Abstract:
Shank length and body weight measurements on 30 male and 30 female chicks from each of White Cornish (WC) and White Plymouth Rock (WR) breed were utilized to study the pattern of development of shank length in chicken. The birds were reared for eight weeks in Kerala Agricultural University Poultry Farm under uniform management. Upto the end of three weeks uniformity could be seen in the pattern of growth of shank length of the four groups. Thereafter WR male had a lead over the rest. The growth pattern of body weight was not uniform in the groups from the beginning. At the end of eight weeks the growth pattern was found to differ between sexes and breeds. Uniformity in growth rates was found in females of the two genetic groups as also between WC male and WR female. All the other pairs were heterogeneous. High correlation between body weight and shank length revealed that longer shank length can be made a criterion for selection for higher body weight. Shank length at the end of the first week was found to be most suitable for this purpose. Shank length has high positive correlation with age. The method of comparison of growth rates recommended by Rao (1958) was found unsuitable for the present study. Among the functional forms examined Modified Exponential, Gompertz and Logistic were found to be unsuitable for expressing shank length as a function of age. Most suitable patterns for expressing shank as a function of age in weeks were found to be linear and exponential. Among these two exponential turned out to be better than the other.
