| dc.description.abstract | This study investigated growth performance and semen characteristics of naked neck Tswana and black Australorp X naked neck Tswana chickens. The birds were raised under intensive management system from day old to 20 weeks of age. In the first study, a total of 66 Australorp x Tswana crossbred chickens and 66 purebred indigenous Tswana chickens were housed in a deep litter house and evaluated for growth performance (body weight) every fortnight from 4-20 weeks of age. The chickens were provided with water and commercial feeds ad libitum. Males of both crossbred and purebred chickens were generally heavier than their age-matched female counterparts at different ages. Body weight was however significantly higher in Australorp x Tswana crossbred males (2920.93 ±57.73) and females (2224.27 ±59.19) than their indigenous purebred counterparts (2467.26 ±59.97) and (1839.31 ±57.04) at 20 weeks of age respectively. There were significant differences in body weight of purebred naked neck Tswana males (1088.56 ±32.47) and females (931.54±30.88) from 10 weeks of age. Growth was also more enhanced in crossbred Australorp x Tswana males than Females. Crossbreeding can therefore be used as a strategy to improve growth performance of indigenous Tswana chickens raised under an intensive management system.
In the second experiment, semen parameters of the birds were evaluated. Semen collection from sixty four (64) purebred naked neck Tswana and sixty four (64) crossbred (Black Australorp X naked neck Tswana) sires at 20 weeks of age was accomplished by the abdominal massage technique Semen parameters with respect to ejaculate volume, pH, sperm motility, sperm concentration and sperm viability were examined for each cock. Crossbred cocks had significantly higher (p<0.05) ejaculate volume (0.41 ± 0.005), sperm motility (81.79 ± 0.66) and ejaculate concentration (4.78 ± 0.03) than their purebred naked neck counterparts. However, the degree of semen pH (7.05 ± 0.03), semen color (1.00 ± 0.09) and the percentage of live (76.8 ± 29.4) and dead sperm (23.2 ± 29.1) showed no significant differences (P>0.05) between the 2 chicken breeds under study. | en_US |
