A schematic representation of different growth curves of broiler
chickens as described by Leeson and Summers (1991) is given in Fig. 1.
Lines A, B and C represent three potential growth curves of broilers that
reach approximately 2 kg body weight at 42 days of age. If birds grow at
a uniform rate, growth will be as depicted by line B and represents
perhaps a biological ideal as far as minimizing stress is concerned
i.e., continual steady growth with no major period of slow or rapid
growth. However, few animals grow with such ‘statistical’ precision. Birds
which grow through lines A and C both reach 2 kg weight at 42 days, yet