Authors: AHMAD SALAHI, MOZHDEH MOOSANEZHAD KHABISI, ALI ANISSIAN
Abstract: Shank length is used as a tool for the determination of fertility, body weight, estimates of frame size, and the monitoring of growth and development of pullets. This study was carried out to investigate the effects of infectious bursal disease (IBD) on shank length, diameter, body weight, shank length and body weight growth curves, and mortality rate in males and females in the rearing period in broiler breeder flocks. In this study, 2 broiler breeder flocks (Ross 308 flocks) and 800 breeder chicks (both females and males) were selected for shank length and diameter assessments. All the management, nutrition, and geographical statuses were similar, except for one flock that was infected with IBD. Results of this study showed that IBD presence in the flock decreased shank length in male and female chickens compared with the control group. Shank length in male and female chickens at 20 weeks of age was 0.53 and 0.02 cm, respectively, which was less than that in the controls, but these differences were not statistically significant. Shank diameter in the diseased male and female chicks was also smaller than that in the controls, although this difference was not also significant. There were no significant differences in the body weight of both sexes at 20 weeks of age. Body weight to shank length ratio in the diseased males was higher than that in the controls, but in female chickens it was less than it was in the control group after 12 weeks. Mortality rate in diseased males was 2.26% more than that in the control group (P < 0.05) but mortality in females was not different from that in the control group. After observing clinical IBD in both male and female chicks, antibody titers against IBD virus were found to have increased compared to the control group (P < 0.0001). It could be concluded that male chickens are more sensitive to IBD than females.
Keywords: Shank length, shank diameter, body weight, mortality, broiler breeder, infectious bursal disease
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