The experiment was carried out at Bangladesh Agricultural University (BAU) Poultry Farm, Mymensingh. Accordingly, dwarf chickens (48 females and 12 males) were collected from different upazilas of Rangamati, Mymensingh, Tangail and Rangpur districts based on their phenotypic features to develop a foundation stock. After collection they were quarantined and maintained at BAU poultry farm. The experiment was performed at BAU Poultry farm for a period of 26 months from March 2013 to April 2015.The hatching eggs were collected from the foundation stock and incubated. Birds of generation one (G1) and two (G2) has generated from the foundation stock (G0) and maintained at BAU poultry farm.
Reproductive traits: Artificial insemination was practiced for all experimental birds. Insemination was done twice a week and collected semen of each cock was distributed to 6-9 hens. A total of 499 eggs; (241 from foundation stock, 102 from 1st generation and 156 from 2nd generation) were collected and hatched. The eggs were candled at 7 and 14th day of incubation and finally fertility, hatchability, dead-in-germ and dead-in-shell were recorded. Chicks were leg-banded after weighing the DOC. Eggs and birds were weighed individually using an electronic balance. During rearing egg weight, hen day egg production, age and weight at sexual maturity of birds were recorded.
Carcass traits measurements: A total of 33 birds (12 females and 9 males of IDC, 6 females and 6 males of the normal shanked chickens) were slaughtered at 24 weeks of age. The collected birds were fasted for 12h, and then slaughtered, weighed, eviscerated, dressed, dissected, and the meat stripped from carcass following the method of Jones (1984). The recorded data of each bird were live weight, head, heart, gizzard, neck, breast meat, thigh meat, drumstick meat, skin, abdominal fat, wing meat, trimmed meat, dark meat (thigh meat + drumstick meat+ wing meat+ trimmed meat), total meat (breast meat + dark meat), and weight of thigh bone, drumstick bone, wing bone, and neck weight. An electronic balance was used to weigh chickens, the carcasses and the various cuts. Meat yield traits were converted into percentage of individual live weight prior to analyzing the data statistically.
Determination of egg quality characteristics: A total of 64 eggs (32 from IDC and 32 from CNS) were used to determine the egg quality characteristics. The egg quality characteristics recorded as egg shell weight, shell dry weight, shell (%), shell thickness and shell membrane thickness, Haugh unit, albumen dry matter (%), yolk color score, yolk index, fresh yolk and yolk dry matter (%). Egg weight was measured with the help of egg weighing balance. The length and width were measured by a slide calipers and their mean values were recorded. Eggs were carefully broken into two halves and the contents were gently poured on a flat horizontal glass, and the albumen and the yolk were carefully separated to measure their respective weight and height. The egg shell was also weighed after being dried under room temperature, however the membrane was removed carefully before measuring the egg shell thickness which was then measured as the average of three points (narrow end, middle and wide end).
Statistical analysis of experimental data: Mean along with standard error was estimated for reproductive traits. Student test (Independent sample t-test) was performed to the significant deviation between different parameters of meat yield and egg quality traits between IDC and CNS. Data analysis was performed using Statistical Package for Social Science (SPSS) software version 16.0 (2007).