterile and can not

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be used for breeding. These hybrids are usually raised for their meat and in some cases for their liver (foie gas) and usually referred to as mule or hunny (Olson ,1985) 2.1.1 Domestication of duck Pottery duck models excavated in the Yan-Shi-Menkou mountain in Fu Jian in Southern China provided evidence that domestication of duck occurred during the New stone age between 4000 and 10000 years ago (Wucheng, 1998). Clay models unearthed in Shanxian country, central Henan province suggested that ducks were domesticated during the Yangshao culture about 4000 years ago (Jianhua, 1984). Ducks were domesticated in China at least 3000 years ago. The archaeological evidence along with a favourable environment and agriculture suggested that ducks were probably domesticated in southern China at least 1500 years before they were separately domesticated in western Europe. Watson (1969) indicated the possibility of even an earlier domestication in describing the finding of pottery models of ducks and geese at Lung Shan site in Hupei about 2500BC in company with models of sheep , dogs, turtles, and fish. Zeuner (1963) has speculated that duck domestication may also have occurred in Mesopotamia from Sumerian times beginning 2800 BC , into the Assyrian period (900-600 BC). There is also indication that ducks were kept as domestic birds in ancient Egypt (Zeuner, 1963). According to Harper (1972), translation of Egypt papyri confirms that geese, chickens, and pigeons were being raised from the fifth century BC to the seventh century AD , but ducks were seldom mentioned and any reference probably was to wild fowl. According to the early writers, the Greeks and Romans kept ducks, but indications are that the birds were wild and had to be confined within netting enclosure (Harper, 1972).

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2.2 Muscovy Duck The Muscovy duck is one of the greater wood ducks included in the subfamily Anatinae tribe cairini (Clayton, 1984). The duck is reported to be the predominant water fowl in Africa, Asia and Latin America. It thrives well under free range condition in tropics and Neotropical environment (Haln et al., 1995; Farrell, 1995). Evidences indicate that under natural conditions the Muscovy duck is a tropical bird and lives in marshy forest. Its robustness and hardiness enable it to adapt to different climates and habitats. They are sexually dimorphic, the male being almost twice the weight of the female (Leclercq and De Cerville, 1985;. Larbier and Leclercq, 1994). They noted that aggression and sexual display among the birds are simple and not well differentiated. Parkhurst and Mountney (1988) described Muscovy duck as a species that produces less fatty carcass. Larbier and Leclercq (1994) added that Muscovy ducks are characterized by having large pectoral muscles and are sexual dimorphic in favour of the male. Phuoc et al. (1994) supported this when they reported that French male Muscovy duck can grow to be quite large weighing 5-7 kg, while the female can attain 2.5 3.5 kg. Townsend (2002) reported that Muscovy ducks are unique because of their bright rest crest around their eyes and above the beak. He observed that they do not swim much because their oil gland is under-developed compared to most ducks. It is on this note that Halns et al. (1995) reasoned that the duck is not generally a duck or goose but suggested closeness to goose than ducks on the basis that it eats grasses as geese do and has similar long incubation period of 36 days compared to that of domestic ducks. Despite these observations Muscovy is still considered duck. Derrell and Guy (1989) were of the view that despite the variability noted in Muscovy and its uniqueness, distribution and extensive range it is however the least studied

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of all new world water fowls. Most informations on Muscovy duck are historical and sparse Delacour (1959), Wetmore (1965), and even recent literature discuss the species only on general terms (Bolen, 1983). Jacquert and Sanveur (1995) made similar observations that, not withstanding the economic importance of the domesticated Muscovy duck in a number of countries a few reported its performance. 2.2.1 Origin of Muscovy duck There are diverse reports on the origin of Muscovy duck; most writers are of the opinion that South America is the origin of the domesticated Muscovy duck (Johnsguard, 1978; Hahn 1995, ) e.t.c . Mohammed (1996) reported that Muscovy originated from South America and that it was domesticated by the Columbian and Peruvian Indians and then introduced to the other world by the Spaniards and the Portuguese in the 16 th century. Townsend (2002) reported that the Muscovy originated from Brazil and that they are the only domestic ducks that do not derive from the Mallard stock. He further reported that the Muscovy duck had probably been domesticated for centuries by South American indigenous culture at the time of its introduction to European Colonialist. He added that both patrilineal and matrilineal ancestors of domestic Muscovy are the Wild Muscovy ducks. Encyclopaedia online explain the origin and domestication of Muscovy as domesticated in Peru and Columbia by the pre-Columbian Indians and that the Mallard was domesticated in China about 2000 years ago. Donkin (1989) described the domestication of Muscovy duck in Africa and that it was introduced into Africa by the Portuguese in sixteen century and had a wild relative, C. hartlanbi, which is indigenous to the forest zones of West Africa. Townsend (2002) described early sources relating to the spread of Muscovy duck in West Africa although he was reported to draw a wrong conclusion that it was pre Columbian introduction.

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2.2.2 Characteristics and potentials of Muscovy duck 2.2.2.1 Morphological characteristics Reports on morphological characteristics of Muscovy ducks particularly in Africa are scanty in literature. Few studies Hahn et al. (1995) and Schaef (1995) described plumage colour pattern in Muscovy duck. Plumage colour among Muscovy ducks have been reported to be a combination of black and white ranging from mostly black to white (Hahn et al., 1995) . Hassan and Aliyu (1996) studied the plumage colour pattern of Muscovy duck in North Western Nigeria and reported that four strains were observed black, white, mixture and creamy, and that black/white mixture constituted 80% of the population. Hassan and

Mohammed (2003) in their report on same ecotype gave a contrary result in which the black strain was more in number, representing 41% of the entire population with the black/white strain significantly heavier than other strains. Various colour patterns were also reported by other workers, (Schaefer, 2002 and Hahn et al., 1995), who reported additional plumage

colour pattern as Blue, Blue/white and chocolate types and similarly reported that the muscovy have more distinctive features such as red face with prominent caruncle at the base of the bill and a low erectile crest of feathers and that their feet are equipped with strong sharp claws for grabbing trees. Hassan and Mohammed (2003) further described the Nigeria Muscovy as having bill colours ranging from black to white, bill length of about 7.03 and 6.02cm for males and females respectively, and added that significant positive correlation exists between body weight and bill length. Tegnia et al. (2007) summarized the morphological characteristics of African Muscovy and reported that mean metatarsals diameter, thoracic perimeter, body length, length of bill, foot length and wing length in male were 1.3 , 29.5, 57.5, 7.0 27.1 and

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27.8 respectively while the average for female were 1.2, 25.8, 51.0, 6.3, 23.3 and 26.9 respectively. 2.2.2.2 Age at sexual maturity Age at sexual maturity is the time between the date of hatch and the date of first egg. Age and weight at sexual maturity are influenced by genetic make up of the individual and it is influenced by feed intake, light, duration of day length and other environmental factors (Morris and Fox, 1960; Wessels, 1962). Ola (2000) reported that Muscovy duck attained sexual maturity at 28 weeks of age (about 6.33 months), further adding that though Muscovy can attain maturity earlier. They have limited breeding capacity especially during the dry season and may delay egg laying to beginning of rainy or wet season. Duru et al. (2006) in their findings reported a higher value of 7.70+.044 months as age at first lay of egg by Muscovy duck in a peri urban management system under semi-humid condition in Nigeria. Variability in age at sexual maturity of other duck breeds had also been reported. Sexual maturity in Khaki Campbell was reported at different ages by different authors, such as 18 weeks by Klandorf and Harvey (1984), 20 weeks by Hetzel and Gunawan (1984) and 23 weeks by Eswaran et a. (1984). Kalita et al. (2004) in their findings reported age at sexual maturity in Khaki Campbell, Desi and their crosses as 169.10+9.95, 229+10.06 and 219.89 +10.54 days, respectively. Age at sexual maturity has been suggested to be an important life history trait (Oli and Dubson, 1999), with substantial potential for influencing fitness. They noted that within species a genotype that attains sexual maturity early often has a greater probability of realizing fitness because its offspring start reproducing earlier than others and thus is

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expected to have a higher fitness than in late maturing genotype. Stearns (1992) had a contrary view on early maturity and feels that late maturity allows for additional growth and experience that will substantially increase future reproductive output. Tanka and Rosenberg (1952) earlier reported that selection for early sexual maturity increases the number of eggs per day of life and contributes to an overall feed efficiency. Morris (1966) reported that age when the hen is able to reproduce (age at sexual maturity) is not the same as age when the hen is able to produce (age at first egg). It can be expected therefore that age at first egg can be earlier or later than age at sexual maturity. Kalita and Deka (2005) reported that age at sexual maturity for Muscovy duck in a rural area of Assam in India ranged from 300-365 day. A similar result was also reported earlier on by Avanzi and Romboli (1979). Mahanta et al. (2001) reported for age at sexual maturity. However, sexual maturity of both sexes of Muscovy duck was reported to be 20 24 weeks (Panda and Kumar, 2004) and 29 -30 weeks (Sauveur and De Carville, 1985). 2.2.2.3 Egg production Egg production is influenced by several factors such as strain, feed, mortality, health and management practices, age at point of lay, peak lay and persistency of lay (North, 1984; Petek, 1999). Sauveur and De Carville (1985) reported that Muscovy duck species have less expressed seasonal character in egg laying compared to other species of Anas genus. Some authors noted that the magnitude of egg production in ducks is dependent on the extensive and intensive management systems, including battery cages as well as on nutrition programme (Avens et al., 1980; Hetzel and Gunawan,1984; Hetzel, 1984, Scot and Dean,1991; Farrell, 1995) Several studies on various egg production characteristics under intensive production have been reported (Tikk and Vint, 1988; Romboli et al., 1984; Osman, 1997) . These

