Influence of major genes for crested-head, frizzle-feather and naked-neck on body weights and growth patterns of indigenous chickens reared intensively in Kenya

Abstract

The influence of major genes for crested-head (Cr), frizzle-feather (Fr) and naked-neck (Na) on body weights and growth patterns of indigenous chickens reared intensively was investigated and compared with normal-feather (na) gene. Birds were individually weighed at hatch and every two weeks up to 30 weeks of age. Growth patterns were modelled using the Gompertz-Laird function. The genes influenced body weights and growth patterns at various ages. The Cr gene had significant (P < 0.05) negative effects on body weights (between 52.2 g and 112.3 g) from 18 weeks onwards and low absolute growth rate from 10 to 22 weeks than na, but higher initial specific growth and maturation rates than the Na gene. The Fr gene had significant negative effects on body weights (between 28.2 g and 75.1 g) from 8 to 16 weeks than na, but a higher relative growth rate than Cr from 12 to 16 weeks. The Na gene had significant negative effects on body weights (between 24.7 g and 134.6 g) from 8 weeks onwards than na. It was concluded that Frfr and Nana genotypes are not ideal for cool environments in Kenya and indigenous chicken genotypes have varied growth potentials and patterns that can be improved to increase production.

Characterization of indigenous chicken production systems in Kenya

“…The high performances for IC in medium-to high-potential agricultural zones than those in the ASALs could be due to better management in terms of feeding and housing which allows chickens to express their genetic potentials. This concurs with previous studies which have reported an improved performance of IC in semi-intensive and intensive production systems (Magothe et al 2010;Ochieng et al 2011). This implies that the performance of IC can be improved by good management.…”

Phenotypic Characterization of Indian Naked Neck Chicken Under Tropical Climatic Conditions

“…Patra et al (2002) identified higher body weight from 4th week onwards in NaNa genotype. Reddy et al (2008) observed lower (877.60±0.10 g) 6th week body weights in naked neck gene line compared to the present findings and might be due to favourable effects of selection and feeding regimens followed and other managemental variations like environmental temperature and season (2010) and Magothe et al (2010) reported lower body weights for naked neck genotypes than their normal counter parts from Kenya under free range conditions and temperate conditions, respectively. The higher body weight obtained in the present study indicates a more pronounced effect of Na gene in response to tropical climatic conditions.…”

An Extended Boltzmann Model for Forecasting Biogas Consumption in Rural China

“…In some literature, Eq. (2) is named as the Gompertz-Laird model (Nahashon et al, 2010;Roush and Branton, 2005;Miguel et al, 2007;Magothe et al, 2010). This model is more commonly used than its original form, therefore, the Gompertz-Laird model is used for describing the evolution of biogas consumption in rural China.…”