Productivity and Natural Disease Resistance Potential of Free-ranging Local Chicken Ecotypes in Tanzania

This study was carried out to investigate the productivity and the natural disease resistance potential of free-ranging local chickens in Tanzania. A total of 84 adult free-ranging local chicken ecotypes were studied, namely: Mbeya, Morogoro-medium, Ching’wekwe, Kuchi and Singamagazi. Adult body weight, body length, shank length and egg weight were assessed and compared. Average body weight for hens and cocks was 1441g (800 to 2,300g) and 2261g (1000 to 3500g), respectively. Egg weight averaged 41.6g (27 to 72g). Mean body length for hens and cocks was 21.6cm (17 to 26cm) and 24.6cm (21 to 29cm), respectively, and mean shank length 9.7cm (7 to 12cm) and 12.7cm (8.5 to 15cm), respectively. Between ecotypes significant differences were seen in the above parameters. The disease resistance potential was tested on 10 offspring of each ecotype, excluding the Mbeya. Twenty chickens (five from each of the four ecotypes) aged 12 weeks were inoculated with Newcastle disease virus while another 20 aged 20 weeks were inoculated with Salmonella gallinarum. Five chickens per group that were not challenged were used as controls. Following oral, ocular and nasal drop inoculation with Newcastle disease virus, the chickens developed clinical signs of Newcastle disease as from day three after infection. Mortality started on day five after infection, and all but one chicken were dead by day seven after infection. The 20 chickens, infected orally with S. gallinarum, showed clinical signs of fowl typhoid on day three after infection. Mortalities started on day seven after infection and by day 12 after infection 13 chickens had died. Seven birds survived without visible signs of the disease, including all five from the Kuchi ecotype and one each of the Morogoro-medium and Ching’wekwe ecotypes. At necropsy enlarged and congested liver and spleen, and catarrhal enteritis of the small intestines were seen. The surviving birds were sacrificed on day 14 after infection. Neither the sacrificed surviving birds nor the controls showed the above necropsy picture. It was concluded that free-ranging local chicken ecotypes in Tanzania differ in both productivity and disease resistance potential

Phenotypes including immunocompetence in scavenging local chicken ecotypes in Tanzania

A study was conducted to determine the variations in physical characters and immunocompetence among scavenging local chicken ecotypes in Tanzania. Eighty-four adult scavenging local chickens from four eco-climatic regions of Tanzania were studied. Measurements of adult body weight, body length, shank length and egg weight and observations of plumage colour and pattern, earlobe colour, skin colour and the shape of the comb were conducted. The antibody response to sheep red blood cells, serum haemolytic complement and the cutaneous response to phytohaemagglutinin-P were assessed. Five ecotypes were identified nd named Mbeya, Morogoro-medium, Ching'wekwe, Kuchi and Singamagazi. Singamagazi and Kuchi were significantly heavier, with longer shanks and heavier eggs than the other ecotypes. The average adult body weight for males ranged from 1621 g (Mbeya) to 2915 g (Singamagazi). Average female weights ranged from 1108 g (Morogoro-medium) to 2020 g (Singamagazi). Mean egg weights ranged from 37.65 g (Ching'wekwe) to 45.61 (Singamagazi). The Kuchi had mostly rose and walnut combs, while the other ecotypes were mostly single combed. In each ecotype there were chickens with a high or low antibody response to red blood cells, but there was a significant difference between the ecotypes

Productivity and reproductive performance of the free range local domestic fowl ecotypes in Tanzania

A study was conducted to assess the productivity and reproductive performance of seven free-range local domestic fowl ecotypes in Tanzania named Ching'wekwe, Mbeya, Morogoro-medium, N'zenzegere, Pemba, Tanga and Unguja. Average weekly weight measurements and growth rates were evaluated for each ecotype and sex as was egg weight, fertility and hatchability. Significant differences existed between ecotypes in all the five parameters studied. Ching'wekwe showed consistently low mean weekly weights, daily growth rate and mean egg weight contrary to Morogoro-medium and Tanga ecotypes. Egg fertility was low with only N'zenzegere and Unguja ecotypes exceeding 75%. Hatchability was also low ranging from 55% (Ching'wekwe and Morogoro-medium) to 74% (Pemba). It was concluded that genetic and phenotypic diversity exists in the local domestic fowl ecotypes of Tanzania. The diversity constitutes a valuable resource for use in breeding programmes for improvement of the health and productivity of the local domestic fowls and in designing proper conservation strategies. Further studies are required to identify genetic markers associated with productivity and disease resistance within the local domestic fowl ecotypes. In depth studies on the performance of the Tanzanian medium ecotypes (Morogoro-medium and Tanga) is required to ascertain their suitability for promotion throughout the country