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authors and other researchers conducting studies on Muscovy duck species established that under intensive breeding conditions, the duck reached laying capacity of 120-150 eggs for two reproductive seasons. Retailleau (1997) gave higher value of egg production or laying capacity for Muscovy duck in an intensive breeding, and obtained an average of 210 in two reproductive cycles. Some Russian authors- Chipchiryuk (1980), Sauveur and De Carville (1990), Sogomonov and Rahmanov (1988) reported that in a 5- month laying season Muscovy duck laid about 62-100 eggs. Earlier Romboli et al. (1984) reported that 45 to 100 eggs were laid by Muscovy duck in the first year of reproduction depending on the breeding cycle. Significant differences exist in egg production or laying characteristics of Muscovy duck in other regions of the world compared to that obtained in African Muscovy duck. Mopate et al. (1999) reported that local Muscovy duck in Ndjamena, Niger Republic produced 14 to 15 eggs per clutch with an average of 2.6+1.2 clutches per year. Similar observation was reported earlier by Mourthe (1989) in Chad. Similarly Banga et al. (2007) reported that Muscovy duck in rural area of Congo Brazzaville lay an average of 14.6 +3.0 eggs per clutch with a maximum of two clutches per year. Mohammed (1996) also reported similar trend in Mozambique for Muscovy duck. On the contrary Panda and Kumar (2004) reported average egg production of Muscovy ducks in Assam district in India to be 45-60 eggs per annum. A similar finding was reported earlier by Mahanta et al. (2001). Kalita and Deka (2005) however reported lower egg numbers from the same zone in Asia. Though this variability exists, egg production in Nigerian Muscovy ducks tends to follow same pattern with those reports obtained from sister African countries. For instance Hassan and Aliyu (1996) and Duru et al. (2006) reported local Muscovy in Northern Nigeria, Ola (2000) in western Nigeria, Etuk and Abasiekong (2005) from Eastern Nigeria. Clayton (1984) claims

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that much of the high egg production of domestic duck is an expression of natural fecundity given appropriate opportunity and owes little to artificial selection 2.2.2.4 Egg weight Romboli et al. (1987) reported egg weight in three strains of Muscovy ducks, black, white and sepia as 81.2, 84.3 and 84.8g, respectively. Another report by Harun et al. (2001) recorded 84.5g as egg weight of Muscovy duck raised in an intensive management system. Nickolova and Gerzilow (2000), however reported lower value of 70.6g as egg weight in Muscovy duck. Egg weight in the Muscovy duck is reported to be higher than other domestic ducks. For instance, Sanveur and De Carville (1985) reported egg weight that ranged from 77 to 83g in the Muscovy duck while Karaca et al. (1996) reported egg weight of 69.9g in Pekin duck. Testik and Sarica (1991) also reported 71.5g as egg weight for the same breed (Pekin). Isguzar and Testik (1999) noted that there is high variability in egg weight of Pekin and most water fowl species and added that ducks reared under extensive condition produce lighter eggs averaging 54.8 to 64.2g when compared to those raised intensively whose egg weights normally exceed 70g. Several authors related egg weight to other production parameters, Khurshid et al. (2004) reported that increase in hatchability increases with egg weight, where as increase in egg shell weight and thickness result in a decrease in hatchability in birds. Similar observation was made by Shanaway (1994) for Japanese quail. 2.2.2.5 Fertility of Muscovy duck egg Fertility refers to the fertile status of group of eggs laid over a period of time by single bird, by small group of birds or by commercial flock, and is usually expressed as the

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percentage of total egg laid (Bodi et al., 1996). It has been widely reported that egg fertility is affected by age of the breeders, exposure to light, nutrition, management, mating ratio and semen quality (North,1981: Stahl et al., 1986: Peeble and Brake 1987). Narahari et al. (1988) added that other factors affecting egg fertility include breeding system, period of lay and parent live weight. Compared to other domesticated poultry and to the ducks of Anas genus Muscovy duck species are reported to be distinguished by very high degree of egg fertility (Nickolova, 2004). Over 92-93% on the average had been reported for the Muscovy duck (Bagliacca et al., 1989; Bodi et al., 1996; Bogenforst et al., 1996, Bondarenkoa, 1997) Tikk and Vint (1998) reported very good egg fertility of 96-97% between 3-18

weeks of laying in a year old Muscovy duck in Poland. Meltzer (1988) and Chipchiryuk (1980) reported that at the beginning of a reproductive season,(April to May), a high egg fertility of the species 94-98.25% was recorded. Earlier Baglicea et al. (1989) reported that peak egg fertility for one-year old Muscovy duck was in the second month of the laying period and was usually 85-95% depending on the variety. Nickolova (2004) reported that spermatozoa concentration of Muscovy duck was usually highest in March-April, an indication that fertility of egg was highest at that period. Though he noted that despite that, egg fertility of Muscovy duck was usually high (above

