Comparative growth and livability performance of exotic, indigenous chickens and their crosses in Tanzania
Livestock Research for Rural Development
Tanzania Livestock Research Institute - Mpwapwa, P.O.Box 202 Dodoma, Tanzania; Department of Animal Science and Production, Sokoine University of Agriculture, P. O. Box 3014, Morogoro, Tanzania
A study was conducted in central Tanzania to compare growth performance and livability of two exotic stocks namely Broiler (B) and Black Australorp (A), and two indigenous chickens sourced from warm (W) and cool(C) ecological zones and their crossbreds. The four parental stocks were used in 4x4 diallel crossing to produce 16 genetic stocks totaling 1256 experimental chicks. Birds were fed on nutritionally balanced diets to meet their requirements as per age and physiological stage. Variables studied were livability from day old to 48 weeks of age and body weights at day old, 4, 8 and 12 weeks of age. The data on growth traits were recorded on individual bird basis and analyzed using the General Linear Models procedure of SAS (2003), while frequency procedure of SAS (2003) was used for livability analysis. Results revealed that genetic stocks differed in body weight at various ages. The broiler genetic stock (BB) was the heaviest at all ages. Among the indigenous ecotypes, the genetic stock from cool ecological zone (CC) was heavier than that from warm ecological zone (WW). However, at 12 weeks of age, the cross between the indigenous chickens from warm ecological zone and broiler (WB) in female birds as well as the cross between the broiler and indigenous chickens from the warm ecological zone (BW) in male birds had body weights which were close to that of straight broiler stocks (BB). The mean body weights of 12 weeks of age of the crosses ranged from 625g in the cross between indigenous chickens from the warm ecological zone and the indigenous chickens from the cool ecological zone (WC) to 1537g in the cross between the warm ecological zone and the broiler stocks (WB) for female birds. Similarly at 12 weeks of age, the mean body weights for male birds ranged from 894g in the cross between the indigenous chickens from the warm ecological zone and Black Australorp (WA) to 1833g in the cross between the broiler and indigenous chickens from the warm ecological zone (BW). Livability also differed significantly (p< 0.001) among genetic stocks in favor of the cross between Black Australorp and broiler (AB) females and its reciprocal (BA). The survival rate for female birds ranged from 32.3% in the indigenous chickens from the warm ecological zone (WW) to 72.3% in the cross between the broiler and the Black Australorp stocks (BA).The additive genetic contribution from the broiler stocks (BB) was higher than those of other stocks with respect to body weights. It is concluded that if is aimed at improving body weight and overall survival rate, then both broiler and Black Australorp crosses would offer the best option under moderate input production conditions. © 2015, Fundacion CIPAV. All rights reserved.