author(s)
Saravanan R, Thirunavukkarasu D, Jeyakuamr M and Vasanthakumar T

abstract
The tribals of Kolli hills rear “Chirunkothu chicken” for subsistence under backyard poultry farming system. This bird plays an important role in meeting out protein requirements and food security of households. This activity engages the tribal women members of the households. Chirunkothu chicken are self-propagating and are known for their adaptability, disease resistance, sturdiness and the ability to thrive on low plane of nutrition. These birds are reared under zero (low) input system with meager input coming out from outside of farming system / household. These chicken meat have been getting higher premium rate than other desi birds among the consumers on account of taste and farming system. Wide variation was observed with regard to morphological traits viz., Plumage pattern, plumage color and shank color. Males were significantly heavier than females at all ages in 4, 8, 16 and 24 weeks of age. The body weight of males and females were 175.12 ± 4.65 and 152.83 ± 5.38 at 4 weeks; 343.21 ± 7.61 and 312.83 ± 5.92 at 8 weeks; 622.61 ± 112.18 and 585.60 ± 18.59 at 16 weeks and 1025.80 ± 36.41 and 970.34 ± 24.75 grams at 24 weeks of age, respectively. The egg weight of Chiruvidai chicken were smaller than those of normal egg with mean weight of 36.99± 0.18 gm and the egg shell colour ranging from brown to off-white in colour. Although almost half of the eggs had Haugh unit values ranging from 36 to 50, 1 out of 10 had almost no thick albumen and all eggs are falling in “B” grade category. The measured mean values of specific gravity, Albumen percent, Albumen Index, Haugh Unit, Shape Index, Shell percent, Shell Thickness (mm), Shell weight (g), surface area (cm2), Yolk percent and Yolk index were 1.033 ± 0.312; 52.14± 0.14, 0.058± 0.37, 38.59± 0.40, 74.73 ± 0.20, 10.52± 0.05, 0.29± 0.01, 3.98± 0.01, 57.85± 0.12, 37.56± 0.22 and 0.26± 0.01.