92%) throughout the reproductive period of March to August. This corroborated Szyniunk et al. (1991) who reported that average egg fertility for between 3 and 8 weeks of the laying season in one-year old Muscovy duck was 96.77%. Higher value of fertility of Muscovy duck eggs was recorded for tropical types, particularly in Nigeria, 90.96%, by Ola (2000) an indication of high fertility of egg in the breed. Few reports recorded lower values of percent fertility in Muscovy duck eggs. Isguzar (2005) reported that percent fertility among three varieties of Muscovy ducks black,

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black-white and white strains were 63.4, 33.5 and 34.5%, respectively. Environmental factors must have played some vital role in this regard. 2.2.2.6 Hatchability Hatchability is one of the prerequisites for the better propagation of breed (Farooq et al., 2001). It refers to the proportion of fertile eggs that continue development and produce viable chicks. Hatchability has been reported to be affected by physiology, age of the breeder, egg size, nutrition, genotype and possession of major genes (Huntan ,1981; Buss, 1982 ; Peter et al., 2004). To a large extent it is a function of fertility except when there is presence of major genes that reduce embryonic livability (Peters et al., 2004). The authors added that lower hatchability can be observed in a flock if embryonic mortality is high and fertility is low. Variation in embryonic mortality may be due to poor egg holding period, unbalanced nutrition, stressful condition, the parent flock was exposed to or any other fault in incubation and hatching equipment(Peter et al., 2004). The size of the eggs is also one factor that influences hatchability in most poultry. Farooq et al. (2001) and Murad et al.(2001) reported significant influence of egg size and shell weight on hatching performance of Japanese quails. The authors reported lower hatchability of small-sized eggs and those with poor shell quality. Shanaway (1994) also

reported better hatchability in large-sized eggs. Similar report of better performance based on egg size was reported earlier by Schader et al.(1985). In Muscovy duck the process of hatching is reported to span between 28-35 days for the eggs to change a microscopic germ into a downy chick capable of walking, eating and expressing its need by its voice and action (Banerjee, 1991). Several authors have reported the exceptionality of Muscovy duck eggs in hatching. Serbul (1986), Murae (1988), Bonima and Velez (1992) reported that hatchability of Muscovy duck eggs under artificial incubation

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was always found to be lower than under natural incubation, suggesting that heat supply by conduction normally may result in a better embryo temperature and development than by convection. This is evident in the report of Isguzar (2005), who recorded 41.1, 35.6 and 4.7% as hatchability values of fertile eggs of black, black/ white and white strains of Muscovy ducks .Similar values were earlier reported by Hahn et al. (1995 and Fattouh et al. (2003). In contrast, higher values were obtained in tropics using natural incubation as reported by Mopate et al. (1999) who found out that hatchability of Muscovy duck eggs reared in urban households in Ndjamena Chad was between 80-85% during rainy season (June- November) and 59-78% during dry season (December to May), with a mean brooding period of 63+25 days. These values were similar to those reported by Romboli (1990) and Gueye et al. (1998), but lower than those reported by Hassan and Aliyu (1996) for Muscovy duck in Northern Nigeria. Ola (2000) also recorded high value of 72.57+11.7% for Muscovy duck in Southwestern Nigeria. Sanveur and De Carville (1985) reported a hatchability of 80% among rural Muscovy ducks in Assam, India. These indicate the viability of muscovy in tropical environment. The importance of water for swimming as an essential component of mating behaviour and welfare of many domesticated water fowls, as well as a source of moisture for their eggs in incubation has been reported by several workers (Rauch et al., 1993; Harun et al., 1998) . However, Narahari et al. (1991) and Harun et al. (2001) reported that absence of swimming water did not affect hatchability of Muscovy duck eggs. This may explain why Muscovy ducks are easily kept either in traditional extensive system or in modern harsh dry system.

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2.2.2.7 Hatch weight of ducklings Weight at day old is a potential attribute of an individual and if this weight is favourable there is the tendency that better weight will be achieved in the later part of the life of the individual. Baeza et al. (2001) reported day-old body weight of Muscovy duck as 45g. They further added that the mean weight of male and female ducklings were similar at hatch, but became significantly higher(P