Local Domestic Chickens: Their Potential and Improvement
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Date
2009-07-15
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Abstract
This study was conducted to assess the potential of indigenous chickens and improve their performance in traits of economic importance by incorporating in them the naked neck and frizzle genes, and also genes from a commercial layer (exotic breed) through crossbreeding (local naked neck/frizzle males × commercial females).
Study One
A survey was conducted to assess the current performance of local chickens in the Ashanti Region of Ghana. One-hundred and thirty five (135) local chicken keepers from Bosomtwe Atwima-Kwanwoma, Ejisu-Juaben and Asante-Akim South Districts were interviewed. All the keepers practised the extensive system of production with flock sizes averaging 22 in the ratio of 4: 6: 12 for cocks, hens and chicks respectively. A small amount of feed supplement was given either everyday or occasionally. Mortality of chicks (between day-old and six weeks) and total mortality (annual mortality for the entire flock) were 50% and 65% respectively. The average weights of cocks, hens and eggs were 1.55kg, 1.13kg and 42.80g respectively. The clutch size per bird ranged from
9-13. The major challenges faced by the keepers included diseases, predation, lack of funds to increase stock and construct structures, small sizes of birds and eggs, low numbers of eggs laid and poor fertility of eggs. Local birds provide immense benefits for keepers but their productivity is significantly hindered by genetic and management problems.
Study Two
Another survey was conducted to evaluate the potential of indigenous naked neck
(Nana) and frizzle (Ff) birds within the indigenous chicken population in the Ashanti
Region of Ghana. The study involved ninety (90) interviewees who were local chicken keepers in Bosomtwe Atwima-Kwanwoma, Ejisu-Juaben and Asante-Akim South Districts. Average body weight of Nana cocks did not differ significantly (P>0.05) from Ff & nana/ff (normal feathered) ones while Nana hens were significantly (P>0.05) heavier than Ff birds, but nana/ff birds did not differ significantly (P>0.05) from the two genotypes. Nana layers were significantly superior (P<0.05) in egg size, number of eggs per clutch and number of eggs per bird per year to Ff layers which were significantly better than nana/ff layers. However, clutches of eggs per year did not show any significant difference (P>0.05) among the three genotypes. Eggs from Ff layers had a significantly higher (P<0.05) hatchability compared to those from Nana & nana/ff layers. Eggs from Nana layers were significantly better (P>0.05) in Haugh unit and egg shell thickness compared to those from Ff & nana/ff layers and eggs from Ff layers were significantly better (P>0.05) in Haugh unit compared to those from nana/ff layers. Mortality was significantly lower (P>0.05) in Nana birds followed by Ff & nana/ff birds respectively. The carcass of Nana birds had a significantly higher (P>0.05) dressing percentage than that of Ff and nana/ff birds. Naked neck and frizzle genes improve the productivity of local birds but the naked neck gene appears to be more effective than the frizzle gene.
Study Three
The first mating in Experiment Three was between four indigenous naked neck males and thirty-six Lohmann commercial females in a ratio of 1: 9. This produced offspring in the proportion of 48.7% Nana to 51.3% nana in the F1 generation. Nana birds were significantly better (P<0.05) in body weight, body weight gain, number of eggs per
clutch, hen-housed and hen-day rates of lay, egg size, Haugh unit, shell thickness, survivability and carcass yield, than their nana counterparts. However, age at first egg and egg size to body weight ratio were significantly better in the nana birds compared to the Nana ones. In the second mating, ten males and one hundred females of F1 Nana birds were selected and mated inter se in a ratio of 1:10. This produced 16.8% NaNa,
54.5% Nana and 28.7% nana offspring in the F2 generation. It was observed that Nana and NaNa birds were significantly higher (P<0.05) in body weight, body weight gain, number of eggs per clutch, hen-housed and hen-day rates of lay, egg size, Haugh unit, shell thickness, survivability and carcass yield, compared to their nana counterparts. However, chick survivability was significantly better (P<0.05) in the nana birds compared to Nana and NaNa ones. Using birds that show the naked neck phenotype in local chicken production will enhance productive and reproductive performances significantly.
Study Four
Five local frizzle males were mated to forty Lohmann commercial females in a ratio of
1:8. This produced almost equal numbers of offspring, that is 50.2% Ff and 49.8% ff in the F1 generation. The Ff birds were significantly superior (P<0.05) to their ff counterparts in terms of body weight, number of eggs per clutch, hen-housed and hen- day rates of lay, Haugh unit and carcass yield. However, survivability was significantly better (P<0.05) in the ff birds compared to the Ff birds. The second mating was made between ten males and one-hundred females of F1 Ff birds. It was done inter se in a ratio of 1:10. This produced offspring in the proportion of 22.4% FF, 51.5% Ff and
26.1% ff in the F2 generation. The F2 Ff and FF birds were significantly higher (P<0.05)
than their ff counterparts in number of eggs per clutch, hen-housed and hen-day rates of lay, Haugh unit, shell thickness, survivability and carcass yield. However, body weight, body weight gain, egg size and chick mortality did not differ significantly between the frizzles and the ff genotypes. Using frizzle (FF, Ff) hybrids in local chicken production will increase productivity markedly, though to a lesser extent than the naked necks (NaNa, Nana).
Study Five
In a comparative study involving all the five genotypes (NaNa, Nana, FF, Ff and nana/ff) reared under intensive, semi-intensive and extensive management systems, it was observed that the NaNa and Nana birds performed better (P<0.05) than their FF and Ff counterparts in body weight, body weight gain, number of eggs per clutch, hen- housed and hen-day rates of lay, egg size, Haugh unit, shell thickness, carcass yield and economics of production. It was also economically most profitable to rear all the genotypes (NaNa, Nana, FF, Ff & nana/ff) under the semi-intensive system followed by the extensive and the intensive systems respectively. Aside genetic improvements, rearing local birds under the semi-intensive system will improve profitability significantly.
Description
A Thesis submitted to the Department of Animal Science, Kwame Nkrumah University of Science and Technology in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy.